ZCO ZC420 v Kahles K318i v Schmidt Ultra Shorts v Minox ZP5

wjm308

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Three scopes walk into a bar, the first is a ZCO, the second a Kahles and the third a Schmidt… and so the joke goes, but in reality, it was 6 scopes, and Minox joined the party as well and the punchline of the joke is… well read on and we’ll get there. Right before SHOT 2018 I was thrilled to hear about all the new Ultra Short scopes that were coming to market to challenge the reigning champion and original innovator of Ultra Short style scopes – Schmidt & Bender. Two makers stood out – Kahles with the K318i and a newcomer to the sport – ZCO with their ZC420, I was so enamored with all the new releases I started a thread on the Hide called “2018 – Year of the Ultra Shorts” where I highlighted a number of scopes from different manufacturers, but it was the alpha level I was most interested in. Over the years I’ve owned 3 Schmidt and Bender Ultra Shorts, and for one reason or another I was always left wanting (mostly in the reticle department) so when the K318i with SKMR and ZC420 with MPCT reticles were announced I began to speculate how good these optics would be and whether they would rival the reigning Ultra Short champion – Schmidt & Bender. About this time last year I bit the bullet and purchased a K318i soon after it was released and quickly fell in love with this scope, it had amazing glass, was very short and had a very usable reticle for what I like in the SKMR3, I have considered it the best ultra short scope both optically and mechanically as compared to the Schmidt’s even though it does not have the best FOV of the bunch, so when a fellow shooter told me he bought a ZCO ZC420 we began to plan an outing where we could review a bunch of these at one time and find out which ultra short will rule them all.

A bit of background, I’ve been shooting for over 35 years was in the Army in the late 80’s, got into hunting in the 90’s and began my pursuit of long range shooting around 2012. Almost all my rigs serve dual purpose as both hunting rifles and long range, due to time commitments I do not compete, but I love to shoot when I get the chance and I love to improve my long range skills as well as have optics that can help me in the field especially when the light gets low. Thus, my pursuit for the perfect long range/lightweight scope began and that rabbit hole has taken me all over the place. FFP was another priority, but if you are looking for a lightweight FFP optic you will find few options. My journey has taken me through US Optics, Valdada/IOR, Vortex, Bushnell ET, March, Premier, Kahles, Schmidt and Minox ZP5 to name a few, some were duds, some were great but not quite right and then there’s the ultra shorts. My first was the Schmidt & Bender US 5-20 which is truly short but with amazing glass, fell in love with that scope right away but wasn’t too thrilled with the reticle. Part of what I like about ultra shorts is the magnification range as well as the weight as compared to their full size cousins, I’ve put a personal limit on my scopes not to go over 35oz because of the application mentioned above and most ultra shorts fall within this range. Those are my credentials for what it’s worth, I have been doing reviews of scopes for a number of years now but don’t pretend to have any special insight in evaluating scopes other than my experience and what my eyes tell me (though I admit my eyes are getting older which makes using better glass that much better).

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EDIT: What is an Ultra Short

Part of this information I have gleaned from ILya's article on Ulta Shorts, but have added an additional qualification for max magnification. The phrase “Ultra Short” was originally coined by S&B first with their 5-20 then with their 3-20 (but they were not the first to build a short design). In principle, how short you can make a scope is a function of how large the objective and ocular lenses are. The larger they are, the harder it is to make a scope short. Also, keep in mind that short does not have to mean light (and light can be subjective). With that in mind, here are my qualifications for what overall scope length, based on objective size as well as magnification are what I deem to be an Ultra Short long range scope:
Greater than 50mm Objective with 18x or greater max magnification: Under 15″
40 to 50mm Objective with 18x or greater max magnification: Under 14″
While not a requirement for Ultra Short, my personal preference is that the scopes be kept at 35oz or less.

The Scopes

One might ask, why didn’t I include some other Ultra Shorts and there is one reason - I wanted to stick with alpha class (sorry Leupold Mark 5HD and others, you simply aren’t there). Why did I include the Minox ZP5 5-25x56 and 3-15x50 – very simply the ZP5 5-25x56 reigns as the best scope I’ve ever looked through (I have not experienced Tangent Theta, but I have experienced Premier and all three are sisters when it comes to the original design by Optronika) and the ZP5 3-15x50 represents the closest we had access to that would be close to the venerable TT315 series, that being said, I tend to view “Ultra Short” designs as having magnification greater than 16x but in a tube shorter than traditional scopes of the same magnification so we use the Minox ZP5’s as more of a baseline here.

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The Purpose
The purpose of this evaluation is not to give you any kind of “long term” results but simply to identify “initial impressions” of areas that are sometimes identified in spec sheets like the one above, but often times there are features to scopes that simply have no spec but do make a difference for the discerning long range shooter. The ultimate goal was to evaluate the brand new ZCO ZC420 that has just begun to hit the market, essentially, does the ZCO live up to its hype – “Zero Compromise Optic” and can this new manufacturer really put out a scope worthy of being considered “alpha” quality. Well that’s exactly the question that we set out to answer, and when I say we I’d like to give a huge shout out to @jwknutson17 who was kind enough to join me at my 1000 yard range and bring some scopes with him, it was great to put some rounds down range and have fun with optics, I also typically do these evaluations alone and rely on only my eyes so it was nice to have a second set of eyes and see if we both agreed (which you’ll find below, we sometimes didn’t).

Diopter Adjustment
A quick note before we get started, in order to perform any kind of optical evaluation with riflescopes it is of utmost importance that you set your diopter correctly. During CA testing I noticed the Minox ZP5 3-15 reticle was all over the place (indicating parallax was way off) but what it turned out to be is this was a brand new scope that had not yet been adjusted and we found the diopter dialed all the way out, once we dialed in the diopter the parallax/reticle was rock solid. There is a lot of “recommendations” from manufacturer’s and from the community on setting diopters, but I must admit this is one of the trickiest (and yet one of the most important) procedures to get right, so I highly recommend you spend some time understanding how to properly set your diopter.
Here is my recommendation, but I don’t take all the credit, much of this comes from advice provided by hk dave, ILya and my eye doctor:
  1. Initial setup: Loosen the lock ring in front of the eyepiece (if it has a lock ring) and while looking at a blank wall or the sky, rotate the eyepiece several turns counterclockwise (in the positive + direction) until the reticle is visibly out of focus. Then turn back clockwise until the reticle is focused as sharply as possible (but be careful not to go too far; however, when doing so be sure you are not staring through scope while turning back clockwise, you should glance through the scope for no more than a few seconds then stare out into the distance while making a small adjustment and then glance back – do this until the center and the edge of the reticle appear sharp.
  2. Fine tuning: Find a target that is very far away, so that it looks sharpest when the side focus is at the infinity setting. As you look through the scope (important that it remains steady) you can mess with the diopter by making minute adjustments either CW/CCW and see if the reticle and/or image improves any. You can also check parallax to ensure that small head movements don’t close the POA to shift.
  3. Closeup tuning: Now find a target that is closeup, say 100 yards away, set your side focus until the object comes into best focus, does the reticle still look sharp? Check parallax to make sure there is no shift.
Once you’ve performed the above 3 steps you should be set with your scope, it might be wise to mark your ocular and the scope tube with a pen or marker (especially if you don’t have a locking diopter) so you can return to this position if your scope is ever bumped out of alignment.

Ergonomics and Mechanics
I define ergonomics of a riflescope as the overall fit and finish along with how easily accessible certain features are. I define mechanics of a riflescope as the “feel” of certain controls and their usability and repeatability. Older versions of the Schmidt & Bender low profile Ultra Short turrets had too much resistance with MTC and would cause over travel by sometimes .2 mil, new 2019 18 mil turrets were too mushy for my taste and provided very little tactile/audible feedback, the 14 mil turrets have much better tactile/audible feedback and some 18 mil versions are better, I am still bothered by the big illumination tumor and wish Schmidt would come out with a PMIII version with illumination next to parallax like most other mfr’s have adopted. ZCO had the best overall tactile/audible feedback but the Kahles and Minox were not far behind. Keep in mind I am not a turret purest, unless a turret is really bad I have no issues getting by with it. The locking turrets on the ZCO have the best resistance I have experienced, Schmidt is not bad and neither is AMG but ZCO seems “just right”. Keep in mind that ergo and mechanics can be very much subjective and will be based on the user and their preferences/biases.

Ergo and Mechanics rankings: ZCO ZC420 4-20x50 > Minox ZP5 3-15x50 >= Kahles K318i 3.5-18x50 > Schmidt US 3-20x50 >= Schmidt US 5-20x50

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That dreaded CA
Some of you are thinking “why so down on California?”, but while I have my issues with California (I grew up there) what I mean by CA is Chromatic Aberration. For those who still may not know what this is I recommend you look it up, or better yet just follow this link to a great explanation - https://photographylife.com/what-is-chromatic-aberration. We can argue “‘til the cows come home” on whether or not CA has a negative effect on the usefulness of a riflescope, after all, we are not taking pictures through our scopes (well… actually I am, but only for this review), put plain a simple - CA bothers some people more than others (and if you haven’t noticed CA in your scope I’d recommend you not try to find it). Will CA cause you to miss a target? Doubtful, but it does have an effect on micro contrast as well as scotopic vision when the light gets low that could, in fact, degrade image quality (IQ), and let’s face it, when we are paying this much money ($3000+ for all these scopes) we are expecting to get the utmost in IQ. Because CA does bother me, especially in high end optics it is something I look for and evaluate. I did a review of the Kahles K624i Gen III when it was first introduced and I soon realized that scope performed very poorly when it came to CA, so much so that it affected the low light performance when I was comparing to other scopes with smaller objectives, and if there was any hint of snow on the ground (I live in Colorado) the annoying purple fringe was all over the place.

CA usually rears its ugly head the most with high contrast situations so having something white with a dark background will usually induce CA more than say green grass in front of brown dirt, but as previously mentioned CA can affect IQ even when you don’t “see it”. For those who still may be missing the concept here, take a look at the below image showing what CA looks like (Note: This is not from a scope within this test):

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Enough background, let’s get down to how these scopes performed. I will preface the results by saying this – all of these scopes performed extremely well when it comes to controlling CA, I have seen much worse scopes, and ultra short designs prove to be a challenge for the optical engineer to create an optical formula that is going to perform similar to that from a more traditional (longer) scope. I would be perfectly happy with the CA performance of any of these scopes, but that being said, this is an evaluation, so let me share my thoughts along with some through the scope images.

Speaking of “through the scope” images, I will give my typical disclaimer: DO NOT USE THESE IMAGES as an indicator of the IQ of any of these scopes (in fact, don’t use any image on the internet to do so), riflescopes are designed for the human eye, they are not designed for a camera sensor and as such if I do not hand hold the camera perfectly you may begin to see optical aberrations in the resulting images, these are NOT indicative of the scopes design but of my own shakiness and/or misalignment. Also, do not use these images to judge how bright or dark a particular scope is, while I set my camera to manual, I forgot to set the ISO to manual and with different overhead conditions (clouds coming in and out, etc.) the resulting image may have compensated, I assure you all these scopes appeared very bright.

Did we see some CA through these scopes, the answer is yes but it wasn’t “in your face” as some scopes exhibit. Now let me make another disclaimer: Images taken through a riflescope using another optical system (like a camera and lens) are not an “accurate” representation of what you see with the naked eye. So, don’t take images you find here or on the internet and immediately discard any particular scope because you see a heavy purple fringe along the edge, because CA is compounded by the fact that the camera lens also exhibits CA and if you are not perfectly centered to the scope, being offset might induce more CA than usual.
To my eyes, both Schmidt & Bender’s seemed to have the most apparent CA of the bunch, followed by the Kahles K318i which seemed very close to the Minox ZP5 3-15 but the surprise was the ZCO ZC420 which showed very minimal CA, and if we’re nitpicking (which I am) I felt the ZP5 5-25x56 was still the best overall, that being said the ZC420 being an Ultra Short design was very impressive that it bested all the rest and came very close to the traditional design on the 5-25.

CA Rankings (including ZP5 5-25 as baseline): Minox ZP5 5-25x56 > ZCO ZC420 4-20x50 > Minox ZP5 3-15x50 >= Kahles K318i 3.5-18x50 > Schmidt US 3-20x50 >= Schmidt US 5-20x50

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wjm308

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Optical Performance
Sometimes I throw up eye and resolution charts to test how well a particular scope performs to my eyes, these are very subjective tests which can be affected by a number of factors and we simply did not have time to perform such evaluations on this day. I’ve had enough experience with the Schmidt & Bender Ultra Shorts as well as the Kahles K318i to say these are top performers in this area, I have no difficulty recommending these scopes to the most discerning shooter. The ZCO (and the Minox) also fall well within this category, the sight picture through the ZCO is nothing short of amazing. I remember the first time I looked through alpha quality glass (first Premier then Schmidt) and seeing that “pop”, all these scopes provide that experience with the ZCO ZC420 and Minox ZP5 5-25x56 providing the most “pop” of them all. To put up a ranking would surely be splitting hairs, so I will avoid that for now.

Field of View (FOV)
Probably one of the most overlooked factors within any scope design is FOV. If you look at the specs above you’ll see some different numbers even though some share the same magnification, and in the case of the ZC420 and K318i, you’ll notice that the FOV is larger for the ZCO at 4x than it is for the Kahles at 3.5x. Optical design or “formula” plays a big part in FOV and I’ll take a scope with greater FOV over a scope with lower magnification almost every time (all other things being equal). Tunneling can also have an effect on FOV and I can assure you that none of these scopes exhibit any noticeable tunneling. With FOV I think the mantra “a picture is worth a thousand words” holds true, so instead of boring you with my diatribe I’m going to let the images speak for themselves (I will throw in a few notes here and there), but once again please do not use these images to get an idea of the IQ/Optical performance of the scope, all the scopes performed extremely well in this regard.
Note: Due to lack of time we did not include the S&B US 5-20 in these tests. Also, we tried our best to keep the center of the reticle in the center of the steel coyote; however, some images were a little off but hopefully still show off how much, or in some cases how little, each scope is capable of. Keep in mind that outside of the lowest and highest magnification settings we used the indicator on the zoom ring as best would could to dial the appropriate magnification, user error and/or incorrect numbering position can play a factor in the actual magnification. Finally, these images were taken when clouds were coming in and out so do not judge one image as brighter or darker than another.

3x FOV Test: Since the ZCO and Kahles cannot go to 3x I’ve used their lowest magnification settings respectively to represent the widest FOV capable for all these scopes.
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The clear winners here are the Schmidt & Bender and the Minox as they are the only scopes that go to 3x, by mfr specs the Schmidt has a slight edge in FOV. It is no surprise (based on specs) that the ZC420 has slightly more FOV than the Kahles even though it is 4x vs. the Kahles’ 3.5x (some may note the image of the Kahles appears to be more magnified than that of the ZCO; however, all images were resized to provide the same sight picture and thus provide a side by side comparison to FOV, this is not a magnification test, but a FOV test).

5x FOV Test: Now things start to get interesting since all these scopes can handle 5x. Once again the Schmidt and Minox appear neck and neck, but the real surprise is it seems the ZC420 may actually have the most FOV of them all. The K318i continues its trend to have the least FOV and by a considerable margin compared to the ZCO.
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10x FOV Test: Interestingly enough, at 10x the Minox seems to have pulled ahead and yields the most FOV out of the bunch but the ZCO is not far behind and might even match the Minox if it weren’t for us being a bit “off” in center crosshair alignment on the coyote. The K318i is lagging once again and still provides the smallest FOV of the bunch.
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15x FOV Test: Let’s call this the “sweet spot” of long range shooting. More often than not atmospherics and mirage play a big factor in dialing down our scopes, I probably use 15-20x more often at long range, while 20x and up I usually use when I’m doing closeup paper punching. In the image below, I notice a slight difference in magnification between images which may be due to precise setting on the zoom ring. Here the Minox seems to have the advantage but the Schmidt and ZCO are not far behind, good news for the Kahles as it seems to have gained some and appears to be picking up. (Note: you may notice a yellow banding around the outer edge of the ZCO’s sight picture, I was able to observe this through the scope with my naked eye when I was in certain eye positions, I’d like to follow-up with jwknudson17 to see if this disappears once mounted on the rifle or if any other ZCO owners have noticed this phenomenon with their scopes.)
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18x FOV Test: The max for the K318i and above what the 3-15x can handle (hence its absence from the image), once again the ZCO and Schmidt seem really close with maybe a slight edge to the Schmidt, but the Kahles seems to have fallen out once again even though the reticle is off to the right slightly we clearly don’t see as much.
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20x FOV Test: The Kahles drops and we see the Schmidt and ZCO at their top magnification. With this image we can see that the two scopes are not on the same plane which may be causing somewhat of an optical illusion when determining FOV; however, it seems the Schmidt has a slight edge in overall FOV and specs would also indicate this.
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FOV Rankings: Schmidt US 3-20x50 >= ZCO ZC420 4-20x50 >= Minox ZP5 3-15x50 > Kahles K318i 3.5-18x50
Lessons learned: I realized after the fact that the scopes were not all in the same location which caused some of the objects within the site picture to appear "offset", in future tests I will try better to ensure that each scope is centered and mounted in the same location.
 
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wjm308

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Depth of Field (DOF)
DOF is another often overlooked feature within riflescopes but can make a huge difference under field conditions. That little dial, usually on the left side of your scope, is sometimes called the side focus; however, this dial is really to ensure that your reticle is parallax free at a given distance, with a well-designed scope your focus and your parallax should go hand in hand. In brief, parallax is an error with your reticle in relation to your eye position, think of getting behind your scope and seeing your crosshairs dead center of your target and you notice your Point Of Impact (POI) is off by .2 mil or more, you might blame wind or say you pulled it etc. but it could also be parallax error and even though it looked like the reticle was dead center it was actually off. It’s easiest to induce parallax by wiggling your eye position behind your scope, if you do that, do you see your reticle move within the sight picture while the background stays the same? That is parallax and now you have to fiddle with the parallax dial until that reticle stays solid with relation to the background. Some scopes are more finicky than others and require a lot more parallax adjustment than other scopes with a greater depth of field. For this evaluation we set the parallax on all the scopes to 300 yards (some don’t have markers so it was our best guess) and then we set magnification to 15x and placed the scope so the sight picture had objects both near and far, not only did we look to see if these objects were in focus but we also checked for parallax to make sure the reticle did not change with relation to our eye position. I call this the “set it and forget it” setting because you can shoot the majority of near and far objects without ever having to fiddle with that parallax. I’ve struggled to even consider putting up images because it’s so hard to get my camera to focus properly through the scope that any blurriness you might see in a picture was due to the user and not to the scope. Jwknudson17 and I were in agreement that all these scopes showed exemplary DOF and this is one area where we disagreed on which we thought “looked” the best. One final thought, this was a hot day in Colorado, I’d say mid 90’s and mirage was quite heavy and each of these scopes had outstanding IQ and depth even through the mirage.
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DOF Rankings: Schmidt US 3-20x50 = ZCO ZC420 4-20x50 = Minox ZP5 3-15x50 = Kahles K318i 3.5-18x50
I’ve ranked them all as equal, I thought the ZCO and Kahles looked best at all ranges and jwknudson17 thought the Schmidt looked best. This is further evidence of “in the eye of the beholder”, all these scopes are so good in so many ways that you won’t make a wrong decision by choosing one over the other.

Color Analysis
It was very difficult for jwknudson17 and I to discern major differences to color during the bright midday sun and bland brown dirt background with mostly green bushes all around, all scopes performed exceedingly well and represent some of the best alpha glass, maybe things will change once we are able to do some low light testing and find some more interesting subject matter to look at.
Color Rankings: Schmidt US 3-20x50 = ZCO ZC420 4-20x50 = Minox ZP5 3-15x50 = Kahles K318i 3.5-18x50

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Pop/Contrast (what is micro-contrast anyway and why should you care)
Have you ever heard the term “pop”, or “wow” when someone looks through their first alpha scope, someone might say “that image really comes to life” or “there’s so much depth, it almost looks 3D”. These are all terms that relate to the ability of a particular scope to resolve something called micro-contrast. This is a term I’m familiar with from my professional photography days and it used to be that you could only gain this effect in your images by having a really good lens that actually resolved this detail, but these days you can enhance an image taken with an average lens through post processing; however, there is no post processing with riflescopes so it’s left to your eye to do all the processing of the image viewed through the scope which means to get that pop or wow, you have to have an optical formula that transmits that detail. But what is that “detail”, what actually defines that “pop”? This is where micro-contrast comes into play and if you watch some of ILya’s (@koshkin) videos you’ll hear him talking about micro-contrast. All optical/glass systems like riflescopes have this and an ideal description comes from - https://lenspire.zeiss.com/photo/en/article/micro-contrast-and-the-zeiss-pop-by-lloyd-chambers

Mr. Chambers writes: “Preserving the contrast of the subject matter is what makes an image look alive and real. High overall contrast with high micro contrast such as with ZEISS Otus lenses delivers what one might term “pop” or “3D rendering” or “brilliance” or the “bite” of fine details. High overall contrast and high micro contrast deliver a visual impact that is compelling. In low contrast conditions such as overcast skies, shadows at dusk, etc, it becomes even more important for a lens to deliver the maximum contrast, or the image looks even more dull and lifeless. In shade at dusk, I term this the “penetrating power” of a lens.”

This description is for a camera lens; however, the concept applies to riflescopes as well. In good daylight situations it might be very difficult for some to discern micro-contrast between scopes, especially with boring backdrops like steel plates stuck in brown dirt sitting in the bright midday sun; however, as noted above, when you get yourself into low contrast situations the lesser scopes begin to reveal their deficiency’s and when compared side by side you begin to see noticeable differences like being able to “see” into the shadows and discern more detail, is that a steel plate blending into the background or is it just a rock, is that a branch or the tine of that trophy buck or bull, that’s where scopes with better micro-contrast really come to life. In the long range community, you may have heard some say “this scope allowed me to see through mirage”, well no scope actually does that, it’s almost like saying my scope allowed me to see through fog; however, what these users are actually experiencing is scopes with better micro-contrast and while it may not allow them to “see through” mirage, it certainly helps to see more detail which gives that impression.

With that lengthy description aside, let’s focus on the scopes at hand. On this particular July day in Southern Colorado it was probably somewhere in the mid ‘90’s (for some reason my Kestrel wasn’t working – most likely user error) and mirage was pretty heavy, especially as jwknutson17 and I were ringing steel at 1000 yards. During our testing as well as our shooting, we found all these scopes to perform extremely well with mirage, definitely worthy of their alpha class designation; however, to my eyes I felt the ZCO, ZP5 and Kahles did this slightly better than the Schmidt. In similar fashion that first impression when looking through each scope comes as no surprise they follow pretty much the same order.
Pop Rankings: ZCO ZC420 4-20x50 >= Minox ZP5 3-15x50 = Kahles K318i 3.5-18x50 > Schmidt US 3-20x50

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Reticle
You can see how the reticle’s look in many of the images above and you can get an image from most manufacturers. Reticle choice is very much personal preference and I am a minimalist when it comes to reticles – I am not a fan of Horus style/busy reticles and like Christmas tree styles as long as the tree is not too intrusive. I do prefer reticles that have .2 mil hash marks especially for wind because I’m a dial elevation and hold wind shooter. My favorite reticle has been the Minox MR4 but as I get older my eyes appreciate reticles that are a bit thicker. The reason I love the MR4 is that the Christmas tree itself is all dots whereas reticles like the SKMR3 and MPCT2 have solid horizontal stadia that I don’t like as much. That being said I love the thickness of the MPCT reticle, to my eyes it is just right. It would be a difficult decision between the MPCT2 and MPCT1, I rarely hold elevation which is where the tree really helps especially with wind holds but how often would I actually do that. Again, no list here, you choose the reticle you love best based on your style of shooting, all these reticles are more than capable.

Conclusion
If we consider this evaluation to be a battle between the alpha class ultra shorts the verdict is still out as more time needs to be had behind the ZCO in differing conditions (I’ve had plenty of time behind the K318i and the Schmidt’s in the past); however, based on my day with the ZCO (and comparing with the others) I feel pretty confident in saying the new ZCO ZC420 will more than likely take the crown as the new Ultra Short to “rule them all”. Does that mean the Kahles and Schmidt should be thrown into the trash heap, certainly not, they are all worthy of alpha class (and easily beat lesser scopes) but have their pros and cons, but what ZCO has done with their first release is nothing short of amazing and worthy of consideration if you are in the market for an Ultra Short scope, and if you don’t require greater than 15x of magnification then the ZP5 3-15x50 proves itself as a very worthy contender itself (especially at some of the used prices you can find these scopes for). Should you go out and sell your Schmidt US 3-20 to pick up the ZCO, well that's more of a personal question on whether or not you feel the ZCO can give you an edge you don't already have, if you're very particular with turrets and reticles then the answer might be yes, but both the Schmidt and the Kahles are very worthy contenders and will serve their respective shooters well for years to come.
 
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wjm308

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LOW LIGHT EVALUATION

@jwknutson17 and I had the chance to get out last week and do a quick review of these scopes in fading light. I have good news and I have bad news.

First the good news, all these scopes delivered like alpha scopes in low light.

The bad news, it has been a very wet summer in Colorado and as such the mosquitoes are on the rampage and we were fresh meat for their voracious appetite. As such, we were unable to conduct the full breadth of the evaluation which I usually like to do with a high and low contrast chart at 12x on each scope as the light fades from sunset to 30 minutes beyond.

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We had the Minox ZP5 3-15x50 and the Schmidt Ultra Short 3-20x50
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And of course we also had the Kahles K318i 3.5-18x50 and the ZCO ZC420 4-20x50
ZCOvKahlesvS&BvMinox_LL_Eval_003.jpg


CLARITY
Clarity can mean different things to different people, so let me define it here as the scopes' ability to produce an image that is detailed, a scope with good clarity is going to show detail throughout the sight picture and represent accurately the objects therein. Micro contrast is definitely going to play a role here especially with edge definition. In low light it's important for a scope to allow the shooters eye to differentiate between a branch or the tine of an antler. As mentioned above, the mosquitoes were crazy and swarming around us like flies on a dung heap, jwk brought a jacket but I was in short sleeves and they were relentless if we slowed to look through a scope. As such we could not keep steady long enough to do these scopes justice and we decided to just evaluate the best we could. At the end of the evening I made the comment it would have been fun to have had a video so you could all see are amazing dance moves as we tried to dodge the little bloodsuckers. Even though we could not stay still long enough for a thorough evaluation both jwk and I came away with the impression that all these scopes performed incredibly in low light. If there was one scope that struggled ever so slightly, both jwk and I agreed that the Schmidt Ultra Short showed the least amount of clarity within the image, this was seen in the lichen on the rocks behind the test target, the details in the lichen appeared sharper in the Minox, Kahles and ZCO than they did through the Schmidt which also aligns with my experience with two previous Ultra Shorts. Does this mean you should skip on the Ultra Short because it's a bad scope? Certainly not! We're talking the best of the best and to be at the bottom of the best (in one category) means you're still better than the rest, I would not pass up on the Schmidt Ultra Short if it meets all your other requirements for your type of shooting, you will be very pleased with this scope.

ILLUMINATION

We also conducted a quick illumination test and the scope with the brightest (by a considerable amount) illumination was the Kahles, cranked to full power the brightness in the fading late was almost too bright to look at, followed by the ZCO. I would be interested to see how the ZCO would do on it's own in bright sunlight (I should note that we only tested the red illumination and did not test the green illumination to see if that "appeared" any brighter to our eyes). Both the MR2 reticle in the ZP5 3-15 and the MSR reticle in the US 3-20 only have center crosshairs that light up with illumination, while the Schmidt did very well it seemed the ZP5 was a little brighter; would either of these scopes be daylight bright - highly doubtful, but very usable illumination when the light gets low and only having the center cross light up helps with identifying dead center for close up shots.

CONCLUSION
While I wish we didn't have to battle nature and could have spent more time conducting more thorough HC/LC testing, jwk and I both came away with the impression that all these scopes performed exceedingly well in low light.

On a side note, I've been looking for a new set of binoculars and rangefinders and had purchased a pair of Maven B.2's through Maven's demo program, I had the 11x45 and the 9x45 to compare to some Swarovski Swarovision EL 10x42's and I'll post an "initial impressions" in another thread in the "Observation Devices" forum, but a sneak peak is that we were both very surprised with the Maven's IQ.
 
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Covertnoob5

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Awesome write up! Thanks for taking the time! The ZCO is definitely amazing. Glad you finally got a chance to look through one.

I would only say that although the Schmidt performs admirably, I don’t exactly consider it an ultra short. It’s 13.6” long. I know it’s mostly arbitrary but where do we draw the line at length for the “ultra short” category?
 

hk dave

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It’s funny, I know this is kind of off topic but I was thinking about this myself. I’ve been thinking of what scope to slap on my SCAR 17 with 22” 6.5cm barrel... and felt a shorter scope made sense.

Just for fun looked at the Razor GenII specs and found that the big boy is only 14” long which amazed me.

So that’s an interesting thought, what makes a scope an US. My thought is it has to somehow me a combination of magnification and length.
 

CavScout85

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This write up and cstactical having the zp5 mr2 for $2099 is having an adverse effect on my wallet.
 
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rydah

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People taking the time to do stuff like this is the number one reason I signed up to the hide. Thanks for that very helpful insight.
 

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Thank you for taking the time to put this review together it was done very well.I only own the ZC4X20 out of those scopes and can not say enough good things about it,I find myself for the first time that I might have found my dream scope.Until ZC comes out with Gen2.
 

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Nice review, thanks.

I just got a ZCO 420 last week, looking forward to getting it to the range.

Curious to see the low light evaluation.
 
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brianf

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hard to read on my phone, tried for a while
has anyone compared this write up to Koshkin's
would like to see if results are the same
that would eliminate the possibility of a bad scope from wither review skewing the results
 

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The 5-25 vudu seriously has my attention for my 300 norma improved build. I also looked thru the 3.5-20 sb ultra short, and it's a beauty, although double the price. The vudu weighing 29oz and 11.5" in length is a very compact design.
 

wjm308

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I would only say that although the Schmidt performs admirably, I don’t exactly consider it an ultra short. It’s 13.6” long. I know it’s mostly arbitrary but where do we draw the line at length for the “ultra short” category?
I agree noob, the Schmidt 3-20 is a "long" Ultra Short, but it is a 3-20x50 under 14" long where their standard 3-20 is 15.2" so in comparison the Ultra Short may not be "Ultra" but it is shorter.

I suppose I should define what I deem as Ultra Short and will update my first post to include this:
Part of this information I have gleaned from ILya's article on Ulta Shorts, but have added an additional qualification for max magnification.
The phrase “Ultra Short” was originally coined by S&B first with their 5-20 then with their 3-20. In principle, how short you can make a scope is a function of how large the objective and ocular lenses are. The larger they are, the harder it is to make a scope short. Also, keep in mind that short does not have to mean light (and light can be subjective). With that in mind, here are my qualifications for what overall scope length, based on objective size as well as magnification are what I deem to be Ultra Short:
Greater than 50mm Objective with 18x or greater max magnification: Under 15″
40 to 50mm Objective with 18x or greater max magnification: Under 14″
 

wjm308

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Thank you everyone for your kind remarks, as jwknutson17 mentioned, it takes a long time to write up these evaluations/reviews and also to put together the pics. I wish I had a better system to take through the scope pics (have been on the fence with the scoped vision type device) so getting my full size DSLR with lens in the right spot is not an easy process. Hopefully the images help and not hinder because sometimes the image is slightly blurry due to user error and not due to the scope itself.
 

Covertnoob5

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Honest question, but So are the razor 2, k525, and tango 6 ultra shorts?

ETA: I think it should be 14” for both categories but that’s all personal preference/definition
 

wjm308

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Honest question, but So are the razor 2, k525, and tango 6 ultra shorts?

ETA: I think it should be 14” for both categories but that’s all personal preference/definition
Yes, based on my criteria the Razor Gen II's and the K525i also just slips in, I do consider those short optics, but maybe there needs to be "short" and "ultra short", but then people might get confused because Schmidt calls their 3-20 an "Ultra Short". Other than Schmidt and EoTech I don't think anyone else uses any kind of "short" designation, there is no industry standard for this unfortunately, part of why paying attention to some specs is a good thing.
 

canezach

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Just so I'm understanding this clearly: You have my number. You went to the range. You reviewed a bunch of alpha scopes. You didn't call me?!?! 😡😡😡😡😡

All joking aside, great review! More importantly, it's factual and unbiased. Good job, buddy!
 

wjm308

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Just so I'm understanding this clearly: You have my number. You went to the range. You reviewed a bunch of alpha scopes. You didn't call me?!?! 😡😡😡😡😡

All joking aside, great review! More importantly, it's factual and unbiased. Good job, buddy!
But you told me you hate alpha scopes - good glass is for wimps you said, just kidding :D Seriously, my schedule has been horrendous of late and this was rushed to meet our schedules, but I would definitely love to shoot with you again, I think you'll like the range more now, they have a lot more steel out there. But no 6 Dashers, that thing was way too easily ringing that steel out there, I'll give you a 22 Hornet, that will be more fair ;)
 
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wjm308

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Your Kahles set at 3.5x is magnifying more than the ZCO at 4x
Read my notes, this is due to the resizing of the images to get the sight picture to look the same for a comparison of FOV, this also makes the SKMR3 reticle look just as thick or close to the MPCT2; however, this was not the case, the SKMR3 is quite a bit thinner when looking through the scopes.
 

918v

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So the Kahles has a smaller image circle at 3.5x? Is it tunneling or is it smaller throughout the magnification range?
 

D_TROS

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...
Lessons learned: I realized after the fact that the scopes were not all in the same location which caused some of the objects within the site picture to appear "offset", in future tests I will try better to ensure that each scope is centered and mounted in the same location.

Just a quick pointer. I nvr thought of this technique until an optics engineer told me. When checking FOV, jus tlook at the mil markings on the retc. Ie on your last pic of the 3-20 and the ZCO at 20x, the 3-20 FOV goes to roughly 10.5 mils and the ZCO is 9.5 mils so as you guessed, the 3-20 is indeed larger by a magnitude of 2 mils (1 on ea side if that makes sense)

Anyway, cool write up. Im also located north of Denver and if you do any fun comparisons again, PM me.

Last, would like to see how a March 3-24 stacks up. Its the best ive seen in compact scope by far.


GL
DT
 

wjm308

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So the Kahles has a smaller image circle at 3.5x? Is it tunneling or is it smaller throughout the magnification range?
None of these scopes tunnel, at least not to the point that I can detect. The Kahles just has a smaller sight picture, the ZCO is massive, it felt bigger than all the others; however, I wasn't paying as close attention to this, but maybe I should next time out. Let me see if I can do some crops that are more 1:1
 

koshkin

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Just a quick pointer. I nvr thought of this technique until an optics engineer told me. When checking FOV, jus tlook at the mil markings on the retc. Ie on your last pic of the 3-20 and the ZCO at 20x, the 3-20 FOV goes to roughly 10.5 mils and the ZCO is 9.5 mils so as you guessed, the 3-20 is indeed larger by a magnitude of 2 mils (1 on ea side if that makes sense)

Anyway, cool write up. Im also located north of Denver and if you do any fun comparisons again, PM me.

Last, would like to see how a March 3-24 stacks up. Its the best ive seen in compact scope by far.


GL
DT
That is how I initially check the FOV, but be careful to check it on all sides since sometimes reticles are not perfectly centered in the scope. Also, this assumes that the reticle is calibrated correctly.

You can also check FOV using the turrets if you have verified the clicks to be accurate: find a well defined object/edge somewhere, fix your scope in place and twist the turrets until this object moves from one edge of the image to another.

ILya
 

wjm308

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Just a quick pointer. I nvr thought of this technique until an optics engineer told me. When checking FOV, jus tlook at the mil markings on the retc. Ie on your last pic of the 3-20 and the ZCO at 20x, the 3-20 FOV goes to roughly 10.5 mils and the ZCO is 9.5 mils so as you guessed, the 3-20 is indeed larger by a magnitude of 2 mils (1 on ea side if that makes sense)

Anyway, cool write up. Im also located north of Denver and if you do any fun comparisons again, PM me.

Last, would like to see how a March 3-24 stacks up. Its the best ive seen in compact scope by far.


GL
DT
Sometimes the answer is staring us in the face! That almost makes too much sense, just use the reticle to determine how many mils at each mag setting, most of these reticles go pretty far down except for the MR2. Having mentioned that, I think I need to add some notes to my above post, thanks DT! But it's not as fun as my method ;)
 
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wjm308

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That is how I initially check the FOV, but be careful to check it on all sides since sometimes reticles are not perfectly centered in the scope. Also, this assumes that the reticle is calibrated correctly.

You can also check FOV using the turrets if you have verified the clicks to be accurate: find a well defined object/edge somewhere, fix your scope in place and twist the turrets until this object moves from one edge of the image to another.

ILya
Is it safe to assume that with alpha class scopes the reticle is centered and calibrated correctly? I remember this coming up in another thread recently.
 
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wjm308

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Last, would like to see how a March 3-24 stacks up. Its the best ive seen in compact scope by far.
I had the March 3-24x52 a few years ago, what would you like to know? Glass wise it is definitely a contender, in my middleweight scope review from 2016 it actually handled CA better than Schmidt's 3-20 in some situations, but did not quite match in resolution though it was quite good. Where I found the March 3-24 lacking was in parallax and DOF as well as FOV, sure it went down to 3x but FOV was very narrow throughout the range, felt like a straw compared to the others. Parallax I found I had to play with quite a bit to get right, these other scopes are much more forgiving.
 

Covertnoob5

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I had the March 3-24x52 a few years ago, what would you like to know? Glass wise it is definitely a contender, in my middleweight scope review from 2016 it actually handled CA better than Schmidt's 3-20 in some situations, but did not quite match in resolution though it was quite good. Where I found the March 3-24 lacking was in parallax and DOF as well as FOV, sure it went down to 3x but FOV was very narrow throughout the range, felt like a straw compared to the others. Parallax I found I had to play with quite a bit to get right, these other scopes are much more forgiving.
I also had a 3-24x52 and will day that while that scope did some things ok. I feel it’s not in the same class as the zco420.
 
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wjm308

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I also had a 3-24x52 and will day that while that scope did some things ok. I feel it’s not in the same class as the zco420.
I will also say this, at over $3k for the March, unless I absolutely needed a super lightweight FFP scope (but it comes with its drawbacks as mentioned above), I think this scope is overpriced for today's market, especially with the Nikon NX8's offering the same erector (8x) but at less than $2k and a better reticle IMO. I know March is getting new distributors (eurooptic is one of them) and pricing still seems to be up in the air, but if price of the illuminated 3-24x52 still comes in near $3k I would not hesitate one bit to recommend to anyone, get the ZCO or even the Schmidt or Kahles - in a heartbeat, they are truly that much better. Considering the NX8 pricepoint, I'd wouldn't pay more than $2500 for a new March and used would expect them to dip near the price of the NX8's and even then the NX8 might still be the better scope... I am very tempted to grab an NX8 to see if it's really all that it appears to be (I have never owned a Nightforce so definitely not a fanboy, but curious to see how good this scope is for the price)
 

koshkin

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I will also say this, at over $3k for the March, unless I absolutely needed a super lightweight FFP scope (but it comes with its drawbacks as mentioned above), I think this scope is overpriced for today's market, especially with the Nikon NX8's offering the same erector (8x) but at less than $2k and a better reticle IMO. I know March is getting new distributors (eurooptic is one of them) and pricing still seems to be up in the air, but if price of the illuminated 3-24x52 still comes in near $3k I would not hesitate one bit to recommend to anyone, get the ZCO or even the Schmidt or Kahles - in a heartbeat, they are truly that much better. Considering the NX8 pricepoint, I'd wouldn't pay more than $2500 for a new March and used would expect them to dip near the price of the NX8's and even then the NX8 might still be the better scope... I am very tempted to grab an NX8 to see if it's really all that it appears to be (I have never owned a Nightforce so definitely not a fanboy, but curious to see how good this scope is for the price)
March is an interesting company and I think I will be re-visiting a couple of March scopes, configured a little differently from the ones I have seen before. I want to mess with the 3-24x52 with their tree reticle and 1-8x24 Shorty with the FMC-3 reticle and different illumination switch.

ILya
 

HR218

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Wow!...............Just Wow!

Thank you wjm308.

I am so thankful for the time invested in the comparison, photography and review write up of these US scopes. Definitely causes one to ponder what time will tell for the ZCO line of scopes. Is there even BETTER coming from them...........How?

I can't wait for the additional write ups to be added.

HR218
 
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March is an interesting company and I think I will be re-visiting a couple of March scopes, configured a little differently from the ones I have seen before. I want to mess with the 3-24x52 with their tree reticle and 1-8x24 Shorty with the FMC-3 reticle and different illumination switch.

ILya
Which tree reticle for the 3-24, the FML-T1? If March had a better reticle for the 3-24 it would change a lot, but I don't like the FML-T1. It sounds like March will be coming out with some new reticles, they are definitely looking at adding some new ones for their upcoming 5-42x56 Highmaster which I would be very interested in if they do get the reticle and mechanical worked out, should be a real contender. From those who've seen it in the SFP scopes, the High Master glass, which uses a triple lens structure for their front objective consisting of two Super-ED lenses and one proprietary one, is quite impressive and may rival some of the best alpha glass so we'll have to wait and see, would love to compare a 5-42x46 to my ZP5. Really hoping March is able to get these new reticles out soon...
 

koshkin

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Which tree reticle for the 3-24, the FML-T1? If March had a better reticle for the 3-24 it would change a lot, but I don't like the FML-T1. It sounds like March will be coming out with some new reticles, they are definitely looking at adding some new ones for their upcoming 5-42x56 Highmaster which I would be very interested in if they do get the reticle and mechanical worked out, should be a real contender. From those who've seen it in the SFP scopes, the High Master glass, which uses a triple lens structure for their front objective consisting of two Super-ED lenses and one proprietary one, is quite impressive and may rival some of the best alpha glass so we'll have to wait and see, would love to compare a 5-42x46 to my ZP5. Really hoping March is able to get these new reticles out soon...

Did you have mechanical problems with March?

The 3-24x52 I want to look at is indeed with the T1 reticle. I tested that scope before T1 was available, so I am kinda curious. On paper, there are things about the T1 reticle I like and things I do not. It got me sufficiently curious that I want to see it in a scope. I have some ideas on reticles that would work, so perhaps I will convince March to use one of my designs.

I will see if I can get my hands on one of the 5-42x56 prototypes. However, I will likely refrain from publishing too much about it until I test a production version.

ILya
 

wjm308

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Did you have mechanical problems with March?

The 3-24x52 I want to look at is indeed with the T1 reticle. I tested that scope before T1 was available, so I am kinda curious. On paper, there are things about the T1 reticle I like and things I do not. It got me sufficiently curious that I want to see it in a scope. I have some ideas on reticles that would work, so perhaps I will convince March to use one of my designs.

I will see if I can get my hands on one of the 5-42x56 prototypes. However, I will likely refrain from publishing too much about it until I test a production version.

ILya
No mechanical issues, in fact, I love the zero reset, turrets were a bit mushy but easy to dial. My biggest gripe was with reticle and parallax/depth, oh and illumination - I did not like the controls and it was not usable during daytime.
 

koshkin

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No mechanical issues, in fact, I love the zero reset, turrets were a bit mushy but easy to dial. My biggest gripe was with reticle and parallax/depth, oh and illumination - I did not like the controls and it was not usable during daytime.
March has a much better, IMO, 6 position illumination dial that for some reason noone know about. I am going to try to get oth the 3-24x52 and 1-8x24 Shorty with that illumination dial.

ILya
 

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March has a much better, IMO, 6 position illumination dial that for some reason noone know about. I am going to try to get oth the 3-24x52 and 1-8x24 Shorty with that illumination dial.

ILya
I would be curious if this new illumination module can keep up with other long range scopes for what we call daylight bright, not red dot bright, but usable in shadow areas, I find that to be a benefit at times. When I bought my 3-24x52 I think Shiraz was selling two modules, the one I had was only usable once the light got low.