Vortex Impact and similar scopes

I will just apologize right up front that this is going to be a bit lengthy.  

I have been intrigued with the Vortex Impact (and the identical Hawke Optics Nature and Burris XTS-2575 - which is an incredibly stupid name by the way) since its introduction to the market. Basically my decision to buy one of these scopes came down to two primary reasons:

1. I have long been interested in the design of these scopes which is wholly different from the standard prismatic spotting scope to which most of us are accustomed. (Much more on this to come later.)

2. While I need a spotting scope to fill my needs right now,  I really want an ED scope, which I can’t just yet afford (at least, not without incurring grand and terrible punishments from the domestic goddess.) 

This scope, with its under-$200 price tag, will allow a stop-gap for both of these issues.

The Vortex Impact: the scope itself.

The Impact comes as a package that includes the scope, a very nice carry case, a small “table-top” tripod, and covers for both the objective lens and eyepiece.  Let’s address each of these briefly.

Lens Caps:

The eyepiece cap is a simple, plastic, friction-fit cap common to most compact binoculars. It’s nothing fancy but, the fit is good and tight and won’t come off easily by itself. The objective lens cap on the other hand, is fantastic.  It is a screw-on deal made of hard plastic that cannot physically come off at all unless unscrewed, similar to my old B&L Discoverer. This is very positive protection for the objective lens and I like it a lot.  More manufacturers should do this for their scopes.

Tripod:

The “table-top” tripod that comes with the scope is nothing to brag about. It definitely is not a “field-worthy” unit. The adjustments are fairly crude and not terribly user friendly.  In addition, there is a heavily-greased spring on the back side of the tripod that is exposed and not only will readily gather dust but, if you’re not careful, will spread grease on your hands. Not cool.

Carry Case:

The provided carry case is really quite nice.  It is a cordura case that is sized appropriate to hold both the scope and the tripod.  It is well made and even includes double-stitching at the seams. In addition, there is a Velcro-attached, removable shelf to separate the tripod from the scope allowing better protection for both. 

The Scope:

The Impact is a very cute little spotting scope.  It is described as “compact” which it certainly is in comparison to other full-size Cat scopes but, it is still about the size (shorter but fatter) as a 60mm Nikon Fieldscope. It is however, noticeably lighter. The design of catadioptric scopes precludes them having a straight eyepiece, which bothers me a little but, I’m sure I can get used to the angled eyepiece.  After all, birders love the things.

When looking at the objective lens, the mirrors are very obvious.  Unlike a prismatic scope where, if you look through the objective lens you see things as if they were really far away, when you look through this scopes objective lens, you see a distorted reflection of yourself.

The scope at least appears to be well built and rugged but, I do need to mention a little problem I had with it within the first hour of it arriving at my home.

There is a small piece of plastic just forward of the focusing knob that, in addition to giving the scope a sleeker appearance, seems to serve as an extra bit of protection for the knob from inadvertent impacts. This piece of plastic fell off almost immediately after the scope arrived.

A careful look will show where it was held to the scope only by two tiny dots of super glue. It also reveals how inconsequential this piece of plastic is to the operation of the scope.  With this in mind, I chose not to send the scope back for repair/replacement under the VIP warranty and instead, I just reattached the piece with two additional drops of (higher-quality) super glue.

This little “tragedy” does not make me worry too much about the overall build-quality of the scope as (like I said) this piece of plastic has no effect on the operation of the scope.  It was also very quickly and easily fixed but, I do feel like to be fair, I had to mention the issue.

The Vortex Impact: the optics - continued

O.K., now where was I?  

Oh yes, the optics….

I took the scope out for a pleasant evening of glassing eagles, mule deer, and antelope on a mountainside not far from my home.   This can actually be done right off my front step though; you won’t generally see quite as many animals.

Field of View

As noted earlier, the Impact (along with all other Cat scopes) has, resulting from part of its design, a relatively narrow Field of View as compared to prismatic scopes at similar magnifications. To give you an idea of what we are looking at here, I have composed a chart that compares the FoV of the Impact at its lowest 25x with the calculated FoV of a few comparable scopes at that same magnification. (I did also throw in the Pentax PF65ED with the 20-60 XF eyepiece.)

This narrower FoV was definitely noticeable. It (in addition to another issue to be discussed shortly) made things more difficult to acquire in the scope.  Once I acquired the object of my interest in the scope it was no trouble to keep them there, even the flying birds and running antelope. It was just the initial task of getting the glass on them that was a challenge. I’m sure that a person could get used to this and become quite proficient with practice.  Also, the Impacts FoV is not as narrow at 25x as all of the prismatic scopes.  The Pentax PF63 will only give you about 78 feet (though, at least with the Pentax you can dial down the magnification for the finding of the animal and then dial it back up once they are in the scope.) Nevertheless, this comparably narrow FoV does represent a real shortcoming of the design.

Chromatic Aberration

As discussed previously, as a Cat scope, the Impact uses mirrors to reflect rather than prisms to refract the light entering the scope.  Because of this there is no “splitting up” of the different color waves of light and thus, no need to try to bring them back to the same point of focus. What this means is that a Cat scope’s mirrors do not create the problem that results in chromatic aberration like a prismatic scope does. In other words, there is NO chromatic aberration in a Cat scope.

Even though I understood this concept intellectually, it was still quite a revelation to see it first hand. Try as I might (and I really tried hard) I could not find any circumstance where I could see any evidence of chromatic aberration – just as it should be. As a result, color fidelity was absolutely spot on.  Resolution was also greatly helped and (as will be discussed further in a moment) achieving good focus at higher-than-normal magnifications was made imminently possible.

Magnification range

The Impact has a 25-75x magnification range.  According to all the available literature, achieving super-high magnifications in a Cat scope is a very real option. This theory may be true and magnifications of 100x and beyond may be possible for super-high quality (and thus super-expensive) Cat scopes but, the budget class Impact definitely started to show the limitations of its capabilities around 50x and by 75x it was pretty much useless.  Some of this is no doubt due to the limitations of the eyepiece (which is the primary limiting element in most scopes) and I would like to see what this scope would be like with a high-quality fixed magnification eyepiece but, that’s probably not going to happen anytime soon. This result is very similar to most variable power prismatic scopes at their highest magnifications. You should keep in mind however, that most standard scopes won’t even reach 50x before the image through them is too muddy to be of very much use so; while the Impact doesn’t quite live up to its billing in the magnification department, it still demonstrates a distinct advantage over comparable refractor scopes.

Image Clarity

At its lowest magnification (25x – which is about as high as many refractor scopes will go without showing image problems) the image from the Impact is really quite stunning – especially considering the scope costs less than $200. As mentioned color fidelity was flawless – due largely to the lack of the dreaded CA. Resolution was also excellent.  Edge clarity was as good as I’ve ever seen but, here we have to take a little detour.

Common phraseology in the optics-obsessed person’s world generally includes the term “sweet spot” which is used to describe the amount of the image from the center that retains the very best clarity before deteriorating somewhere out toward the edges. With the Impact (and other Cat scopes as well) this phrase must be altered to say something like the “sweet doughnut.” It was totally unnoticeable at 25x but, as you turned up the magnification the very center of the image started to show the same kind of focus problems normally associated with the image edges in refractor scopes.  Around this “hole” and going right out to almost the very edge was the part of the scope that retained the best image clarity and it became necessary to position the item of interest in this outer 2/3 portion of the FoV to be able to get the best resolution and focus. No doubt, this is due to the presence of the center obstruction on the objective lens and it wasn’t at all difficult to position the animal in the correct “sweet” area for the best picture.  It does take some getting used to however, and is a bit annoying. For the photographer on the other hand, this might even prove advantageous as it could serve to force the individual to use the outer 2/3 of the FoV – thus facilitating better composition in their photographs. 

The Angled Eyepiece

I have asked the question, “which is better angled or straight” about eyepieces before.  Angled eyepieces seem to be quite popular, especially among birders but, I had never used one.  The design of Cat scopes does not allow for a straight eyepiece so; this was to be my first foray into the angled world.

In short, I hated it.

In conjunction with the already narrow FoV, the addition of the angled eyepiece increased the challenge of lining up the item of interest to a degree that really was unacceptable. Then too, much of my glassing (especially for antelope) is done from a vehicle using a car window mount. The angled eyepiece made this a real exercise in patience development.  I actually had to kneel on my car seat to get high enough to use the scope.  Now, I’m a rather small-statured man (standing all of 5’6”) so; this wasn’t an impossible task but, it sure was a nuisance.  The angled eyepiece I’m sure, would be just fine on a tripod (especially since a comparably smaller, lighter, and more stable tripod could be used) but, since this only represents maybe 40% of my glassing needs, it just won’t do at all. I know that some people really like, even prefer the angled eyepiece.  I’m just not one of them.

Conclusion

So, where does this leave us?  To reiterate what has already been said, ALL optics involve compromises. This scope is no exception.  It has some really good points and some other areas that are lacking. Is this scope going to change the optics market as we know it?  No.  Are people who paid 5-10x the price going to suddenly start weeping, wailing, and gnashing teeth because of the huge sums of $$$ they “wasted?” No. Is this scope going to cure me (and you?) of the ED glass bug?  Well…    No.

The Impact is really very good. I worry that I will have “damned [it] with faint praise” and this is not my intent at all. It is imminently useable and offers great value for its very modest required investment. In a communication I had with Paul Neess of Vortex Optics he indicated that they believe this scope is at least as good (if not better) than anything else out there in its price class.  I would tend to agree.  Certainly if you are on a fairly restrictive budget and simply cannot pay more than $200 - $300 for a scope, you will be selling yourself short if you don’t at least put the Impact on your short-list of options.  

In the end and despite its being a very good glass, I believe I will be returning the Impact. You see, the problem I have is that I don’t really want a “good” spotting scope nor do I want one that will “do everything I ‘need’ it to do.” I’ve already had such scopes and now I want something better.  I want a great spotting scope.  I want something that is a cut above. I want something that is not just useable but rather, something that is a pleasure to use.

Yes, I’m going to have to come up with a lot more money to make this happen but, I’m willing to wait.

lucznick, thank you. It sounds like a decent 200 yard shooting range scope.

Frank, you will like the Skyline ED, but it's a bit on the big/long side, just don't drop it  .