Have you ever wished that your scope had just a little extra magnification to either get that better sight picture or to possibly better identify the target? Or perhaps you have found the perfect scope but it just didn’t have the magnification range you wanted? The BulzEyePro optical booster tries to help address some of those issues by allowing you to screw on an additional optical boosting lens to the eye piece of your scope.
BulzEyePro offers three different styles of boosters that attach to the eyepiece, the #1 screws onto a threaded eyepiece and is the one we reviewed here. The other two styles are designed with a rubber housing that can fit onto any 1″ or 30mm tube scope. The screw on #1 style will only fit certain scopes, of which Leupold is one. We have a Leupold VX2 that went to the Leupold Custom Shop to get a set of target knobs installed with a custom BDC for the Lapua 6.5×55 123gr factory loaded ammunition. This is all mounted on a custom 6.5×55 rifle that we just finished. The scope has a German #1 reticle and I thought this would be as good a scope as any to test the booster on.
The quality of the booster appears to be high with a nice brushed aluminum housing with nice machining. You can see the coatings on the optical lens and the threads are well cut, etc. The aluminum has no coating but that should be fine and as you can see in our picture below a Butler Creek ® flip-up cap covers it with no problem.
The threads on the Leupold eyepiece are very fine and typically there is some buildup of dirt and oil in the threads. As such, the first time you attach the booster it can be a chore as you work it onto the threads cleaning the threads out along the way. But after the first time it doesn’t seem to be a problem. By introducing an additional magnification lens to the scope, there is a concern about properly focusing the scope, and this is a problem. Typically, and it worked for our scope, you need to screw the eyepiece focus all the way in and then attach the booster. This allows the reticle to become sharp and focused though with only a limited amount of adjustment if it were needed.
There are several different booster lenses available and the one we have here is a 3x. Now, this does not indicate that all of the magnification is 3x greater making a 3-9x a 9-27x, and, to be honest, I am not sure what the 3x stands for unless it is a 3x magnification lens. When I asked what type of magnification boost I should be getting I was told about 30%. This would make our 3-9x a 3.9-11.7x (call it 4-12?). This seems to be about right, though that might seem a bit high still.
The effect of the booster on the scope is that it magnifies everything including the reticle. While it does effectively do that, I seemed to notice that the eye relief appeared to be shorter with the booster attached. So I decided to measure it and sure enough, it is significantly shorter. Without the booster attached and the scope set on 9x my crude measuring showed the eye relief to be 3.75″ at its shortest. I then attached the booster leaving it at max power (9x on the scope, near 12x in theory with the booster) and measured it again. The eye relief was 2.875″, almost a full inch shorter. I set the power ring on 7x which puts the boosted power close to 9x to compare the eye relief at the same power, and it was just short of 3″, a full .75″ shorter than normal. Now, this was with our one sample scope we tested it on, a Leupold VX-2 3-9x, and admittedly a fairly crude measuring method, but it is still significant enough to be noticed and it would be a problem with this scope with a light rifle chambered in a magnum cartridge. As it is, a heavy rifle chambered in 6.5×55 swedish does not recoil enough to cause any problems, but I think I know now why they came out with the #2 and #3 styles with the rubber eyepiece to protect your head in case you get a scope kiss.
The fact that you are adding an additional magnification lens to the scope does bring up some concerns about interfering with the optical system and diminishing the optical quality of the scope. The lens is manufactured by a different company with different equipment and there are different lens coatings applied in different quantities, so one would assume that there would be a noticeable impact and it is true on our test scope. At full magnification we did notice a slight dimensioning of sharpness in the scope picture. It was not too bad but you did notice it on the higher powers.
When shooting, it performs about as you would expect. Your scope is now a bit higher magnification and you get all the rewards of more power. I shot some 100 yard groups with and without the booster and while the accuracy of the rifle was the same, it was, as you would imagine, a bit easier to get the tighter groups with the extra magnification. We did some long range shooting with the booster as well and nothing really jumped out as being a major problem with using the booster beyond the slight degrading of the clarity.
Overall, the booster does what it is designed to do and the construction of the unit appears to be of high quality. But with the reduced eye relief and reduced quality of the over all optics, it probably is not totally suitable for long range tactical work. Perhaps if a team wanted to keep one in their kit for some extra boosted power for more detailed observation, I could see a place for it in your kit to increase your flexibility. It is small and would be very easy to toss in a pocket or rifle cleaning kit, etc. But for us, it will not be a permanent attachment to the scopes on our rifles.