Just curious.

For example, a Nightforce 3.5-15X50 vs 3.5-15X56. Most all the spec's on these two scopes are VERY close to the same except for the objective size.

Would the 56mm model have a NOTICIBLE not theoretical advantage in the field were brightness is concerned?

I'm putting together a "bean field" rifle and late afternoon deer are the target. This will not be a walking around gun so I feel like I could put a big ugly scope on it IF there was a big advantage to doing it. If the difference isn't much I'd just go with the 50mm model.

Thanks,
Terry

I went with the 3.5x15x50 myself.I don't see any significant difference with the 56mm.

I doubt you could notice any difference.

I'd go 56 if it were mine.

TC1,

I hope this is not answering a question you did not ask. When the 6 1/2-20X Leupold 50mm's came out I called to find out if there was a difference that could measured. Customer service, of course, repeats what they have been told. She said the machine could detect a 5% difference over the 40mm, but only when the scope was set on its highest mannification.

When I compared my 12-42X56mm with my 4 1/2-30X50 Bushnell with both set on 30X, I didn't notice much difference, but it was duringthe day. The glass set on 30X on the Bushnell seemed to be about the same for resolving detail. Not so good on the bottom end.

Never the less, I would go with the 56mm because it is not a carry gun. You know the addage: If a little is good a lot is better.

or if a little is good, a lot could be only a waste of money?

Brightest scope I ever looked thru in lowlight was a Zeiss Victory with a 56mm objective. My best friend has the Nightforce NXS 5.5-22with a 56mm Objective. The Nightforce is much heavier and is not as good in lowlight but it was designed for ruggedness first and foremost.

The 56mm - lets you use about one more power - and get the same light. My Nightforce 5.5x22X56 was the brightest scope I had ever owned - or even looked though.

TC1- i bet a zeiss 2.5-10x50 would do the job quite well

My Zeiss scopes with Lotutec coating are very good early in the morning and after the sun goes down.

Theoretically, the 56 mm scope would be brighter as it's all about exit pupil. A 50mm scope would deliver a 5mm exit pupil on 10x and a 56mm scope would deliver a 5.6mm exit pupil. However, I have identical Zeiss scopes, except one is 50 mm and the other is 56 mm, and I can not tell any difference. The only reason I bought the 56 was because a 50 was not available at the time. I do have an 8x56 Swarovski and I am glad it is a 56 since it is a fixed 8x.

As somebody already said, a 56mm will let you use a slightly higher magnification as the light fades and if the magnification on the scopes is set the same, say X4, a 56mm would give you a little extra hunting time at last light, but no more than say about 10 minutes..

Those have remarks have to be qualified by saying that its only the case if all other factors between the two scopes are equal ie same coatings and their lenses in the same condition.

I have tested a few scopes side by side and have sometimes been surprised by the results. For instance, I had an older 6x42mm Swarovski Nova which I tested side by side against a 6x42mm M8 Leupold and a 7x50mm Meopta..I full expected the Meopta to be the brightest because of the larger objective, but in fact the Swaro was a touch brighter and remained useable a tad longer at last light...

quality optics trump BIG optics almost all of the time. a good 42mm should be better than an average 50mm.

Bob,

I would certainly agree with that statement.

Th other thing to factor in is the type of reticule a scope has...It doesn't matter if its a really bright 56mm European scope if the reticule is too fine for low light work. We are allowed to take deer up to one hour after sunset and when the light is fading fast, generally the first thing you loose is the fine cross hairs when you put them on the dark shape of a deer.

Its for this reason I prefer a heavy German No4 or No7 reticule, or even better, an illuminated one..

Regards,

Peter

I would look at a Ziess 2.5-10x50.

Scopes are the same except for the objective.

Crittergetter offered me a great deal on a Zeiss 3-12X56mm scope today. I'm still undecided though.

Terry

even if the image difference (in size, ie: 50 mm vs 56 mm) is negligible when comparing apples to apples of quality - in your mind it makes a difference.

I use 56's only here in SC.

I have used Leupolds, Kahles, Swarovski and Meopta... now - all of these were not 56's - just the Meopta's and the Swarovski.

All are gone except the Meopta's - I have three of them and love them.

I have one for sale now... 3-12x56 Illuminated Red Dot - in 100% new condition... $725 shipped. May trim a little off if someone is interested.

The 3-12x56 Zeiss is the BRIGHTEST and SHARPEST scope I have ever looked through - but it is not the best low light scope I have ever used - my PH Swaro and the Meopta'a are IMHO.

Jim

I have hunted Europe a good bit & the scopes used for night hunting were generally 56MM with Illuminated reticle. These were not stalking rifles, but special purpose high stand shooting tools for primarily night hunting. I never had the opportunity to test the few 50MM vs. 56MM, but I believe the gillies would have used the best available. Since you are not hunting at night I doubt the 56MM would be of any practical advantage. My 50MM Conquest & 40MM Leupolds have allowed me to hunt long past legal shooting time in the U.S. Buy the best glass you can afford.

The 56mm will be brighter, whether or not there's enough difference to you is another story. There's no question, however, that you will get a touch more low light performance out of the 56mm. FWIW, I've got quite a few deer rifles with 36-40 mm scopes but when the hunting gets serious my main rifle wears a 2.5x10x56 swarovski, I don't find the size to be out of place. Too much is made of the size of 56mm objectives, they're not that big and their size is hardly noticed after a couple of hunts.

The fact is that the larger the objective lens,the higher the scope must be mounted.If you don't achieve a proper cheek weld to the stock,your shooting will suffer.

Optically, a Zenith 3-12x50mm is hard to beat in resolution and low light performance(compared to the 50mm Zeiss and Swaro). It's heavy though and not cheap. You can't go wrong with a Zeiss or Swaro 2.5-10x50 either. Overall I like the Swaro the most(as a construction, weight and optics combo). If you buy any of those three, 50mm will be fine and the mount wont be as high as a 56mm scope. If you want the brightest scope you can get, get a fixed power 56mm one.
Aicman

Too much is made of this also. Unlike shotgun shooting where gun fit is critical, rifle shooting is more mechanical and a decent rifleman should be able to adapt to a higher scope mount. I've got scopes mounted in heights from low leupold dual dovetails up to swarovski rails with the 56mm objective and I shoot the same with them all. I don't buy that you have to have a certain cheek weld to shoot a rifle well, it hasn't been my experience.

That is your opinion,my opinion differs greatly.If you have to shoot quickly in a hunting situation,a proper cheek weld certainly does help in obtaining the proper eye/scope alignment necessary to find the target in the scope quickly,steady the crosshairs on the target,and reduce parallax to a minimum,in order to make a quick ,accurate shot.I also find recoil much easier to tolerate with a proper cheek weld.

TC1,

Some have brought up the 56MM as too large because it needs to be mounted high. I am having a custom rifle made. The stock will be wood with a high cheek piece because I want to take advantage of a high mounted scope.

Run the numbers though the ballistic computer with your hunting load for a scope mounted 1 1/2" above the bore and one mounted 2 3/8" above the bore. It's like gaining 100 feet per second over the one mounted 1 1/2" high.

Many British & European shooters, myself included, tend to use a more upright head position on the stock and generally have no problem with 50mm or 56mm scopes. This assumes the stock "fits" correctly and the comb is of the right style and height..I could agree that a lower scope allows for my cheek to be in fuller contact with the stock, but even with an upright head position, I can still get enough contact to achieve a decent stock weld and keep my head in a more natural upright position. I also suspect a more upright head position makes things a tad more comfortable when it comes to felt recoil as well...

Having said all that, I did notice someting the other weekend which could explain the different perspectives on the issue. I had a try of a friends rifle on which he has a 50mm Leupold using a Pitcanny (sp?)rail and Warne mounts. The rings and mounts were way too high for this particular scope and I defninately had problems getting a good cheek weld..I also noticed that the issue was compounded of the long eye relief of the Leupold. Basically because my eye is that much further back than I was use to, and because my cheek weld was less than solid, I found it very difficult to keep my eye consistantly centred looking into the ocular of the scope .

No doubt had I spent some time with the rifle, I would have gotten used to it, but it made me think that scopes with longer eye relief do make the issue of cheek weld more critical and perhaps thats why many American shooters who favour Leupold have a different perspective on the subject to us Brits and Europeans..

Regards,

Peter

I agree with your calculations about exit pupil, however, I read somewhere that the human eye cannot use an exit pupil higher than 4.5. Does anyone have any definitive information about this?

Kevin,

I was always under the belief that the maximum was 7mm for somebody in their prime with perfect eyesight and that it got smaller as you aged, to typically about 5mm..

Having said that, a scope with a slightly larger exit pupil than the human eye is still advantageous as it gives a margin of error with your critical alignment...That of course has to be balanced with the fact that if your eye is not centred looking at the exit pupil, any parallax issues will be compounded...

Regards,

Peter