Who likes 50 mm objectives on their scopes? I know they let in more light. What other pros and cons are there? Just trying to make a decision. Thanks for any help.

Just my opinion, but I would first exhaust the better 40mm scopes before I decided to move up to a 50mm.

Many times, not always but many times, a better quality 40mm will appear brighter than a lower quality 50mm or even sometimes a 56mm scope.

Resolving power is what makes a good scope good...and resolving power is a function of quality of glass, coatings and manufacturing techinque, NOT of size.

Downside of a 50mm obj. on a hunting rifle is weight, having to use high rings (head may be off the stock) and the fact that the bell is wider than the rest of the rifle and is therefore the first thing to bang into everything while hunting. I don't hunt with anything bigger than a 44mm objective.

Here is my 2 cents on this:

You couldn't give me a scope with a 50mm front objective - well you could but I wouldn't use it!!!

They don't gather any more useful light under "any" hunting conditions than a 40mm objective will.

They totally mess up the lines of a rifle in my opinion (easier to bump, etc.)

I shot a hyena in the dark with a flashlight with a 1.5-5x Leupold VariX-III, which has a 24mm front objective (no problem) also picked up a leopard in a tree at 80 yards with the same scope.

I agree with Rick's & jsteven's advise above - just stay with quality optics and you won't have any problems seing what you want to shoot!!!

quote:

Originally posted by Leo M:

What other pros and cons are there?

Sometimes (but not always, mostly speaking about Zeiss) a wider field of view and more adjustment range. My Zeiss Conquest 3x9x50 ($419 from theopticzone)seems much clearer than my 3x9x40.

I prefer a 44mm objective, but I like the 50's and they do gather more light. Now 56mm is too much. IMO, 40mm is as much under just right as 50mm is above just right.

If the 50 mm works, go for it. Lets take a look at the numbers.

The 50mm objective really doesn't gather any more light than a 40, what it does give you is a larger exit pupil, which will allow your pupil to see more light. This is good.

The scope will have to sit higher. The difference betwwen the radii between the two is 6mm. For the SAE inclined, that would be roughly 1/5". Not too bad. Most folks with drop's in there stocks (CZ, SAKO, etc) don't notice much difference, I can't imagine straight stockers (remington, winchester's et.al.) probably won't notice at all.

I have scopes of various objectives, but anything that will throw a 5mm exit pupil will be much better at first and last light.

John

Larger exit pupils allow for a wee-bit more freedom in head/eye placement behind the scope...but not all that much.

A normal adult pupil will only dilate to about 5mm in total darkness so I’m not sure what practical advantage that extra mm in exit pupil size is going to give you that you would be able to perceive.

Hey, if you don’t mind the extra size and weight use whatever sized scope you think is going to be best for your eyes.

The only 50mm objective scope I have used, is on a gun I bout for next to nothing and intend to use it as a base for an upcomming project. The scope in question is a simmons pro 50 2.5-10. It is ok glass, but I have an older Burris fullfield 6x that is much clearer and lets more light in. The scope mounts on the simmons are extra high weavers, so you can imagine how high one has to hold there head inorder to use the scope. I intend to sell the simmons pro 50 inorder to payfor some lower rings to mount my Burris.

Eye sight is sort of like hearing...everyones is a bit different. My hearing is so bad that about the only thing that I hear clearly is the ringing in my ears! It would be a total waste of money for me to buy an expensive sound system or speakers because most of what they would provide would not be discernible to my ears. I have had friends play their expensive sound systems for me and they sound just like my car radio to me.

Scopes are pretty much the same. Personally, I can’t tell a damned bit of difference between the brightness of a 50mm and a 40mm scope...but I can tell very slight differences in resolution between scopes.

I have a Leupold (Vari-X III) with a 50mm objective and a Zeiss (not Conquest) with a 56mm objective and they are probably my two best scopes.

Look and see what you like and buy what works for you. The last few scopes I bought had smaller objectives but I pick different tools for different jobs. The bigger objectives were picked for stand hunting where being able to judge game animals at first and last light is critical.

Oh -- I have a Redfield Ulitmate Illuminator with a 56mm objective and have never warmed up to it.

Well, to tell you the truth I don't like 50mm objectives either.

My preference is for 58mm Adjustable Objectives like the one shown here with the 35mm tube:




Gives massively better resolution in low light conditions.

DMCI* ... I would hope that a USO w/ a 35mm tube and 58mm objective does well in low light situations ...


VERY nice looking rig there, from top to bottom ... I'd imagine she's a rag-holer at almost any sane range?

I asked almost exactly this question of the optics experts where I work (Lockheed Martin). Here is a summary of what they said.

The key to image brightness is the size of the exit pupil, relative to the aperture of your eye. The size of the exit pupil is calculated by the objective aperture divided by the magnification, so a 3-9x40 scope's exit pupil is 13.3mm at 3x and 4.7mm at 9x.

For most of us 40+ year olds, our eyes don't open up much past 5mm. So from objective aperature alone, any scope at or above 5mm exit pupil will be the same brightness for us (at/above 7mm for you young whipper-snappers). Other factors, such as the number, quality, and type of coatings, polish on the lenses, etc. make a difference too, but that has nothing to do with aperture.

The limiting aperture of the eye also limits the contribution to resolving power from the large objective (the diffraction limit), since it is the light from the edges of the objective lense that is lost.

That is not to say that excess exit pupil is not useful. It increases the width of the eyebox, since you can move your smaller eye aperture around inside the exit pupil of the scope, without reducing brightness, etc. It also limits the contribution to the image from the edges of the optics, where it is more difficult to control the surface figure of the lenses, which helps image quality too.

So, if you like using your 3-9x40 at 9x in low light situations, then a 50mm (of equal quality) would mean a little more light to deal with, but if you're like me, and tend toward the 3x end in low light, it won't make any difference in brightness.

Hope this helps,

BigJake, hit it right on the head, so to speak. For allot of people, especially us older gents, all of this so called “brightness“ advantage of large objectives is only something we read about, but seldom see.

He also accurately points out one of the downsides of having a large magnification range in variable scopes. While allot of the newer variables supposedly retain a constant eye relief throughout the zoom range they cannot provide the same sized eye-box. That box gets progressively narrower and narrower as the power increases and may require re-positioning of the head and eye to center the eye with the exit pupil.