I am planning on a new scope for my deer rifle. The scope I'm planning on a offered in 40 and 50 mm objectives
What are the pros and cons of a 50mm over a 40mm.
What are the pros and cons of a 50mm over a 40mm.
40 vs 50mm objective
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It really depends on what you will be doing with the scope. If you're going to be using it in broad daylight at a reasonable distance, then you can stay light weight and go with 40.
If you plan on shooting at distances over 100 yds at twilight or sunset, the larger 50mm will make sense, but will cost you a little more weight
If you don't mind the extra weight, the bigger diameter you can go, the better.
Think of a scope like a camera F stop. The more light you can let in, the more clarity / detail you'll get, but, you pay out the ass for it.
So far there is a lot of misinformation in this thread.
Let's clear some things up.
Letting more light in doesn't have anything to do with clarity, whether or not light will get to the eye, or if the pupil can make use of it. That's why a 50mm BSA is nowhere near as bright and clear as a 20mm Swarovski...glass quality and coatings.
What difference does it make then?
When you're a kid your pupil will dilate all the way up to 7mm, unfortunately, the adult pupil with only dilate to about 4mm, coincidentally that's the exit pupil diameter of a 40mm scope. Ever wonder why so many scopes are 40mm..there ya go. So, what's that mean as far as brightness goes?
Imagine your pupil (light sensing part of the eye) is a plate that is 4 inches in diameter. Now, take a 5 inch diameter plate (light projected onto the eye from a 50mm lens) and place it over the 4 inch plate. There will be a half inch of "wasted" light all the way around the 4 inch plate. Even though the lense is putting more light (as long as the lenses are of the same quality) to the pupil, the pupil simply can't dilate enough to use the extra light. In other words, as long as you're over the age of about 25 or so, an objective lens over 40mm will not improve the brightness of the image based on light transfer alone.
So, what can be done to get a brighter image? Better quality glass and coatings. The fewer contaminants in the glass, and higher the quality of coatings, the more light can get through the barrier (the lens) and to the eye. In other words, if you want more brightness and clarity, spend more money, don't go for a larger objective lens.
So what are the benefits to a 50mm objective lens then? FOV, Field of view. For hunters, the larger objective lens can make finding game in the scope easier, but you will sacrifice scope mounting height and weight obviously. On higher powered scopes you may see some minimal benefit brightness wise on a larger objective lens but not until the magnfication is cranked way up, reducing exit pupil.
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Yes it does. A scope on 3x with a 50mm objective lens with have a larger fov than a 3x scope with a 40mm lens. Of course it won't if you are comparing apples to oranges or don't include the second variable (magnification).
It does increase field of view if magnification is the same. Two scope on 3x, the one with the larger obj lens will have a wider field of view...sorry, but that's a fact.
No, you simply don't understand what you're talking about. The size is only one variable. If the glass is of poor quality, the light isn't getting through. If you compare two identical lenses quality wise, then yes, but just because more light gets through doesn't mean it'll be brighter, and is sure doesn't affect clarity at all.
Larger lenses DO NOT always let more light in. Again....look at a Tasco 50mm compared to a Zeiss 20mm. Are you saying the Tasco is brighter than the Zeiss? Yes. That's what you're saying.
When you don't know what you're talking about, do everyone a favor and don't comment. You're putting out information that's totally false.
No it doesnt'. The quality of the glass and coating are hugely important variables to consider when measuring how much light gets "in".
It's your reading comprehension that's the problem, not Leupold's website.
So you're telling me a 50mm Tasco is brighter than a 20mm Nightforce? Ok, cool.
Field of view is governed by the eyepiece and magnification, not the objective. The larger objective simply allows more light in, it does not affect fov.
I'm saying if you have a 40mm leupold and a 50mm leupold, the 50 is going to be brighter at dusk and dawn.
Not necessarily. Only if your eye can make use of the.........fuck forget it. Yeah you're right. Larger objective lenses are always brighter. You win.
I'm done.
I've never seen him quit so quicly. We were all right, just looking at it from different angles.