Scope Objective Lens Size

truck driver

Ammo Smith
Mar 11, 2013
7,187
711
I have scopes with object lens from 24-44mm with the 42mm being my favorite size. I see where most scope manufactures are dropping the 44mm and going with a 50mm.
How much difference is there between the 2 except 6mm in size? I can use low ring mounts with the 44mm will I need to go to mediums with the 50mm?
 
Going to a 50mm you're most likely going to have to go with med rings.
Meopta and Swarovski haven't dropped 44mm scopes. I don't care for 50mm scopes either. If I want more than 44mm I go to 56mm. I use a Docter Unipoint 3-12x56 for tower stand hunting. For anything else I use a Meopta 4.5-14x44 mounted in low rinds. I use Talley rings so I can switch scopes with out loosing zero.
Billy
 
I like my scopes mounted as low to the bore as possible and for years never went larger than 40 mm. I now have two with the 44 mm lens, and will not go bigger. I just don't believe for my personal situation that a larger lens will buy me anything. The 4 rifles I hunt the most with all have rails so a little height is gained there.
 
My 2 M70s I run Talleys on and both are lows with 44mm scopes on them and I have room for lens caps. The Ruger has Factory low rings on with a temporary 42mm on it that I plan on up grading. The scopes I'm looking at are 50mm since I can't find the power range and reticle I want in 42&44mm with in my price range.
 
I have one scope with a 50mm objective. Much as I like it, I won't buy another. In fact, I've passed on a couple of good buys precisely for that reason. You will have to go with at least medium rings to keep the scope in play.
 
I've been going the opposite direction. The last few scopes I have purchased are straight tube objectives. I know I am giving up low light performance, but they are light and quick to get on target.
 
I had a 50mm on a carry rifle and I hated it . it was big and clumsy to carry . I didn't have a good cheek weld . I think I was trying to justify this scope so one evening I took 3 or 4 scopes to my field and did a light gathering test . it was only a few days after this I had that scope for sale . good glass with good coatings beats a large obj lens . two of the scopes I tested were a 4.5-14x50 30mm tube VXIII , 4.5-14x40 1inch tube VX3 , and a couple others . I thought the 30mm tube with the 50 mm obj would beat out the others on low light gathering , I was wrong . I also had a burris scope that was a 4-16 power , I think . it was a long scope and I didn't like it either . I think I sold it after one range trip . so watch the over all length of the scope too .
 
Jim nailed it,............. "good glass with good coatings beats a large obj lens."

All things being equal the larger obj will get you a small amount of help in low light. Upgrade to good glass and a 40mm will get the job done. I've got one scope with a 50mm and am not looking for more. Got lucky with it because it is a very long scope and the obj end is far enough down the rifle to be past the taper on the barrel so the low mount works. For me it is far more important to have the correct cheek weld, screwing with that is not worth any amount of help from the larger objective.

Besides, in the last 10 years gains in coatings and their applications has taken tremendous jumps. For scopes, if you reach the VX3/conquest level the glass is good enough that a 42-44mm objective does more than my old eyes can handle anyway. Any step up from there is gravy. Where I do most of my hunting a low light scope is very beneficial so every scope I have bought has had that in mind. Objectives in the 42-45mm objective range is more than enough for me to see clearly well beyond legal. And I'm a slut when it comes to low light forgiving optics..................... :shock:
 
Case and point here the new Leupold VX2s are certainly better than my 20 year old VXIII's......
In some our testing Sightron S1 models were as good or better than older VXIIs even though they cost less than half.....
I have a pair of Cabelas Intensity HD binos, that are as bright and crisp as a 30 year old Zeiss roof prisms, same power, same size obj.
The HDs cost 25% in our 2017 money, what the Zeiss cost in 1985 dollars?....... A year ago a bought a VX3 4.5x14, and it had such poor eyebox qualities, it was tough for myself, or the dozen other guys that tryed it to get behind it, horribly sensitivity to where your eye had to be or would totally blackout. I had $99 scopes that were vastly better. Dumped it imeadiately, could have just been that one scope???
Lots of testing going on the internet lately comparing LR scopes in the $1000/1500 range to some new brands just out newish to the market, down in the $500 range. And the test are not great for some old stand by names......
I agree with Jim, my 3x9x40 1" Zeiss Conquest, blew away a 30mm 4x16x50 Millet, in low light tests.....
I have shot a half dozen huge whitetail buck with the Zeiss
When most scopes would have been done 5 min before, not only the glass but the heavy German reticle was still visable long after a finer duplex type would have disapeared.......
 
For Normal hunting situations there is no gain in going bigger ,us older fellows eyes can't even use available light from most cheaper 40 mm .Lol . That said think about this ,no matter how expensive your scope or how clear the lenses it is no better than they shooting glasses you are looking through to see through it .

Sent from my XT1093 using Tapatalk
 
ozarkpugs":edkp5s90 said:
For Normal hunting situations there is no gain in going bigger ,us older fellows eyes can't even use available light from most cheaper 40 mm .Lol . That said think about this ,no matter how expensive your scope or how clear the lenses it is no better than they shooting glasses you are looking through to see through it .

Sent from my XT1093 using Tapatalk


I agree with your point that the most important glass to have is your binos. 100% on that.

I have an experience where the scope was not able to pick out a buck where my binos did. Several times I could easily see him standing in a dead pile of brush, they were the same color. My Victory binos made him stand out well. I'd lower my bions, raise the scope and could not find the buck. It was very low light, cloudy evening and within the last 5 minutes of legal. Several times I tried but the Mid-range (at the time) scope could not distinguish the buck in the brush.

Now, how often will this happen? Who knows for sure. From then on I decided to have a scope that will has the ability to see the contrast and color shades. That scope is probably 18 years old now and does not have the far better coatings that mid-range optics now have.

thanks.........chs
 
c. schutte":1j83se69 said:
ozarkpugs":1j83se69 said:
For Normal hunting situations there is no gain in going bigger ,us older fellows eyes can't even use available light from most cheaper 40 mm .Lol . That said think about this ,no matter how expensive your scope or how clear the lenses it is no better than they shooting glasses you are looking through to see through it .

Sent from my XT1093 using Tapatalk


I agree with your point that the most important glass to have is your binos. 100% on that.

I have an experience where the scope was not able to pick out a buck where my binos did. Several times I could easily see him standing in a dead pile of brush, they were the same color. My Victory binos made him stand out well. I'd lower my bions, raise the scope and could not find the buck. It was very low light, cloudy evening and within the last 5 minutes of legal. Several times I tried but the Mid-range (at the time) scope could not distinguish the buck in the brush.

Now, how often will this happen? Who knows for sure. From then on I decided to have a scope that will has the ability to see the contrast and color shades. That scope is probably 18 years old now and does not have the far better coatings that mid-range optics now have.

thanks.........chs
Another thing is being able to see the reticle in poor light against a dark back ground. My low light scopes have illuminated reticles and 56mm objectives. Good glass is very important. My 44mm Meopta is brighter and has better resolution than most 50mm scopes I've compared it too.
Billy
 
My latest is a VX3i...which is supposed to have the latest and greatest lens coating from Leopold. It will be interesting to see how much of an improvement I can detect.
 
Well that sucks....Glad I bought 40 mm scopes with a lifetime no fault warranty (y) Sorry, IMHO 40 mm is enough. :roll: I have one 50mm lens scope and ANY of my 40 MM leupolds will beat it in low light. Granted that isnt a great scope (name deleted to protect the innocent and save me embarrassment). If its that D@## dark maybe the shot aint worth it? :roll: :idea: On top of that bigger lenses are heavier, bulky, and wont make you a better shot. Honestly a fixed power 32mm is a fine hunting optic. A 6x of that variety has killed many head of game on the plains. Sorry in case you haven't guessed its a peeve of mine. CL
 
jimbires":3asvgqg0 said:
I had a 50mm on a carry rifle and I hated it . it was big and clumsy to carry . I didn't have a good cheek weld . I think I was trying to justify this scope so one evening I took 3 or 4 scopes to my field and did a light gathering test . it was only a few days after this I had that scope for sale . good glass with good coatings beats a large obj lens . two of the scopes I tested were a 4.5-14x50 30mm tube VXIII , 4.5-14x40 1inch tube VX3 , and a couple others . I thought the 30mm tube with the 50 mm obj would beat out the others on low light gathering , I was wrong . I also had a burris scope that was a 4-16 power , I think . it was a long scope and I didn't like it either . I think I sold it after one range trip . so watch the over all length of the scope too .


DrMike":3asvgqg0 said:
I have one scope with a 50mm objective. Much as I like it, I won't buy another. In fact, I've passed on a couple of good buys precisely for that reason. You will have to go with at least medium rings to keep the scope in play.

I'm with Jim and Mike. I can't like a 50mm on a carrying rifle. Objective seems like it always contacting the ground when I lay it down to glass. Hunting in dark woods like some others I'm sure they are great but for carrying they bug me.

The reticle means a bunch as well, even if you can see the animal but not resolve the reticle all of the brilliance is lost on me.

If you're hunting the west you won't be let down with a normal scope. Keeping the ice and snow outta the lenses and being able to quickly get on your gun means more to me.
 
I bought one of DrMike's 50mm scopes for my Son's 270wsm in a Model 70 he likes it. However I have nothing larger than 42mm and really do not want any objective larger. I too use Talley lightweight lows on my rifles :wink:.
With a 30mm tubes on my scopes I find they work in all my hunting situations.

Blessings,
Dan
 
My understanding has always been the objective size depends on the magnification you want to use. This fact appears to be missing from this conversation.

Objective size divided by power = exit pupal size. Therefore a 40X10 = 4 mm exit pupal which is about as big as older eyes get anyway. For low power the smaller size is adequate. If you must go 20 power, you probably want a 80 mm objective. Even my spotter isn't that big.

The scope on my dual purpose hunt/silhouette rifle is a 40X20. At bright sunny matches this is just fine as I doubt my pupal is even close to 2 mm. For hunting in bright sunny AZ this would also be OK. For dark days and dark timber, turn the power down.

On the ring height issue I generally go as low as I can and really like the old Leupold VX-3L models with the cut out at the bottom. These are not readily available anymore and I am glad I have one on my .340 wby.

Interestingly many of the dedicated silhouette shooters I shoot with use elevated rings with 40mm scopes. This keeps the weight down and allows shooting with a level head (sorry) as not tilting your neck helps accuracy.
 
First of all, a 30mm tube does nothing for light gathering ability. The only advantage it brings to the table is windage and elevation adjustment! This is straight from the engineers of every optic manufacturer.

Second as whitesheep stated, the objective lense diameter divide by the magnification gives you the exit pupil size of the scope. This determines how much light is gathered through the optic and delivered to your eyes.

A young person's (20's) eyes can dilate the pupil to 7mm. As we get older, our eyes grow weaker and the reticle cannot dilate as well to the point when we get to our 50-60's, our pupils will only be able to dilate to 4-5mm. So regardless of the exit pupil size of the scope, only so much light is able to be taken into your eyes. Which means that even if a 50 mm scope can deliver an exit pupil of 7mm to yours eyes on roughly 7 power magnification, if you are in your latter years of life, your eyes will not be able to take in all of the available light.

With that being said, While I am not a big fan of large objective lenses, I do have 3 with obj bells of 50mm; 2 of the Leupold VX-L
'S with the cutout that allows for lower mounting on the rifle (on my 250 AI and 270 Wby used in open field hunting) and a Swarovski on my Sako target rifle in 260 Rem. The largest obj lense on the rest of my hunting rifles is 42mm, which I prefer for their weight, lines and that they do not take the knocks and bangs of larger scopes during everyday use in the field, truck, or scabbards on horse or atv.

The Leopold VX-II today is the older VX-3, which makes them a quality optic, at a better price and value than the newer higher end Leupolds.


Sent from my iPhone using Tapatalk
 
I've had a couple 50 mm scopes, and like most here, greatly prefer objectives around 40 mm. That said, all my scopes top out at 14x or lower, and all are used for hunting where convenience of the smaller bell is important to me. If I used/needed higher mag scopes though, I'd probably opt for the inconvenience of the larger objective to take advantage of its strengths -- on scopes of equal glass quality, the superior light gathering ability can be a big plus, AND it makes the "eye box" more forgiving, making that scope easier to get behind.
 
Back
Top