Can anyone quantify the advantage of 50mm vs 40mm objective

[apache12]

So if the field of view and power of zoom is the same for two equal scopes that only have a difference in objective size is their any studies on how much light gathering advantage a 50mm gains over a 40mm? For example do you get 10 minutes more hunting time or rather once sun sets is it better marketedly from then until dark

 

Just wondering about things while I wait for my early bull rifle tag 😄

[Sneaker]

They go into this discussion at great length with the Vortex guys and the Meat Eater crew in this podcast, you'll learn all you need to know and some you didn't:

 

http://www.themeateater.com/podcasts/podcastepisode009/

[Red Dog]

In all honesty, working a lot in the field and utilizing glass, it depends on how much low light hunting you are expecting to do. Also, I'd try to use a friends 40mm and 50mm and see how much longer it'll last for you. I have had friends look through my objectives at low light condition and claim they can't see any better than in their binos than in my Vortex/Swaros. It all depends on you.

From my experience, the 50mm lens undoubtedly transmits much more light, but is also heavier, so it's a bit of a trade-off if you're looking to hike in far. Also, the wider field of view is a huge plus in having a bigger objective lens.

Also, what type of environment are you going to be in? If you're going to be in thick brush, then less light goes through that area, so I'd stick with a bigger objective. But if you're going to be in relatively open areas during the dusk/dawn hours, I'd stick with the smaller if it's a considerable difference in price.

btw, side note, 100th post.

 

[lancetkenyon]

A 56mm objective made the difference in the most important last 4 minutes of my cousins elk hunt last year. Quantify that.

[apache12]

Field of view is the same from 40 to 50mm. FOV is based on the mag side not the objective side as I understand Leupold spec show the same FOV from 4.5-14x40mm to 4.5-14x50mm

[metau]

If memory serves me right, it all has to do with exit pupil diameter. You take the objective lens size and divide by the magnification to get the exit pupil. The human eye can dilate to about 6-8mm(depending on age and other factors), so the closer you can get the exit pupil of your scope to your max dilated size the longer you will be able to see through your scope. Of course, this also assumes the quality of glass and coatings in the scope are good enough to help and not hinder this.

[.270]

The equation is small wiener=big scope. Or is that bc? Hel I can't remember. I always try to use a 40 objective or smaller. But mostly because I don't like the high profile. For several reasons. Most of my scabbards for horseback won't fit a 50 and I don't like to crane my neck to look through a high scope. Don't know or care about all the differences. Lark

[8OWHUNT247]

An extra hour of hunting per day.

[forepaw]

You might take a quick look at the article on www.24hourcampfire.com/ by John Barsness entitled "Riflescope Brightness".

 

forepaw

[apache12]

Good article

 

Exit pupil is Important. It's why I like 8x40 bino over 10x40

[azsugarbear]

The largest Coues I have taken (see pic at left) was at last light. The scope was a 56mm Nightforce and the shot was about 300 yds. Even then, I had trouble pulling him out of the brush because it was so dark. The task would have been impossible with the most expensive 40 mm scope available. Simply not enough light.

 

I understand all the trade offs, but being able to hunt (see game) another 10-12 minutes later or earlier can make all the difference. These trophies get big by retiring well before sunrise and not leaving their beds until dark. For me, I want the most light I can gather. Now having said that, we need to recognize the difference in quality of glass and coatings for light transmission. I know some high end 40mm scopes that will provide more light than 50mm or 56mm scopes in the mid and low price range.

[Couzer]

There are only 2 disadvantages on the 50mm, heavier and bulkier, other than that the 50mm is superior to the 40mm

[AZbowhntr]

I lost getting a lion a couple years ago because of not being able to see it through my scope. I could see it clearly with my 56's but when I tried to find him in my rifle scope it was too dark. He was down in a canyon and it was difficult to see. After that I have started switching my scopes over to 50mm and couldn't be happier. I had just enough clearance that I didn't have to replace rings or anything.

[Titanium700]

I'd rather worry about tube diameters.

I'd take a 30mm tubed 40mm objective over a 1" tubed 50mm any day.

[Couzer]

My choice was a 1" tube 50mm objective over the 30mm tube and a 40mm objective. No regrets, I have enough room for 1350 yards. My whole rifle setup with scope is just under 9.5 lbs and the clarity is outstanding