Objective lens size for hunting

[hoogle]

G'day,

Just wondering what people think on objective lens sizes for hunting setups.

40mm or 50mm is common of course. Is there really any advantage going up to the big stuff like a 56mm objective for a hunting rifle?

How much more visibility is that really going to give you in low light?

Would like to see what peoples info is to compare to my gun guys opinion.

Thanks.

[Chronos]

It tends to be magnification driven.

If you're shooting a 3-9 magnification range in low light a 40mm should still gather enough light but bump that up to 12 power you may want a 50mm.

Now say you want more magnification again, a bigger objective lens would be required to gather enough light in poor conditions

The reverse is true, a dangerous game rifle might wear a low mag 1-5 power and might only need a 20mm to 30mm objective lens

A simple test is to divide the objective lens diameter by the magnification, the goal is a number around 7 (7mm exit pupil)

For example, 40mm objective divided by 6 power gives a 6.6 mm exit pupil, making it suitable for low light hunting, in fact many early morning rabbits would agree

Bump that up to 24 power the available light on your 6-24X40 on your .22 now has an exit pupil if 1.6mm.

Now a 56mm scope at 24 power would give you a 2.6mm exit pupil, probably not enough in really bad light but still almost double what a 40mm would give you.

I've seen this in practice at a 500m fly shoot last year where I was shooting with a 60mm objective lens and my wife a 40mm scope both at around 30 power

As the light deteriorated I stil had a clear bright image, where as she had issues seeing the target with the image dark and grainy

Hope that makes sense

Chronos

[AusC]

in fact many early morning rabbits would agree

Not sure they're in much of a state to agree with you

[Chronos]

yeah AusC, a few of them completely lost their heads when they saw one for the first time

one thing i forgot to mention was the trade off in weight that comes with large objective lenses and the mounting height issue, partially overcome by leupold with their now discontinued VX-7 range



Chronos

[Warrigul]

G'day,

Just wondering what people think on objective lens sizes for hunting setups.

40mm or 50mm is common of course. Is there really any advantage going up to the big stuff like a 56mm objective for a hunting rifle?

How much more visibility is that really going to give you in low light?

Would like to see what peoples info is to compare to my gun guys opinion.

Thanks.

Don't get too hung up on objective size, glass quality has a bigger effect on what you can see. Big scopes are a pain in the arse at times.

I am a legendary "cheap scope" person but on my .243 I run a Leupold simply because I shoot mainly dusk and dawn. Everything else is mainly Nikko stirling.

[Triang]

Couldn't tell you where I read it but the jist of the story was this.

On the larger objectives they do let more light through. More glass = more light that's just physics. BUT! What a person can detect is a different matter.

In lab tests these bigger lenses brought in 5-6% more light or something like that to the machines, but to the human eye people couldn't really appreciate the difference.

The wrap up was that if you buy something crap, it will be crap. Buy something with decent quality glass and it will work well. Buying above that though, there is limited if any gain while the price goes way up.

Something good quality like a middle of the line Leupold is will do 99% of the job as one twice the price for hunting.

[Chronos]

Couldn't tell you where I read it but the jist of the story was this.

On the larger objectives they do let more light through. More glass = more light that's just physics. BUT! What a person can detect is a different matter.

In lab tests these bigger lenses brought in 5-6% more light or something like that to the machines, but to the human eye people couldn't really appreciate the difference.

The wrap up was that if you buy something crap, it will be crap. Buy something with decent quality glass and it will work well. Buying above that though, there is limited if any gain while the price goes way up.

Something good quality like a middle of the line Leupold is will do 99% of the job as one twice the price for hunting.

I think you may have misread something there, a 50mm lens can bring in something like 55% more light than a 40mm lens, not 5-6%

There's a huge difference between good glass and crap glass as far as light transmission goes, you will see this when you look into the shadows through a good scope and the scope image is brighter than with the naked eye.

There are some good articles to read if others are interested

http://www.chuckhawks.com/straight_scope.htm

http://www.accurateshooter.com/optics/s ... nsmission/

[headspace]

I have a 3-9 x50 Leopold on my 308 for precisely the reason that most game is active in the early morning late arvo times and tend to lay up during the day. The more light you can gather the better.
JD

[Triang]

Dunno what I did there...

Was supposed to say 50-60, not 5-6. Zero button stuck...

I agree there is a big difference between crap and good glass. IMO there is less to be had between good and "great" glass.

Just not work the extra cost in case I find. To my eye and from other comments I've read anyway.

[bigfellascott]

Don't get too hung up on objective size, glass quality has a bigger effect on what you can see. Big scopes are a pain in the arse at times.

I am a legendary "cheap scope" person but on my .243 I run a Leupold simply because I shoot mainly dusk and dawn. Everything else is mainly Nikko stirling.

Your as bad as me Warrigul, I have 3 Jap Tascos and a Phillipines one too, all have been doing the job no worries at all and have compared them to the more expensive scopes and they really don't give bugger all away to them - I've even compared my 4x and 6x fixed Tascos to I think it was a 3-9x36 Swarovski Habatchi and they were actually brighter than it under the light and every bit as good in the daylight too, the biggest surprise was the Nikon 3-9x50 it was so much brighter and clearer than the Habatchi it was a real eye opener to say the least (certainly wasn't expecting that result I can tell you) I assume the real diff re performance was the Objective lense size?

I've even done a comparison with the Nikon up against the Swaros and Zeiss and I can tell you that a lot of people where very surprised at how the Nikon went with even Swaro owners saying it made them wonder where the extra $$$ were in the Swaro if the Nikon could produce such good results for a few $100 dollars. We were testing them under the spotlight by the way - again another surprising result considering the price diff between them all.

The Objective size I think is key to having bright optics under low light conditions - it just seems to make a lot of difference from my experience - I see Zeiss make a 72mm Objective I think it is, that would be amazing under low light conditions!

[Xerox]

The Objective size I think is key to having bright optics under low light conditions - it just seems to make a lot of difference from my experience - I see Zeiss make a 72mm Objective I think it is, that would be amazing under low light conditions!

Ditto in my experience.

In any half decent light it makes no difference. At the cusp of that last light though, the bigger objective definitely comes in the winner.

[Chronos]

Ditto in my experience.

In any half decent light it makes no difference. At the cusp of that last light though, the bigger objective definitely comes in the winner.

You notice it when you're using decent binos at dawn. Then you lift your scope to your eye and can't see what you could with the binos. Then you realise you're scope isn't as good as you thought and you should have spent the extra cash.

Chronos

[Lorgar]

In any half decent light it makes no difference. At the cusp of that last light though, the bigger objective definitely comes in the winner.

You notice it when you're using decent binos at dawn. Then you lift your scope to your eye and can't see what you could with the binos. Then you realise you're scope isn't as good as you thought and you should have spent the extra cash.

These ^

I have the Bushnell Elite 6500 which is a good scope with a 50mm objective lense. Good glass, all the fancy lens coatings etc. and I can tell you from personal experience...

I've been out hunting shortly before sunset when it's been raining and foggy and you can only see sharply with your naked eye to about 25-30 metres. Beyond that everything starts to get foggy, dark and blurred and gets worst the further you look.

Looking at say 50m through my scope, the scope really cuts through it all and the target is clear, sharp and appears brighter than looking with the naked eye.

Looking through at the same thing through mates smallers scope though it's the opposite, things get darker and more clouded. That's not with terrible scopes either... One has a Leupold, another has a lower model Bushnell. Not as good due to other factors too, but anyway... Some info for you...

Look though the same scopes in daylight at the range though and they're all back to looking much the same.

That's my experience with them.

[bigfellascott]

In any half decent light it makes no difference. At the cusp of that last light though, the bigger objective definitely comes in the winner.

You notice it when you're using decent binos at dawn. Then you lift your scope to your eye and can't see what you could with the binos. Then you realise you're scope isn't as good as you thought and you should have spent the extra cash.

These ^

I have the Bushnell Elite 6500 which is a good scope with a 50mm objective lense. Good glass, all the fancy lens coatings etc. and I can tell you from personal experience...

I've been out hunting shortly before sunset when it's been raining and foggy and you can only see sharply with your naked eye to about 25-30 metres. Beyond that everything starts to get foggy, dark and blurred and gets worst the further you look.

Looking at say 50m through my scope, the scope really cuts through it all and the target is clear, sharp and appears brighter than looking with the naked eye.

Looking through at the same thing through mates smallers scope though it's the opposite, things get darker and more clouded. That's not with terrible scopes either... One has a Leupold, another has a lower model Bushnell. Not as good due to other factors too, but anyway... Some info for you...

Look though the same scopes in daylight at the range though and they're all back to looking much the same.

That's my experience with them.

Yep that's been my experience - the 50mm objective was way brighter and had better colour rendition than both the Swaro and Leupold with smaller Objectives although the Leupold was just as good under the light but during the day it seemed slightly duller and less sharp than the Nikon for some reason, as I said I'm guessing that was to do with the diff in Objective size 36mm for the Swaro, 40mm for the Leupold and 50mm for the Nikon.

[MeccaOz]

It tends to be magnification driven.

If you're shooting a 3-9 magnification range in low light a 40mm should still gather enough light but bump that up to 12 power you may want a 50mm.

Now say you want more magnification again, a bigger objective lens would be required to gather enough light in poor conditions

The reverse is true, a dangerous game rifle might wear a low mag 1-5 power and might only need a 20mm to 30mm objective lens

A simple test is to divide the objective lens diameter by the magnification, the goal is a number around 7 (7mm exit pupil)

For example, 40mm objective divided by 6 power gives a 6.6 mm exit pupil, making it suitable for low light hunting, in fact many early morning rabbits would agree

Bump that up to 24 power the available light on your 6-24X40 on your .22 now has an exit pupil if 1.6mm.

Now a 56mm scope at 24 power would give you a 2.6mm exit pupil, probably not enough in really bad light but still almost double what a 40mm would give you.

I've seen this in practice at a 500m fly shoot last year where I was shooting with a 60mm objective lens and my wife a 40mm scope both at around 30 power

As the light deteriorated I stil had a clear bright image, where as she had issues seeing the target with the image dark and grainy

Hope that makes sense

Chronos

I appreciate that Chronos, makes alot of sense and helps alot

[farmerstuff]

40 Is plenty. Hunting scopes should be light & small. That's why is hard to beat a VX2 /VX3 Luepold with a 33 to 40 objective lens, for hunting.

[brand]

40 Is plenty. Hunting scopes should be light & small. That's why is hard to beat a VX2 /VX3 Luepold with a 33 to 40 objective lens, for hunting.

Yer, can't say I've ever had any complaints with my 40s.

[Lorgar]

Yer, can't say I've ever had any complaints with my 40s.

It really is just that twilight period.

95% of the time no difference.

[hoogle]

Thanks all around guys for the info.

I might go with a 50mm Meopta I think now after reading some other stuff here too.

Bigger lens but the price is still right

[bigfellascott]

Thanks all around guys for the info.

I might go with a 50mm Meopta I think now after reading some other stuff here too.

Bigger lens but the price is still right

I reckon she'll do the job just fine mate - enjoy!

[disko]

Yeah mate they're good.

I have the 4-12x50mm Meopta. Go for it.