Scope obj size

[jamross65]

Yeah , you will have more field of view on a large objective lens at higher mag .

No advantage worth bothering about in the real world, and how much field of view do you need in a rifle scope? I could understand that desire in a spotting scope or bino's for scanning an area but why necessary with a rifle scope when you have already spotted and acquired your target before hand???

 

[nuttyspaniel]

As already stated by others a 42mm 50mm or 56mm would do for stalking. Myself I opt for a 50mm I believe it offers myself the best of both worlds, good light gathering and a better more comfy cheek weld than a 56mm. My scope is a 3-9x50 and is set on 7 all the time.


Nutty

 

[black lab]

Swaro 8x56 does it for me

ATB
Wullie.

 

[bongo]

What do you intend using the scope for?
Woodland, hill, both?
Woodland...6x42
Hill.....6x42

thinking of a bit of everything

 

[bongo]

Thanks for all those , for me a variable is best ie 4-12 , and ive always gone 4-16x50px adj or simalar and have x2 6500 elites , but think i will try a x40 none px adj , so say a 4-12x40 none px adj and mid range quality , as was said a cheap scope with a big lens is not the best idea, but see my dilema when im used to scopes with x30mag with px adj + x50 , would something like a 4-12x40 be average , albeit the x40 concerns me .

 

[Code4]

There are a lot of variables to take into account when selecting a scope. I now prefer a scope roughly in the range of 2.5-10x42 with 30mm tube for my hunting/stalking scopes.

Reasons:

Lower sight line.
Anything over 42mm Obj restricts the FOV for my old eyes.

I place a higher value on quality of lenses, coatings and construction than mag range or gizmos.

 

[Taff]

The main advantage of 6 x42 is you can get top quality scopes off this site, cheap, as they all seek the holy grail of vari scopes, while us folks save our money and get the deer

 

[enfieldspares]

I use two Zeiss Diavari 3-9x36 and 1.5-4.5x18 plus I have yet to do anything with an old Kahles 4x32.

When I shot my first deer it was with a Pecar 4x81 (except that 81 was something other than 81mm as that would have been massive) on a Churchill Mauser in 270 Winchester.

 

[Selous]

4-15x50 is the dogs danglies for me. I accept that it tends to stay on 8 power most of the time....but not all. If I get a longish shot at a roe (say 150m or so) I will wind it up to 12 or 14 providing the deer is unaware and that I have a steady enough rest.

 

[ejg]

In the meantime I shot a few deer with open sights, have a S&B Zenith 3-12x50 which is good but too heavy and
my favourite I have two of 6.5-20x50 Conquest. I don't really mind once I'm out I'll use anything but
I won't take a 150yd neck shot with a 6x42, absolutely no problem with the conquest. With our high grass you might
as well stay home if you don't take neck shots.
I have the 6.5-20 always on 6.5 mag, if their is time I crank up the mag I do and if not, then it stays at 6.5.

Took this stag at just under 5m this year with the Conquest, meaning it even works at close range as long as they are not running....

edi

 

[Muir]

I prefer low magnification scopes. 4x32 is fine, as are 3-9x40 or 42MM. I can't shoot off hand very well with scopes larger than 5X and all of my shots seem to be off hand these days. I also like the smaller objectives as they keep the scope lower to the bore and comb which makes for faster target acquisition.

I am convinced that "larger objective" does not mean a brighter scope, or more "light gathering". Quality optics will do more in a 32mm than crappy optics in a 55mm. JMHO.~Muir

 

[HuN73R666]

The simple rule is that you divide the objective size by the magnification and your target is 7mm, which is the average pupil size of an adult. 42mm / 6 mag gives you 7mm. So does 56 / 8 mag! So claiming that one objective size is the best, is only half the story. It all depends on the mag which it is coupled with.

 

[HuN73R666]

I agree with this too Muir. Glass quality does play a big part in light transmission. But if you are comparing the same glass then the formula holds true.

I prefer low magnification scopes. 4x32 is fine, as are 3-9x40 or 42MM. I can't shoot off hand very well with scopes larger than 5X and all of my shots seem to be off hand these days. I also like the smaller objectives as they keep the scope lower to the bore and comb which makes for faster target acquisition.

I am convinced that "larger objective" does not mean a brighter scope, or more "light gathering". Quality optics will do more in a 32mm than crappy optics in a 55mm. JMHO.~Muir

 

[Tamus]

I've got 36mm, 42mm and 50mm glass by Swarovski and S&B in fixed and variable specs

I've never felt that my 3-9x36 1" tubed Swaro lost any meaningful performance to my 6x42 Swaro or 1.5-6x42 30mm tubed S&B (or vices versalated)... in any light conditions... and I'll never buy 50mm glass again as it really adds nothing but bulk and weight to a stalking rifle... IMHO. However, the different mag powers do all serve useful purposes according to what each rifle is meant for. As for 56 and 72 mm glass... I'm sure there must be a reason why people buy it... I just can't see or think of any valid reason why I would.

 

[HuN73R666]

As you said tamus it depends on the application. Some long range target shooters require very high magnifications. These high mags reduce the size of the image hitting the pupil. The smaller the image the less light/clarity. If you have used very high mag scopes you will notice that the slightest movement of your head alignment means you loose the image. That's because with a much smaller image there is less room for error.

I have just bought a Swaro 8x56mm scope for my new rifle. In comparison it feels half the weight of the S&B equivalent. So again, objective size is only part of the story.

I've got 36mm, 42mm and 50mm glass by Swarovski and S&B in fixed and variable specs

I've never felt that my 3-9x36 1" tubed Swaro lost any meaningful performance to my 6x42 Swaro or 1.5-6x42 30mm tubed S&B (or vices versalated)... in any light conditions... and I'll never buy 50mm glass again as it really adds nothing but bulk and weight to a stalking rifle... IMHO. However, the different mag powers do all serve useful purposes according to what each rifle is meant for. As for 56 and 72 mm glass... I'm sure there must be a reason why people buy it... I just can't see or think of any valid reason why I would.

 

[Sharpie]

Exit pupil is always quoted as objective diameter divided by magnification.

I.e. 6x42 = 7mm or 8x56 = 7mm.

Well maybe, if the 'scope is perfectly designed. But they aren't all, and some don't make the full use of the objective lens.

Then you will hear arguments that the middle-aged pupil won't open more than e.g. 5mm, so a 7mm exit pupil is wasted.

But thats not the case.

A decent size exit pupil means the alignment of your eye is less critical. In a hunting situation time wasted lining up exactly with the 'scope because otherwise it dims or blacks out is no good.

Thats also why you should consider a variable magnification. Even if 90% of the time it is left on e.g. x6, if you have to follow up a deer you can wind it back to x2 or 3 and have 2 or 3 times bigger exit pupil, which makes it much less fussy for eye position, wider field of view, greater depth of field, much faster for a followup shot.

Boar shooters etc. know this, and use low mag. 'scopes with objective lenses that give far bigger exit pupils than are strictly required for light gathering.

Likewise target shooters can make good use of e.g. a x30 50mm scope with a tiny 1.7mm exit pupil which ensures precise alignment, once they have managed to line their eye with it, which can be a struggle.

Now that x4 and even x6 zoom ranges are available, it seems like an idiosyncratic choice to limit yourself with a traditional fixed 'scope. Even the old 3-9x40 does the job better than a fixed x6 IMHO.

I've recently bought a 2.5-10x50 which seems to cover most bases, and its not particularly big either. I'm hoping it works out OK.

 

[Simjim33]

At any given magnification a larger objective lense will give you a brighter image.

Please explane the physics behind this!

No scope in the world can "gather" light! Which by that idea would be the only way to make the image " brighter"

As light travels in waves and is absorbed by black pigments. How would a scope obj funnel more light into the tube?

Only light that travels directly down the tube will be seen. All other light will be deflected or absorbed.

I would go so far as to say that 42 obj offers the same amount of light from a physics piont of reference. But even then you get losses.

Both my hunting scopes are 42mm obj. My target shooting scope is 60mm. But that is only because that size obj was on the scope with the mag I wanted.

The thing is. In low light. My 6x42 £30 second hand Niko gold crown. Works as good as my ziess conquest 3-9x40.

I think the only time I would change a scope. Would be a brand Change to say a S&B 6x42. Not because I could see clearer( as the above physics will hold out regardless of maker). But because there is a perceived strength of build difference. This will only happen if the Niko breaks.

Dont hold your breath!

This is not in any way a dig at stag1933 by the way!

 

[Willie]

Swarovski 8x56 for me, not cheap but not expensive compared to the good quality variofocals with illuminated reticules on the market.
Willie

 

[W16OEN]

Keep it simple - general purpose. I use 8x56 fixed S&B and same in Swaro both 30mm tubes. Good in woodland and further out on the hill and low light gathering at dusk

 

[Bigboab29]

I used to have a s&b 8x56 which was great at first/last light, i sold and bought a z6 2.5-15x44 and if i put it on 8 mag (where it stays most of the time) there is no difference in the brightness of the image even tho the obj is 12mm less. I also had a 4-12x50 meopta meopro which was good at low light as well, i sold this and bought a swaro av 6-18x50. With these scopes set on the same mag the swaro was a lot brighter and clearer than the meopta in low light. Probably should be brighter tho seen as its 4 times the price.

If i compare the z6 with the av on the same mag even tho the av has the bigger obj the z6 is still a lot brighter at last light. Not sure if this is due to the av having more glass in it or just the fact it is an older model and the z6 has better lense coatings.