Variations in magnifacation

Dawnraider

Well-Known Member
Having recently put a Luepold VXL 4.5-14 on my new 30.06 i leave it set around 7-8 when out stalking, spotted a few roe with my 8x binos and when i've put my scope on them i thought they didn't appear so magnified through the scope.Yesterday i had to check my zero on it and also took along my .243 that wears a 2.5-10 S&B Zenith to try out some new loads,any way had the S&B set on 10 and the Leupy on 10 the difference in mag between the two was startling,i screwed the Leupy upto 14 and even then i dont think it was quite as much mag as the S&B on 10.Anyboby else noticed differeces like this, do the Americans measure differently to the Europeans when it comes to magnification,i just can't see why there should be so much difference,or have i got a duff scope, it functions fine on the zoom so i can't see that there could be anything wrong with it.
Neil.
 
Dawnraider,
some scopes have adjustments on the rear(diopter ring)undo the locking ring on your leup and try and wind it out, the magnification should be greater as you screw it out,but be aware that the focus will be affected.If you have a side focus wheel then you can compensate with it..
you could be as much as 30% less mag if it is screwed in to much..


regards
griff
 
Cheers Griff i'll give it a go, i think i adjusted it when i got it for my eye focus it hasn't got side focus though just paralax adjustment.
Smullery sorry i don't understand, do you mean there is a difference between the two scopes in the way they magnify.
Cheers Neil
 
Griff just tried it and yes the mag goes up but the recticle just goes all fuzzy,it appears to be set right for my eye.
Neil
 
HI mate

You will find that there are distinct differences in magnification not only between American and European scopes....but also between bino's and scopes of the same magnification!!

I have had dozens of different scopes of both American and european manufacture over the years, and all have been different in their mag range. The European ones tend to magnify more then the American ones...usually by one as previously pointed out, so a Yank 6 usually equates to a europe 7-7.5. Don't ask me why 'cos i haven't a clue!!...lol!!
Bino's usually go the same way.....scope 8x (swarovski and Docter) equates to the 7x on my ziess binos.
Just for the record, you may even notice a distinct difference in the scope positioning with regards to eye relief with yank and european scopes!....with the europeans being less critical which allows for easier rifle mounting in different shooting positions (hence british snipers use s&b scopes as opposed to leupolds).


ATB
Steve
 
Neil,

Whilst it may state that it is x10 you are not starting from 1. On a variable mag scope divide the largest mag setting by the smallest. This gives the true range of magnification. So, on a 2.5 - 10 Scope an object will appear 4 times larger on maximum mag than on minimum.

Stan
 
Thanks Steve i'm glad its not just me then thought i was going dolally to start with,not a lover of the Leupold anyway to be honest its on there as a temporary measure till i get something else sorted i robbed it off my .17hmr just to get it going so won't have to live with it to much longer i hope.
Stan i think i see where your coming from with that,i always thought that 8x meant that it actually looked 8x bigger than it did with the naked eye,learn something new everyday,thank you.
Neil.
 
Neil,

The optics can only magnify the fixed volume of light reflected by an object "as it arrives on the objective lens". This has no relation to the term naked eye. A fixed magnification will indeed magnify by that so say you have x8 Binos then the "spot of light" will be magnified x 8. Doesn't mean that it will appear eight times larger than without the binos.

Using a variable optic 2.5 - 10 means the "spot of light" will only be 4 times larger on max than on min.

The larger the difference between min & max the more steps of magnification you have and thus the appearance of the object size increasing for the same twist on the variation.

Stan
 
Thanks Stan,i never was much good at physics my heads starting to hurt already but i see what you mean,so if i get a 3-12 the rate of mag will be the same as my 2.5-10 but the end view will obviously be a bit larger overall,i think.
Cheers Neil.
 
I must admit that my understanding of this was that 10x, for example, meant just that: so that if I look at it from 100yds using 10x binoculars, it appears as though I were looking at it from 10yds with the naked eye.

It is interesting to note the difference in range of magnification between the two 'scope under discussion, and that would certainly make the change in apparent image size from lowest to highest mag different between the two.

Neveretheless, I'd expect one maker's 10x to be the same as another's.

I'm very confused!
 
Dalua,

x10 mag from one manufacturer will be similar to another. It's the starting point that changes. The size of the aperture, glass coatings, number of lenses, refraction v reflection in binos, etc. Exact magnification of a defined light source is what is measured. Nothing to do with the MK1 human eyeball (of which two are used in binoculars) and the interpretation by the human brain to give size.

In the case of Riflescopes only a fixed mag scope is starting with a base reference of 1. Variable mag scopes can use many lenses/mechanics and differing starting mags so the perception of size changes. As you increase mag the field of view decreases. The "target" in the middle appears a lot bigger if you decrease field of view but still maintain the same mag.

A lot of subjective work going on here.

In Neil's case if you want to compare differing manufacturers you have to compare same objective size, min and max variable mag and use the same eye relief.

Stan
 
I think I've got it: the apparent size of the image at 10x in the two 'scopes might be different because of its size relative to the two different of the fields of view. Is that it?

I suppose differences in resolving power might also give a different impression of 'size' of image?
 
I have often thought that the image I see in my Binoculars (8.5 x42 ELs) is larger than the image I see through the scope even at a higher magnification, say 10 or 12x. The only explanation I can think of is due to the eye relief being different and so the bino image being closer to the eye 'appears' larger because the eye relief of the scope, at say 3.5", places the image that much further away from the eye it 'appears' smaller. I hope that makes some sense!

Regards,

KRS
 
KRS,

Correct. Back to the MK1 eyeball. All different and, two eyeballs in a bino, will make the target object appear larger than in a mono of exactly equal spec.

With a scope the more eye relief you have the further away you are putting your eye from the image presented on the ocular of the scope, because this is actually what you are looking at, not the original object.

Remember what your mother told you,

Too much X isn't good for you ;)

Stan
 
I concur, and the eye relief and positioning is far more critical on my Leupold than on my european/Jap scopes. However what this does mean is your head is in the same position each time you shoot with the Leupold, hence removing a varriable.

When I first got my Mil dot Hakko I remember checking the mill dot spacing by cutting a piece of wood and viewing it at 50yds. I think Mil dot only works at 10x, anyway I found that on the scope I had to be a bit over x10 on the mag ring to equate to the correct mil spacing.

It was not much out, but it was just for a matter of interest.

I do have a pecar scope in which the mag appears low and nomally have it set on about x5, which seems to equate to x4 on most other scopes.

D
 
Dalua,

x10 mag from one manufacturer will be similar to another. It's the starting point that changes. The size of the aperture, glass coatings, number of lenses, refraction v reflection in binos, etc. Exact magnification of a defined light source is what is measured. Nothing to do with the MK1 human eyeball (of which two are used in binoculars) and the interpretation by the human brain to give size.

In the case of Riflescopes only a fixed mag scope is starting with a base reference of 1. Variable mag scopes can use many lenses/mechanics and differing starting mags so the perception of size changes. As you increase mag the field of view decreases. The "target" in the middle appears a lot bigger if you decrease field of view but still maintain the same mag.

A lot of subjective work going on here.

In Neil's case if you want to compare differing manufacturers you have to compare same objective size, min and max variable mag and use the same eye relief.

Stan
Stan.

Are you talking about light transmission, not magnification. Light transmission is relevant when comparing glass types, refractive indicies, coatings, internal stray light reduction. An image viewed through a scope 100m in the distance at 10x magnification, would appear to be 10m away if viewed with the human eye.
What you are discussing on variable magnification is the effective objective diameter, again this will not be magnification but image brightness (light entering ojective diameter - light leaving via the exit pupil: exit pupil = objective diameter (mm)/ magnification (x) = exit pupil (mm).

mak
 
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