scope objective lenses?

[Scotch_egg]

I have found the leupold VX111 6.5-20x40 and the 6.5-20x50 at very good prices and need to know what advantage if any the 50 objective lense would give. I like the idea of a small scope, keeping things tidy. But how mush light will I really loose?

 

I have a S&B 8x56 on my stalking rifle and find the 56 objective lense a little ott.

 

I know that many of the members have alot of experience and have been through this before, for themselves. I would appreciate your views and advice before I jump in a the deep end.

[stag1933]

Hi.

The human eye can take in approx. 7mm of light beam at darkness with a fully dilated pupil.

If a 6.5-20x40 scope and a 6.5-20x50 were each set at 10 power they would give out a light beam of 4mm and 5mm respectively.

The bigger objective lense lets through more light.

At a 20 power setting these figures would become 2mm and 2.5mm.

It is just a question of dividing the magnification into the diameter of the object lense. Your 8x56 gives out a beam of 7mm.

 

If the scope is to be used mainly at night the larger objective will be advantageous.

 

HWH.

[Guest 308Panther]

Keep in mind the tube size plays a big part if not bigger as well...

Leupold usually uses a 30mm tube with a 50mm lens

and a 1 inch tube with a 40 mm lens...usually.

 

In the case of 6.5-20 x 40 and 6.5-20x 50

the choice between the 2 would be a no brainer....

 

6.5-20x50....Hands down every time.

 

And the choice would have nothin to do with the amount of light as the human eye/mind can only process so much light...and even a good 40mm lens can easily gather more light then your brain and eye can use....where the light waves are aborbed is in magnification.Not in the size of the lens.The higher the mag the more light is absorbed.

 

This is the reason I would chose the 6.5-20x50.

You will have more internal adjustment range on the turrets as a result of it bein on a 30 mm tube.

This will come in very very handy on shooting long range....

Depending on caliber and trajectory a good guess at where the differance is, would be around 700 yrds or so...maybe a touch farther.

 

Hope this helps

 

308Panther

[stag1933]

Hi .308 P.

Carl Zeiss would not agree with you if he was still alive.

Germans usually evaluate a scope sight by what they call the `twilight factor`.

This is derived by multiplying scope magnification by objective lense diameter and taking the square root of this figure.

For example with the LEO. set on 20 mags with a 40mm front end it would have a twilight factor of 28.2 and the guys existing S&B scope with 8 mags and 56mm front end would have a factor of 21.1 .

If I was sitting up a high-seat waiting for an old Porker to appear in very bad light give me the 8x56 every time.

Even for dusk and dawn forays on Deer I would go for his S&B every time but if he wants his scope for daytime use then that is a different ball game, but do not forget that as you INCREASE magnification you DECREASE field of view.

It is also good to remember that the larger beam of light derived by the larger object lense makes it less critical where you place you eye for a quick shot.

 

On my work tool, a .270 Carl Gustaf, I have a Swarvoski 3-12x56mm Nova. [one of the steel, 30mm tubed good old guys.]

[Scotch_egg]

Thank you both for your replies. The rifle it is going on will be a .243 that will be used at any time day or night.

 

308 panther I note that you mention tube size plays a large influence. Both are 30mm tubes, does this make a difference to your recomendation?

 

many thanks

[Alycidon]

Hi .308 P.

Carl Zeiss would not agree with you if he was still alive.

Germans usually evaluate a scope sight by what they call the `twilight factor`.

This is derived by multiplying scope magnification by objective lense diameter and taking the square root of this figure.

For example with the LEO. set on 20 mags with a 40mm front end it would have a twilight factor of 28.2 and the guys existing S&B scope with 8 mags and 56mm front end would have a factor of 21.1 .

If I was sitting up a high-seat waiting for an old Porker to appear in very bad light give me the 8x56 every time.

Even for dusk and dawn forays on Deer I would go for his S&B every time but if he wants his scope for daytime use then that is a different ball game, but do not forget that as you INCREASE magnification you DECREASE field of view.

It is also good to remember that the larger beam of light derived by the larger object lense makes it less critical where you place you eye for a quick shot.

 

On my work tool, a .270 Carl Gustaf, I have a Swarvoski 3-12x56mm Nova. [one of the steel, 30mm tubed good old guys.]

 

I would agree with what you are saying but my 3x9x36 Ziess outperforms every other scope I have at night set between 6 and 8x usually. I also shoot a 4x14x40 VX111 on a 25mm tube and a Swaro 6x24x50 on a 30mm. The VX111 comes a very distant third but for reasonably well illuminated targets it works fine and has never gone wrong.

 

Given your two options I would also go 50mm.

 

A

[Guest The Equaliser]

On my work tool, a .270 Carl Gustaf, I have a Swarvoski 3-12x56mm Nova. [one of the steel, 30mm tubed good old guys.]

 

 

They dont make scopes like they used to Hubert i prefer my old Pecar variable to all of them and clarity is second to non and i think its the only scope ever manufactured with interchangeable reticules. 30mm tubed steel with 42mm object lens

[Guest 308Panther]

I suppose I should have used a differant word than absorbed.

When light passes thru a lens it slows down and is bent...this is called refraction.

There is a certain amount of light that is lost (absorbed) when light is refracted and as magnification increases..This is how I should have worded it.

So as you increase magnification not only does your field of view diminish so does the brightness of the image.

Has Carl Ziess stopped turning in his grave yet??

 

Between the 2 Leupolds ...I would still choose the 50mm one.I knew there was a couple Leupold's offered with a 30mm tube and a 40 mm objective...Wich ones I couldnt remember.

 

Twilight factor....Interesting concept.

 

308Panther

[stag1933]

Hi EQ.

Our local Police used to have Pecar 4-10 x 50mm scopes on their rifles and these had the 2 screw interchangeable reticule system.

These were steel scopes with 26mm tubes.

A downside on this useful bit of kit was the fact that the reticle was not centered as is the norm today and if the mounts were not precisely fitted the image was not in the centre of the picture.

Parker Hale were the importers in the 60s.

 

Some years ago in Ireland we did a twilight test on scopes. We set our scopes on 8 power and used a grazing Sika Staggie beside a dark forest as the test object.

When compared with Zeiss and Optolyth binocs also on 8X my Nova had the brightest image [set on 8X]. Scopes of the other guys were not as bright either.

HWH.

[ejg223]

You've all possibly seen this result before, they tested

a few scopes in a lab some years ago.

 

* Docter Tipcontrol 3-12x56

* Kahles Helia 3-12x56

* Meopta Meostar R1 3-12x56

* Nikon MOnarch E 3-12x56

* Schmidd&Bender Zenith 2,5-10x56

* Swarovski Habicht PVI-2 2,5-10x56

* Zeiss Victory Diavari VM 3-12x56

 

 

Measured Value / Modell Docter Kahles Meopta Nikon S & B Swaro Zeiss

Transmission 1 Day 84,30 91,40 92,20 93,00 91,40 89,40 92,40

Transmission 2 Day 86,00 92,40 92,10 93,60 92,00 90,40 92,90

 

Average Day 85,15 91,90 92,15 93,30 91,70 89,90 92,65

 

Transmission 1 Night 80,50 88,10 88,20 90,60 91,40 87,90 90,10

Transmission 2 Night 81,60 88,80 87,90 90,60 91,90 88,50 90,20

 

Average Night 81,05 88,45 88,05 90,60 91,65 88,20 90,15

 

 

Average total 83,10 90,18 90,10 91,95 91,68 89,05 91,40

 

 

 

I think it was a German Lab, german's where not impressed that a Nikon came in first.

 

I'd go for 50mm over 40mm any day.

 

edi

[ejg223]

Couldn't get the text to copy well,

another try.

 

Docter Tipcontrol 3-12x56 Day 85,15 Night 81,05 Total 83,10

 

Kahles Helia 3-12x56 Day 91,90 Night 88,45 Total 90,18

 

Meopta Meostar R1 3-12x56 Day 92,15 Night 88,05 Total 90,10

 

Nikon Monarch E 3-12x56 Day 93,30 Night 90,60 Total 91,95

 

Schmidt&Bender Zenith 2,5-10x56 Day 91,70 Night 91,65 Total 91,68

 

Swarovski Habicht PVI-2 2,5-10x56 Day 89,90 Night 88,20 Total 89,05

 

Zeiss Victory Diavari VM 3-12x56 Day 92,65 Night 90,15 Total 91,40

 

This test was done before Leupold had the 56mm scope.

The big winner is schmidt with the night values, seems they sacrificed

a bit of the day values with coatings for night use.

 

Many people criticized this test at the time, saying it was tested with

machines and not the eye.

edi

[Redfox]

Seen that before Edi, thats why I buy S&B, but as for Nikon, my cameras are nearly all Nikon and they are capable of the highest stds if we can pay for it.

Swaro are pretty good and I have 2 of their 6-24x50s which are ok.

Zeiss do make good stuff but their main bag is scientific and medical optics followed by imaging, so scopes are well down the line, plus they still expect us to pay for the name!

Good post for anyone wanting scope comparison.

Redfox

[Scotch_egg]

right then, thanks for all the input fella's. Most informative.

 

It will be the 50mm objective I got for. I'm getting the scope from the states and its a bargain at the moment cos optics planet have a sale. The 8.5-25x50 is only $850 so it may even be this model.

 

happy shooting

 

Dave

[ejg223]

Hi Dave,

how about the Zeiss conquest 6.5-20x50 at 899$

at Optics Planet. Might have better glass, but is only 1"

 

Redfox,

we've got Zeiss and Nikon microscopes at work and

sometime I prefer the Nikon. Not bad at all.

I've just sold my 223 with S&B 4-16x50 and fear that

I might not be able to afford a S&B when my new 22-250

arrives. So I'm considering a Conquest. We'll see.

 

edi

[Scotch_egg]

Edi,

 

I like the zies but really want a 30mm tube, some thing I have never used before.

 

As for rings I have a choice of Leupold or Warne. Both similar prices, but what are the best?

 

cheers again

 

Dave

[ejg223]

Sorry Dave I haven't used neither

Leupold nor Warne mounts. Warne look nice though.

Most mounts that I had up know were dissapointing in

precision, mostly one of the pair was higher than the other

and needed a bit of tweeking. Be it millet Sako or

whatever else they sold me around here.

 

edi

[Guest 308Panther]

I have used Leupolds Rings with no trouble at all.

Dovetail Ring on my Win 70 .308

QRW (Quick Release Weaver) on my CZ 452 .17 HMR

QRW on my DPMS Panther LR-308 (AR-10)

And I have had a few "Rock&Roll" sessions testing 20 rd mags

and they didnt shoot loose.

 

Warne,I havent tried but I do hear are good stuff also.

 

308Panther

[Redfox]

Warne are split vertically, there is no good engineering reason for that and they catch on everything too as well as marking your expensive scope. I have had a lot of Sako optilock rings and never had a difference in height, they must have given you odd rings or something. They certainly work well and dont mark the scope. The Leupolds are good and providing you buy them from someone who knows what they are doing the will work fine.

Other than Sako/Tikkas own, I buy Leupold bases and Burris Signature series rings which are designed to fit the Leupold ( Burris) bases and have inserts like the Sako rings, they also do additional inserts ( you get std and +.010" in the pack) in increments of .010" up to .040" to allow for receiver differences and some peoples need in target shooting to offset one end, either up/down or left/right. I have used these quite a lot and again never had any problems with them.

I have a natural aversion to paying upwards of a grand for a scope and then crimping the main tube or gouging lumps out of it with the majority of rings sold.

For those with no adjustment i.e Warne, Hillver etc unless you are going to spend the time to lap them with lapping paste and a 26/30mm bar and know what you are trying to acheive, damage and strain on the main tube are a certainty and its one more thing to worry about in the search for accuracy. I have never had any of the scopes move on any of my rifles using the insert rings up to 375 H&H cal, I have also fired 3 shots then removed the scope with bases and re fitted it and fired three more shots on the same target, with no loss of zero, using both my 243 and 270 Sakos.

[ejg223]

I have had a lot of Sako optilock rings and never had a difference in height, they must have given you odd rings or something.

 

I have a 26mm Sako set which is ok and a 30mm set that isn't, S&B almost at the end of

hight adjustment. A friends Optilocks where also off, so we shimmed em up.

Otherwise the optilocks seem to hold tight.

The millets are injection moulded steel and not machined so around +/- 0.2mm

would be normal.

 

edi

[Redfox]

If they are out I would have sent them back as there is no excuse for them not being identical.

I have to say though, after the experience with a new Sako 75 d/l 243 it would not surprise me if your friends receiver were a bit out, things have definitely gone a bit poor since Beretta took over.

Having said that they re-barreled my 36 yr old 243 and made a perfect job of it last year, so they can still do the business given a chance.

Also all my ring sets pre-date the Beretta takeover.

Redfox

[Guest 308Panther]

The only manufacture I know of that numbers and machines the rings

as a matched set is Badger Ordnance.

 

308Panther

[stag1933]

There are some crappy mounts about !

A friend has an ancient BRNO .243 with a poor quality no-name 6X scope on it and has been putting an evil eye on my old steel 3-12X56 Swarvoski Nova for some time.

I found him one advertised in Scotland which he bought. He went to our local guy to get some mounts and as none to fit were in stock had some Millets ordered for him.

He brought them here for me to fit, and what a load of rubbish they were .

Bearing surfaces on the claws for the action dovetail were less than half that of his old Parker Hales and one claw was longer than the other,so consequently with the shallow BRNO dovetails it would be impossible to mount this ring in alignment with the other.

I told him to take them back but the guy at the shop tried to fit them and found what I had said was correct. Now he is trying to get his money back, [ nearly £50 ] and still hasn`t got the Nova on.

 

Ref. Redfox and Sako mounts, I too have had NO problem with 4 sets of Optilock and their predesessors.

HWH.

[Redfox]

As Ian knows as well as me with modern CNC machining and increasingly laser measurement a set of rings and bases can be held within 1/2 to 1 thousanth of an inch and still be cheap as chips.

Cast steel whether gravity or pressure moulded is ok and relatively cheaply, but stresses can be left in the cast without more expensive normalisation done.

Machined steel is best and there is no reason today for them not to be spot on first time. Incidentally .2mm is .00787" nearly 8 thou, which in most cases would give 6-8 inches difference in point of impact at 100 yds! not that good.

As already said if I found a siginificant difference in a pair of rings/bases they would go straight back for replacement.

I have only had this once with a pair of Leupold rings/bases and the difference was in the bases ( for a Rem 700), even here I tend to suspect that the seller had had several pairs out and mixed them, the replacement pair were fine and I still have them.

Redfox

[col48]

The only manufacture I know of that numbers and machines the rings

as a matched set is Badger Ordnance.

 

308Panther

 

hi -

 

http://www.kenfarrell.com/

 

http://www.kenfarrell.com/00186.html

 

 

http://www.kenfarrell.com/00186-GF.html

 

 

hi i use them and every time i zero my rifle, i do not have to alter anything,it is all ways bob on.

 

ATB

Colin

[Scotch_egg]

i'm going for the cheap option, leupold mounts from the states with the scope. Yes I know that I should support local business but I cannot afford the "bling" at the prices the uk offers kit,

 

I will be shooting at ranges up to 500yds. I have only just started reloading and have been using an 8x scope at 100yds and have had (in my view, bloody) good results. I want to reach out on a budget and like to be a little different hence the thompson centre encore i havetsaid yes too....

 

I'm in the hebrides at the end of the month now if you want some long range rabbits, this is where you want to be!

 

ps

 

If any one has any stalking in the area (cheap) pm me. I love stalking and will be travelling with my father who has never stalked.

 

regards

 

David