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What scope is better for night hunting

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pyro View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote pyro Quote  Post ReplyReply Direct Link To This Post Posted: April/22/2007 at 14:14
Originally posted by RifleDude RifleDude wrote:

I'm not a believer in the "twilight factor" number concept.



Do you also think that the earth is a disk?


Have you ever used the 72mm Zeiss and compared it against a 56mmor simlar scope?

A buddy of mine shot a boar that we both couldn't see with our 8x56 binos,
there IS a difference, it is up to the user to decide if it is worth the very high costs
and the aditional bulk.

Here in Germany it is forbidden to use NV aiming devices, so this is the next best thing to use.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote RifleDude Quote  Post ReplyReply Direct Link To This Post Posted: April/22/2007 at 15:44
Originally posted by pyro pyro wrote:

[QUOTE=RifleDude]
Do you also think that the earth is a disk?


Have you ever used the 72mm Zeiss and compared it against a 56mmor simlar scope?



The "twilight factor" number places too much emphasis on magnification.  It is the square root of the product of magnification X objective diameter.  I believe it is a bogus, largely meaningless number that doesn't take into account the quality of the optical system.  It also doesn't factor in the DISADVANTAGES to low light viewing of increased magnification, namely greatly reduced FOV and amplified optical aberrations.  I am not alone in this thinking.
http://www.birdwatching.com/optics/myths2006-9.html
I have never found increasing magnification to improve my ability to see in low light.  In fact, just the opposite.  I have never compared a 72mm scope to smaller objective scopes, but I have compared plenty of 56mm scopes to 42mm and 50mm scopes, and the bottom line is that the relative brightness between any two scopes always comes down to which one has coatings and optical design better optimized for low light.  A larger objective will transmit more usable light to the eye than a smaller objective up to a point, but the key to maximizing light transmission is matching the optimal objective size to the magnification.  A 7mm exit pupil provides the theoretical maximum amount of light transmission your eye can use.  As you go up in magnification, the image becomes increasingly dimmer, so it requires a larger objective lens to get the same amount of light transmission as the smaller objective at lower magnification.  At the exact same magnification, the larger objective lens will transmit more light, but a 10 X 72, 8 X 56 and 6 X 42 of equal optical quality will all transmit the same amount of light to the eye, period.   The  10  X 72 will only produce a larger image than the 6 X 42, not a  "brighter" image.
Ted


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Post Options Post Options   Thanks (0) Thanks(0)   Quote RifleDude Quote  Post ReplyReply Direct Link To This Post Posted: April/22/2007 at 15:48
Originally posted by www.technika.nu www.technika.nu wrote:

The bigger the fronlens and the bigger the magnification the more light will pass through it.



Sorry, but that is incorrect.  The bigger front lens can transmit more light, but as you go up in magnification, the amount of transmitted light DECREASES, so you have to use a larger front lens to regain the amount of light transmitted.  Given equal optical quality, any two optics delivering 7mm exit pupil will transmit the same amount of light to the eye.  Beyond that point, increasing the size of the objective doesn't give a corresponding increase in light transmission.
Ted


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Post Options Post Options   Thanks (0) Thanks(0)   Quote 22LR Quote  Post ReplyReply Direct Link To This Post Posted: April/22/2007 at 16:00
I just cannot imagine to carry hunting rifle topped with a 72 mm tube. Last year I hunted boars at night in Poland with Diavari 50 mm, which was as bright as I needed. There is also issue of target recognition and I would never push limit to 72 mm, which IMO could give you a false sense of safe shot. Here at home, none of my rifles has bigger lenses that 42 mm this is all what I want at dawn and dusk. My two cents.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote RifleDude Quote  Post ReplyReply Direct Link To This Post Posted: April/22/2007 at 16:07
Originally posted by www.technika.nu www.technika.nu wrote:

Otherwise if the fact should have been the opposite and a 4x32 or a 6x42 or a 10x72 let through the same amount of light to the eye even a 1x7 or a 2x14 would allow the same amount of light to the eye.

In such case there would be no need of optics for low light hunting, but there is, mostly times you cannot see the animal with your bare eyes but there is no problem to see them with a good scope or binocular.

 



There is actually a LOSS of available light through an optic, even the best optics.  The finest optics on the planet cannot transmit 100% of available light, which is the theoretical maximum.  The best scopes and binoculars made transmit somewhere around 94% max.  What you are referring to is the effect of magnification, which enables you to see objects in low light you couldn't with your naked eyes because they appear closer.  However, past a certain point, increasing magnification does not improve your ability to "see" in low light because of diminishing returns and the tradeoff of reduced FOV and blurrier images of higher magnification.  This is another reason why the "twilight factor" calculation is basically a meaningless concept.

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Post Options Post Options   Thanks (0) Thanks(0)   Quote www.technika.nu Quote  Post ReplyReply Direct Link To This Post Posted: April/22/2007 at 16:26

Rifle dude

 

I do fully agree with you that "twilight factor" is humbug, meaningless sh*t.

So we can leave that behind us.

Same thing with transmission, no scope are transmitting 100%.

 

The bigger the front lens are the more light it does take in.

If you where right the 2x14 should be as usefull as a 6x42 or a 10x72 , and as it's not as good you are simply wrong.

More light  is passing the scope and reaching the eye.

 

I do fully agree with you that FOV is very important when low light hunting, but when shooting at distances as 120 yards the FOV is around 4-5 yards with the better optics and that is enough for the shot.

 

First, a human eye can use more exit pupil than 7mm.

Some individuals have actually larger pupils than 7mm and can therefor use it.

Another problem is that it's not a simple task to put the eye EXACTLY behind the scope, so if you really need all the light that is going through the scope the exitpupil needs to be bigger.

If you put your eye off center 1mm and the exit pupil and your eye is both 7mm then you are loosing 25% light.

 

This discussion is not about what scope that is good for low light hunting, it's about what kind of scope that is best for low light hunting, as that was actually the question.

And for many people that do night hunting under a full moon a 4x32 is often enogh, espesially if its snow.

But to answer the question, Zeiss 6-24x72 is the best scope for low light hunting for the discussed distances.

 

Regards Technika

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Post Options Post Options   Thanks (0) Thanks(0)   Quote RifleDude Quote  Post ReplyReply Direct Link To This Post Posted: April/22/2007 at 16:45
Originally posted by www.technika.nu www.technika.nu wrote:

The bigger the front lens are the more light it does take in.

If you where right the 2x14 should be as usefull as a 6x42 or a 10x72 , and as it's not as good you are simply wrong.

More light  is passing the scope and reaching the eye.

 

I do fully agree with you that FOV is very important when low light hunting, but when shooting at distances as 120 yards the FOV is around 4-5 yards with the better optics and that is enough for the shot.

 

First, a human eye can use more exit pupil than 7mm.

Some individuals have actually larger pupils than 7mm and can therefor use it.

Another problem is that it's not a simple task to put the eye EXACTLY behind the scope, so if you really need all the light that is going through the scope the exitpupil needs to be bigger.

If you put your eye off center 1mm and the exit pupil and your eye is both 7mm then you are loosing 25% light.

 



First of all, if your eye is on-center enought to see the full FOV, then it is getting all the light the scope is capable of transmitting.  Secondly, if you look at a manufacturer's website that publishes light transmission values (like Swarovski) then you will see that their higher magnification, larger objective diameter scopes transmit LESS light than their more modest magnification, smaller objective diameter scopes.  Higher magnification reduces light transmission, all else being equal.  I'm not saying that a 2X14 model scope would be as effective as a 10X72, because to a point, increasing magnification helps you to resolve the target in low light.  Increased magnification is helpful until it starts to degrade image quality and the ability to find the target.  What I am saying is that super high magnification actually works against you by making target aquisition more difficult, especially on a moving animal, and I believe a 6X max magnification scope is a better choice for the short distances mentioned in this post for low light because of much better FOV, lower scope mounting, and a sharper, better defined target image, with the same apparent brightness as a target viewed with the 72mm objective scope set at 10X.
Ted


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Post Options Post Options   Thanks (0) Thanks(0)   Quote Hunter111 Quote  Post ReplyReply Direct Link To This Post Posted: April/24/2007 at 00:24
Hello again,

Now i´m a little bit smarter tahn before :) Where i can find the best price for -Zeiss 3-12x56 illuminated with the smallest possible dot. ? (i must from webshop)

One guestion more. What do you think nightforce 5,5-22*56 or 3,5-15*56? my opinion is that they are no very good in lowlight conditions ?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote RifleDude Quote  Post ReplyReply Direct Link To This Post Posted: April/24/2007 at 10:19

Originally posted by Hunter111 Hunter111 wrote:

Hello again,

Now i´m a little bit smarter tahn before :) Where i can find the best price for -Zeiss 3-12x56 illuminated with the smallest possible dot. ? (i must from webshop)

One guestion more. What do you think nightforce 5,5-22*56 or 3,5-15*56? my opinion is that they are no very good in lowlight conditions ?

 

I don't know if SWFA is able to ship to your area or not, but I would personally get either the #40 or #60 illuminated reticle in the Zeiss.

http://www.swfa.com/showcategory.aspx?categoryid=310&sb= Name&so=asc&page=2

Where did you get the idea that Nightforce scopes are no good in low light?  Their optics are pretty good in low light, but not quite as good as Zeiss, S&B, and Swarovski, in my opinion.  I believe their illumination system isn't the best design because the entire reticle is illuminated, which can overpower the target unless you set the brightness to an extremely low setting.  Setting the illumination brightness isn't very convenient at first because you have to remove the side focus knob and adjust the rheostat with a small screwdriver.  Then, you are limited to only 1 brightness setting.  The biggest problem I see with those two NF scopes for hunting is they are unnecessarily large for an all purpose hunting rifle, and you don't need tactical style turrets for hunting, which can get hung up on obstructions.  Of those two, the 3.5-15-56 is better suited to your stated average shooting distances than the 5.5-22X56, but both have way more magnification than really needed for short distance shooting.

Ted


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Post Options Post Options   Thanks (0) Thanks(0)   Quote Hunter111 Quote  Post ReplyReply Direct Link To This Post Posted: May/07/2007 at 09:20
Ok thanks for answeres.

But whenwe talk a little bit NVS optics. What are good models and what to buy with reasonable charge.
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