Rifle Scopes flashkillers and light transmission

[Dsparil]

does a flashkiller at all diminish the amount of light that a scope can transmit? does it kill clarity at all? I'm planning on getting a 6-24x scope for my zastava and the sunshade from vortex, imo, is obnoxiously long, was thinking of using the flashkiller instead of the sunshade.

 

[sirhrmechanic]

Re: flashkillers and light transmission

Shades vs. ARD's more or less do two different things.

The sunshade keeps the sun from washing out your sight picture when bright light comes into the tube at an angle. Shade ensures that the light entering the scope is coming from the target, and that your scope is not gathering light from the sun or off-angle sources. The shade can actually improve your scope's perceived performance under lots of circumstances.

The flashkill/ARD is intended to prevent your scope lens from reflecting light back to a target. Any ARD that occludes the objective lens will reduce brightness somewhat.

If you are hunting or target shooting or shooting competition, you will likely benefit from the sun shade. You really only need the ARD for environments where the targets are shooting back.

Cheers,

sirhr

 

[AlabamaShooter]

Re: flashkillers and light transmission

I killed the two birds with one stone, I have 2" sunshades + ARD's on my two USO's. My eyes cant tell if there is a real difference in clarity/brightness with it on or off. But that being said it seems to make a difference on those really bright days, less eye strain as I am a tad bit light sensitive. Plus I do like the sunshade/ARD combo because it does add a little protection for the objective lens of the scope if you dont have a flip cap cover on it. Plus as much as I hate to admit it, I do think they look good

 

[Chiller]

Re: flashkillers and light transmission

Have both and my eyes do tell a difference. For what I do the sunshade is worthwhile.

 

[AUJohn]

Re: flashkillers and light transmission

ARD's MUST block some light and can have other mild effects. Use one if you NEED it or want to be in fashion.

Sunshades solve mutiple problems and offer additional protection from conditions like rain. All my scopes that can be fitted with them, have them and they never come off (other than lense cleaning).

 

[kmussack]

Re: flashkillers and light transmission

Antireflection Devices (ARDs) and Sunshades do exactly the same thing. Each increases the amount of tunnel that off-axis light must pass through to reach the objective lens. Length to diameter measurements of either an ARD or a Sunshade can be expressed as an aspect ratio.

For instance; a Sunshade with an inside diameter of 2-inches and a length of 4-inches has an aspect ratio of 1:2. An ARD that has a honeycomb consisting of 1/8-inch “diameter” cells that are ¼-inch long has the same, 1:2 ratio.

The downside of an ARD is that some light is obstructed by the shadowing from the honeycomb. The upside to and ARD is that a much higher aspect ratio can be achieved with a much shorter assembly. A typical ARD with 1/8-inch “diameter” cells that are a full 1-inch long provides an aspect ratio of 1:8 whereas a 2-inch diameter Sunshade would need to be 16-inches long to provide the same aspect ratio.

The greater the aspect ratio the more off-axis reflection is prevented.

Neither device can protect against light reflection from a source which is in the field of view or “on-axis”.

An additional benefit of an ARD is that it can enhance concealment by painting it a light “earth” color thereby mitigating the “black-hole” effect (a target indicator).

 

[Rafael]

Re: flashkillers and light transmission

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kmussack</div><div class="ubbcode-body">Antireflection Devices (ARDs) and Sunshades do exactly the same thing. Each increases the amount of tunnel that off-axis light must pass through to reach the objective lens. Length to diameter measurements of either an ARD or a Sunshade can be expressed as an aspect ratio.

For instance; a Sunshade with an inside diameter of 2-inches and a length of 4-inches has an aspect ratio of 1:2. An ARD that has a honeycomb consisting of 1/8-inch “diameter” cells that are ¼-inch long has the same, 1:2 ratio.

The downside of an ARD is that some light is obstructed by the shadowing from the honeycomb. The upside to and ARD is that a much higher aspect ratio can be achieved with a much shorter assembly. A typical ARD with 1/8-inch “diameter” cells that are a full 1-inch long provides an aspect ratio of 1:8 whereas a 2-inch diameter Sunshade would need to be 16-inches long to provide the same aspect ratio.

The greater the aspect ratio the more off-axis reflection is prevented.

Neither device can protect against light reflection from a source which is in the field of view or “on-axis”.

An additional benefit of an ARD is that it can enhance concealment by painting it a light “earth” color thereby mitigating the “black-hole” effect (a target indicator).
</div></div>

Well said, Kevin!
I agree completely.

 

[kmussack]

Re: flashkillers and light transmission

This is an example of an ARD painted to mitigate the "Black Hole Effect".

 

[Rafael]

Re: flashkillers and light transmission

I will agree with the earlier post that all ARD's are not equal.

I had a Tennebraex(spelling?) that reduced brightness considerably. Gave it away.

The USO ARD I have on my SN-3 uses much thinner material and I cannot tell the difference with or without it. I leave it on all the time.