Hi all,
Looking to get a new Rear Iris for my Prone rile, just wondering should I get a Polarised Iris or not. Can anyone tell the pros & cons of a polarised rear iris.
Kim.
PS. I shoot mostly outdoors, Summer & Winter.
Polarise Rear Iris
Moderators: pilkguns, Marcus, m1963, David Levene, Spencer
Hi Kim,
I use polarizing filters in my rearsights for outdoors - I find that one filter on its own can be rotated to take the glare off any distracting reflections I'm getting from the foresight or barrel (which is sometimes useful on sunny days).
The second filter is then worked against the first to cut the overall light level down in a continuously variable manner giving an adjustable grey filter.
One of my clubmates insists that a polarizer can reduce the effect of mirage - he uses one on his telescopic sight for long range, high power shooting - but I'm not convinced about that myself....
The "con's" are - there are two more bits of glass in the optical path to keep clean.
Cheers,
Ken.
I use polarizing filters in my rearsights for outdoors - I find that one filter on its own can be rotated to take the glare off any distracting reflections I'm getting from the foresight or barrel (which is sometimes useful on sunny days).
The second filter is then worked against the first to cut the overall light level down in a continuously variable manner giving an adjustable grey filter.
One of my clubmates insists that a polarizer can reduce the effect of mirage - he uses one on his telescopic sight for long range, high power shooting - but I'm not convinced about that myself....
The "con's" are - there are two more bits of glass in the optical path to keep clean.
Cheers,
Ken.
Another way to look at it, no pun intended. I debated about a polarized rear sight iris and ended up with a Gehmann double.Found that for various reasons i didnt like it and promptly sold it for a big loss.I now use,though seldom a front sight screw in,comes in both single/double.This maybe an alternative way to see if its works for you at a fraction of the cost.Like Kennyb says its basically just a grey filter.
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If you decide you would like one, let me know. I have one and like it but I've gone to using a green filter on my glasses. mobarron@charter.net
The polarizer lens is not an ordinary grey lens. It can appear to be a grey lens and when used in cojunction with a second polarizer does indeed mimic the effect of a variable grey lens, however its primary use is to cut down strong directional light (or glare) without proportionally reducing total light. It does reduce overall light some especially in pairs. Many irises include an additional grey lens with the two polarizers. As stated before it pretty much just gives more light adjustment options with the attendant complexity and expense. I do not often use mine, but sometimes I need every bit of help it can wring out. I have not experienced problems with mine.
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ShootingSight
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Bad idea. These are gadgets that rarely have a place in shooting.
They are a waste of light. Polarizers range from a 30% loss of visible light for yellow (which also has the least amount of polarizing effect), up to a 70% loss for grey polarizers.
Well, if you can afford to give up that much light, a much better alternative is to reduce your aperture size to improve your depth of field.
Unless you are shooting funky metal plate, the target is buff and will have no glare, and the front sight is viewed in silhouette, so there are no reflective surfacess to give you glare there either.
If you are hunting water fowl, and will likely get glare off the water surface, that's great, but I suspect not many hunters are using target sights.
Now, another solution might be to try and make a front iris out of polarized material. That way the target and the white ring surrounding it is viewed through a hole in the filter, so there is no loss of light, and the peripheral image seen through the front sight has the benefit of polarization. Then add a sunshade to the front end of your sight to reduce glare coming off the barrel.
I reccomend getting black athletic taps, or self adhesive velour and cover up any surfaces that are giving you glare, rather than sacrificing that much light that you need to form a clear sight picture.
They are a waste of light. Polarizers range from a 30% loss of visible light for yellow (which also has the least amount of polarizing effect), up to a 70% loss for grey polarizers.
Well, if you can afford to give up that much light, a much better alternative is to reduce your aperture size to improve your depth of field.
Unless you are shooting funky metal plate, the target is buff and will have no glare, and the front sight is viewed in silhouette, so there are no reflective surfacess to give you glare there either.
If you are hunting water fowl, and will likely get glare off the water surface, that's great, but I suspect not many hunters are using target sights.
Now, another solution might be to try and make a front iris out of polarized material. That way the target and the white ring surrounding it is viewed through a hole in the filter, so there is no loss of light, and the peripheral image seen through the front sight has the benefit of polarization. Then add a sunshade to the front end of your sight to reduce glare coming off the barrel.
I reccomend getting black athletic taps, or self adhesive velour and cover up any surfaces that are giving you glare, rather than sacrificing that much light that you need to form a clear sight picture.
I somewhat disagree with the last entry regarding the benefits of a polarizer. I used a polarizer almost always, usually also with a yellow filter, while on the national team for 10 years, shooting many world cups and on one Olympic team. I agree that many at that level do think polarizers aren't good due to the reduced light. My eyes, however, seem to like lower light. But I've never used two polarizers at the same time. But for me, I got the best contrast and sight picture usually with one polarizer and yellow filter, both indoors and out.
A lot of paper targets do reflect light, especially in the black area if it's heavily printed (Edelmann targets do, at least to my eyes). And adding the polarizer most definitely helped me get a better sight picture.
What I'm getting at is that it's a personal preference and people see things differently. It may be a bad idea for the previous person who posted a comment, but for me a polarizer was a necessity. But also, just slapping on a polarizer can be almost useless unless you spend the time to figure out how to use it properly and where to orient the lines of polarization to reduce glare.
You should first find out if you really need a polarizer. If you know glare is an issue for you, based on extensive range training, then I'd say get one. If you think you need one just because it happens to come with the iris or you see others using it, you probably don't need one.
A lot of paper targets do reflect light, especially in the black area if it's heavily printed (Edelmann targets do, at least to my eyes). And adding the polarizer most definitely helped me get a better sight picture.
What I'm getting at is that it's a personal preference and people see things differently. It may be a bad idea for the previous person who posted a comment, but for me a polarizer was a necessity. But also, just slapping on a polarizer can be almost useless unless you spend the time to figure out how to use it properly and where to orient the lines of polarization to reduce glare.
You should first find out if you really need a polarizer. If you know glare is an issue for you, based on extensive range training, then I'd say get one. If you think you need one just because it happens to come with the iris or you see others using it, you probably don't need one.
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ShootingSight
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- Joined: Fri May 18, 2012 9:37 pm
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As I said, if you are in a situation where you are getting glare off a target, polarizers could be appropriate. In my years of shooting, I have just never run into it, which is why I assume it is rare that a polarizer is necessary.
Now, a yellow filter is another matter. UV light, which is not visible, yet still irritates the retina will flood the eye in the long wavelength range. Typically, Polycarbonate will block 99% of UV up to 400nm, though there is still enough that gets through to cause a loss of contrast. Adding a pale yellow filter will block light up into the 420nm range, so you lose a little blue (yellow is the opposite of blue), but you lose all of the UV, and contrast is improved.
Now, a yellow filter is another matter. UV light, which is not visible, yet still irritates the retina will flood the eye in the long wavelength range. Typically, Polycarbonate will block 99% of UV up to 400nm, though there is still enough that gets through to cause a loss of contrast. Adding a pale yellow filter will block light up into the 420nm range, so you lose a little blue (yellow is the opposite of blue), but you lose all of the UV, and contrast is improved.
Low angle sun washes out the buff A-51 6 bull target at my range enough for me to notice and use the polarizer. The yellow filter is the predominate filter after clear in terms of my usage. I have never needed the polarizer indoors and expect that indoor conditions requiring one are rare. But all that being said with the polarizers integration in the iris, one click and its gone, so I can't say it was ever a negative for me. Everyone has different eyes and different gear philosophies though. Good luck whatever you decide.
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KatoomDownUnder
Art, you need to come over here and shoot on a range that faces west. The back flash in the morning is full on.ShootingSight wrote:As I said, if you are in a situation where you are getting glare off a target, polarizers could be appropriate. In my years of shooting, I have just never run into it, which is why I assume it is rare that a polarizer is necessary.
Now, a yellow filter is another matter. UV light, which is not visible, yet still irritates the retina will flood the eye in the long wavelength range. Typically, Polycarbonate will block 99% of UV up to 400nm, though there is still enough that gets through to cause a loss of contrast. Adding a pale yellow filter will block light up into the 420nm range, so you lose a little blue (yellow is the opposite of blue), but you lose all of the UV, and contrast is improved.
Pete