Is this iris useful?

[MrChipShoulder]

Thank you for the replies

I have two problems I have to work around for my bell target shooting. One is how bright the lit target is, it can vary quite a bit, as a team we shoot on about 10 different targets (maybe more), all differing internal light and with differing lighting in the rooms as well. The other problem I'm still trying to work around is the white or black backgrounds they use.

My own team use a target with a white background and that s fine as the outer ring of light in the sight picture is fine on the white background. But quite a few others use a black backgrounds including my 10M target club. I really struggle on the black backgrounds as the outer ring of what should be white light is not there , so you only get the inner sight picture with the black target dot.

The way I've dealt with the black bell target background thus far is to wind rear iris all the way to the smallest aperture. When like this, as luck would have it, the iris is the same size as the fore sight so that when the sights are perfectly lined up, you only see the centre. If the sights are not lined up, you get portion of light breaking through, so you know that when there is no outer light, the sight is lined up correctly. I'm sure this can't be right, but it's the only thing I've found so far that kinda works.

The problem is even worse at my 10m club as the whole target back stop is black with all sorts of deflection plates and rubbish around each target card. The outer ring of light in the sight picture is all broken up with differing shades of blacks and greys. Personally I'd say this situation is unshootable as I can't use my smallest iris trick as there is no light around the card to brake through, it's just blacks and shadows.

I have got around the above situation with my daughters comp cards at the 10m club by making a removable white cloth background for her. Once the white sheet is behind the target, the problem goes away and she can get a normal outer ring of light in the sight.

In the case of the bell target, I could simply open the iris right up to get a very large outer ring, but then I'm looking at all sorts of lighting and shadows, plus the inner dot can get fuzzy (due to too much light I assume?) and it would be hard to centre accurately. At the 10m club, you cannot do anything as the whole backstop is black regardless.

I have been thinking one fix for the bell target would be a much smaller fore sight tunnel, maybe 10mm rather than the standard 18mm? This would stop the fore sight taking up all of the lit target aperture and then allow the outer light ring to brake through, thus giving a 'standard' sight picture??? Or perhaps one of these with a custom made smaller outer ring to close the outer black ring (I can make then with no problems).

https://ibb.co/7nXMnzz

Here is a picture I took a few weeks ago of the black faced bell targets I shoot on at comps.

https://ibb.co/W32VkLB

Here is a picture of our 10m clubs black backstop.

https://ibb.co/kab77q

Any thoughts would be very much appreciated as I have no idea what is best or expected?

Sorry for the long post.

[tim s]

That's an interesting fix. I'd make two suggestions.

Don't open the iris to increase your field of view. You adjust that through your eye relief. The iris is there for adjusting the brightness of your sight picture; open it a little for darker ranges.

A really small foresight tunnel will be dark. 10mm is really small. Even the old pre-war BSA/Parker-Hale tunnels were over 10mm internally.

The backstop for 10m air shooting should be pale.

[RobF]

If you open the iris be aware that it will reduce your depth of field, you'll see the target blurred more in comparison to the foresight. It will give you more light though. Can't have both, and the opposite is true if you stop the iris down.

Polarisers don't work indoors because incadescent light isn't polarised. Outdoors they reduce glare because the sun sends out polarised light.

As robin says a 1-1.8 iris should do the trick. A yellow filter is about the only useful additions I can think of.

[MrChipShoulder]

Awesome guys, thank you.

So what one of these should I buy :-

This
https://www.intershoot.co.uk/acatalo...-Iris-431.html

This
https://www.intershoot.co.uk/acatalo...is-510-28.html

Or this?
https://www.intershoot.co.uk/acatalo...is-566-33.html

Thanks.

[PhatMan]

MrChipShoulder,

For me, I would have :

#1 Centra 1.8 Crystal https://www.intershoot.co.uk/acatalo...-Iris-431.html

#2 Centra 1.8 Basic https://www.intershoot.co.uk/acatalo...-Iris-644.html

I doubt whether you would ever need an aperture greater than 1.8 mm.

Have fun

Best regards

Russ

[MrChipShoulder]

I'll go for the Centra 1.8 Crystal, thanks,

What made you chose the Centra basic over the Gehmann basic iris just out of interest?

[PhatMan]

MrChipShoulder,

The Gehmann Basic (Anschutz Basic 9775 is the same iris, made by Gehmann) gives range 0.5 --> 3 mm - I do not need an aperture to open so large.

The Centra Basic 1.8 gives range 0.5 --> 1.8 mm, which is the range I most need for target shooting.

I do have the Anschutz Basic 9775 on two (2) of my field rifles, as I sometimes need to use a very large aperture when conditions are gloomy - my field rifles are fitted with 3mm front posts.

Have fun

Best regards

Russ