Rear Iris with opening less thn 0.5 mm

[nemo]

Greetings all,

does such an iris exist?

Kindest regards,

N

[Piefou]

Hi,

Current irises sold by Gehmann and Centra are 0.5-3.0 or 0.8-1.8.

At first i bought only 0.5-3.0 by thinking "hey free adjustement range, nice".

But if you have to be consistently under 0.8mm, there is a problem, and just getting a smaller iris will just be (relatively speaking) harmful to the eye. Same for getting over 1.5mm.

Adding a light grey filter to reduce light, bring closer the front sight to seeing it bigger, duplex for centering ...

Why are you looking for a such small iris ?

[batty]

holy moley! why would you want an iris that small?

[Tim S]

holy moley! why would you want an iris that small?

Hobbits? Mrs Pepperpot?

[batty]

holy moley! why would you want an iris that small?

Hobbits? Mrs Pepperpot?

Borrowers you mean!

[40xguy]

nemo: everyone's eyes are different. don't let someone else tell you what you should be using. do your own experiments and trials and see what works best for you. this is not a "one size fits all" situation. wish you good shooting !!

[1813benny]

Nemo
I don't recall ever seeing one with the smallest opening under .5, however there may be an option to move the rear sight closer to your eye.

Regards
ken

[WingsFan]

holy moley! why would you want an iris that small?

I've turned mine down that small occasionally. Bright clear day with the afternoon sun shining on your target at 50feet.

[nemo]

Greetings all,

thank you for your answers confirming that 0.5 mm is the smallest opening.

Bright clear day with the afternoon sun shining on your target at 50feet.

That is my daily condition, except target at 35 feet. Maybe a filter?

Kindest regards,

M

[ShootingSight]

An aperture that is fixed is easy enough to make, especially if you start with an existing aperture - solder in a piece of thin shim stock, then put it on a lathe and drill it. Drills that small are easy to find.

I would not use a filter. If you have extra light, you may as well use a smaller aperture, so at least you get a benefit in focus for the light you are giving up.

With the exception of perhaps a pale yellow filter, to get rid of UV light, filters will reduce light without giving you an optical benefit.

[batty]

I wrote a guide on how to set up your rear sight placement and your iris. You can find it here https://www.etsy.com/uk/listing/7741927 ... nager_grid

[rlporter507]

two things are going on with the rear iris. depth of focus, and contrast. the iris setting adjusts the depth of focus, while affecting the contrast of front sight and target. a setting of below 1.1mm is to small for most people, but as another said, there are exceptions. setting the rear iris below 1.1 also reduces the amount of target area that is seen. on those occasions when the light is so bright i believe turning the iris down to far is not good. a balance of focal length to see the front sight, and a filter to reduce light for better contrast is a better option. another option if the use of filters is not desirable, is another iris in front of the rear sight, in the sun shade, to reduce light. all that said, a huge amount of time must be spent experimenting with iris size, and filter color to achieve the best combination for your eye.