optics

[salar600]

Today I shot ISSF 50M outdoor with contact lenses and right after with shooting glass. It makes me realize that when I use shooting glasses with -4.50 dioptres instead of contact lenses, the target looks smaller.

Is it possible to change the lense of my glasses to have the same sight picture?

Thanks

[Martin H]

Hi
Although you have the same prescription in both your contacts and your shooting glasses lens, the reason the target image lookers smaller with your shooting lenses is that the lens is a large distance from your eye compared to your contacts.
As you move minus prescription lenses away from your eye (increase the vertex distance) the target image will become smaller and smaller.
Your contacts are very close to your eye compared to your glasses lens and therefore the target image will be noticeably bigger.

If you use shooting glasses with minus prescription lenses (short sighted) you should ensure the lens is as close as possible to your eye to get the biggest possible target image.
Cheers
Martin

[salar600]

Well, you described the phenomena very well.

If there is no way to change the lens to compensate for that (magnification or something else) you make me think about changing my shooting glasses frame...

Thanks, Mart

[bdutton]

You could get a prescription lens and attach it to your rear sight. Shoot with that all of the time.

Use contact in your non shooting eye for looking at the spotting scope.

[salar600]

Ya, looking at this option to.
Thanks

[ShootingSight]

To increase the size of the target you would need to use two lenses in your glasses to effectively create a Gallilean telescope. This is how the adjustable focus apertures work, and they produce about a 1.5x magnification. Not sure that double lenses in your glasses is legal though.

[salar600]

Interesting. I will have to investigate this thing. Do you have something I could read to understand that?