Page 1 of 1

Having trouble focusing on front sight

Posted: Thu Aug 12, 2010 5:57 pm
by 10meter fan
I'm having trouble focusing on my front sight. When I do focus on it, I usually focus on a point somewhere on the top, causing my shots to go high. I think this is because it makes it look like there is less white between the top of the aperture and the target than there really is. What am I supposed to be focusing on when I use a globe front sight?

Also, how do I measure how much white there is in any direction when I focus on the front sight?

Thanks,
10 meter

Posted: Thu Aug 12, 2010 7:05 pm
by Pat McCoy
Try focusing on the bottom and see if your groups go low. What size front aperture are you using? Even when focused on the sight our vision sees a fuzzy bull. If you have too small an aperture the brain has to work the eyes accomodating between the target and sight, but with large aperture there is more light coming thru, making it easier for the eyes to stay on the sight but still see the relationship to the bull.

Posted: Thu Aug 12, 2010 11:23 pm
by mapletune
I'm a beginner so take my comments with a grain of salt~

I usually focus straight ahead. ie. I don't really stare at anything, but try to focus on the "sight picture" whole image. If that doesn't help, I just stare at the blurry target blob while keeping the ring focused.

What I found that made BIG differences were different prescriptions. I have 2 pairs of glasses and also wear contact lenses. All 3 different arrangements give me very distinct sight pictures. Some are real hard to focus on sights, other's make it seem almost natural.

So, it wouldn't hurt to look into dioptre corrections.

Posted: Fri Aug 13, 2010 1:56 am
by RobStubbs
Your focus on the foresight needs to be on the entirety of the ring. You can then centre that ring around the target, which should appear as a slightly out of focus black blob. You need a reasonable amount of white space around the target so as to be able to more easily recognise when it's centered. If you are having problems concentrating on the foresight then you would probably benefit with correcting lenses / shooting glasses.

Out of interest, what size foresight element do you have on your gun ?

Rob.

Focusing on front sight.

Posted: Fri Aug 13, 2010 6:12 am
by Fatman
Hi:
I have a similar problem and wear bifocals. My soultion was to go to the Dollar Store and try out several different magnification reading glasses.

I chose the ones that let me focus at the distance from my eye to the front sight. As this is usually low power the focus is quite broad and I find it works very well. I bought the Aviator style as the lenses are large enough for the purpose intended.

At a dollar a pop you can try several and see which works best. If you are worried about the quality of the lenses, you can still find out which works best and get a quality pair with the same magnification.

Cheers,
Fatman

Posted: Fri Aug 13, 2010 11:43 am
by 10meter fan
What size front aperture are you using?
Out of interest, what size foresight element do you have on your gun ?
I think it's a 2.8. I'd use a bigger one, but the next size up for my gun is about 3.6.

What I found that made BIG differences were different prescriptions
I probably should have mentioned this before, but I don't wear glasses or contacts, so glasses aren't messing me up.

Posted: Fri Aug 13, 2010 12:05 pm
by mapletune
what we mean is, normal vision is used to seeing things at a distance rather larger than the sight, thus focusing on something so near for so long may be awkward for your eyes.

maybe.

maybe not.

some people who don't wear glasses could benefit from dioptre correction to help them focus on near objects (sight) easier.

then again, as you say, that might not be the problem. just throwing ideas out there for people to consider~

Posted: Fri Aug 13, 2010 12:48 pm
by cmj
Might help to go to a bigger front aperature. 2.8 is really tight. A 3.6 even is still pretty tight Would not hurt to try a 4.0 or even a 4.2 front.

Posted: Fri Aug 13, 2010 6:21 pm
by Pat McCoy
I second the 4.0 to 4.2 aperture.

Posted: Sat Aug 14, 2010 5:30 pm
by 10meter fan
OK, the 2.8 aperture I'm using is in my 887 which has a 26 inch sight radius, does the 4.0 still apply?

Also, I'm using an H&R-12 for my small bore rifle, it has a 34 inch sighting radius, what should I be using here? I shoot both 50 foot and 50 meter with this rifle.

Posted: Sat Aug 14, 2010 6:02 pm
by Pat McCoy
Try the larger aperture (4.2) in the Daisy, and if it is too big go to 4.0, but much smaller is detrimental to keeping the bull inside the front sight in standing.

There is a formula, somewhere, for changes due to barrel length, but most folks just try different sizes until they get similar views with both rifles. You can sometimes go down one or two tenths of a mm in prone.

Posted: Sun Aug 15, 2010 5:09 am
by RobStubbs
Agreed with the aperture size, 2.8 is tiny. Try the 4 / 4.2 but give it a good few weeks to get used to it, but it should deffinately help.

As mentioned the glasses are not to correct your eyes, they are to make it easier for you to focus on the foresight - so they make you ever so slightly short sighted.

Rob.

Posted: Sun Aug 15, 2010 10:56 am
by peterz
My eye doc made a terrific suggestion last month: go to a cheap "dollar store" and pick up a flock of "reading glasses" ranging from +1.0 diopter to whatever your reading prescription is (say +2.25) and just try them. For $5.00 yesterday I now have a pretty good idea where she should start fitting a lens with an astigmatism correction too. And until I get that done, I've a pair of spectacles that lets me focus accurately on the front sight and only the front sight.

Probably take a few days or weeks to decide finally between the two corrections that come closest to perfect.

Posted: Sun Aug 15, 2010 12:06 pm
by 10meter fan
but much smaller is detrimental to keeping the bull inside the front sight in standing.
With a 3.6 I should definantly be able to keep the target inside the front sight in standing. Should I still try the 4s, or should I try the 3.6?

Thanks for your help everyone.

Posted: Sun Aug 15, 2010 5:18 pm
by Pat McCoy
Get rid of the 3.6. Go to 4.2 in standing. May be able to use 3.8 in prone, but most use one size to keep the brain involved with only having to deal with one sight picture.

Posted: Mon Aug 16, 2010 8:34 pm
by 10meter fan
I'll try a bigger aperture tonight, and let you guys know how it goes

Thanks for the help

Posted: Wed Aug 18, 2010 6:45 am
by robf
if you have an adjustable, or a set of sizes, simply shoot groups with each, changing the size.

See which gives you the best groups.

Then perhaps look at how other factors affect that, like longer matches, wind, light conditions.

It's just a number.

The main trend in shooters is to go too small.