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Aiming Question
Posted: Thu Jan 03, 2013 5:20 pm
by scairns
Sorry if this has been asked, I simply can not find the information I am looking for. When aiming the rifle I am concentrating on the front site, however it is not possible for me to focus on the whole front aperature. I feel like I am defocussing slightly to be able to "take the whole front site picture into consideration"... What do some of you good air rifle shooters see when looking down your sights. What is in focus and what is not. Where is your full attention focussed.
Thanks for any and all help - it is for me, as well as some juniors I am coaching - my stock answer, focus on your front sight seems a little lame to me when I am confused about it myself.
Scott
Posted: Fri Jan 04, 2013 12:59 pm
by RobStubbs
Classically you are right, the foresight should be in sharp focus. Other elements (rearsight 'peep hole' and target), should therefore be out of focus slightly. Some folks advocate getting your eyesight corrected to fovus just infront of the rearsight, i.e. slightly in the direction of the target.
Rob.
Posted: Fri Jan 04, 2013 1:14 pm
by Tim S
As Rob said, the ideal is to have the foresight in sharp focus. Depending on your eyesight the target is then anything from almost sharp to a fuzzy grey blob.
If you aren't able to focus on the target comfortably, you may need a corrective lens to do so. I'm long sighted, so it's naturally more comfortable for me to focus on the target. When I started shooting I could aim fine thanks to very good acuity, but as I aged this got harder and I found myself having to mentally chose to focus on the foresight. A trip to a good optican got me a lens that did this for me. I'm now in my 30s and on my third lens.
I'd suggest going to a good optician for a checkup. You may need to take your sights/rifle with you, or have a chat beforehand about your specific needs. Non-shooting opticians often think all you need is good long-distance vision, whereas you actually want a focal distance a wee bit ahead of the foresight (my shooting prescription is +1.5 compared to a normal one of +1.0).
Posted: Fri Jan 04, 2013 1:41 pm
by scairns
Thanks Ron and Tim!
Posted: Fri Jan 04, 2013 2:36 pm
by gstarik
Scott,
What is the size of your rear aperture?
The rear iris has two functions: one is the depth of field,and the other is the amount of light coming to your eye.
The smaller the aperture,the better is the depth of field,but a darker sight picture.
You must find the right combination for you in each kind of light.
Usually,the rear aperture will be between 1.15 to 1.4mm. Indoors,usually 1.25 and up to 1.45.
The more light,the smaller the aperture and vise versa.
Guy.
Posted: Wed Jan 09, 2013 4:11 pm
by scairns
I have an adjustable rear aperature which I set as small as possible, to still allow a clear sight piture. Your collective responses got me thinking, and I adjusted my rear sight to eyeball distance (made it longer). THis seems to have solved the problem- at least I have shot a couple of excellent (for me) scores this way. Looking at some other threads, I may try a extra .5 to .75 diopter correction, to see if this helps make the FS focus a little more natural.
Thanks again for the help!
Scott
Posted: Thu Jan 10, 2013 7:29 am
by BobBarber
This may sound elementary since there are many fine points, but, okay, this worked well for me in High School smallbore competition, two national championships with an Anschutz 1413, Iris rear sight adjusted for decent light, but minimum diameter, clear plastic front aperature in either the stock Anschutz front sight or a Freeland front sight. I also used a blinder flap? for my left eye so I would not have to squint.
1. Get a good position and hold on the target.
2. Perfectly center the front sight in the rear sight aperature.
3. Then, without moving much, concentrating on the front sight aperature, perfectly center the the target in the front sight aperature.
4. Squeeze the trigger.
Most Important: In both 2 and 3, pay attention to the light ring around. It should be equal all the way around.
This all becomes second nature really quick, and you don't have to think about it. You just do it every time.
Posted: Fri Jan 11, 2013 3:14 am
by RobStubbs
scairns wrote:I have an adjustable rear aperature which I set as small as possible, to still allow a clear sight piture. Your collective responses got me thinking, and I adjusted my rear sight to eyeball distance (made it longer). THis seems to have solved the problem- at least I have shot a couple of excellent (for me) scores this way. Looking at some other threads, I may try a extra .5 to .75 diopter correction, to see if this helps make the FS focus a little more natural.
Thanks again for the help!
Scott
Some thoughts..
As small as possible isn't ideal for the rearsight iris. Most say start at 1.1mm amd move slightly from there to see what works best for you. Too small lets less light in, can give a greater depth of field and can distort the image. You will find that around the edges of the iris the view goes fuzzy. The smaller the iris the more of that fuzziness, is in the sight picture.
For coaching new shooters I'd personally start with 1.1, perhaps very slightly bigger and leave it alone until they'd mastered the position. New shooters will struggle getting a consistent head position and eye relief so don't make things even harder for them.
Rob.