Lighting variations and adjusting impact point

[wasatch]

At a recent match the lighting was brighter than what I usually practice with, not just the target area but overall lighting was brighter. The target seemed more distinct--less blur, because (i think) my pupils were smaller resulting in greater depth of field.

During the prep period, after dry & live warmup, I shoot 5 shots w/o checking impact to see where I'm grouping (I think that if i check each shot I may attempt to adjust). So I just shoot the 5 shots, then check group, and adjust from there.

Under the brighter lighting conditions I was grouping higher than when I practice with lower light. I think this is because with lower light my pupils are larger resulting in less depth of field and more blur. The blur making the black appear somewhat larger. Without the blur, my sub-six hold is a bit higher. Does this sound reasonable?

in this situation should I try to adjust my hold or adjust my sights? Probably answering my own question here, but I tried adjusting my hold this time. After the match I scanned my targets using TargetScan and it showed that for the match the centroid of my 60 shots was indeed high and i had missed out on some points. So its seems difficult to undo my training to adjust hold and I should've adjusted my sights.

[scerir]

1) Better adjust the sights, I think.
2) The white space (sub-6 area) appeared brighter than usual, so you reduced this white space (sub-6 area) and your grouping was different than usual.

[Rover]

Maybe....but then it could just be you.

[Coolmeester]

Just adjust the sights. It's completely normal.

[ShootingSight]

If you were shooting without the aid of an artificial aperture, you nailed it.

Brighter light = smaller pupil = greater depth of field = less blur line around your target and your post = smaller target bull and shorter post = holding high because the white line is brighter and looks fatter.

Something to consider: add a piece of electrical tape or self adhesive aluminum with a 1/16" (or smaller) hole on the front of your shooting glasses to look through. Your pupil is about 1/8" in bright light, larger in dim light. Using the 1/16" will not only cut your blur in half (blur is proportional to aperture diameter), but it will give you a consistent aperture size, so if lighting changes, your elevation will be stable. If you want such a sticker, email me art@shootingsight.com, and I'll drop a few in the mail for you. It's actually interesting, because you can easily tip your head slightly to compare the sight picture looking through the aperture, versus looking over the aperture, to get a perspective of the difference. It is quite astounding how much better your sight picture gets with increased depth of field.

[atomicgale]

Under the brighter lighting conditions I was grouping higher than when I practice with lower light

Wasatch, I'll support your theory. In the bright light, the "white" on the Sub-6 hold appears (to me) much more distinct i.e. more "BOLD", and thus a higher natural hold. Instinct narrows down that gap in bright light.

For example, I'm set up to practice in my driveway. The target will range from (1) dim, to (2) in the shade, to (3) in the shadow of a tree with mixed - sunshine & shade, to (4) in direct sunlight. Every time in the direct sun, that Sub-6 hold tights up & strikes go relatively high. Now, other side effects in direct sun include that the target is defined, and the front sight goes "fuzz."

Second example - MIXED LIGHTING: Recent local competition in a gym, overall lighting so dim the front sight went to hell in a hand basket. Then they had a 100-watt incandescent light directly over the target. Sight pic? All target, no sight. Bad results.

Proposed solution for next time? (And Rover will love this!!!) Use up my first pellet to shoot out the light!!! Take the "ZERO" and adjust from there . . . . just a thought.

[BobGee]

Small apertures are all good until you cop a cataract!

Bob

[wasatch]

Thanks Art. I'll try making a 1/16" aperture, maybe out of some removable masking tape to keep the ambient light level, similar to a translucent shade over non-shooting eye. I have a multi size leather punch that ought to make a nice hole.

I've tried using an iris and found it distracting, interfering with drawing down on the target.

Also improved my home target lighting... put a large white background behind my target and I bought a cheap 1100 lumen LED flashlight to light the target. I was having the same problem as atomicgale.... bright target surrounded by dark backgound. This alone has reduced the perceived blur size.

[Brian Girling]

Confucius he say:- "Light up - shots up."

First thing I learnt 55+ years ago.

[C. Perkins]

I try to keep it simple.
My sight picture always stays the same, it is what my eyes/mind sees.
Do not try to readjust your sight picture, it would be like using Kentucky windage on all your shots, bad idea.
Sights have these things that you can twist and turn; use them.
Just my .02 cents

Clarence