Sunny vs. Overcast sight picture?

[Skychief]

I need a reminder on this.......

What are the point of impact differences in Sun versus Shade?

  Skychief.

[northmn]

None if your sights are darkened.  The front sight tend to be the problem, especially the shinny silver ones.  Glare off the top can make them shoot low and often the glare on a side will make it shoot to a side as in movement of the sight.  If you tap a front sight to the left it will shoot to the right, which is essentially what the glare does.  Notice later target rifles had hooded sights.  I have seen pictures of flintlocks with full length hoods over the barrel.  One little trick we used to do for a shinny front sight was to rub a little BP fouling on it to get it to corrode a little to eliminate the glare.

DP

[Skychief]

Hmmm........

Thanks northmn.

Let's just say that the shooter's rifle is wearing shaders on both sights.

Anybody else?    Where's a chunk or silhouette shooter when ya need 'em?

 

[Daryl]

DP's correct. Indeed- depending on how thick the top of the rear sight is, ie: flat surface, it-too can give a lot of grief in sunny conditions due to hazing. With a glowing front sight and a bright fuzzy rear sight, detains as to the sides of a notch, top of the rear flat and where the middle of the front sight is become mere guesswork.  With a sourdogh front sight, rounded top to bottom and side it side, the aiming error multiplys.  A fat surface to the rear presents less error than a  rounded one. The top of the rear sight should be angle down, so there is more of a sharp edge toward the shooter.  It must be dull, not shiny - 'corroded' as DP puts it with one method.

Rubbing on gun cases over time can cause front and rear sights to become smooth and 'shiny' on their edges. Periodically touching them with a browing solution (or fouling) can keep them dull rather than presenting like mirrors when the sun is shining.

[Skychief]

Maybe I should have worded my original post differently.   I am not asking about sun/shade effect upon the sights themselves.   Let us imagine that they are protected by shaders.

Sun/Shade will make distant objects appear to move vertically.

If you want to see for yourself you can.    Mount a scope in a way that it can not move (on a workbench, shooting bench, etc).   Have the crosshairs trained on a small and distant object that will not move (rock in a field, small print on a billboard, whatever).

Note when aligning the crosshairs precisely on said object the amount of sunlight.  Check the crosshairs in full sun and dark overcast conditions.   It will appear that either the crosshairs and/or the object moves back and forth vertically, when they have not.


I am suprised some have not heard of this.

Skychief.

[Dphariss]

Maybe I should have worded my original post differently.   I am not asking about sun/shade effect upon the sights themselves.   Let us imagine that they are protected by shaders.

Sun/Shade will make distant objects appear to move vertically.

If you want to see for yourself you can.    Mount a scope in a way that it can not move (on a workbench, shooting bench, etc).   Have the crosshairs trained on a small and distant object that will not move (rock in a field, small print on a billboard, whatever).

Note when aligning the crosshairs precisely on said object the amount of sunlight.  Check the crosshairs in full sun and dark overcast conditions.   It will appear that either the crosshairs and/or the object moves back and forth vertically, when they have not.


I am suprised some have not heard of this.

Skychief.

Its called mirage. It WILL effect bullet impact since the target can appear to be higher than it really is.
Wind of sufficient velocity will blow the mirage flat and negate its effect.
But light winds can cause the target to appear higher and downwind. IE perhaps at a 45 degree from its actual position.

If the sights are shaded they are no effected by sunlight.
How a shooter SEES can be a factor. I can see sights better on bright days than drab days shaded or not.

Dan

[flintriflesmith]

There is also a difference, with iron sights, in how large the black bull appears on the white paper in various light conditions. That makes a bit of vertical difference in impact espectially if you are shooting a 6 o'clock hold.

In using a 6 o'clock hold with a "line of white" between the top of the sight and the bottom of the bull the changing amount will also effect the picture.

Gary

[Candle Snuffer]

This is why a person's first shot is so important and you must remember exactly what you did and where you held in case you need to make mental windage and elevation adjustments at the firing line.  

The first shot (let's say in a string of 5 shots) will tell you everything you need to know for the remaining 4 shots provided conditions have not changed within that time period of the remaining 4 shots.

Iron fixed sight shooters deal with these conditions all the time - probably more efficiently then any other shooter's using a, scope, peep, and even an open iron adjustable sight.  This is why shooting in all light (and weather) conditions are so important.  

It is important as you may not always have access to sight shader's (should the need present itself and they would happen to be allowed in a particular competition), plus,,, learning these conditions you may find yourself shooting in and how to deal with them without the aid of anything but your "unshaded" sight set up will make you a far more knowledgeable shooter.

So practicing in all light and weather conditions is time well spent with your chosen firearm.

Just my two cents worth.  

[roundball]

Amen to the effects of sunlight on sights...the little private range I use on the weekends has a simple concrete bench under an open pole shelter...great for staying dry when its raining and it keeps the hot sun off me during the summer here.

BUT...getting there at first light as I do, the rising sun streams in from my left and lights up the sights so bad that when I'm sighting in or checking a particular load for accuracy, I have to tack up an old blanket on that side so it hangs down and blocks the sun.

[Scott Bumpus]

Old saying in highpower match shooting ( all iron sights)  lights up sights up, lights down sights down.

[northmn]

One of the things about the primitive fixed sights was that once sighted in we left them alone.  I used to remember seeing folks using production guns with their adjustable sights chase the settings around during different conditions.  I always wondered if they ever had a rifle sighted in.

DP

[Skychief]

Old saying in highpower match shooting ( all iron sights)  lights up sights up, lights down sights down.

Thankyou Mr. Bumpus!

[Dphariss]

Old saying in highpower match shooting ( all iron sights)  lights up sights up, lights down sights down.

Thankyou Mr. Bumpus!

HP shooters also shoot farther than you would with a ML and have different sights as well. The farther the range the more important this is. Changing light during a match can be a real PITA unless the shooter has a lot of experience.
If the sights are barley corn or similar of brass or silver bright light may result in your shooting low since the sight will be much brighter and will look bigger in some light conditions.
So the sight that works best in moderate/low light and on dark animals is worse for shooting targets in bright light than a square backed sight made of blues iron or silver painted black.
AND
It depends a lot on the individual's eyesight.
This alone makes it difficult for someone to make the perfect open sight for another shooter.

The sun on the sights problem is why you will see original flint match rifles with full length sight shades.
But in my experience a black sight, iron or hooded, is a very poor choice for dark animals like Bison but its perfect for matches unless shooting at a white aiming point on a charred board.

Dan

[Daryl]

Bright silver or brass in blades or beads are the best open sights for hunting and targets. They are bright when there is little light, and with the swipe of a dry erase felt pen or spray of sight-black, they are dull black and non-reflective for bright targets.

Mirage is nasty- but not so much ar BP ranges.  It's scopes of higher powers that cause the most problems with mirage - and mostly past 100/200 yards.