AP rear sight location question

[Dr.Lee]

If we look at a Morini 162 and the Steyr LP10 from a side view, you can see that the rear sights are placed in very different locations. The Morini rear sight is forward of the wrist joint where as the Steyr is mounted further back almost over the wrist joint. Now assuming we are focusing on the front sight, the closer the right sight is to the eye, the more out of focus it becomes, plus the wider the notch appears. On my 162, I see the front and rear sight in almost equal focus. I have to think one is preferable to the other. Maybe not. Does anyone have thoughts on this or am I just splitting hairs.

Dr.

[JamesHH]

Someone once suggested the rearsight should be over the wrist joint, this way if the wrist moves the foresight moves but the rearsight barely appears to move. Its one less movement to have to think about, Its easier to juggle one ball than two.
If the rearsight is forward (or further back...) then both move.

[Dr.Lee]

[quote=JamesHH post_id=287167 time=1551306848 user_id=19050]
Someone once suggested the rearsight should be over the wrist joint, this way if the wrist moves the foresight moves but the rearsight barely appears to move. Its one less movement to have to think about, Its easier to juggle one ball than two.
If the rearsight is forward (or further back...) then both move.
[/quote]

Agreed. This is how I see this as well. My Toz 35 rear sight is mounted somewhat forward as well. I like it.

Dr.

[GaryN]

I don't have a problem with my wrist joint moving, it is my entire arm that moves.

If you move the rear sight back, for a fixed position front sight, you increase the sight radius.
Not that it makes a difference at my level of shooting.

If the notch is too wide, some sights can be adjusted for width, or you can replace the blade with one with a narrower notch

[Dr.Lee]

For me the question is not so much the notch width but the focus of the rear blade altogether. My Morini 162 rear sight placement allows me to see the rear sight rather distinctly. Virtually the same as the front sight. Other guns with placement further back toward the eye, will indeed increase sight radius but the focus of the blade will not be as sharp as say my Morini. I am asking is one condition preferable to the other ? I hope I explained the question well enough. Typing messages just don't always convey the message.

Dr.

[GaryN]

Focus on the FRONT sight, let the rear sight go blurry.

This is affected by lighting conditions.
- Outside, in bright lighting (a sunny day), the pupil in your eye will contract, to reduce the amount of light going into your eye. This will increase the visual depth of field (DoF), and you could see both sights in focus.
- Go indoors in lower light, and the pupil will open up, to get more light into your eye. This decreases the visual DoF, and you will not be able to see both sights in focus.

[jerber]

Focus on the FRONT sight, let the rear sight go blurry.

This is affected by lighting conditions.
- Outside, in bright lighting (a sunny day), the pupil in your eye will contract, to reduce the amount of light going into your eye. This will increase the visual depth of field (DoF), and you could see both sights in focus.
- Go indoors in lower light, and the pupil will open up, to get more light into your eye. This decreases the visual DoF, and you will not be able to see both sights in focus.

I think you have it backwards

[David Levene]

Focus on the FRONT sight, let the rear sight go blurry.

This is affected by lighting conditions.
- Outside, in bright lighting (a sunny day), the pupil in your eye will contract, to reduce the amount of light going into your eye. This will increase the visual depth of field (DoF), and you could see both sights in focus.
- Go indoors in lower light, and the pupil will open up, to get more light into your eye. This decreases the visual DoF, and you will not be able to see both sights in focus.

I think you have it backwards

It sounds right to me.

Reducing the size of the pupil will have a similar effect to reducing the size of the hole in an iris; the depth of field increases (but the accuracy may reduce because of the reduced amount of light reaching the eye.)

[jerber]

Focus on the FRONT sight, let the rear sight go blurry.

This is affected by lighting conditions.
- Outside, in bright lighting (a sunny day), the pupil in your eye will contract, to reduce the amount of light going into your eye. This will increase the visual depth of field (DoF), and you could see both sights in focus.
- Go indoors in lower light, and the pupil will open up, to get more light into your eye. This decreases the visual DoF, and you will not be able to see both sights in focus.

I think you have it backwards

It sounds right to me.

Reducing the size of the pupil will have a similar effect to reducing the size of the hole in an iris; the depth of field increases (but the accuracy may reduce because of the reduced amount of light reaching the eye.)

So are you saying that if take my good old Canon A1 outside on a sunny day and set my f stop at 1.4(fully open aperture) everything in the pictures will be sharply focused?
Also when I use an diopter on my glasses and shoot outside in day light,my front sight,rear sight,AND my target looks sharp
If I take it off I can only focus on one of them at the time
Even if don't use an diopter,my sight is clearer in darker places than outside in daylight
Explain that to me

[David Levene]

Focus on the FRONT sight, let the rear sight go blurry.

This is affected by lighting conditions.
- Outside, in bright lighting (a sunny day), the pupil in your eye will contract, to reduce the amount of light going into your eye. This will increase the visual depth of field (DoF), and you could see both sights in focus.
- Go indoors in lower light, and the pupil will open up, to get more light into your eye. This decreases the visual DoF, and you will not be able to see both sights in focus.

I think you have it backwards

It sounds right to me.

Reducing the size of the pupil will have a similar effect to reducing the size of the hole in an iris; the depth of field increases (but the accuracy may reduce because of the reduced amount of light reaching the eye.)

So are you saying that if take my good old Canon A1 outside on a sunny day and set my f stop at 1.4(fully open aperture) everything in the pictures will be sharply focused?
Also when I use an diopter on my glasses and shoot outside in day light,my front sight,rear sight,AND my target looks sharp

No,if you reduce the size of the hole then you will have more in focus.

Whenyou talk about using a diopter I presume you mean some sort of iris. That would reduce the size of the hole and bring more in focus, as you describe.

[jerber]

David
What I'm trying to say is,
Regardless of what I'm using(Iris, diopter, glasses...)
When I shoot outside in sunny day when focusing on my front sight,my target is somewhat blurry (and it should be!)
When I shoot inside a range where it is much darker
My target is a lot sharper (not perfect)
Less light the greater the DOF

[Rover]

As a professional photographer, I can safely say, "You have it backwards, Jerber."

[jerber]

As a professional photographer, I can safely say, "You have it backwards, Jerber."

So you're saying that using large aperture (small f stop)
Makes everything sharp focus?

[David Levene]

As a professional photographer, I can safely say, "You have it backwards, Jerber."

So you're saying that using large aperture (small f stop)
Makes everything sharp focus?

He appears to be saying that using a small aperture, large f number, makes more in focus (which is what I have been saying).

[jerber]

As a professional photographer, I can safely say, "You have it backwards, Jerber."

So you're saying that using large aperture (small f stop)
Makes everything sharp focus?

He appears to be saying that using a small aperture, large f number, makes more in focus (which is what I have been saying).

Well that's exactly what I said!!!!
Less light, sharper image!!!
This is what garyn wrote:

- Go indoors in lower light, and the pupil will open up, to get more light into your eye. This decreases the visual DoF, and you will not be able to see both sights in focus.

[GaryN]

Quote David:
Reducing the size of the pupil will have a similar effect to reducing the size of the hole in an iris; the depth of field increases (but the accuracy may reduce because of the reduced amount of light reaching the eye.)

Quote jerber:
So are you saying that if take my good old Canon A1 outside on a sunny day and set my f stop at 1.4(fully open aperture) everything in the pictures will be sharply focused?

jerber, you have your example backwards.

David said, "reducing the size of the hole in an iris."
On your camera it would be like setting the lens to f/16 (closed all the way down), NOT f/1.4 (all the way open).

Smaller diameter iris size = Larger f/stop number.
Larger diameter iris size = Smaller f/stop number.

The f/stop number is the result of an equation, not an absolute number itself (like focal length and diameter of the aperture).
The formula for f/stop is: Focal Length of the lens / diameter of the aperture = f/stop number
50mm lens / 35.7mm aperture = f/1.4
50mm lens / 3.1mm aperture = f/16
As you can see, as you reduce the diameter of the aperture, the f/stop number increases.

DoF increases as you decrease the size of the aperture. (larger f/stop number)

[jerber]

Quote jerber:
So are you saying that if take my good old Canon A1 outside on a sunny day and set my f stop at 1.4(fully open aperture) everything in the pictures will be sharply focused?

jerber, you have your example backwards.


I KNOW THAT!!!!!!!
It's a little sarcasm!!!!?

[High Left]

David
What I'm trying to say is,
Regardless of what I'm using(Iris, diopter, glasses...)
When I shoot outside in sunny day when focusing on my front sight,my target is somewhat blurry (and it should be!)
When I shoot inside a range where it is much darker
My target is a lot sharper (not perfect)
Less light the greater the DOF

Sounds like an eyeball effect ... or defect. Strain or overload from bright light? How about with sunglasses on?

The amount of light shouldn't make any difference to DOF. It's driven by the size of the iris.
BTW, it's actually 'apparent depth of field', an illusion created by your inability to tell it's out of focus. An optical system can only be 'in focus' at one distance.

The other effect of closing an iris is blurring from diffraction. This is what creates the spider webs in a rear aperture sight when it's too small ... could be crud in your eyeball as well ... or both? Anyway, if you look at test results for camera lenses you'll never see maximum sharpness with it stopped way down. And not with it wide open either. F4, plus or minus, is a typical sweet spot.

[Dr.Lee]

Thanks to JamesHH for his reply.
To all others, thanks for NOT understanding my post and hijacking the thread.

Dr.