Live view focusing issue

[Kiwimac]

Advertisement (gone after registration)

A couple of times when using LV I’ve noticed that the image on the screen doesn’t move fully in and out of focus when the focus ring is turned. 
 

The colour overlay on focus peaking also appears to be missing. 
 

in particular this has been with the 28 Summilux fitted when I’ve noticed it. 
 

Anyone seen this or have a fix? The camera is an 11-P Safari. 

Edited July 23 by Kiwimac

[Kiwimac]

I figured out the colours part. 
 

Caused by the slightly illogical fact that even if you turn it on, it won’t show unless you also select the info bars to be on when you’re focusing. 
 

Personally, it would make more sense to me if focus peaking was on or off independently of the info bars, but anyway. …!

[Smogg]

Focus peaking is not related to the info bar. It is related to the settings that you have in Capture assistants\Info profiles. You can create a profile there without an info bar, but with focus peaking.

[Kiwimac]

You can. But it’s still odd (to me at least) that it’s not simply a stand alone thing you can turn on and off with its own button - unless you manipulate the info profile thing. 
 

It feels more cumbersome than it should I think. 
 

I still can’t work out why using the LV sometimes simply doesn’t work for focus though. 

Edited July 23 by Kiwimac

[lct]

4 hours ago, Kiwimac said:

it’s still odd (to me at least) that it’s not simply a stand alone thing you can turn on and off with its own button - unless you manipulate the info profile thing. 

There is no button dedicated to focus peaking indeed but you can choose any user profile by one touch on the status screen (# 16 below). I did it once in 2022 and i'm still using such a profile now.

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

[250swb]

9 hours ago, Kiwimac said:

A couple of times when using LV I’ve noticed that the image on the screen doesn’t move fully in and out of focus when the focus ring is turned. 

DOF? If you are using a small aperture and a wide lens the image may never be fully out of focus. Focus peaking for accuracy should be done with the lens wide open.

[lct]

Advertisement (gone after registration)

Or use focus magnification. Works fine at working aperture too.

Edited July 23 by lct

[250swb]

3 hours ago, lct said:

Or use focus magnification. Works fine at working aperture too.

But the DOF is still the same, focus magnification simply zooms in on the image, it can’t change the DOF or aperture. 

[lct]

Why changing DoF or aperture? Unsure to see what you mean but i may be missing something.

[Kiwimac]

It is a strange thing and logic suggests that the issue had its origin in the translation of the focus to the screen, because if I focus through the rangefinder, it’s completely normal. 
 

It’s just that - sometimes - the image on the screen (zoomed in) doesn’t appear to change focus correctly when the focus ring on the lens is turned. 
 

it’s as if a 100% change in focus from nearest to infinity on the lens shows only as a 50% change, remaining blurry regardless of actual focus. 

[lct]

You mean with focus magnification?

[J S H]

27 minutes ago, Kiwimac said:

It is a strange thing and logic suggests that the issue had its origin in the translation of the focus to the screen, because if I focus through the rangefinder, it’s completely normal. 
 

It’s just that - sometimes - the image on the screen (zoomed in) doesn’t appear to change focus correctly when the focus ring on the lens is turned. 
 

it’s as if a 100% change in focus from nearest to infinity on the lens shows only as a 50% change, remaining blurry regardless of actual focus. 

The LV image on the screen is a direct feed from the sensor. There is no 'translation' taking place, just varying levels of magnification depending on the selected zoom setting. As other members have mentioned - with a wide angle lens, the actual point of focus may not be immediately obvious on the screen even at the highest available level of magnification. This holds doubly true if the lens is stopped down a bit - in that case, it can be hard to determine exact focus even when using the Visoflex 2. 

[Kiwimac]

Perhaps that might be it. 
 

However I’m not sure. Perhaps I’ve not explained it well. 
 

Imagine the lens focus from near too far moves through four points, A, B, C and D. 
 

When turning the lens focus ring, the image on the back appears to start at A and stop at C. The focus ring continues on to D but there’s no visible change in the image on screen at all. 

[Derbyshire Man]

It can't be a camera thing though can it as you are physically turning the focus on a mechanical lens. The camera is simply displaying the hard image produced by that lens without any interpretation (even if focus peaking is on it is just looking for contrast in the image). The effect you describe is the optical behaviour of the lens in question?

[250swb]

12 hours ago, lct said:

Why changing DoF or aperture? Unsure to see what you mean but i may be missing something.

Because focus peaking works with contrast, and with wide DOF using a small aperture almost everything is almost 'in focus' with a wide angle lens. So the focus peaking see's everything as a high contrast subject. Hence the OP's problem (perhaps) of not much happening to focus or focus peaking when he changes focus. To accurately focus with focus peaking the lens needs to be wide open with a shallow DOF. It's easy to demonstrate for yourself, with the lens wide open with focus peaking On find an object in a complicated scene (front to back) to focus on, then as you turn the aperture ring from wide open to f/16 you'll see more and more red (or whatever it's set to) from the focus peaking appear until the original focus point is lost and everything appears to be 'in focus'.

So all you are doing by leaving the lens stopped down is the same as using hyperfocal focusing, you are choosing an acceptable level of un-sharpness across the image instead of choosing a precise point to focus on. That would be a disaster for a portrait shot, less so for a landscape. 

Edited July 24 by 250swb

[lct]

I was not referring to focus peaking but focus magnification and i can only confirm that it works fine at working aperture, even with WA lenses. There is no need to focus at full aperture from this viewpoint. In fact i never do it, or almost so, since i use mirrorless cameras.

[jaapv]

2 hours ago, 250swb said:

Because focus peaking works with contrast, and with wide DOF using a small aperture almost everything is almost 'in focus' with a wide angle lens. So the focus peaking see's everything as a high contrast subject. Hence the OP's problem of not much happening to focus or focus peaking when he changes focus. To accurately focus with focus peaking the lens needs to be wide open with a shallow DOF. It's easy to demonstrate for yourself, with the lens wide open with focus peaking On find an object in a complicated scene (front to back) to focus on, then as you turn the aperture ring from wide open to f/16 you'll see more and more red (or whatever it's set to) from the focus peaking appear until the original focus point is lost and everything appears to be 'in focus'.

So all you are doing by leaving the lens stopped down is the same as using hyperfocal focusing, you are choosing an acceptable level of un-sharpness across the image instead of choosing a precise point to focus on. That would be a disaster for a portrait shot, less so for a landscape. 

A very useful post. Focus Peaking does indeed detect contrast and the effect is that it does not indicate critical focus, but DOF. So when it fails  you need to resort to either switch it off and rely on magnification and your eyesight or, if possible, use it for a suitable part of your image that is in the same plane of focus. As an example, if you are photographing a furry animal and want the eye in focus, choose a spot on the grass just beside the animal in the same plane as the eye, and "walk" the Focus Peaking "DOF" back and forth to put the focus in the middle of the peaking area, and recompose. Keep in mind that DOF is only ⅓ : ⅔  close up and rapidly reverts to 1:1 before/behind the subject when focusing further away.

[jaapv]

1 hour ago, lct said:

I was not referring to focus peaking but focus magnification and i can only confirm that it works fine at working aperture, even with WA lenses. There is no need to focus at full aperture from this viewpoint. In fact i never do it, or almost so, since i use mirrorless cameras.

Using Focus Peaking and Magnification together can be very useful.  Closing the aperture on manual lenses on mirrorless cameras reduces focus precision.

[lct]

Agree for focus peaking + magnification but in practice i see no imprecision at working aperture, depending on the focal lenth of course but even WA lenses can focus accurately this way. The proof is in the pudding... or the bike for that matter.

M11, Summicron 28/2, f/8, full frame & crop:

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

 

[Advertisement]

Hallo,

Look here: Interesting Leica gear

[jaapv]

If you ask me, the critical focus in the second shot appears to be on the branch behind the motorcycle.