Lock exposure, focus and refocus

[fursan]

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I am used to locking the focus point and exposure on my nikons and then recomposing.

 

How would I do that on my M8 without at least disturbing the original focussed object?

 

How do you folks recompose?

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[Guest guy_mancuso]

Hold the shutter to the second stage and it locks exposure.

[charlesphoto99]

Focus and then quickly move the camera??

 

Sorry, I find it a strange question but maybe not if you weren't photographing before the days of autofocus. Which I still don't use, even when shooting with the latest greatest af slrs. They never seem to focus on what I want them to.

[dougdarter]

As Guy said, exactly as you would with an SLR.

 

Press down the shutter halfway until the AE confirmation light comes on - a red dot after the first number in the shutter speed, the recompose using the focus ring as normal.

 

The only trouble can be, is that the amount of pressure needed to fire the shutter is very slight after the AE light comes on.

[Marquinius]

It must be my English, but I don't even understand the question.

 

M8 focus = manual

M8 exposure = manual

 

But I must be missing the real issue here.

[dougdarter]

It must be my English, but I don't even understand the question.

 

M8 focus = manual

M8 exposure = manual

 

But I must be missing the real issue here.

 

The M8 also functions in 'Aperture priority' mode, which means that, with other cameras that feature this mode, if you select an aperture manually, the camera will match the shutter speed automatically.

 

This is fine, if you wish to chose to accept the cameras chosen speed, but in difficult lighting situations, you may wish to alter the chosen speed, say if the subject is heavily backlit, or contre' jour.

 

In this case, you would get the camera to meter on a different part of the selected picture, to achieve the desired speed, lock in the exposure, the re-compose the picture as you originally intended, but using a shutter speed that you have chosen. It's rather like over or underexposing .5 EV or so, but much quicker.

[fursan]

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Thanks for your replies.

 

Maybe I am not asking in a lucid way.

 

say i want to photog a tree in a wood. with a stream to the left. the stream is not

in view until i change position of my the camera.

 

with an dslr, i would focus on the tree and lock focus and/or exposure. recompose the

scene to have the stream included. mostly i would get the exposure and focus on the

tree as when it was locked, so long as the distance to the tree was not changed.

 

with my M8, only the thing in the center is focused. if i change the view would not

the tree go out of focus?

 

exposure lock i understand to be just as my dslr.

 

Am I missing something? my tree after recomposing is out of focus most of the time

with the M8, unless i compose it incl. the stream in the first instance.

 

Now I am confused too!!

[dougdarter]

Thanks for your replies.

 

Maybe I am not asking in a lucid way.

 

say i want to photog a tree in a wood. with a stream to the left. the stream is not

in view until i change position of my the camera.

 

with an dslr, i would focus on the tree and lock focus and/or exposure. recompose the

scene to have the stream included. mostly i would get the exposure and focus on the

tree as when it was locked, so long as the distance to the tree was not changed.

 

with my M8, only the thing in the center is focused. if i change the view would not

the tree go out of focus?

 

exposure lock i understand to be just as my dslr.

 

 

Am I missing something? my tree after recomposing is out of focus most of the time

with the M8, unless i compose it incl. the stream in the first instance.

 

Now I am confused too!!

 

I think I understand:)

 

You are quite correct. If the subject you have chosen is already in focus before acheiving AE lock, then there should be no reason to have to re-focus, particularly if the subject is near the infinity range. With RF's, and with fast aperture Leica glass in particular, you often find that you are working with a very shallow depth of field.

 

This is no problem with a DSLR, which will normally re-focus as you shoot, particularly if in a 'servo focus' type mode. With an RF, the movement to adjust AE may be sufficient to render your subject OOF, so you might need to re-focus before shooting.

 

I hope you can understand this:)

[hankg]

with my M8, only the thing in the center is focused. if i change the view would not

the tree go out of focus?

 

 

 

When you move the camera to reframe you must move it parallel to the plane the camera was in when you focused to keep the distance constant. If you turn the camera you may lose focus depending on where your subject is relative to the point of focus. So you have to move the camera sideways rather then turn the camera when reframing.

 

[Guest Bernd Banken]

Thanks for your replies.

 

Maybe I am not asking in a lucid way.

 

say i want to photog a tree in a wood. with a stream to the left. the stream is not

in view until i change position of my the camera.

 

with an dslr, i would focus on the tree and lock focus and/or exposure. recompose the

scene to have the stream included. mostly i would get the exposure and focus on the

tree as when it was locked, so long as the distance to the tree was not changed.

 

with my M8, only the thing in the center is focused. if i change the view would not

the tree go out of focus?

 

exposure lock i understand to be just as my dslr.

 

Am I missing something? my tree after recomposing is out of focus most of the time

with the M8, unless i compose it incl. the stream in the first instance.

 

Now I am confused too!!

 

Hank has the correct explanation of this subject.

 

Modern DSLR have much more sensitive AF spots which you can select in order to focus not with the center of the screen.

 

Last year a member in this forum told a solution to avoid this problem with Ms: Just move sideways to refraim the scene....

 

Bernd

[Jamie Roberts]

Hank is right, but he's also right for autofocusing cameras if you truly lock the AF.

 

So many people with Canon AF get into trouble if they focus and recompose wide open with a long-ish lens, precisely because they've 1) locked focus with the center AF sensor then 2) changed the sensor to subject distance by re-composing.

 

The cure on the Canons of course is to change the focus selector instead of using focus lock (and a lot of us get rid of the shutter button focus precisely so we can tell the camera when to stop focusing, which is a related problem).

 

On the M8, for complete accuracy, yes, you need to move the camera to maintain the camera-to-subject distance.

 

However, with a fair amount of focal depth, you can recompose anyway for some things, notably groups of people, without really losing very much. So for instance, shooting with a 35 or under at f4 I've never had any problem (with people along a similar plane; note we're not talking a tree that juts significantly forward or back from than the plane of focus).

 

Don't try that with a 90 or a Nocti wide open though Or with your Nikon if you're really locking it down!

[fursan]

Doug,

 

Thanks. I think I am begining to get it in focus:)

 

I think I understand:)

 

You are quite correct. If the subject you have chosen is already in focus before acheiving AE lock, then there should be no reason to have to re-focus, particularly if the subject is near the infinity range. With RF's, and with fast aperture Leica glass in particular, you often find that you are working with a very shallow depth of field.

 

This is no problem with a DSLR, which will normally re-focus as you shoot, particularly if in a 'servo focus' type mode. With an RF, the movement to adjust AE may be sufficient to render your subject OOF, so you might need to re-focus before shooting.

 

I hope you can understand this:)

[fursan]

Hank,

 

Thanks. The diagram makes it very clear.

 

When you move the camera to reframe you must move it parallel to the plane the camera was in when you focused to keep the distance constant. If you turn the camera you may lose focus depending on where your subject is relative to the point of focus. So you have to move the camera sideways rather then turn the camera when reframing.

 

[fursan]

Jamie, yes I am spoilt by the multiple focus points in my dslrs. Thanks.

 

Hank is right, but he's also right for autofocusing cameras if you truly lock the AF.

 

So many people with Canon AF get into trouble if they focus and recompose wide open with a long-ish lens, precisely because they've 1) locked focus with the center AF sensor then 2) changed the sensor to subject distance by re-composing.

 

The cure on the Canons of course is to change the focus selector instead of using focus lock (and a lot of us get rid of the shutter button focus precisely so we can tell the camera when to stop focusing, which is a related problem).

 

On the M8, for complete accuracy, yes, you need to move the camera to maintain the camera-to-subject distance.

 

However, with a fair amount of focal depth, you can recompose anyway for some things, notably groups of people, without really losing very much. So for instance, shooting with a 35 or under at f4 I've never had any problem (with people along a similar plane; note we're not talking a tree that juts significantly forward or back from than the plane of focus).

 

Don't try that with a 90 or a Nocti wide open though Or with your Nikon if you're really locking it down!

[grduprey]

The M8 also functions in 'Aperture priority' mode, which means that, with other cameras that feature this mode, if you select an aperture manually, the camera will match the shutter speed automatically.

 

This is fine, if you wish to chose to accept the cameras chosen speed, but in difficult lighting situations, you may wish to alter the chosen speed, say if the subject is heavily backlit, or contre' jour.

 

In this case, you would get the camera to meter on a different part of the selected picture, to achieve the desired speed, lock in the exposure, the re-compose the picture as you originally intended, but using a shutter speed that you have chosen. It's rather like over or underexposing .5 EV or so, but much quicker.

 

Why not meter manually and then recompose to your hearts desire?

Gene

[grduprey]

Thanks for your replies.

 

Maybe I am not asking in a lucid way.

 

say i want to photog a tree in a wood. with a stream to the left. the stream is not

in view until i change position of my the camera.

 

with an dslr, i would focus on the tree and lock focus and/or exposure. recompose the

scene to have the stream included. mostly i would get the exposure and focus on the

tree as when it was locked, so long as the distance to the tree was not changed.

 

with my M8, only the thing in the center is focused. if i change the view would not

the tree go out of focus?

 

exposure lock i understand to be just as my dslr.

 

Am I missing something? my tree after recomposing is out of focus most of the time

with the M8, unless i compose it incl. the stream in the first instance.

 

Now I am confused too!!

 

M8 = manual focus. Does not refocus on its own. Focus recompose shoot, very simple. No focus by itself.

Gene

[roberth]

I can see the problem you are talking about here focusing, focus curvature within the field of view. This would be greater in wide angle than 50 and up though and the effect woudl be neglible wouldn't it.

[Shootist]

Sorry but most of the replies have lost me, as does the original post.

If I focus on a tree, and set exposure on that tree and lock it by a pressing the shuter release to the second stop, and then recompose by turning the camera, rotating it, the tree should still be in-focus and the exposure the same as it was when I locked it, on the tree.

If you move the camera on a line parallel to the tree to recompose then you are actually making the tree either farther away or closer. Which would/will cause it to go out of focus.

 

Seems simple to me and works for me.

What am I missing here?

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Hallo,

Look here: Leica M

[Perspectics]

Ed, I am with you.

 

Simple question to Hank: Which of the lines is the focus line for a shot like this?

 

IMHO line A is the line along which you will find all object in focus.

 

If its line B then... hm, I'll go home and sleep it over until I understand... please educate me, I'm about to become confused.

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[michael_b_elmer]

Doug,

 

Thanks. I think I am begining to get it in focus:)

Dear Fahim Mohammad (i am not sure, which is your first name), English is not my mother tongur, but I know how difficult it is to translate between languages, since the languages do not always have the same expressions and associations with the words.

 

In my mother tongue (Danish) focusing on something can mean two things. First It means that you give your main attention to something, in other words that you put it in the center or in other words concentrate on it. Secondly, focussing also means setting a lens in such a way that somehting is sharply shown on the picture.

 

Focusing on your tree in order to have the tree appear sharp on your picture does not mean that the tree must be in the center of your picture - it could be and remain sharp (unless you change your lens setting) even if you have moved the camera, so that that the river next to the tree is in the middle of the picture and not as sharp as the tree which remains sharp. Accordingly, if your lens has been set to be sharp at 3 m, it remains sharp at that distance as long as you do not change the lens setting. It is a manual setting.

 

It is something else with the automatic exposure setting on the M8. Here, the exposure will change according to the reflection of light by the subject in the center of the cameras lens. However, you can press the shutter half way down (to a pressure point) until a small red light lights up in the VF and in that way keep the exposure setting, or you could simply set the exposure completely manually by measuring on the tree. Both procedures will keep the tree correctly exposed in your example.

 

I hope this can be understood also when translated into your language.