Viewfinders on DSLR's

In article , Alfred Molon
writes
In article , Kennedy McEwen
says...

In the old days (pre-1990), the tradeoff was made towards the accurate
DoF representation. However, since AF became more common on SLRs, the
tradeoff has shifted towards the brighter image, because the viewfinder
is no longer used for focussing. As a consequence of the demand for
brighter SLR viewfinders, DoF preview accuracy has reduced, to the point
where it is very misleading these days in almost all SLRs, and pretty
useless in many. The actual DoF is always much less than appears in the
viewfinder with modern cameras - unless they have interchangeable focus
screens and one is available that has been optimised for manual focus.

Thanks. So the only way to check depth of field accurately would be to
take one shot and examine it on the LCD screen (zooming into it)?

Pretty much.
--
Kennedy
Yes, Socrates himself is particularly missed;
A lovely little thinker, but a bugger when he's ****ed.
Python Philosophers (replace 'nospam' with 'kennedym' when replying)

In article , lid writes
Alfred Molon wrote:
In article , Kennedy McEwen
says...

In the old days (pre-1990), the tradeoff was made towards the
accurate DoF representation. However, since AF became more common
on SLRs, the tradeoff has shifted towards the brighter image,
because the viewfinder is no longer used for focussing. As a
consequence of the demand for brighter SLR viewfinders, DoF preview
accuracy has reduced, to the point where it is very misleading these
days in almost all SLRs, and pretty useless in many. The actual DoF
is always much less than appears in the viewfinder with modern
cameras - unless they have interchangeable focus screens and one is
available that has been optimised for manual focus.
Thanks. So the only way to check depth of field accurately would be
to take one shot and examine it on the LCD screen (zooming into it)?

Really? I never considered that even in the oldest of days an SLR
screen DOF preview was for looking what was in focus ... it was for
looking at what was really our of focus, to get the proper subject-
background isolation.

I don't think it was ever called a "background isolation preview" button
by any manufacturer, and the reason is that it was meant to be for much
more than that! It was for assessing the depth of field - background
isolation being only an extreme limit of that. If all you are
interested in is a course decision of whether the background is isolated
then the DOF gauge on the lens barrel is good enough for that. Oh,
sorry, most of those have gone from modern AF lenses too.

That still works fine on my Canon 30D.

It only gives you a rough idea, but always understates the level of
isolation, so if you are trying to do anything critical, it is virtually
useless.
--
Kennedy
Yes, Socrates himself is particularly missed;
A lovely little thinker, but a bugger when he's ****ed.
Python Philosophers (replace 'nospam' with 'kennedym' when replying)

Kennedy McEwen wrote:


Really? I never considered that even in the oldest of days an SLR
screen DOF preview was for looking what was in focus ... it was for
looking at what was really our of focus, to get the proper subject-
background isolation.

I don't think it was ever called a "background isolation preview" button
by any manufacturer, and the reason is that it was meant to be for much
more than that! It was for assessing the depth of field - background
isolation being only an extreme limit of that. If all you are
interested in is a course decision of whether the background is isolated
then the DOF gauge on the lens barrel is good enough for that. Oh,
sorry, most of those have gone from modern AF lenses too.

That still works fine on my Canon 30D.

It only gives you a rough idea, but always understates the level of
isolation, so if you are trying to do anything critical, it is virtually
useless.

I have always found that it works quite well for background isolation
purposes. It worked well on my Minolta SRT101, and works well on my
Canon 30D.

Doug McDonald

"Kennedy McEwen" wrote in message
...
In article , Alfred Molon
writes
In article , Kennedy McEwen
says...

In the old days (pre-1990), the tradeoff was made towards the accurate
DoF representation. However, since AF became more common on SLRs, the
tradeoff has shifted towards the brighter image, because the viewfinder
is no longer used for focussing. As a consequence of the demand for
brighter SLR viewfinders, DoF preview accuracy has reduced, to the point
where it is very misleading these days in almost all SLRs, and pretty
useless in many. The actual DoF is always much less than appears in the
viewfinder with modern cameras - unless they have interchangeable focus
screens and one is available that has been optimised for manual focus.

Thanks. So the only way to check depth of field accurately would be to
take one shot and examine it on the LCD screen (zooming into it)?

Pretty much.
--
Kennedy
Yes, Socrates himself is particularly missed;
A lovely little thinker, but a bugger when he's ****ed.
Python Philosophers (replace 'nospam' with 'kennedym' when
replying)


Or take a digital preview shot on a Pentax K100D.

In article , Doug McDonald
writes
Kennedy McEwen wrote:

That still works fine on my Canon 30D.

It only gives you a rough idea, but always understates the level of
isolation, so if you are trying to do anything critical, it is
virtually useless.

I have always found that it works quite well for background isolation
purposes. It worked well on my Minolta SRT101, and works well on my
Canon 30D.

If you are interested in testing its accuracy then you will find it
works a lot better in your Minolta SRT101 than it does in your Canon 30D
- for the reasons I gave earlier.
--
Kennedy
Yes, Socrates himself is particularly missed;
A lovely little thinker, but a bugger when he's ****ed.
Python Philosophers (replace 'nospam' with 'kennedym' when replying)

Kennedy McEwen wrote:
In article , Doug McDonald
writes
Kennedy McEwen wrote:

That still works fine on my Canon 30D.

It only gives you a rough idea, but always understates the level of
isolation, so if you are trying to do anything critical, it is
virtually useless.

I have always found that it works quite well for background isolation
purposes. It worked well on my Minolta SRT101, and works well on my
Canon 30D.

If you are interested in testing its accuracy then you will find it
works a lot better in your Minolta SRT101 than it does in your Canon 30D
- for the reasons I gave earlier.

That's not true. I suspect that you are talking a lot less
blur in the background than I am. I'm referring to blurs that are maybe 1/16
the width of the screen. Not quite accurate enough to be called a bokeh preview,
but that's the idea.

In any case, you are wrong: the 30D's viewfinder absolutely is good enough.

Doug McDonald

In article , lid writes
Kennedy McEwen wrote:
If you are interested in testing its accuracy then you will find it
works a lot better in your Minolta SRT101 than it does in your Canon
30D - for the reasons I gave earlier.

That's not true.

Yes it is, and I suggest you make some tests. I, and others, have.

In any case, you are wrong:

"In any case"? That would include the case that I am right. You
clearly have bigger problems than the use of the DoF preview button.

the 30D's viewfinder absolutely is good enough.
It may be good enough for what YOU want it for. It certainly ISN'T good
enough for what it was intended or any critical DoF control. By
contrast, the Minolta that you referred to was far superior.
--
Kennedy
Yes, Socrates himself is particularly missed;
A lovely little thinker, but a bugger when he's ****ed.
Python Philosophers (replace 'nospam' with 'kennedym' when replying)