......Focus issue... Canon DSLR Rebel

Is it possible for a/this camera to show one thing in the view finder
(focus) and save something different to the card?

I use several lens, but my 85mm prime, which can be very sharp gives me fits
to. I shoot manual focus, I have played with the diopter, and I am aware
that shooting at f1.8 (or close there to) can be very very sharp and narrow
on focus range. But still, I compose and focus and things just don't record
to disc as I shot them, or so it seems. Oh, I wear glasses, if that matters,
my prescription is good.

I get home and I just can't believe half, not all, of my pictures are out of
focus. It is getting to the point where I want to take 3 shots of
everything, like "focus-bracketing".

David A.

On 06/09/2005 12:47 PM, David A wrote:

[...] I compose and focus and things just don't record
to disc as I shot them, or so it seems.

If the focal point is wrong, you should be able to see that. I.E. is
something else at a different distance in focus, or is the whole shot
out of focus? If the latter, you've probably got camera stability
issues. If the former, try a few test shots of a good quality steel rule
with legible markings set on an angle to the lens, such that part of it
is in the foreground, part in the background, and one specific mark at
your focal point. See if the result matches where you think you focused.

"Doug Payne" wrote in message
...
On 06/09/2005 12:47 PM, David A wrote:

[...] I compose and focus and things just don't record to disc as I shot
them, or so it seems.

If the focal point is wrong, you should be able to see that. I.E. is
something else at a different distance in focus, or is the whole shot out
of focus? If the latter, you've probably got camera stability issues. If
the former, try a few test shots of a good quality steel rule with legible
markings set on an angle to the lens, such that part of it is in the
foreground, part in the background, and one specific mark at your focal
point. See if the result matches where you think you focused.


Doug

The whole picture is in focus per se. I am able to see and set a focal
point. The resulting picture ends up with a different focal point. I need to
verify if the focal point is closer or further by default. Your ruler test
sounds like a good place to start.

Thanks - David A.

"Thomas T. Veldhouse" wrote in message
et...
Stan Birch wrote:
On Tue, 06 Sep 2005 16:47:18 GMT, "David A" wrote:
I get home and I just can't believe half, not all, of my pictures are out
of
focus. It is getting to the point where I want to take 3 shots of
everything, like "focus-bracketing".

With the Rebel, the only reliable focusing option, is the centred
single point option.


It shouldn't matter. If it is focused and sharp in the viewfinder, then
it should be focused and shart in the resulting image. I suspect that
the OP is moving the camera a little during the shutter snap. I
suggest taking high speed pictures to test this out and then work on
his/her technique.

--
Thomas T. Veldhouse
Key Fingerprint: 2DB9 813F F510 82C2 E1AE 34D0 D69D 1EDC D5EC AED1
Spammers please contact me at .


Thomas and Stan

I will try the ruler test mention by Doug earlier.

David A.

David A wrote:

Is it possible for a/this camera to show one thing in the view finder
(focus) and save something different to the card?



Yes it's possible the focus screen isn't adjusted right.

--

Stacey

In article qKjTe.13876$IT4.5343@trnddc04, says...
Is it possible for a/this camera to show one thing in the view finder
(focus) and save something different to the card?

I use several lens, but my 85mm prime, which can be very sharp gives me fits
to. I shoot manual focus, I have played with the diopter, and I am aware
that shooting at f1.8 (or close there to) can be very very sharp and narrow
on focus range. But still, I compose and focus and things just don't record
to disc as I shot them, or so it seems. Oh, I wear glasses, if that matters,
my prescription is good.

I get home and I just can't believe half, not all, of my pictures are out of
focus. It is getting to the point where I want to take 3 shots of
everything, like "focus-bracketing".

Maybe the camera is a POS?

--
Look. See. Click. Share.

David, see these instructions from Bob Atkins for testing the accuracy
of focus:

http://www.photo.net/learn/focustest/

Although his method is designed for testing autofocus, a similar method
should be useful for manual focussing too.

Let us know your results...

Peter Marquis-Kyle

"Thomas T. Veldhouse" wrote in message

Wouldn't ALL the pictures be out of focus then? The OP suggested that
just some (about 1/2) of them are out of focus. This is the main reason
I suspect camera movement as the cause of the apparent focus issue.


The pictures are in focus, its just that the focal point I see in the view
finder isn't always the focal point I get when I go home later and load the
pictures up on my PC. They are manual focused shots, and it happens even at
1/200 and above. The 85mm f1.8 prime lens (a very sharp lens) does it.

I will play with the ruler test.

David A.

I don't know if this is relevant or not to the OP, but I tried the test
Peter recommended from http://www.photo.net/learn/focustest/ using my
20D, and I've verified that it's screwing up the focus when using the
center focus point. It appears to be focussing perhaps 1cm short :-( I
had the camera on a tripod, so I'm certain camera movement wasn't the
problem. I found that the other focus points seem to be right. This
could perhaps explain the "50% of photos out of focus" issue. Maybe 50%
of the time it's not using the center focus point.

Does anyone know if this is something that could be recalibrated?

Stacey wrote:

David A wrote:


Is it possible for a/this camera to show one thing in the view finder
(focus) and save something different to the card?



Yes it's possible the focus screen isn't adjusted right.



Wouldn't ALL the pictures be out of focus then? The OP suggested that
just some (about 1/2) of them are out of focus. This is the main reason
I suspect camera movement as the cause of the apparent focus issue.

Eugene wrote:

I don't know if this is relevant or not to the OP, but I tried the test
Peter recommended from http://www.photo.net/learn/focustest/ using my
20D, and I've verified that it's screwing up the focus when using the
center focus point. It appears to be focussing perhaps 1cm short :-( I
had the camera on a tripod, so I'm certain camera movement wasn't the
problem. I found that the other focus points seem to be right. This
could perhaps explain the "50% of photos out of focus" issue. Maybe 50%
of the time it's not using the center focus point.

Does anyone know if this is something that could be recalibrated?

Stacey wrote:

David A wrote:


Is it possible for a/this camera to show one thing in the view finder
(focus) and save something different to the card?



Yes it's possible the focus screen isn't adjusted right.



Wouldn't ALL the pictures be out of focus then? The OP suggested that
just some (about 1/2) of them are out of focus. This is the main reason
I suspect camera movement as the cause of the apparent focus issue.


Not necessarily. If your camera stops down for any picture, a 1 cm
increase in the DOF could mask the problem.

Jan