10D Back Focus

Dan156743 · May 17, 2003

You people just amaze me. Rather than seeing what is there to be seen you look for any B.S. reason you can find to challenge the obvious. I find the reply about the tip of the pen perhaps the most interesting reply of all. The tip of the pen is merely pointing to the location on the rug where the center focus sensor was aimed. The simple fact is if you look through the viewfinder the center focus sensor is in the center of the viewfinder; therefore, it does not take a rocket scientist to deduce the focus point is likewise going to be in the center of the image. The tip of the pen is not in the center of the image ROTF LMAO. I also read replies that tried to void the issue by challenging all sorts of ridiculous things like image size, etc.

Here is a focus test using a sheet developed for focus tests. The sheet has gridlines so I hope we don't hear more about the tip of the pen. The center focus point only was used. I used a Canon 28-70 f2.8L and a 70-200 f4.0L. In both images I used the maximum aperture. The images are unretouched and full size. You can read the EXIF data if you wish. The focus is the same in both images, which makes me feel a little better. At least the problem does not reside with my L lenses. Bottom line. I sent a camera to Canon for repair and they return a camera that back focuses.

28-70 f2.8L. Focal length set at 50mm and aperture at f2.8. The camera was on a tripod at 45 degrees.

http://www.pbase.com/image/16773407

70-200 f4.0L. Focal length set at 200mm and aperture set at f4.0. The camera was on a tripod at 45 degrees.

http://www.pbase.com/image/16773461

FrancisCF · May 17, 2003

Thanks for you inquiry, PearlRider.

I'm a potential buyer of the 10D, just hesitated due to the AF problem.

I've current using EOS 33 and just added an EOS 1v shortly, both camera is fine in AF. Just curious how come the 10D that borrowed the AF system from EOS33/30 or Elan 7 in USA would perform not as expected. I hope the 10D AF issue would be overcomed in the nearly future and I'll buy one ASAP. But the issue seems to be complicated and CS have problem to fix them with easy.

There are a number of 10D with AF problem threw into the CS here waiting for repair/calibration, also one popular camera shop that I buy nearly all my stuff there won't accept any return/exchange of 10D if only for the AF issue, they suggest you send it to CS directly, I've the shop VIP card and originally I can return it in 14 days instead of 7.

Also I'm curious in knowing how come the AF could vary from lens to lens, basically it's the lens that have the AF sensor and the microproccessor to control the lens. Anyone who have some insight into how the lens is tuned to improve AF accuracy?

I'm not bashing Canon, I'm actually a Canon user, though I use Nikon as well. Oh, I haven't tell you that I still have two minolta MF bodies, Minolta is my first camera in '78.

Tell you a story, I've the EF70-200 f2.8 USM and the AFS 80-200 f2.8, I sold the AFS a few month ago. Why? The AFS has very noticeable light fall off at f2.8 and the EF is just a quite acceptable amount at the same aperture. I choose the best performance and not by brand.

PearlRider said:
I really don't know why you follow EVERY thread about 10D focus
like you do and complain so much about a camera you don't even own.
But your participation in this forum is totally limited to this
sort of thread. Do you actually have a camera and, if so, do you
actually USE it? Just curious.

--
Go ahead, never look back

SteveDude · May 17, 2003

Dan said:
You people just amaze me. Rather than seeing what is there to be
seen you look for any B.S. reason you can find to challenge the
obvious.

I for one wasn't trying to challenge anything you pointed out. And I don't think anything I've said was a "BS reason" to challenge the obvious. If you didn't find any useful information in our replies, I apologize. I'm certainly not responding to these threads to tick people off.

Interestingly after downloading the original 2.8 and f4 lens tests, the f2.8 lens isn't rear-focusing NEARLY as much as the F4 lens. In fact, I'd argue that it's very very close. The F4 is clearly not in focus at the line.

I still think you may need to send the lenses in as well as the body to get it fixed - your F4 may actually be slightly out of spec.

Dan156743 said:
I find the reply about the tip of the pen perhaps the most
interesting reply of all. The tip of the pen is merely pointing to
the location on the rug where the center focus sensor was aimed.

I assume that you were talking about me, since I mentioned the confusion over the pen tip. The clarification you just added would have helped in your explanation of the problem I think. I originally thought that you were expecting the pen tip to be in focus.

You seem to have an adversarial tone to your writing. I'm not sure if it's intended, or just is representative of your frustration with this problem you're having.

I do understand your frustration, and I'm sorry we can't help.

Dan156743 said:
The simple fact is if you look through the viewfinder the center
focus sensor is in the center of the viewfinder; therefore, it does
not take a rocket scientist to deduce the focus point is likewise
going to be in the center of the image. The tip of the pen is not
in the center of the image ROTF LMAO. I also read replies that
tried to void the issue by challenging all sorts of ridiculous
things like image size, etc.

Here is a focus test using a sheet developed for focus tests. The
sheet has gridlines so I hope we don't hear more about the tip of
the pen. The center focus point only was used. I used a Canon 28-70
f2.8L and a 70-200 f4.0L. In both images I used the maximum
aperture. The images are unretouched and full size. You can read
the EXIF data if you wish. The focus is the same in both images,
which makes me feel a little better. At least the problem does not
reside with my L lenses. Bottom line. I sent a camera to Canon for
repair and they return a camera that back focuses.

28-70 f2.8L. Focal length set at 50mm and aperture at f2.8. The
camera was on a tripod at 45 degrees.

http://www.pbase.com/image/16773407

70-200 f4.0L. Focal length set at 200mm and aperture set at f4.0.
The camera was on a tripod at 45 degrees.

http://www.pbase.com/image/16773461

--
http://www.pbase.com/stevegrillo , Equipment on profile page

Olga Johnson · May 17, 2003

Dan said:
You people just amaze me. Rather than seeing what is there to be
seen you look for any B.S. reason you can find to challenge the
obvious.

You certainly don't help things, do you? For example, you say:

Dan156743 said:
The focus is the same in both images,
which makes me feel a little better. At least the problem does not
reside with my L lenses. Bottom line. I sent a camera to Canon for
repair and they return a camera that back focuses.

If you don't have a problem with your L lenses, then how do you conclude that your camera is back-focusing? Were those tests done on a different camera? What other lenses are you talking about? What did I miss?

Olga

Dan156743 · May 17, 2003

Hi Olga -

If you click on the links at the bottom of my earlier message which began this sub thread you will see the focus tests. They speak for themselves. If you check the EXIF info you will see they were taken with a 10D, and yes, both tests were completed using the same 10D with different lenses. I only own one 10D.

OlgaJ said:
Dan said:

You people just amaze me. Rather than seeing what is there to be
seen you look for any B.S. reason you can find to challenge the
obvious.

Click to expand...

You certainly don't help things, do you? For example, you say:

Olga Johnson said:

The focus is the same in both images,
which makes me feel a little better. At least the problem does not
reside with my L lenses. Bottom line. I sent a camera to Canon for
repair and they return a camera that back focuses.

Click to expand...

If you don't have a problem with your L lenses, then how do you
conclude that your camera is back-focusing? Were those tests done
on a different camera? What other lenses are you talking about?
What did I miss?

Olga

Olga Johnson · May 17, 2003

Dan,

Perhaps I should try to rephrase my question:

You said that you don't have a problem with your L lenses, and provided 2 examples to show that. But then you still claim your 10D backfocuses.

If your L lenses are not the problem when you have them on the 10D, then I don't understand what the problem is.

Does my question make more sense now?

Olga

Dan said:
If you click on the links at the bottom of my earlier message which
began this sub thread you will see the focus tests. They speak for
themselves. If you check the EXIF info you will see they were taken
with a 10D, and yes, both tests were completed using the same 10D
with different lenses. I only own one 10D.

OlgaJ said:

Dan said:

You people just amaze me. Rather than seeing what is there to be
seen you look for any B.S. reason you can find to challenge the
obvious.

Click to expand...

You certainly don't help things, do you? For example, you say:

Dan156743 said:

The focus is the same in both images,
which makes me feel a little better. At least the problem does not
reside with my L lenses. Bottom line. I sent a camera to Canon for
repair and they return a camera that back focuses.

Click to expand...

If you don't have a problem with your L lenses, then how do you
conclude that your camera is back-focusing? Were those tests done
on a different camera? What other lenses are you talking about?
What did I miss?

Olga

Click to expand...

Dan156743 · May 17, 2003

A little. Go here and click the links in this message. You will see the focus test, which unequivocally reveals back focus.

http://forums.dpreview.com/forums/read.asp?forum=1019&message=5129295

OlgaJ said:
Perhaps I should try to rephrase my question:

You said that you don't have a problem with your L lenses, and
provided 2 examples to show that. But then you still claim your 10D
backfocuses.

If your L lenses are not the problem when you have them on the 10D,
then I don't understand what the problem is.

Does my question make more sense now?

Olga

Dan said:

If you click on the links at the bottom of my earlier message which
began this sub thread you will see the focus tests. They speak for
themselves. If you check the EXIF info you will see they were taken
with a 10D, and yes, both tests were completed using the same 10D
with different lenses. I only own one 10D.

OlgaJ said:

Dan said:

You people just amaze me. Rather than seeing what is there to be
seen you look for any B.S. reason you can find to challenge the
obvious.

Click to expand...

You certainly don't help things, do you? For example, you say:

Olga Johnson said:

The focus is the same in both images,
which makes me feel a little better. At least the problem does not
reside with my L lenses. Bottom line. I sent a camera to Canon for
repair and they return a camera that back focuses.

Click to expand...

If you don't have a problem with your L lenses, then how do you
conclude that your camera is back-focusing? Were those tests done
on a different camera? What other lenses are you talking about?
What did I miss?

Olga

Click to expand...

Click to expand...

The Raven · May 17, 2003

I just think it's odd that you show up at nearly EVERY 10D focus thread to further the idea that there's a big problem. You seem to expend a lot of energy in the pursuit of pointing out this "problem" whenever you can.

The Raven · May 17, 2003

You've determined that your 10D has an auto-focusing problem. Now what do you intend to do about it? Is there anything we can do to help you? I'd still like to see some of your non-testing shots. What made you test the camera for focusing problems in the first place? We're not trying to look for BS to prove you wrong. It just seemed like you were asking a little much of the camera to focus on some fibers when it would've been better to have focused on the pen instead. That's a more clearly defined target for the AF to lock onto. If it had been your intent to force the AF to be confused and fail your test, you succeeded there.

Don Schultz43010 · May 17, 2003

Hi Dan:

Are you aware that the area of apparent focus (DOF) is 1/3 rd ahead and 2/3 Rd's behind the area of critical focus.
Don.

PearlRider said:
You've determined that your 10D has an auto-focusing problem. Now
what do you intend to do about it? Is there anything we can do to
help you? I'd still like to see some of your non-testing shots.
What made you test the camera for focusing problems in the first
place? We're not trying to look for BS to prove you wrong. It just
seemed like you were asking a little much of the camera to focus on
some fibers when it would've been better to have focused on the pen
instead. That's a more clearly defined target for the AF to lock
onto. If it had been your intent to force the AF to be confused and
fail your test, you succeeded there.

Ben Strasser · May 17, 2003

Thank you Don, that is what I was trying to point out to him. If you shoot a persons face, would you want the only thing in focus the eye and have the ear and nose blurred? A macro lens will do this because it is designed that way (sharp focus on a very narrow plane). Most subjects are not flat. If you were able to focus on the exact point under the sensor and nothing else, I am sure he would not be happy. I think Canon brought this whole issue on themselvers by going to a smaller form factor. All of the common lenses and zooms are now telephoto lenses with limited DoF as all telephoto lenses were in the past.

Do the same test at f11 or f16 and see what DoF can do for you and go out and shoot some real life subjects. Good Luck

Don Schultz said:
PearlRider said:

You've determined that your 10D has an auto-focusing problem. Now
what do you intend to do about it? Is there anything we can do to
help you? I'd still like to see some of your non-testing shots.
What made you test the camera for focusing problems in the first
place? We're not trying to look for BS to prove you wrong. It just
seemed like you were asking a little much of the camera to focus on
some fibers when it would've been better to have focused on the pen
instead. That's a more clearly defined target for the AF to lock
onto. If it had been your intent to force the AF to be confused and
fail your test, you succeeded there.

Click to expand...

FrancisCF · May 17, 2003

Same as you, you seem to be in my opposite side, haha!

Did I mention there is good 10D in the following link posted before in one of my reply?

http://www.danielckchan.com

The webmaster ask me whether I've bought the 10D now, unfortunately I know some photogs bought flawed 10D, my favourite camera won't let me exchange 10D if only for the AF problem which they know it, just to protect themselves from taking the responsibility of Canon.

What am I wrong if I'm telling you the truth, with the good and the bad? I post here not because to please you, right?

If Canon fix the Canon 10D without those hasse to and fro repair, I'll buy one soon. I enjoy my present gear, EOS33, 1v as well as the F100. I don't care whether when the 10D will be right in AF. Tell you I've 3 DC at hand, the Canon G2 (a bit heavy, large aperture, not so good exposure meter, not bad colour, good battery life, not so good AF in very dim light with the AF assist lamp, could be I got a bad sample, but CS think it is OK), the Nikon 995 (light, excellent exposure metering, no AF assist lamp, no sophiscated Nikon flash system, so so colour out of the box, so so battery life), the Oly 3030z (a too old version, just let my son use it).

May be I'm a bit picky, this is logical for me in the film world since 1978.

PearlRider said:
I just think it's odd that you show up at nearly EVERY 10D focus
thread to further the idea that there's a big problem. You seem to
expend a lot of energy in the pursuit of pointing out this
"problem" whenever you can.

--
Go ahead, never look back

Dan156743 · May 17, 2003

I have shot plenty of real life subjects. That is what called my attention to the back focusing issue.

Ben Strasser said:
Don Schultz said:

PearlRider said:

You've determined that your 10D has an auto-focusing problem. Now
what do you intend to do about it? Is there anything we can do to
help you? I'd still like to see some of your non-testing shots.
What made you test the camera for focusing problems in the first
place? We're not trying to look for BS to prove you wrong. It just
seemed like you were asking a little much of the camera to focus on
some fibers when it would've been better to have focused on the pen
instead. That's a more clearly defined target for the AF to lock
onto. If it had been your intent to force the AF to be confused and
fail your test, you succeeded there.

Click to expand...

Click to expand...

Dan156743 · May 17, 2003

What I find interesting is the area behind the focus point on the rug picture is in focus. The same is true of the focus test using the clearly distinguishable grid lines. In other words, both the rug test and the gridline test are the same. With this thought in mind seems like your analysis is not reasonable. Given the rug picture and gridline picture demonstrate the same back focus I don't see how you can reasonable conclude the rug test confused the auto focus sensor. Oh well!

PearlRider said:
You've determined that your 10D has an auto-focusing problem. Now
what do you intend to do about it? Is there anything we can do to
help you? I'd still like to see some of your non-testing shots.
What made you test the camera for focusing problems in the first
place? We're not trying to look for BS to prove you wrong. It just
seemed like you were asking a little much of the camera to focus on
some fibers when it would've been better to have focused on the pen
instead. That's a more clearly defined target for the AF to lock
onto. If it had been your intent to force the AF to be confused and
fail your test, you succeeded there.

Peter Phan · May 17, 2003

The 70-200/4L is not a macro lens. It, therefore, is limited to a mimimum focus distance that varies depending on the focal length you have zoomed the lens to. (The minimum focus distance labeled on the lens is for a particular focal length. I don't remember which one.) It may be that you have just barely exceeded that minimum focus distance limitation, forcing the plane of focus to fall just behind the actual point that you had focused on.

But regardless, given the subject matter, the apparent working distance, and the extremely minimal depth of field, that's what you would expect from any camera. If I were to repeat that test with a different body, for example a Canon film body if you had one of those before you switched to digital, you'll find the same results. Also, repeat the test with a macro lens. That way, you would be eliminating the minimum focus distance issue.

Dan said:
For all who doubt 10D's have focus problems here is a photo to
view. Since I dont have all of the fancy technical equipment that
Canon has I set up a very simple focus test.

The image was shot with the 10D mounted on a tripod and at 45
degrees. I used a Canon f4L lens. The center of the picture is
immediately to the left of the tip of the pen. I used the center
focal point of the camera only.

The pityful thing about this image is that I just got my camera
back from the Canon New Jersey repair facility. This picture
represents the degree of quality and customer service that Canon is
building into their product. The bottom line is there is no excuse
on Canon's part for selling a $1500 camera body that wont focus,
especially after it undergoes warranty repair at their own facility.

http://www.pbase.com/image/16753690

Peter Phan · May 17, 2003

Furthermore, with macro photography, you're dealing with extremely critical focus tolerances because of the extremely narrow depth of field. That's why, even when using autofocus macro lenses, macro shooters prefer to manually focus. This is not a "faulty camera" issue. It is well within the tolerences of an autofocus lens, particularly a zoom autofocus lens! Don't fret. Your camera is just fine, and your lens is just fine, too!

Dan said:
For all who doubt 10D's have focus problems here is a photo to
view. Since I dont have all of the fancy technical equipment that
Canon has I set up a very simple focus test.

The image was shot with the 10D mounted on a tripod and at 45
degrees. I used a Canon f4L lens. The center of the picture is
immediately to the left of the tip of the pen. I used the center
focal point of the camera only.

The pityful thing about this image is that I just got my camera
back from the Canon New Jersey repair facility. This picture
represents the degree of quality and customer service that Canon is
building into their product. The bottom line is there is no excuse
on Canon's part for selling a $1500 camera body that wont focus,
especially after it undergoes warranty repair at their own facility.

http://www.pbase.com/image/16753690

Dan156743 · May 17, 2003

A complex analysis; however, I was at least 2 meters from the focal point exceeding the minimum focus distance of 1.2 meters; therefore, the theory the plane of focus fell behind the actual focus point does not hold up. Oh Well, like I said earlier, every reason one can imagine to avoid the obvious.

Peter Phan said:
But regardless, given the subject matter, the apparent working
distance, and the extremely minimal depth of field, that's what you
would expect from any camera. If I were to repeat that test with a
different body, for example a Canon film body if you had one of
those before you switched to digital, you'll find the same results.
Also, repeat the test with a macro lens. That way, you would be
eliminating the minimum focus distance issue.

Dan said:

For all who doubt 10D's have focus problems here is a photo to
view. Since I dont have all of the fancy technical equipment that
Canon has I set up a very simple focus test.

The image was shot with the 10D mounted on a tripod and at 45
degrees. I used a Canon f4L lens. The center of the picture is
immediately to the left of the tip of the pen. I used the center
focal point of the camera only.

The pityful thing about this image is that I just got my camera
back from the Canon New Jersey repair facility. This picture
represents the degree of quality and customer service that Canon is
building into their product. The bottom line is there is no excuse
on Canon's part for selling a $1500 camera body that wont focus,
especially after it undergoes warranty repair at their own facility.

http://www.pbase.com/image/16753690

Click to expand...

Dan156743 · May 17, 2003

This was not a macro shot and exceeded the minimum focus distance. Like I said earlier. Real life shooting is what drew my attention to the matter.

Peter Phan said:
Dan said:

For all who doubt 10D's have focus problems here is a photo to
view. Since I dont have all of the fancy technical equipment that
Canon has I set up a very simple focus test.

The image was shot with the 10D mounted on a tripod and at 45
degrees. I used a Canon f4L lens. The center of the picture is
immediately to the left of the tip of the pen. I used the center
focal point of the camera only.

The pityful thing about this image is that I just got my camera
back from the Canon New Jersey repair facility. This picture
represents the degree of quality and customer service that Canon is
building into their product. The bottom line is there is no excuse
on Canon's part for selling a $1500 camera body that wont focus,
especially after it undergoes warranty repair at their own facility.

http://www.pbase.com/image/16753690

Click to expand...

riokid · May 17, 2003

but the problem with the younger generation is they probably have never seen a lens with the distance scale on it.

I have used Nikons since its early days (late 50s early 70s) and we even study the published dof chart supplied with the lens.

Do these squeeky wheels even know where the focus ring is?

GPB said:
-- Greg

Dan said:

For all who doubt 10D's have focus problems here is a photo to
view. Since I dont have all of the fancy technical equipment that
Canon has I set up a very simple focus test.

The image was shot with the 10D mounted on a tripod and at 45
degrees. I used a Canon f4L lens. The center of the picture is
immediately to the left of the tip of the pen. I used the center
focal point of the camera only.

The pityful thing about this image is that I just got my camera
back from the Canon New Jersey repair facility. This picture
represents the degree of quality and customer service that Canon is
building into their product. The bottom line is there is no excuse
on Canon's part for selling a $1500 camera body that wont focus,
especially after it undergoes warranty repair at their own facility.

http://www.pbase.com/image/16753690

Click to expand...

riokid · May 17, 2003

Allen-W said:
The problem is, you are using a Bic pen. The 10D wont respect
anything less than a Paper-Mate.

Dan said:

For all who doubt 10D's have focus problems here is a photo to
view. Since I dont have all of the fancy technical equipment that
Canon has I set up a very simple focus test.

The image was shot with the 10D mounted on a tripod and at 45
degrees. I used a Canon f4L lens. The center of the picture is
immediately to the left of the tip of the pen. I used the center
focal point of the camera only.

The pityful thing about this image is that I just got my camera
back from the Canon New Jersey repair facility. This picture
represents the degree of quality and customer service that Canon is
building into their product. The bottom line is there is no excuse
on Canon's part for selling a $1500 camera body that wont focus,
especially after it undergoes warranty repair at their own facility.

http://www.pbase.com/image/16753690

Click to expand...

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