canon 10d near focus problem

[Red Squirrel]

Hi,
Just got my 10d and decided to do a few tests - photos always seem a little blurred..I'm focusing on the upside down "+40"
Am I experiencing front focus??

I'm using a 24-85 usm @ 85mm on a tripod

Here's the exif data, maybe someone here can help??
and a link to the 100% crop

thanks....

http://community.webshots.com/album/114303937NMenim



File Name
IMG_0197.JPG
Camera Model Name
Canon EOS 10D
Shooting Date/Time
04/02/2003 22:16:15
Shooting Mode
Manual
Tv( Shutter Speed )
1/180
Av( Aperture Value )
4.5
Metering Mode
Partial
ISO Speed
100
Lens
24.0 - 85.0 mm
Focal Length
85.0 mm
Image Size
3072x2048
Image Quality
Fine
Flash
On
Flash Type
Built-In Flash
Flash Exposure Compensation
0
Red-eye Reduction
On
Shutter curtain sync
1st-curtain sync
White Balance
Shade
AF Mode
One-Shot AF
Parameters
Contrast Normal
Color saturation Normal
Color tone Normal
File Size
1344KB
File Number
101-0197
Custom Function Settings
01:Long exposure noise reduction
0:Off
02:Shutter button/AE lock button
0:AF/AE lock
03:Mirror lockup
0:Disable
04:TV,AV and exposure level
0:1/2-stop
05:AF-assist light
0:On(Auto)
06:Shutter speed in Av mode
0:Auto
07:AEB sequence/auto cancellation
0:0 => - => +/Enabled
08:Shutter curtain sync
0:1st-curtain sync
09:Lens AF stop button Fn, switch
0:AF stop
10:Auto reduction of fill flash
0:Enable
11:Menu button return position
0:top
12:SET button func, when shooting
1:Change quality
13:Sensor cleaning
0:Disable
14:Superimposed display
0:On
15:Shutter release without CF card
0:Possible without CF card
Drive Mode
Self-Timer Operation[/quote]

[slin100]

That is not a good target for testing focus. There are far too many high-contrast targets on which the camera can lock on. You need a subject with a single high-contrast target next to a ruler that is nowhere near the focus point. This will insure that the camera locks focus on one and only one point.

[Red Squirrel]

I don't think it's the fault of the autofocus. I had the same results when manually focussing.
It looked sharp in the viewfinder, but not on the resulting image.

[defordphoto]

Slin is right. You need to focus on and actual object with a ruler nearby (I thought sure I'd never see another photo of a ruler!). I'll bet his camera is fine as this problem was fixed a long, long, long time ago (in a world far, far away).

[Red Squirrel]

ok everyone - I've taken your advice and photographed some real objects - screws!

http://community.webshots.com/scripts/editPhotos.fcgi?action=showMyPhoto&albumID=1143039 37&photoID=114548793&security=acIolD

But, same result - front focusing.

So can the lens be adjusted or is my 10d to blame??????

[slin100]

I tried the diopter, but the problem is it's sharp at the wrong point.
I think it's the lens though as it seems a lot better with my 75-300 usm

If it is the lens, can it be adjusted anyway?
Even if you have fantastic eyes, I find it hard to believe that the viewfinder and the image would show different focus points. After all, it's an optical viewfinder. It can't be out of whack for only one lens.

Personally, I've always found it hard to judge focus in the viewfinder, especially with a wide-angle lens. On a 10D it's especially hard because the viewfinder image is smaller than a film SLR and because there is no optical focus aid like a split prism.

Since you have two lenses with overlapping focal lengths, why don't you try the focus test I suggested at the same focal length?

[RichardtheSane]

I had the same results when manually focussing.
It looked sharp in the viewfinder, but not on the resulting image.
That could be down to the diopter adjustment on the viewfinder.

[Red Squirrel]

I tried the diopter, but the problem is it's sharp at the wrong point.
I think it's the lens though as it seems a lot better with my 75-300 usm

If it is the lens, can it be adjusted anyway?

[defordphoto]

The screws are no different than the ruler. You need one different, distinct object to focus on and then something (like a ruler) next to that object to see where the camera focus is. Try some different lenses too. It could be a lens incompatibility. I see it's a 24-85. Who makes the lens?

[Tom W]

The screws are no different than the ruler. You need one different, distinct object to focus on and then something (like a ruler) next to that object to see where the camera focus is. Try some different lenses too. It could be a lens incompatibility. I see it's a 24-85. Who makes the lens?

Maybe like this:

http://home.comcast.net/~trwilk3/Images/KnifePic.jpg

Shot at 1/90, f/6.7, 105 mm on a 28-105 mm lens, no flash. Used two worklights and adjusted color balance accordingly.

Autofocus, center only. I placed the autofocus right on the center of the knife.

[Tom W]

Here's a 100% crop of the knife:

http://home.comcast.net/~trwilk3/Images/100CropKnife.jpg

Other than the nasty pocket dust buildup, its very sharp. Focus is right on the money.

[Red Squirrel]

the lens is a canon 24-85 usm - I never had any problems with it on my 50E.
I tried my canon 75-300 usm and that is a lot better.

[Tom W]

the lens is a canon 24-85 usm - I never had any problems with it on my 50E.
I tried my canon 75-300 usm and that is a lot better.

I don't know what else to say, other than just take some pics. The one problem with angled rulers is that the focus "point" size isn't the same size and shape as the little square. There is some overlap and if that overlap leans slightly below the focus mark, the camera/lens combo may focus at the bottom or the top or anywhere within the length of the real focus zone.

Try this - tilt the ruler the other way, so that the top is closer to you and the bottom is farther away and see if the situation changes.

PS - For some reason, Webshots will not let me look at your images. It says I'm not a member of the "community".

[IanD]

PS - For some reason, Webshots will not let me look at your images. It says I'm not a member of the "community".
Tom,
You think it is trying to tell you something :?: :?: :?:
:lol:

[Tom W]

PS - For some reason, Webshots will not let me look at your images. It says I'm not a member of the "community".
Tom,
You think it is trying to tell you something :?: :?: :?:
:lol:

What do I have to do, buy a Gitzo to be accepted?

Speaking of Gitzos, I bought two light-duty Walmart tripods yesterday. But before you scoff, let it be known that they are for the sole purpose of use as light stands (though I would have no problem setting the S-400 on one of them). They were cheap and very effective for the purpose. :)