Part Blurred images with 20D

[paul45111]

I purchased a 5 month old 20D from a friend at the end of July, and have been using it with an EF 28-70 F2.8L which I previously used for many years with an EOS 1 & 3 without any problem.
I cannot upload a pic as i'm at work, but the pic is visible on my site via the link below.

http://www.toton-rail.co.uk/fullsize/37405toton6d44.jpg

At the bottom right corner of the image, the bushes are very blurry whilst everything else is sharp, including all other grass etc at same distance from lens as the blurred grass. On closer inspection of other shots taken since, they are also showing blurring in the same area, to different extents, but some do appear ok, so it maybe affecting shots intermittently.
Has anyone come across this thing before? I'm going to carryout some test shots to try and replicate the problem and try and confirm it's the camera body rather than the lens at fault.
As far as im aware, the friend i bought the body off never had any problem of this kind.
Any feedback appreciated.

Link to another pic with similar blur to the right:
http://www.toton-rail.co.uk/fullsize/37406derby2.jpg

[guitarboy]

Could it have been windy? Mabye the wind blew the grass and then caused the grass to blurr. Hope I helped

Jacob

[paul45111]

Could it have been windy? Mabye the wind blew the grass and then caused the grass to blurr. Hope I helped

Jacob

Thanks for replying, it was a still day and i'd have been using a fast enough shutter speed to stop the train, so this would've covered any movement in the grass. The link to the second pic shows blowing of track workers and a building too.

[ofdphoto]

Strange problem.

I'd shoot a scene that's a little less complex (eg. a brick wall!) at different apertures and lengths and see if you can observe any patterns in the blurring. From that we might be able to figure out what's causing it. Do you have any other lenses to try?

[Nikolas]

Have you got a skylight filter on?
does this do it with other lenses?
It looks to me like the front element of the lens is loose.
It happened to my 100-300 f5.6L and being somewhat mechanically inclined I removed the front element which to my surprise was too easy indicating it had come loose.
I cleaned it and put it back in tight and now it works perfectly.
Hope that helps.

[paul45111]

Thanks guys. Yes, there's a 1A filter on the zoom. I've got a 50mm f1.4 so i'll do some test shots with both lenses. the front element seems ok, no movement from the glass..

[ScottE]

According to the EXIF one picture was shot at f/4 and the other at f/4.5. The bottom right portions of the picture are much closer to the camera than the rest of the scene that is is sharp focus. You could have a depth of field limitation.

Check the lens/camera by shooting test shots of something that is parallel to the camera to eliminate depth of field as the cause. If one shot is sharp from corner to corner you cannot blame the camera or lens for other shots.

Try re-shooting the images using f/8 or f/11 to get more depth of field to see if that makes a difference.

[paul45111]

According to the EXIF one picture was shot at f/4 and the other at f/4.5. The bottom right portions of the picture are much closer to the camera than the rest of the scene that is is sharp focus. You could have a depth of field limitation.

Check the lens/camera by shooting test shots of something that is parallel to the camera to eliminate depth of field as the cause. If one shot is sharp from corner to corner you cannot blame the camera or lens for other shots.

Try re-shooting the images using f/8 or f/11 to get more depth of field to see if that makes a difference.

I'll do some test shots in daylight later today, I'm thinking it's not simply a DOF problem as I've used the lens at f4 and wider for railway photography for some years with 100asa film and never had a problem such as this. on the second picture with buildings in the background, the image is sharp on the trees and building in the background all the way across until it reaches the right hand 1/3 of the shot.
I have to admit that after years of using 100asa film, i've not yet got into the habit of upping the asa on the 20D to give me greater use of f stops.

[BassBiggieD]

could be the filter, have you tried any shots without the filter

[Michael]

I agree with ScottE. To narrow depth of field was my initial reaction when reading what the OP wrote. Then looking at the picture, it was also what I thought. Try a smaller aperture (larger f number) and see what happens.:)

Mike

[Tee Why]

I think it's due to the aperature, the things in the foreground are not at the depth where the focus is.

[Kenji]

Hi Paul,
Really nice Railway shot.
I find it difficult to see where the DOF blurred parts of the shot should be. The engine is well in focus, I would have no problem with the foreground being blurred. The grass between the Signal and the carriage is blurred also the trees in the distance, but the trees behind the carriages aren't. I like the picture, perhaps this is what it should look like as you are shooting at f4.

Anyway why not run a test by shooting a similar scene. Put your camera on a tripod, then take a number of shots rotating your camera for each shot. If there is a problem with your camera/lens. The fault will remain constant, but the blur will show on the image in a different place... right, top, left, bottom.

It's worth a try.
Best wishes,

[StewartR]

Anyway why not run a test by shooting a similar scene. Put your camera on a tripod, then take a number of shots rotating your camera for each shot. If there is a problem with your camera/lens. The fault will remain constant, but the blur will show on the image in a different place... right, top, left, bottom.I think that's a brilliant idea. If the problem is related to the lens or camera, then taking a photo with the camera held upside down (you don't really need a tripd for this) would put the blurry area in the top left rather than the bottom right. Of course you'd need to ensure the picture had objects at similar distances from the camera in both places, to eliminate DOF issues, but that shouldn't be difficult.

[Bob_A]

I'm with ScottE on this one. The blur on the lower right side for both of these images looks totally normal for using f/4 or f/4.5. Test away though ...

[Nikolas]

I disagree
If you look at the second picture you can clearly see the overhead bridge behind the locomotive is in sharp focus then as it heads towards the right it starts to get out of focus.
This is either a loose element or a dodgy uv screen
My money is on the loose element. (which may appear set in place but has actually moved a mm or 2.

[paul45111]

Many thanks to all who replied, I have now carried out several tests and identified that the 28-70L is at fault.

I have since been in contact with someone who had a similar problem with their 24-70L, they described the fault (as diagnosed by Lehmans camera/lens repairers of Stoke on trent) as a columnation PCB fault , which they described as "the tiny motors attatched to the focus ring were not pulling the barrel straight back , if you imagine 3 motors working in unison but the other 1 not doing so, then you get the barrel distortion and the out of focus pic".
Therefore the lens will be off for repair ASAP.......

[Nikolas]

I came closest what do I win?
:lol: :lol: 8-) :razz:

[kevin_c]

I came closest what do I win?
:lol: :lol: 8-) :razz:

The 'I'm a smart a*se' award - Glad you got to the bottom of the problem Paul - Some nice shots on your website by the way, brings back a few memories...

[Kenji]

I agree with Kevin, Paul you have many really good shots on your website; I am sure you are looking forward to getting your lens back from repair and you can get rail-side once more.
Regards,

[paul45111]

I came closest what do I win?
:lol: :lol: 8-) :razz:

Hi Nikolas, well done, you win... errr... an apple for being top of the class!:D

Thanks for the kind comments re my rail pics, they are mostly scanned 35mm colour slides, with a few digi images off my 20D since this July (which are all mostly slightly blurred on the right hand side of course!)

Paul