Jump to content

EOS 5D MkIII Focusing


Gary Holliday

Recommended Posts

I reported a focusing problem on a previous thread. I've since had the body sent off for a warranty repair to the CMOS:

 

"Dismantle to reset body depths, full reprogram and re-calibration to return to standard."

 

I then sent the repaired body off to a Canon approved centre to calibrate my 135mm L 2.0 lens to the Mark III.

 

I'm not convinced that this camera is pin sharp...what do you think of the three images attached?

 

A few shots taken on an overcast day a moment ago.

400 ISO

250s - f8

JPEG.

No additional sharpening in Photoshop

 

5S9B0854.thumb.JPG.130eb16f90e10a1db6dda7b4e2072778.JPG

 

5S9B0860.thumb.JPG.7c20d3f2d4fc1b6835805581db8f2715.JPG

 

5S9B0858.thumb.JPG.292e1e4c395385aeb4addab2791624a9.JPG

Link to comment
Share on other sites

It looks like a wall full of bricks to me... even at 100%. The red bit doesn't look quite right, but it's a chunk of missing brick, so there's no real telling how textured the surface is (or isn't)... Of more concern might be image 2, especially if the point of focus was the center flower.
Link to comment
Share on other sites

The pictures (flowers aside) don't look alarmingly bad to me.

I wouldn't trust my handholding skills at 1/250 with a 135mm.

I also wouldn't expect AF to visibly miss at f8.

Mine doesn't work great at f2.8. - I'm currently reading up on AF micro adjustments. If your service center really set them note down the value they picked and do a t least some testing. - Doesn't Magic Lantern perform automated adjustments on your Mk III?

Link to comment
Share on other sites

The single centre focusing was selected so you can see which flower by the composition

You might have used focus and recompose. If the central flower was the point of focus, then your AF is off. Did you take more than one: are they all like this? If so, then you need to adjust the AF. If you were not using a tripod then you could be rocking back and forth just enough for it to be off (AI servo deals with that), or the wind could be blowing and moving the flower out of the plane of focus. You need to consider these other possibilities too before you decide the AF is off.

Robin Smith
Link to comment
Share on other sites

Looked at EXIF on the first photo.

 

Camera: Canon EOS 5D Mark III

Lens: Canon EF 135mm f/2L

Exposure: Manual exposure, 1/128 sec, f/8, ISO 400

 

1/128th second according to the embedded exif data in the photo.

At only 1/128th sec I wouldn't rule out camera shake.

 

Try doing the test again with a tripod.

The Canon 5D Mark III can do micro adjustments and save those adjustments data for a specific lens.

Here is a guide on how to perform this test and task and save yourself some money by doing it yourself.

LINK

Edited by Mark Keefer
Cheers, Mark
Link to comment
Share on other sites

If camera shake were the issue, then ALL the flowers would likely be smeared. You shouldn't have sharp ones behind the plane of focus. That makes zero sense. unless a random breeze puts those particular flowers moving in the exactly the same direction as the camera at that particular moment... possible? yes. but also extremely highly improbable? yes.

 

That center point one shot was used means that it is likely there is a fault. Redoing w/ a tripod seems the obvious next step. Also redoing at f2 would be a good idea, since shooting at f8 covers up any faults by a good degree.

 

At 135mm I often have no problem (even w/o IS) pulling crisp shots out @ 1/125. However, putting it on a tripod is critical to do an objective measurement of AF accuracy, as well as shooting near and far stationary subjects.

Link to comment
Share on other sites

If camera shake were the issue, then ALL the flowers would likely be smeared. You shouldn't have sharp ones behind the plane of focus. That makes zero sense. unless a random breeze puts those particular flowers moving in the exactly the same direction as the camera at that particular moment... possible? yes. but also extremely highly improbable? yes.

 

That center point one shot was used means that it is likely there is a fault. Redoing w/ a tripod seems the obvious next step. Also redoing at f2 would be a good idea, since shooting at f8 covers up any faults by a good degree.

 

At 135mm I often have no problem (even w/o IS) pulling crisp shots out @ 1/125. However, putting it on a tripod is critical to do an objective measurement of AF accuracy, as well as shooting near and far stationary subjects.

 

I agree with you on the flower shot. My comments were based on the first photo, brick shot. One problem for us to Monday morning quarterback this on the flower shot, where was the original focal point when the camera achieved focus lock. Was it a focus and recompose? We can't be sure.I agree I have achieved good focus at 1/125sec. But I can not be sure of the OP, this is 135mm, how far was he from the subjects, how steady are his hands for the first shot. Did he focus recompose on the flower shot? If he is going to do this right, set up a tripod and do a real test. There are ways to display the focal point to share in a post like this. Gary please follow up with better test shots off a tripod and what you found, was it actual front or back focus issues or just shooting error.

FocalPointExample.thumb.JPG.33f667b693fc4a940ef77309bbf33817.JPG

Edited by Mark Keefer
Cheers, Mark
Link to comment
Share on other sites

Looked at EXIF on the first photo.

 

Camera: Canon EOS 5D Mark III

Lens: Canon EF 135mm f/2L

Exposure: Manual exposure, 1/128 sec, f/8, ISO 400

 

1/128th second according to the embedded exif data in the photo.

At only 1/128th sec I wouldn't rule out camera shake.

 

Try doing the test again with a tripod.

The Canon 5D Mark III can do micro adjustments and save those adjustments data for a specific lens.

Here is a guide on how to perform this test and task and save yourself some money by doing it yourself.

LINK

 

I probably uploaded the wrong photo out of the test photos. The first shot would have been that shutter speed, but then I moved up a stop to 1/250s.

 

All my shots are not sharp, even subjects that don't move. my handheld technique has always been good, hold camera tight to face, don't breathe or move, wait for wind. My critical indoor studio tripod shots are also not 100% sharp.

 

The retailer has been good, so will receive a new body later this week. I'll upload some comparison shots.

Edited by Gary Holliday
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...