My eyes are bleary, my 10D pics blurry... or are they?

[slejhamer]

Help please! My eyes are starting to cross after staring at these images for too long. I'd appreciate any comments or suggestions as to whether you think they show sufficient reason to send my camera to Canon for service.

Based on the results of several different focus tests, my 10D with Canon 28-135mm lens consistently front focuses, as can be seen in this shot, taken at f4.5, 50mm, 20 inches to subject, tripod, timer, IS turned off.

http://members.cox.net/mschlesinger/focustest1.jpg

I have had the same result with other focus tests referenced on this site and elsewhere.

But here is something of interest (to me, if no one else): While sipping a well chilled Pinot Grigio at the dinner table and pondering trans fatty acids, I focused on the "nutritional facts" of a tub of Not Butter. Center-point was selected for the AF, where I have drawn the red square (confirmed in the FVU.) This was also taken with f4.5 at 50mm, hand held for 1/60s, with IS turned on.

http://members.cox.net/mschlesinger/focustest2.jpg

As can be seen from this 67% crop, the letters upon which I focused, while not exactly crisp, are readable. Also, the napkins and bottle show that DOF in front of the focus target was sufficiently shallow.

http://members.cox.net/mschlesinger/focustest3.jpg

(Note: on the above two images, I did apply USM of 50-0.3-0 after resizing for the web, simply to get the sharpness back to approximately what it was before resizing.)

Finally, the letters do sharpen up nicely with some additional USM, and other non-test pics I've taken have had similar results.

http://members.cox.net/mschlesinger/focustest4.jpg

Now, take my word that other tests I've done show a tendency to front-focus as in the first image. Still, these results are not nearly as bad as some others I have seen. As I have no prior experience with digital SLRs, I pose the question to those with experience: are the above images unacceptable? I'm really not sure, and I guess I'd say I'm not terribly pleased with the results, but then again I could probably live with them. Am I being too nitpicky regarding these results?

Thanks in advance,

[Littlebike]

I am somewhat in the same boat as you in regards to focus issues and am still trying to figure out how good good is.

I would like to know where you found the focus scale you are using in your first picture.

[lightandlife]

All digital camers will either front focus or back focus, just like the first swing may overshoot or undershoot a given target. Sometimes a golfer gets a hole in one (I am not a golfer). The question is the extent of error, i.e., whether it is acceptable or not in naked eye.

Your first pic is an example of front focusing. While you aimed at 0 inside the central focusing square, the image is sharpest at the number 20, meaning a front focusing problem. Where is the bottom focusing square, you do not say. If the number 20 is inside the central focusing square, you have no problem. If it is inside or close to the bottom focusing square, it is serious. In my case, the sharpest image point or area was just above the bottom focusing square, and I returned it. If it is inside or just below the central focusing area, I would say it is acceptable. Beyond that you know your 10D's focusing distance falls short of the actual target, probably by more than 10% (just a guess), and you will not be happy.

Sometimes the truth is painful. But I would choose the truth instead of living in oblivion. If you are not happy, just send it for repair, and Canon will fix it. Don't put up with it. I am sure Canon wants you to be happy with your 10D.

[dmalek]

Maybe i'm stupid, but do you choose the AF point yourself or did u ask the camera to select it automatically???

Personnaly I had trouble in default mode, but with fn13 i get back the way my old EOS were used to work.

[Roger_Cavanagh]

Mitch,

The problem with taking pictures of sloping rulers is that you cannot be certain _exactly_ where the AF sensor picks even with only the centre point enabled. The sensor is larger than the actual marking on the focus screen, so could even choose a point outside the square.

Try the test suggested by Canon Germany (http://www.rogercavanagh.com/helpinfo/23_focuscheck.htm). It won't tell you whether your camera is FF or BF, but it's much easier to do and assess.

Regards,

[slejhamer]

Littlebike: the test chart came from a link that Pekka posted. Look for the "10D focus issue demystified" thread. This is actually one of two charts available from the same site. The second is better as it has a cut-out to create a non-sloped focus plane, but the result was the same for me.

Lightandlife and dmalek: the focus point was set by me as the center focus point only, and it was placed directly over the horizontal bar. The first image is a crop of a 100% zoom; I should have mentioned that before - the horizontal bar is in the center of the original. I have confirmed the placement of the AF box using the FVU, as instructed by Canon.

Roger: I understand about the sloping ruler possibly causing errors, but I've done the test in many different ways (including an off-sheet focus plane similar to the one Pekka recommended) and the result was very similar - about 2cm front focus at 50mm, much worse at 28mm.

This morning I ran the test you suggested - a magazine page taped to the wall. The initial AF shot was not bad, but my manually focused shot was superior to the AF image when viewed at 67% or larger. I guess I will be packing the gear and shipping it to Canon... ugh.

Interestingly, I also ran the test using the ST-E2 as an AF assist and got very inconsistent results. The first pic taken with the ST-E2 showed focus that was similar to what I had achieved manually. (Of course I had turned the focus ring slightly before focusing so that the lens was not already in focus.) Then I moved the focus ring to the extreme distance ranges (macro and infinity) and ran the AF - the results were actually worse than I had gotten using the camera-only AF. Odd.

One point I didn't mention - this is my 2nd 10D; the first was much worse than this one, but the dealer exchanged it. Given the similar serial number (6-series) it may have been a bad batch; who knows. Heck, it could be the lens, too, as I don't have an alternate one with which to test. Maybe I'll go buy the little 50mm 1.8 and run the same tests with that one before sending everything off...


:(

[jeffg]

Had same suspisions with my 10D, had a sigma 28-300 and found it to be front focusing, only by stopping down did it improve (but not brilliantly)

Bought a second sigma lens 17 - 35 ex which was much better but on the tests I have done the focus was poor at wide apeture throughout the zoom range and only became 'sharp' when I stopped down below f11

I decided that the 28-300 was so poor (after reading reviews etc, which I should of done before buying duh) that I traded it in for a 24 - 85 Canon lens, what a difference at fully open the same subject (a bag of compost on patio) was very sharp and only needed a slight adjustment with CL1E, the images of the Sigma Ex are as sharp but only when stopped down to f11

[KennyG]

Cameras have been front and back focussing for years, long before digital. The only reason the focus subject has become such a hyped up issue now is, in the days of film very few people had the ability to examine their pictures at such high magnifications. Get some of your 10 year old slides scanned and be the judge, you will be shocked at how bad they are with the same level of scrutiny you apply to today's DSLR's.

The ruler test as carried out by most home users is flawed. You need perfect lighting, no reflections and a high contrast well defined focus point, neither of which apply to the picture above.

I prefer taking someone's picture in soft late evening light, with focus on the eyes, using a good quality lens like an 85mm 1.8 and judging by a real-world picture.

Both my 10D bodies have nailed-on focus with everything from my 50mm 1.4 right through to my 500mm L prime, and I have never taken a picture of a ruler!

I worry that owners of DSLR's have bought them thinking that using them it is a simple matter of point and shoot in idiot mode. How someone can spend a few thousand dollars on a camera and lenses to take pictures of their children and cat is beyond me (rant over). These are the same types who have nothing better to do with their cameras than take pictures of sloping rulers. Get real and start taking worth-while pictures. If the odd one is OOF, trust me, the world isn't about to end and life will go on.

Kenny

[slejhamer]

KennyG wrote:
Get real and start taking worth-while pictures. If the odd one is OOF, trust me, the world isn't about to end and life will go on.




Thank you for your advice. I've taken more than a few shots that did not involve sloping rulers and tubs of fake butter. These just happen to be the ones I posted here. Perhaps because I have no fast cars in my gallery you would not find any of my pictures "worthwhile," but others have and that's what matters. Not one is of a cat, by the way. :)

Here's the point: A close-up flower shot that is OOF by 2cm looks terrible in a 5x7" print, as does the landscape in which the degree of error is in yards. It was the consistency of apparent front-focusing that led me to do the tests, imperfect as they may be, for confirmation. My finding: this is a camera (or lens, maybe) that, when set to AF, can not produce a sharp image of black-and-white text on a wall lit by a 500w halogen flood. Focus on someone's eyes? Right.

As noted, it may be the case that my camera is fine and I've got a bad lens. I will determine that this weekend. It's also possible that I'm in with the

[CyberDyneSystems]

Here's the point: A close-up flower shot that is OOF by 2cm looks terrible in a 5x7" print, ...


Stop it Slejhamer,. you're Killing ME!!!! :D roflmao!

//wiping iced coffee OOF of my screen :)

[sjprg]

All my lenses and 10D are at Canon for service. When the name on a ship is blurry at 200 yards on a bright beautiful day, I would say the image IS blurly, The same picture with a different brand camera confirms it by being exactly what would be expected. I've been carring my 7i for backup lately.
Cie la vie!
Paul