Canon 50D doesn't seem sharp

[Phil Atkin]

I'm dissatisfied with the images I'm getting from my 50D. They often aren't as sharp or vivid as I would like. I don't know whether I'm being unreasonable in my expectations or whether there's something wrong with my kit.

The mountain scene illustrates my problem. It doesn't do the original justice, and there was plenty of light. It was shot with an EF-S 15-85 at f7.1, 1/125s, ISO100.



I set out to try to microadjust the focus on this lens, and took test shots tripod mounted, 1/13s@f5, ISO100. Again the image seems soft, and in fact I can't do any microadjustment because all the marks on the scale seem equally soft! (This is a ~450 pel crop from the centre).



I did a similar test with the 50mm/f1.8 lens, also at 1/13s@f5, ISO100. The characteristics are different (more CA, for a start) and in general it seems that the more distant marks are in better focus, but still the softness seems overall, rather than specifically to do with defocus.



Finally, I should mention that I was not able to achieve noticeably sharper images by focusing manually. Also that the above were converted to JPEG using PS Elements and default settings.

Anyone have a view on whether my equipment or my expectations or my skill is to blame?

[Poljazz]

Have you used the diopter corrector in your viewfinder? The framelines and information should be made as sharp as possible.

[Phil Atkin]

Yes. But the problem is in the captured images, not how they look through the viewfinder. The Diopter adjustment has no effect on captured images.

[Polar01]

Where you mirror up and remote release as 1/13 sec is pretty slow.

Allan

[Phil Atkin]

No, but the results of those tests reflect the more general problem, which is illustrated by the mountain scene. The camera was mounted solidly on a tripod with the stabilizer off. The slow shutter actually means that any contribution to blur from camera motion is a less significant fraction of the whole exposure.

[Adrian]

The top picture made me wonder what setting you are using for white balance and what priority settings you had on the camera and whether some degree of exposure compensation was in play. The post implies that the photos were in raw originally so presumably you were not using any of the scene settings available in the menus? The washed out colour should be easily correctable in processing the raw image.

I presume you don't have another body to test the lenses. I think my starting point would be to reset the camera to default settings and do some test shots at a variety of apertures and see if you ever get sharpness. Is this a new camera and lens kit? (ie has it always been soft or did you used to get sharp images?)

[Polar01]

Lets talk the mountain scene, the foreground is pretty sharp, you are using f/7.1 with your 15-85mm lens. Lets say you focused on something about 20ft away at 15mm then everything from 3ft away to infinity would be in focus, as soon as you got to 37mm your depth of field would now be only approx. 580ft, now go to 50mm now 30ft, at 85mm only 8ft. Even if you focused on something 100ft away you depth of field would be 1000ft in focus. If you are shooting landscape with objects in the foreground and distance than at least f/11, better f/16. I often use a 35mm or wider set at f/18 focused on something 8ft away so everything from 4ft to infinity is in focus.
Did you notice that you had wind, now the 1/125 sec shutter would have been fast enough to stop any movement in the leaves close up but still could have set up movement in the tripod especially if the centre stand was raised, how do I know you have some air movement look at the water in the pond the wind is coming towards you right to left so stabilizer on may have been of some help. However I believe that it is lack of Depth of Field that is you problem with the mountain image not equipment.

Cheers:

Allan

[Manfred M]

I think this is more of a PP / camera setting issue than anything else.

Your exposure does look off a bit. In mountain shots, I find that haze and sometimes be an issue and soften the overall image.

A slight exposure adjustment and a bit of work on curves seems to sharpen it up nicely. If you want a bit more "oompf", playing with the vibrance or saturation will give the shot more "body", but I didn't go there.

[Phil Atkin]

Thanks Adrian. Yes, the original was RAW, with no scene settings in play. WB was automatic. AFAIK, the camera is still at its default settings for everything relevant. The only other body I have is much older, but perhaps it's worth a try. The problem isn't new, but I've found myself thinking about buying much more expensive cameras & lenses and I'm trying to find out what is really wrong, in order to avoid trying to fix the wrong problem.

[Phil Atkin]

Thanks Allan. I have three images of the mountain scene and in each case the chosen autofocus point was on the mountain. Strangely, the distant slopes seem less sharp than the foreground; perhaps this is evidence for the 'haze' theory. The mountain scene was handheld with stabilizer; I have three shots and they are very similar in terms of sharpness.

[Manfred M]

Thanks Adrian. Yes, the original was RAW, with no scene settings in play. WB was automatic. AFAIK, the camera is still at its default settings for everything relevant. The only other body I have is much older, but perhaps it's worth a try. The problem isn't new, but I've found myself thinking about buying much more expensive cameras & lenses and I'm trying to find out what is really wrong, in order to avoid trying to fix the wrong problem.

Thanks Adrian. Yes, the original was RAW, with no scene settings in play. WB was automatic. AFAIK, the camera is still at its default settings for everything relevant..

Two things to remember Phil - the camera settings (those not affecting the metering mode or focus point selection), i.e. white balance, contrast, etc. have NO impact on your RAW file; it is simply what your sensor recorded. If you shoot jpeg; the camera will add sharpening, contrast, etc. to the image.

As this is a RAW image, no in-camera sharpening occurs; and of course your camera will deliver a slightly soft image, thanks to the AA filter. If shooting RAW, some degree of sharpening in post-processing is required.

[Phil Atkin]

Thanks Manfred. I'm quite surprised by how much sharper your image looks than mine, when you say that all you have done is adjust the pixel-by-pixel intensity/colour mapping, with no sharpening. You may be right about haze in this case; the image is from Iceland and I often found that there was cloud at ground level there! Nevertheless, the problem with softness is something I've observed many times with this lens/camera combination, and the problem can't have been haze in all cases. However, perhaps it's looking more like an issue with contrast rather than focus.

[Phil Atkin]

Manfred: my initial reaction was a huffy "Yes, I know all that". But I guess I hadn't thought that my expectations of sharpness come from comparing my RAW images against JPEGs (generally from other cameras, because I always shoot RAW). And I hadn't thought about the fact that there may be more sharpening applied to those processed images I'm comparing against. But as I said, the image I've posted is not completely direct from the sensor because it's had Elements' default sharpening applied to it. And DP Pro (my usual RAW processing tool) also applies a default level of sharpening; I find my images soft despite this.
Do you have a feel for the amount of spread, in pixels, that I can expect the camera's AA and noise reduction to cause?

[DanK]

Phil,

First, both your 50D and your 15-85 should be able to produce very sharp images. I use both. Check out my smugmug site.

Second, as Manfred says, most of the camera settings are not relevant to this problem. You can ignore white balance, and as long as exposure is reasonably close--close enough to show detail--it won't matter either.

At this size, I personally can't tell whether the mountain shot is actually abnormally soft. The lack of contrast certainly creates a soft appearance, as Manfred shows, but that is not the same as a deficiency in actual sharpness of the image.

I would redo the text shots at a faster shutter speed, using bright lighting to make this feasible. This will rule out factors like vibration from the mirror, although that is not the culprit.

My next step after that would be to try a focus test chart like this one, at a 45 degree angle to the lens, as a first test to see whether you have severe front or back-focus issues. If you do, the 50D has MFA. I would do this first with center-only AF and then with MF. If these show nothing on the chart in sharp focus, then I think you have a problem with the body. I would show you what this is supposed to look like, but I just migrated my smugmug site to their new interface last night, and I am having trouble linking to the photos I have stored there but generally don't show.

Dan

Since you have an old body, I would duplicate every test with both bodies.

Keep in mind that a minor amount of softness is normal, given the anti-aliasing filter. However, it should be minor.

[Phil Atkin]

Thanks Dan,
Good to hear that I should be able to do better without spending a fortune!
I'll try the more sophisticated test chart and improved imaging conditions as you suggest (although I stopped the previous experiments when I discovered that nothing seemed sharp so I couldn't see how MFA could help. We'll see...). What do you suggest for focal length and shooting distance?
I certainly have an old body, although I don't see... Ah, you mean the camera. The problem with that is that it's a much older model so won't be directly comparable. But worth a try.

[DanK]

Phil,

I'm not certain what the optimal distance is, but I think both Canon and FoCal have it on their websites somewhere. I vaguely recall 50x focal length. However, you don't need to be precise for this purpose. I think you will get your answer even if you are quite close, because you are checking for a serious problem, not a minor discrepancy in focusing.

You didn't say where you got your 50D. I'm assuming you bought it used. If you bought it from a vendor that guarantees what they sell (here in the states, a number of the more reputable used equipment vendors do), you should be able to swap it if it turns out that the body has been damaged. If not, Canon service may cost a fair amount, relative to the currently low prices of 50Ds.

Good luck. Once you get this resolved, I think you will find the 50D a very capable camera, and the 15-85 is a very high quality lens.

Dan

[Phil Atkin]

Dan,

I used a focal length of 50mm at around 2.5m, so that's about right.
I bought my 50D new, but several years ago. It's been repaired twice for serious problems (i.e. won't turn on), most recently a couple of months ago. I'm not really sure what sort of problem with the body could cause this: if the sensor were not parallel, or not at the correct distance from the lens, then it should be possible to achieve correct focus somewhere in the field of view, shouldn't it?
Anyway, thanks for the reassurance and I'll try the next set of experiments when I have a moment.

Phil

[Manfred M]

Thanks Manfred. I'm quite surprised by how much sharper your image looks than mine, when you say that all you have done is adjust the pixel-by-pixel intensity/colour mapping, with no sharpening. You may be right about haze in this case; the image is from Iceland and I often found that there was cloud at ground level there! Nevertheless, the problem with softness is something I've observed many times with this lens/camera combination, and the problem can't have been haze in all cases. However, perhaps it's looking more like an issue with contrast rather than focus.

I suspect you might want to tweak your PP workflow; certainly in this image, that appears to be the main issue.

Iceland is funny; it seems to be either crystal clear or you are cursing the atmospherics (the downside of a maritime climate where the Gulf Stream and the Arctic air seem to be forever fighting); I've been there a couple of times, so I know what you mean. Having a blue, rather than grey sky is a bonus!

[inkista]

One small suggestion for the focus test if you haven't already thought of it--use manual focus to take AF accuracy out of the equation, and use liveview and 10x magnification to focus, not the viewfinder.

[DanK]

Phil,

I have my smugmug site working again, so here are two examples of test shots I took with my 50D. Neither was with the 15-85, but that lens should not be dramatically different. You can see that the 50D should be giving you very sharp images.

Dan

http://dkoretz.smugmug.com/photos/i-...q3P4tHN-X2.jpg
http://dkoretz.smugmug.com/photos/i-...GLMkZR7-X2.jpg