5D MKII focus questioning

[shybuck]

I've had my new Canon now for about 6wks. This shot (A) was taken @ f20, iso100, Auto focus. The 24-105 lens was out all the way to 105mm. The camera was on a tripod, IS off AF on, w/remote and ML. Nothing was applied to this shot it's straight out of the camera CR. It's shown here @ 100%.

The next example ( was shot the same way @ f18, 97mm.

I'm not happy with the clarity of these shots. Am I too critical? I realize this lens won't be the best at 105mm @ f20, but is this acceptable? I have played around with the micro adjustment on this lens for hours with no discernible results before the trip out west. I heard both sides of the critique corner about this lens giving me no real balanced opinion about the lens.

Before processing in CS4, I want a better focus output. I want to be able to print these images at sizes up to 24" by whatever. Would you be happy with this? Should I send back to Canon? What other tests could I perform?

I would be thankful for anyone's comment on this who is familiar with this set up. Thanks again in advance.

[dchew]

I suggest two things:

First, try shooting at a wider aperture, say f/8, with this lens.  You are probably diffraction limited at f/18 and f/20.  Second, next time you are in a situation like this, try one version focused manually using Live View at 10x, then compare them to the auto focus results.  

If those were 100% crops, I would say that's what I would expect from this lens at those apertures.

Dave

[daws]

As Dave notes, the 24-105 is much sharper at f8 at all zoom lengths. On my 24-105/5DII, diffraction limiting is noticeable at f11, and quite objectionable by f16.

Check out the 24-105's ISO Chart comparisons at The-Digital-Picture.com. Even though the tests go down to only f16, it'll give you a fair idea of how diffraction limiting softens the 24-105 at various zoom lengths and at apertures smaller than f8.

Two other things I do to improve the sharpness of my 24-105 when it's on a tripod: manual focus at 10x magnification in live view, and a 16 oz. beanbag draped over the lens and camera (and allowed to settle after placement). And at 105mm, even with my heavy tripod on solid ground and geared head, any wind is liable to take some toll on sharpness.

Even with optimum conditions and best technique, the image will still be a bit soft out of the camera, so judicial capture sharpening and output sharpening techniques are a must. A search of this site will give you excellent pointers and direct you to additional resources.

One last suggestion: if you plan to do a lot of tripod work with the 24-105 at 105mm, and want 24" prints, you may wish to look at the Canon EF 100mm f/2.8 Macro. Currently being replaced by version II, the I version, although not an L lens, is significantly sharper than the 24-105 at 90-105mm, and quite inexpensive now that the II is out.


EDIT: Sorry, forgot to answer your questions. From what I can tell from your photographs, and from my experience with the 24-105/5DII, there's likely nothing wrong with your lens.

[lisa_r]

shybuck, I suggest you have a print made and have a look at it. I suspect you will be bowled over by how good it looks. You might be forgetting that at 100% view you are effectively looking at a 6.5 foot print from 12" away (as rendered on your 72ppi monitor.)
Try other f-stops as the fine gents are suggesting, but these images are sharp enough for almost any size print.

[madmanchan]

What do you mean by "straight out of the camera CR"?

Is there sharpening applied to the image? I imagine so ...

[shybuck]

shybuck, I suggest you have a print made and have a look at it. I suspect you will be bowled over by how good it looks. You might be forgetting that at 100% view you are effectively looking at a 6.5 foot print from 12" away (as rendered on your 72ppi monitor.)
Try other f-stops as the fine gents are suggesting, but these images are sharp enough for almost any size print.

thanks for your reply, perhaps I'm overly critical on the sharpness. I don't know. This camera is so new to me. I'll do some printing and reconsider

[shybuck]

What do you mean by "straight out of the camera CR"?

Is there sharpening applied to the image? I imagine so ...

no sharpening applied, just a camera raw file.

[shybuck]

As Dave notes, the 24-105 is much sharper at f8 at all zoom lengths. On my 24-105/5DII, diffraction limiting is noticeable at f11, and quite objectionable by f16.

Check out the 24-105's ISO Chart comparisons at The-Digital-Picture.com. Even though the tests go down to only f16, it'll give you a fair idea of how diffraction limiting softens the 24-105 at various zoom lengths and at apertures smaller than f8.

Two other things I do to improve the sharpness of my 24-105 when it's on a tripod: manual focus at 10x magnification in live view, and a 16 oz. beanbag draped over the lens and camera (and allowed to settle after placement). And at 105mm, even with my heavy tripod on solid ground and geared head, any wind is liable to take some toll on sharpness.

Even with optimum conditions and best technique, the image will still be a bit soft out of the camera, so judicial capture sharpening and output sharpening techniques are a must. A search of this site will give you excellent pointers and direct you to additional resources.

One last suggestion: if you plan to do a lot of tripod work with the 24-105 at 105mm, and want 24" prints, you may wish to look at the Canon EF 100mm f/2.8 Macro. Currently being replaced by version II, the I version, although not an L lens, is significantly sharper than the 24-105 at 90-105mm, and quite inexpensive now that the II is out.


EDIT: Sorry, forgot to answer your questions. From what I can tell from your photographs, and from my experience with the 24-105/5DII, there's likely nothing wrong with your lens.

I appreciate your suggestions very much. I had not thought about the live view option with magnification. I'll give this a try. I'm surprised the 100mm macro will be sharper not being an L  lens. Seems a lot of research is to be done before buying the next lens.

[daws]

I'm surprised the 100mm macro will be sharper not being an L  lens. Seems a lot of research is to be done before buying the next lens.

The 24-105 is a good walkaround and landscape lens. With attention to good shooting technique and with proper post processing and printing, it can produce very nice landscapes. It is a zoom lens, and of necessity a compromise compared with some other prime lenses in Canon's line. (For example, the differences in sharpness, distortion and CA between the 24-105 at 24mm and some other 24mm prime lenses in Canon's line are obvious in chart-comparison tests like those on The-Digital-Picture.com.)

But I think what matters is less chart comparisons, and more how your lens and camera work for you in the real world of shooting, processing and printing. What matters is that you utilize the entire production chain of lens, camera, shooting technique, processing software, processing technique, printer and printing technique, to deliver the technical quality of print that you want at the size that you want. The lens is an important part of that chain, but it is only one part.

[telyt]

... I'm surprised the 100mm macro will be sharper not being an L  lens.

In my experience "L" by itself does not guarantee sharpness, neither does a lack of "L" guarantee a lack of sharpness.