Pin sharp images

[realityinabox]

Lens: EF 85mm F1.2L @ f1.2, 1/800, ISO 100

You can't expect much more than a thin sliver of the frame to be in focus as f/1.2. That, combined with the fact that very few lenses are completely sharp wide open (the 85L not being one of them), and I'd guess that your results are typical for that lens. Just figured out how to view the shot, looks like about what I'd expect at f/1.2.


I don't know what you're looking for in terms of sharpness, but this shot was taken with my 5DII and 27-70L (btw, this is not a crop, I positioned myself as to have her face fill the frame, thus using far more pixels per inch than if I had shot much wider and had to crop down to this composition. If this were a crop of a larger image, I couldn't rightly expect tack-sharp focus to this extent)






<table id="Inbox" cellspacing="0" width="100%"]
<tbody>
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<td width="30%"]Camera:</td>
<td>[b][url="/cameras/canon/eos_5d_mark_ii/]Canon EOS 5D Mark II[/url][/b]</td>
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<td width="30%"]Exposure:</td>
<td>0.005 sec (1/200)</td>
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<td width="30%"]Aperture:</td>
<td>f/5.0</td>
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<td width="30%"]Focal Length:</td>
<td>70 mm</td>
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<td>


ISO Speed:
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100
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As you can see, the area around the eye is in sharp focus, but her nose isn't. I was shooting pretty close to the MFD to get the composition I wanted, but shooting at f/5 gave me the sharpness I wanted. If I had shot at f/2.8, I'd probably have lost most of that sharpness.


You have to remember, as somebody else pointed out, you are almost never going to view a shot as large as you can on a computer screen. Try getting prints of a few of your tack sharp shots and see that sharpness "disappear", then get a print of one of your non-tack sharp shots and compare. I'd be willing to bet they will make very similar prints, depending on the size.


Prints can't display at the same insane resolution as a 100% crop on a compute screen can. Looking at a grab at 100% on a screen would essentially be the equivelent of putting your nose up to an 11x16 print. Prints (like televisions) are meant to be view at a distance, combined with the "loss" of resolution when in print, and that tack sharp shot isn't quite as important.


I think that subject framing is also a major factor. In my photo above, it is important that her eye be in sharp focus because her eye fills far more of the frame than in your shot. I would assume that in my shot, having the eye larger in frame also makes it easier to achieve that tack-sharp look.



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Sorry guys, image is too large. But if I resize will you guys see the issue?

Which is exactly my point. Pixel peeping is fun, but it can get out of hand IMO. Sometimes reminds me of little boys in the middle school locker room. Tack sharp does matter, but only to an extent, and only in certain situations. In the photo you provided, your subject rather small in the frame, and you shot wide open (typically the softest part of the lens), so yes, she isn't tack sharp. But when it comes down to it, does she need to be in this shot?
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[jho288]

Thanks so much for your reply and your photo looks great!


My wife just said it is very sharp and that's what I want to achieve too. Perhaps I need to go back and re-look at my choice of aperture. That's probably my problem.


I'll upload another one of my son and not sure if it was hand shake or what.





Thanks alot for your input

[realityinabox]

After looking through some of my photos from that same shoot, it is clear to me that the size of thesubjectin frame andapertureselection make a huge difference in sharpness.





This shot is at f/2.8 and is a comparable subject framing as the shot you uploaded. As you can see at 100%, it isn't tack sharp, but when looked at medium or even large, it is quite acceptable. The same would go for your shot.


http://farm2.static.flickr.com/1339/4731047902_c3af123905_o.jpg


In this one, the subject's face is a very small portion of the frame, shot at f/5.6. As you can see, her face is not tack sharp at 100% (not even close), but when you click on medium or large, the shot is still in focus. So, even stopping down the aperture isn't the whole ball game, it would seem.



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http://farm2.static.flickr.com/1420/4730413933_e26f524250_o.jpg


Now, if you had filled the frame with your subject's face, and dialed down a few stops on the aperture, you should get some extremely sharp shoots, especially with that 85L of yours. Keith B had some amazingly sharp shots of one of his friends up not to long ago with his 85L, similar tight framing, and shot at about f/5.6. You could see the pours on his subject's face in perfect detail, and the eyes weremesmerizing.

[jho288]

Hi there,


Wow that's great, new insight. So basically from what I'm reading and linking these back to my usual shots, is the aperture and the size of the subject that fills the shot.


For portraiture, achieving sharp shots would be easier to obtain as the subject's size is bigger, great example with the f/5.0 shot. (and great picture too)


I see what you mean, I'll dig up some photos too to see if the sharpness is deeply related to size of the subject.


What about if your using 70-200 and shooting at MFD 200mm, i suppose it will also depend on the size of the subject against the frame.


I'll probably try a test shot light metered to obtain the correct fstop. Hopefully something comes up.

[neuroanatomist]

I see what you mean, I'll dig up some photos too to see if the sharpness is deeply related to size of the subject.

Take the simple example of focusing on an eye. Perceptively, 'eye sharpness' is often (and most easily) judged by how easy it is to distinguish the eyelashes from one another. If the subject is closer (or you're using a longer focal length), the eye takes a larger portion of the image. That means there's more physical separation of the eyelashes based on where they fall on the sensor, and thus it will appear sharper.