Sharpness question on T2i

Change lenses, focal lengths and apertures and see what you get.  You need to isolate the problem.  It depends on whether it's a RAW photo or out-of-the-camera JPEG and what in-camera sharpness you chose for the JPEG.

Digirame wrote:

Change lenses, focal lengths and apertures and see what you get. You need to isolate the problem. It depends on whether it's a RAW photo or out-of-the-camera JPEG and what in-camera sharpness you chose for the JPEG.

It's a pretty common issue with my 50mm prime and wide angle.  I'll explore more with an aperture (though not sure I have a lot of flexibility there, since I'd prefer not to go higher on ISO).  And yes, it's a RAW.

For each lens, there's a sweet spot for sharpness depending on the aperture and focal length chosen.  Check a lens review to see what that might be.

Stan in NH wrote:

You might also want to try shooting at f/8 to increase your depth of field. That's a very busy image, and it's hard to find where the point of focus actually is ... if that's the issue.

1/320 should be fast enough to minimize camera shake, but I don't know if you're using a lens with image stabilization or not.

As Digirame already asked, is this raw or jpeg? Has there been any post processing? It is also possible that you have a soft lens, but you'd have to have access to other lens to prove or disprove that.

Image stabilization is on, and RAW.  I did a lot of research on the L lens, it's supposed to be a very sharp lense.

Here's where my beginner nature is shining through.  I'm trying to investigate a low aperture as a possible culprit.  If I kept this at 1/320 and boosted to f/8, the ISO would need to be 2000.  Shouldn't I be avoiding high ISOs like this though?

At this point, trying to figure out the focus, I would suggest using AV at f/8 with auto ISO and see what you get. In daylight, I doubt the camera will boost the ISO that high, and I'd worry about that last.

I like this advice, thank you.  Am I being too cautious with 1/320?  I mean, I don't have a steady hand, but am I over compensating?  What is the average shutter speed for a 100mm lense.  I always heard it was best to match the lense focal range.  So a 100mm lense is 1/100mm.  But I also heard to never go under 1/300.  So I really don't know what the best practice is.

The back of the chair, which is further back than your focus point, appears to be in better focus than the spot you focused on.  I think your lens is back focusing.  If all your lenses are doing that, then it could be your camera.

Do you have access to another camera to test the lens?

Olga Johnson wrote:

The back of the chair, which is further back than your focus point, appears to be in better focus than the spot you focused on. I think your lens is back focusing. If all your lenses are doing that, then it could be your camera.

Do you have access to another camera to test the lens?

Interesting. I don't, but I've been seriously considering a 5D. If this is a condition my camera can be victim to, that'll definitely push me into a new purchase.

All in all, if at least the area I focus the dot onto is sharp, I'd be happier.  I definitely expected more from these L series lenses based on many Youtube video reviews I watched.

Stan in NH wrote:

I don't think I've seen this asked here, but have you used manual focus? Are the results the same using AF and manual focus?

Excellent idea! Also I think the T2i has live view. If LV is sharp, then you know there is a fault of the camera in focusing.

I really appreciate this.  Thank you.

Stan in NH wrote:

I don't think I've seen this asked here, but have you used manual focus? Are the results the same using AF and manual focus?

I have.  My eye is not strong through the viewfinder to ignore the beeps, but I've tried it.  Focusing until I hear the beep and see the little green focus circle.  Same results, unfortunately.

Olga Johnson wrote:

Stan in NH wrote:

I don't think I've seen this asked here, but have you used manual focus? Are the results the same using AF and manual focus?

Excellent idea! Also I think the T2i has live view. If LV is harp, then you know there is a fault of the camera in focusing.

I know they use a different focusing system for live view.  I don't use it (because I shoot outside a lot and I just can't see the screen with the sun), but that makes total sense to try.  I will.