topic Re: Trouble focusing Canon 60D in EOS DSLR & Mirrorless Cameras

Trouble focusing Canon 60D

TotallyRhonda — Fri, 27 Jan 2017 16:29:50 GMT

Hello,

I am having trouble getting my shots to be in sharp focus. I am shooting on a tripod with ample light. I am using a 24-70mm Canon EW-83L lens. The F stop is set at 16. Exposure is 1/50 and the iso is 250. When I zoom into the carpet it is blurry. Can anyone help me figure this out?

Re: Trouble focusing Canon 60D

kvbarkley — Fri, 27 Jan 2017 16:33:29 GMT

How much are you zooming? If it is over 100% you are asking the computer to make up information.

Re: Trouble focusing Canon 60D

TTMartin — Fri, 27 Jan 2017 16:44:57 GMT

@TotallyRhonda wrote:
Hello,

I am having trouble getting my shots to be in sharp focus. I am shooting on a tripod with ample light. I am using a 24-70mm Canon EW-83L lens. The F stop is set at 16. Exposure is 1/50 and the iso is 250. When I zoom into the carpet it is blurry. Can anyone help me figure this out?

Your use of f/16 is the issue.

With a APS-C sensor generally after f/8 you start to loose sharpness due to diffraction.

With the 60D you'll likely see maximum sharpness from that lens at f/5.6.

Re: Trouble focusing Canon 60D

ebiggs1 — Fri, 27 Jan 2017 17:05:58 GMT

TotallyRhonda,

Is this the lens you have, EF 24-70mm f/4L IS USM lens? Canon EW-83L is a lens hood.

At any rate I d/l your sample and I think it is pretty good for the gear you have. I couldn't determine your focus point because the entire sample looks the same to me. You might be a victim of the diffraction limit. I don't know what it is for the EF 24-70mm f/4L IS USM lens but I suspect it begins at f16. Try the same photo at f11 anf f8. Diffraction happens because light begins to disperse or "diffract" when passed through a small aperture.

You didn't mention the focal length? The greater the distance from aperture to sensor, the greater the magnification. This increases the magnification of the airy disk, too. What this means is, what was sharp at 70mm @ f16 will not be the same as 24mm @ f16.

Re: Trouble focusing Canon 60D

Waddizzle — Fri, 27 Jan 2017 19:13:58 GMT

@TotallyRhonda wrote:
Hello,

I am having trouble getting my shots to be in sharp focus. I am shooting on a tripod with ample light. I am using a 24-70mm Canon EW-83L lens. The F stop is set at 16. Exposure is 1/50 and the iso is 250. When I zoom into the carpet it is blurry. Can anyone help me figure this out?

In addition to diffraction effects of the f/16 small aperture, you should also bear depth of field in mind.

http://www.dofmaster.com/doftable.html

You could also be seeing blur from some camera shake, too. There is no harm in using ISO 800. Try to get your shutter speed faster. Compare hand held shots to shots taken from a tripod. Beware that tripods can shake, too. I get my sharpest photos by locking up the mirror and using the shutter delay timer.