Calibrating Focus on 5D Mark III?

fjrabon · Oct 30, 2012

dorian7 said:
Thanks for the tips here is one that I am very happy with the focus:

View attachment 24424 View attachment 24425

ISO160, 1/100, f1.8

see how much better the eye on here looks than the earlier one I posted.

You're likely seeing the difference between an 85mm handheld shot with 1/80 sec v. 1/100 sec. 1/80 with an 85mm is starting to get to the territory where you will need good technique to really get tack sharp photos, where 1/100 is fast enough with an 85mm that you'd have to have bad technique to get unsharp photos.

JustinL · Oct 30, 2012

why is your shutter speed so slow at 1.8? It would seem like you're shooting in a dark room, use a flash get the shutter up more.

gsgary · Oct 30, 2012

Put your iso up 400 or 800 and close your aperture so both eyes are in focus

imagemaker46 · Oct 30, 2012

That camera has a great iso range, use it.

MLeeK · Oct 30, 2012

Your problem has nothing to do with back or front focusing. It's the aperture, distance to the subject and the low shutter speed.
Some people can hand hold as low as 1/50 of a second as long as your subject is a still life, however it's not very often. I always teach no slower than 1/80 if you are rock steady and your subject is not alive. 1/125 for the average steady person and a stationary not moving subject. 1/250 for a live child.

dorian7 · Oct 30, 2012

Thanks for all the help everyone! I have been told in the past that you should be fine anything above 1/60, so I didn't give it a second thought until now. Next time I will turn the iso up and the shutter speed. I should work on my holding methods as well since there may be a time where turning up the iso is less of an option.

I love the wealth of knowledge on this forum. Thanks again.

MLeeK · Oct 30, 2012

dorian7 said:
Thanks for all the help everyone! I have been told in the past that you should be fine anything above 1/60, so I didn't give it a second thought until now. Next time I will turn the iso up and the shutter speed. I should work on my holding methods as well since there may be a time where turning up the iso is less of an option.

I love the wealth of knowledge on this forum. Thanks again.

In the meantime check out a DOF calculator and get a feel of how VERY shallow DOF will be at f/1.8 Online Depth of Field Calculator
At 5 feet from your subjects you had about 4 inches of REASONABLE sharpness front to back. The Circle of confusion is only .03MM. That's your sharpest point. Keith can explain DOF better than I can