Please Help Me Tweak My 7D to Improve Image Quality

Started Mar 10, 2013 | Discussions thread
TTMartin Veteran Member • Posts: 7,304
Re: Thanks Zee!

steve88 wrote:

. . . Why can't the image be better coming out of the camera so that post-processing doesn't require a PhD? . . .

It can, you just need to make sure that from your point of focus you have adequate depth of field.

In neither of the photos posted that was the case. In the first photo, there is a lot of depth of field (due to the subject distance), but, the point of focus is behind the batter (point of focus may have been moving from/to the backstop).

In the second photo, the point of focus is on the runners front hand, but, there is inadequate depth of field for the runners face and body to be sharp.

Either your point of focus has to be spot on (hard for fast moving sport photos), or your depth of field has to be a little deeper to compensate for it.

The closer the subject the shallower the depth of field. So someones football player photo taken at 200mm f/2.8 and from 100 feet away, will have a 4 times greater depth of field than another photo taken at 200mm f/8 and 30 feet away.

Subject distance 100 ft - 200mm - f/2.8

Depth of field
Near limit 96.1 ft
Far limit 104.2 ft
Total 8.15 ft
In front of subject 3.91 ft (48%)
Behind subject 4.24 ft (52%)

Subject distance 30 ft - 200mm - f/8

Depth of field
Near limit 29 ft
Far limit 31.1 ft
Total 2.04 ft
In front of subject 0.99 ft (48%)
Behind subject 1.06 ft (52%)

 TTMartin's gear list:TTMartin's gear list
Canon PowerShot S100 (2000) Canon PowerShot SD1000 Canon PowerShot G1 X Canon EOS 40D Canon EOS 400D +26 more
Post (hide subjects) Posted by
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow