[gd]

This is a picture of my girlfriend's brother-in-law and his son.
It might be the best portrait style pic I've taken....

Here are my two questions:

1 - Do we think that the background is a little bright for the foreground?
2 - I was using a zoom lens from about 5 metres away (15 feet for our US based citizens ) does this explain why the child is sharp, but the adult is a little less sharp. i.e. is it a focus thing or a depth of field thing.. or both?

This is my latest issue, where I'm getting good composition, but finding that I get one subject sharp and the other less sharp. I figure DOF and focus play their part.. but what can I do to ensure two subjects are sharp in my pic?

Can/should two subjects be sharp in a picture?

[slejhamer]

i.e. is it a focus thing or a depth of field thing.. or both?

Both. Remember that focus exists only on a plane that is parallel to the lens. DOF is the distance in front of and behind that plane in which objects appear to be in focus, but they really are not. So in the above, let's say you focused on the boy's ear. With a long lens and wide open aperture, the DOF may not be deep enough to include daddy in the zone of acceptable sharpness.

For example, according to this HANDY DEPTH OF FIELD CALCULATOR, my 70-200mm lens set at 200mm, f/4, on my Canon 10D, focusing on a subject 15 feet away, will have total DOF of approximately three inches! And remember that some of that is in front of the focal plane, some behind, so the distance from the plane of focus to the far limit of acceptable sharpness will be more like two inches (or less.) No way daddy's going to be sharp.

Bottom line is that if you're using a very long lens, you need to stop down the aperture in order to get greater DOF (at the expense of shutter speed, of course.) Or get your subjects closer to the same plane of focus, if possible.

[gd]

thanks slej. That's awesome...

I figured I understood the of concept to mess around with it and let my aperture be my DOF, but I wasn't giving enough consideration to an "APPROPRIATE DOF APERTURE". You have delivered me a level of detail I can now work on to understand.

According to my meta data and the site you provided (which I've now bookmarked) I had a range of 14.5 to 15.6 feet to get them all in and sharp at f4.0. I would have had double the distance at f8.. which is interesting.

In my shooting course my instructor has mentioned bits about focussing 1/3 into my scene for sharpness across the whole scene (which the calculator also suggests) but I've not yet really connected that into my set up.

[shuttertalk]

Technical discussions aside, I love the shot gd! The facial expressions are so similar - it's almost comical! Like father, like son, eh?

[Don Schaeffer]

http://www.shuttertalk.com/forums/images...a_boyz.JPG


1 - Do we think that the background is a little bright for the foreground?

Yes. I think it would be better if the background were slightly darker than the foreground or if you could at least dim the highlights.

--Don

[gd]

thanks Don... this has been my feeling as well... so to get a variety of opinions I thought I would post.

Thanks ST. As I said at the start.. it might be the best portrait I came up with.

In colour, it's ok... the back ground is a mess of colours... but in sepia/b&w its a much better expression, I think.