Views from the 28th Floor

[bburton]

Originally Posted by Wonka

Roy,

Please help me understand some basic photography stuff here. When I look at your pictures everything seems to be in focus, yet you shot them all at f/4. I thought when you wanted stuff like this to all be in focus you need to shoot at f/8, f/11 or even higher. I thought when you shoot at f/4 or lower only the specific item you are focusing on will be in perfect focus? What am I missing? Thanks.

It does somewhat seem counter intuitive. However, here's a little online depth of field calculator:

http://www.dpreview.com/learn/?/Glos...f_Field_01.htm

Plug in some of Roy's EXIF data, and you'll see that he was working with a pretty big DOF, i.e., that area where all objects are in focus. For example, one I tried where he might have been focusing on a building 200 meters away, he had a DOF of 14 meters to infinity. Try it.

[Roy]

Bruce, what are you using to figure that out with? I don't see how you do it. I'm glad you answered Wanka's question though because I don't know what the answer is. I figured I just got lucky! LOL. Looking back now, I should of used a higher f stop.

Duh, I see now. You used the calculator and plugged in some numbers. I don't even remember where my focus was on most of these but it's true, there was a huge DOF. So I guess I did get lucky. I don't take many shots from 280 feet or whatever it was up in the sky.

[bburton]

Originally Posted by Roy

Bruce, what are you using to figure that out with? I don't see how you do it. I'm glad you answered Wanka's question though because I don't know what the answer is. I figured I just got lucky! LOL. Looking back now, I should of used a higher f stop.

Duh, I see now. You used the calculator and plugged in some numbers. I don't even remember where my focus was on most of these but it's true, there was a huge DOF. So I guess I did get lucky. I don't take many shots from 280 feet or whatever it was up in the sky.

Roy, I was thinking specifcally of your shot of The Tower across downtown and just estimated numbers not provided by your EXIF. The surprising point, as you said, is how much DOF there really is in such shots even with relatively large apertures.