Depth of field

[mikeyg]

Hi all.

Got a newbie photographer question, so please bear with me. :-)

With regards to depth of field in tabletop photography, I understand that if I physically bring the camera back and away from the subject my depth of field is greater. BUT what if I bring the camera back BUT use a zoom lens to get in closer, am I defeating the purpose?

I hope this makes sense and you're not going DUH! :-)

Thanks much!

[Jon]

Yes. Depth of field is affected by three things: lens aperture, lens focal length, and subject distance. If you back up, you'll get a greater depth of field. If you zoom in you'll get a shallower depth of field. If you stop down your lens, you'll get a greater depth of field. If you want to control your depth of field, consider using a smaller aperture and slower shutter speed (if it's within a reasonable range) rather than backing up.

[mikeyg]

Thanks Jon, thats what I had thought.

When I use a fixed 50mm lens, it gives me the sharpest image when I pull the camera back for a greater dof.....but the downside is that the useable image is smaller....I was hoping that if I used a 28-100 zoom and pulled back the camera and then used the zoom to get a larger useable image that my dof wouldn't be affected......when I have the camera closer with teh fixed 50mm and stop down the lens, my dof IS greater but the overall pictues isn't as sharp......I guess I just need to keep experimenting to find the balance.

Thanks much!

[AjP]

here is really nice visual calculator and explanation (http://www.dofmaster.com/dofjs.html)s, kinda gives you and idea

[foxbat]

And here's another great explanation:

http://www.oncloserinspection.com/Photomacrography/Photo_Myths/DOF1/DOF1.htm