Depth of field with close up photos

[brighamr]

Hi

I am photographing things like a melon or an apple with a Nikkor 210/5.6W on a Sinar F2 from above

I shoot at f64 and set focus 1/2 way between the top and the lowest visable point i.e the waist of the thing
This is about 100mm of depth

To fill frame I take the lens close till it fills the ground glass then move the rear standard away untill I get focus on the waist
I note the position of the rear standard and then back away some more until the top becomes sharp
I note the new position and then split the differance


looking at the photos nither the top or the waist are sharp
the camera is set up so that the melon is full frame 4x5
would I be better off with a wider lens to get things as large as possible with as much depth of focus or should I use a longer lens

which way to go ?

I guess a macro lens will just get me bigger without increasing the depth

thanks for any ideas

robin

[Jim Noel]

You may be getting into diffraction with the very small aperture.
At the distance you describe an indicated f 64 is closer to f 128.

[Jim Galli]

You have a couple of choices really. You can shoot the melon at f5.6 with a razor thin area of perfect definition of your choosing and leave the rest to the viewers iimagination, or you could forget the big camera and photograph it with a Canon G9 or some such. A 1/3 inch chip behind a 13mm lens is fabulous for melons. A large format camera is fabulous for shallow depth of field perfectly placed.

[Pete Watkins]

Jim,
Would using camera movements help DoF when taking closeups?
Pete

[David A. Goldfarb]

You've got a Sinar F2. Use the DOF calculator. Here's a handy post over on APUG with instructions--

http://www.apug.org/forums/forum44/2...tml#post249564

That said, it looks like for the composition you want, you can't really get the DOF you want on 4x5" without stopping down more than is reasonable. The options are to make the image work with less DOF or shoot a smaller format (or use less magnification and crop).

A wider lens will not give you more DOF, if you are framing the subject with the same magnification. You'll just get less working distance.

Swings and tilts usually don't help much with this kind of subject, where everything that you want to be in focus doesn't lie in the same plane.

[Jim Galli]

Jim,
Would using camera movements help DoF when taking closeups?
Pete

Certainly using camera movements can help you get what you're after but my point is that I feel the strength of the large and larger cameras isn't to have every molecule pin sharp, but rather to use the great creative strength available in selective shallow focus. Pin sharp pictures are easy as pie with a £120 digi. The digi cannot equal the beauty of selective focus that the large camera can achieve. Just a different way of looking at things.

[Michael Roberts]

If you want the entire subject to be tack sharp, another option is to back off to increase DOF, then crop the image so the subject fills your print.

Another option: I've had good experience with shorter focal length lenses, and 3+ bellows. I think part of your problem is your lens focal length is too long so DOF is less than with a shorter focal length lens. I suggest you try a 90-127 length lens.

The problem is a tough one b/c DOF is very limited at macro distances with longer lenses.

Weston solved this in his still lifes by stopping down as much as possible and using a similar focal length to yours for 8x10, which meant he could be much further from the subject. He also halved some of his fruits and veggies to present a flat plane toward the lens.

[Pete Watkins]

Thanks Jim,
I realise about the creative possibilities available with some of the LF lenses available. I've been a long time admirer of your style of photography and I've just been peering through an old (but beautiful) magic lamtern lens on the front of my B&J.
Thanks again,
Pete.

[ic-racer]

100mm of depth! Thats not do-able with reasonable results. The only way around it is to go to a smaller format (as pointed out) which, all things being equal, will produce a smaller depth measured on your focusing standard.

Check out Depth of Field in Depth By Jeff Conrad on the LF home page. See how the graph shows a miserable resolving power at just 10mm of focus depth.

[cowanw]

Since depth of field is related to Magnification is there any relationship to magnification (enlargement) in the darkroom. i.e. Does using a smaller format really offer more depth of field if you are enlarging to the 8x10 size of the larger format.

Is there a relationship such as Magnification of enlargement decreases sharpness as magnification of negative decreases depth of field.

Such that the end result is just as unsatisfactory?
Regards
Bill