How to photograph a ring all in focus?

I photograph rings with a canon 100 f2.8 macro and despite the fact that I went all the way to f22 I still did not get sharp focus on the back of the ring. Is there another way? Does anybody use shift and tilt lens to do one piece of jewllery and which one?

show pics?

focus stacking? youd need a tripod

Use a shorter focal lenght, and crop more?

EmmaRose mentioned focus stacking and it indeed is a technique that can produce pretty amazing results to those familiar with the depth-of-field problems in macro shooting. There are a number of macro shooters on this forum who use it to capture and process various images things like bugs come out amazing.

Tilt and shift lens.

You'll have to either focus stack or buy a tilt lens. Stepping back and cropping in does not alter DoF.

Also, if you're judging DoF based on 100% views, don't. Judge it at the final viewing size.

toxic wrote in post #10114683
Stepping back and cropping in does not alter DoF.

Yes it does. The further you move from the subject the greater the depth of field, assuming the same settings of course.

Example: 50D (or similar; no extension tubes) with 100mm and f/22 will give you about 0.2" depth of field with a subject distance of 12". Move back to four feet away and the depth of field is now 4.6".

Mike

Mike-DT6 wrote in post #10115036
Yes it does. The further you move from the subject the greater the depth of field, assuming the same settings of course.

Example: 50D (or similar; no extension tubes) with 100mm and f/22 will give you about 0.2" depth of field with a subject distance of 12". Move back to four feet away and the depth of field is now 4.6".

Mike

And when you crop it you enlarge the image more, which reduces DoF, and now you're back where you started.

toxic wrote in post #10115046
And when you crop it you enlarge the image more, which reduces DoF, and now you're back where you started.

That's just plain wrong. How in the world would cropping a shot ever change the DOF? Get your facts straight mate

No you're not because you've photographed the ring with a 4.6" depth of field instead of 0.2". Now you have your ring in focus. Cropping into that in-focus ring will not reduce the depth of field. You're just creating a smaller image featuring a 4.6" depth of field.

EDIT: Andreas beat me to it!

Mike

Booyah!

Mike-DT6 wrote in post #10115036
Yes it does. The further you move from the subject the greater the depth of field, assuming the same settings of course.

Example: 50D (or similar; no extension tubes) with 100mm and f/22 will give you about 0.2" depth of field with a subject distance of 12". Move back to four feet away and the depth of field is now 4.6".

Mike

Only because moving back to 4' makes the subject 1/4 the size in the frame.

If you mounted a 400mm lens and shot from 48" to capture the same 1.8" long captured area in the frame, the DOF remains 0.17"!!!


If you merely crop the first one (100mm at 4') and blow that section up, the DOF is still 0.17" What matters in DOF is how big the out of focus disks are in the final print, as the eye's ability to detect 'out of focus' is what matters. NOT how you got there (100mm at 48" cropped and enlarged vs. 400mm at 48")


[edit 5/2/10] The statements I above in this post are bogus, as they were made based upon a DOF calculator program which is NOT accurate!

It's not a case of 'only because'. The statement made was that it doesn't increase the depth of field by moving away from the subject, then cropping the image afterwards, which is quite simply wrong.

Mike

DoF, by definition, is related to enlargement. When you crop, you have to enlarge the image more to arrive at the same final viewing size. This reduces the circle of confusion and makes the DoF smaller.

Cropping an image taken with a 50mm lens to the same FoV as a 100mm lens yields the exact same DoF for the same framing. This is proved in the perspective tutorial at the top of this forum.