LF Digital Setup

[shlomi]

I've tried asking this question in the MF forum, but I got MF answers.

I am trying to find a setup which will not be too expensive but will give me good results for close up (macro) with a digital sensor.

I would like to improve DOF sharpness mostly, for objects around 1"-1'.
Now I am using Canon 1Ds3 at f/22 and of course I would like to see something better, otherwise what's the point.
The main problem is diffraction.

I've tried Mamiya ZD with Mamiya 120mm Digital, and I saw good results at f/32.
Other non digital lenses from Mamiya Zeiss and Schneider with not good results.

My conclusion was that I need a digital lens.
So I found these LF lenses:
- Schneider 120mm f/5.6 Apo Digitar M
- Rodenstock 120mm f/5.6 Apo-Macro-Sironar digital

Rodenstock literature recommends movements to get DOF sharpness rather then closed aperture.

So my questions are:
- Assuming I have the digital back and lens, what would be a cheap way to connect them? It seems I need a sliding back adapter to focus? I found a solution for $4500 (Horseman LD) or a sliding back adapter for $2500 with a used Linhof for $500. Is this right?

- Will the lenses I mentioned above give me a result much better than Canon or Mamiya? Is this worth the trouble for this specific application?

 

[Lars]

The digital LF lenses such as Digitar 120 differ relevantly from a DSLR lens in image circle. The Digitar 120 is rated at some 100 mm or so image circle - actual coverage is closer to 190 mm, though resolution, fall-off and plane flatness makes image deteriorate a bit towards the edges (but not a whole lot). Compare that to the diagonal of 43 mm for 24x36 format.

Focal plane tilt/shift movements are useful for extending/replacing DOF if the subject matter is flat. If you are shooting a 3-dimensional object such as jewelery then stopping down is unavoidable. This will lead to diffraction.

I would guess that the problem you see isn't related to lens quality.

As you move up in sensor format size, DOF will become more of a problem. A solution could actually be to move to a smaller sensor format. To get a feel for that, try using a digital compact camera at macro setting. This might give you some insight into what happens when sensor size changes.

 

[BBSea]

shlomi, have you considered focus stacking instead?

http://en.wikipedia.org/wiki/Focus_stacking

 

[shlomi]

Yes, I have been using stacking.
It works, but it is a poor man's solution - requiring work and doesn't get the best quality.
So far I have moved from Canon to Mamiya and I am seeing nice improvements in image quality.
DOF is much bigger - the loss of DOF due to the bigger sensor is cancelled by the gain in being able to use f/32 with no bad diffraction.
I am working towards integrating digitars and then I expect further improvement.
I can still do stacking on Mamiya source just as well as on Canon source and the results are better.