Switching to a digital workflow is sometimes a complex process. Here our (so far) 12 golden rules to the digital path - or what is worth considering.

1) The mechanical precision of all elements is crucial.

That is where many studio cameras find their "Waterloo" and where most cameras and accessories originally made for film use fail. One of the difficulties: many photographers have never had the occasion to compare 1:1 what their backs could deliver when used with adequate camera bodies and lenses. Since you get a picture with nearly any camera body or lens, you might never realize that you remain far below what your back could deliver with proper equipment. It is no help that some back manufacturers don't seem to be very interested in anything besides their "closest surroundings". Some  even dare to call their backs "cameras"!

2) Only high-end material should be used.

We think mainly of the often neglected components between the front element of the lens and the sensor chip in the back. They are as important as the camera body itself. The lens mountings, helical mounts, lensboards, groundglasses, back adapters as well as the design of the connections between all the elements. Bayonets as well as rotating or sliding backs are often a source of trouble caused by inadequate mechanical precision. It is the weakest link that sets the level of the complete quality chain.

3) All elements must be perfectly adjusted.

What was and is tolerable with 4x5 or 8x10 inch sheet film is not acceptable with 33x44mm, 37x37mm, 36x48mm or 37x49mm sensor chips. When something was and is not perfect mechanically when using LF,  you could close down the diaphragm to f 22 or 32 or even more. Furthermore you did and do in any case use much longer focal length lenses for the same angle of view. Longer focal length lenses are more tolerant than short lenses as regards mechanical precision. With digital backs you use shorter lenses which make the slightest divergence only too obvious. Tolerances in the range of +/- 1/10mm were and are acceptable in LF photography but with digital backs we are at +/- 1/100mm.

4) The performance of the lenses must be on the level asked for by the digital backs and their chips.

A resolution of, for example, 25 pairs of lines per mm may be OK with LF - but digital backs demand at least 60 (7.2/6.8 micron sensors) pairs of lines per mm and over 80 lp/mm with the newly announced backs of 50 and more megapixels (6 micron sensors), and they need a much lower lateral color aberration. A instructive example of the growing demands: some time ago there were photographers and journalists wondering why they could not get better results from their then new 33 MP or 39 MP backs than what they had got before from their 22 MP backs. One of the reasons was the fact that they used lenses that were often barely able to cope with the 9.0/1000mm pixels of the 22 MP backs and could of course not keep up in performance with 7.2/1000mm or 6.8/1000mm pixel chips (= 28, 33 and 39 MP backs - in 2008 the newly announced sensors of 50 MP and more feature 6/1000mm pixels).

5) Generally,  the f-stops between f 8 and f 11 should be used.

A few lenses allow for max. 4.0, 4.5 or f 5.6 - and even they get better at e.g. f 8. In any case: one rule remains - avoid f 16 and forget about f 22, etc. The reason: diffraction.

6) Generally, the lowest sensitivity settings are those that should be used.

Recommended speeds: ISO/ASA 50, 100 and 200. Avoid ISO/ASA 400 and forget about higher speeds. The reason: noise.

7) The Dalsa chips are less prone to "color cast" than the Kodak chips.

The reasons for "color cast" are not just the design of the chip or the angle of the light falling on the chip. We have seen "color cast" when Dalsa chips and a 100mm focal length lens have been used. Other reasons play their role, too. All back manufacturers have difficulties with "color cast", at least when camera movements are used. So, what can be done against "color cast"? See below, point no. 9.

8) The Kodak chips are less prone to "center fold" than the Dalsa chips.

"Center fold" has very probably something to do with the design (two-sided outreading) of the Dalsa chips. So what can be done against "center fold"? See below, point no. 9.

9) All back manufacturers offer special tools to correct or avoid "color cast" and/or "center fold".

These tools work differently, depending on the manufacturer, and they are sold under different names. You and we may dislike the fact that it is unsatisfactory to pay US$ 25,000.00 or even more for a back and then to have to use "correction tools". But it is in fact the only solution! Correctly used, these tools really do work, and in the end you get great results. Please do not forget: it is also far from easy to use filters and other means to get perfect results when using film.  The difference is probably just that many photographers/labs are or were used to this film-kind of "correction" and that they first have to understand/use/learn to use the new "correction tools"  supplied by the digital back manufacturers.

10) Exposure Limitations:

Note that the longest exposure time for digital backs is generally 30-32 seconds. Some Phase One models have a special modus ("XPose+") that allows exposure times of up to an hour. The time needed for one exposure always doubles as you have to count in the "dark slide subtraction" with the same exposure time as the capture performed after every shot.

11) Movement Restrictions:

Do not use camera movements (e.g. shift or tilt) with digital backs that have been declared unsuitable for such movements by their manufacturers (e.g. Phase One P30).

12) Two final points:

a) the development of backs/chips will not stop, but waiting for a "definitive" level is becoming dangerous now - at least for professional photographers. Their customers are asking more and more for end-to-end digital image data, b) the photographic industry (selling worldwide about 6,000 to 8,000 backs each year) is probably not of very great importance to chip manufacturers. We cannot say whether the back manufacturers do enough and swing enough weight to keep the chip manufacturers on their toes. All we know is that we are forced to accept what we get.