Agfa Copex Rapid – Development Tests

The EU seems to produce a rich array of unusual (“speciality”) films – from Adox, Rollei, Spur and others (many of which are rebranded Agfa-Gaevert films). Trying to get any of these in Japan, let alone their specialist developing chemicals, is hit and miss – generally stockists are ‘sold out’ or when there is stock it is often expired film. I was fruitlessly looking for one of the Adox films and came across this Agfa panchromatic microfilm (intended for copying documents) at a reasonable price (about EUR7/roll) so I bought all the remaining stock (9 rolls) to give the film a try. The film is identical to SPUR DSX and the recommended developer was SPUR Dokuspeed SL, also difficult to find and expensive.

Looking around on the net I found a review (Alex Luyckx blog 88) and some suggested developers and times on the Massive chart, together with some other reviews. Copex Rapid is a very high contrast film, similar to Technical Pan so I looked in Anchell’s Darkroom Cookbook for suggestions (Burton 195 and POTA).

Round 1:

After some thought I decided to shoot one film and cut it into four strips to try the developer/times given below. The film was shot within a period of 5 minutes in early morning light using a Leica M3 and Zeiss Planar lens with a yellow filter. Three subjects were chosen, each photographed at f4 and 1/50th, and +/- one stop, giving 3×3 images repeated 4 times. Exposure was determined using a Minolta Spotmeter F averaging zone 2 and 8 readings. The front door image turned out to be the most useful because of the large uniform area.

1. Rodinal 400:1 45 minutes with one inversion; can it be coaxed into giving a full range of tones with this film?

2. Burton 195 6 minutes continuous agitation.

3. POTA 15 minutes, 3 inversions every minute.

4. Rodinal 200:1 60 minutes with one inversion at 17deg C.

The first three developers were at 20deg C, a water stop was used and films fixed for a little under 2 minutes (according to one suggestion 30-60 seconds may be enough because of the very fine grain).

On initial casual inspection the Rodinal 400:1 seemed underdeveloped, the Burton 195 about right and the POTA over-developed – the edges were also slightly fogged. After scanning (BlackBox 135, Sony A7Rii and Sigma 105mm Macro) I saw that POTA had a strange swirling pattern (although contrast was best), Burton 195 was far too contrasty and the Rodinal negatives were the clear winner although not perfect and it showed some odd development around the door handle. The results from Rodinal 200:1 were best using the one stop under exposed negatives but even then the highlights were blown out.

Round 2:

On a second film I took four sets of five frames of the front door in brighter light a little later the following day, exposing from -2 to +2 stops around the central reading on the spotmeter. I developed these as follows using an acid stop before fixing.

5. Anchell suggests diluting Burton 195 to half strength and developing for 50% to 100% longer. I tried 9 minutes development time and reduced agitation to two inversions every 30 seconds. Contrast was greatly improved though now there was a slight swirling pattern visible.

6. POTA would have been best if only I could get rid of the swirling pattern, but what is the cause? One article (Reudiger Hartung on flickr) said film should be pre-soaked to avoid streaking, which I did for two minutes. Agitation was two inversions every 30 seconds. The result was much less swirling pattern but still some. Background fog and contrast started to rise – hints I ignored at my peril.

Round 3:

A little further searching and pre-washing with dilute (2%) sodium carbonate was suggested to remove the anti-halation layer, followed by a water wash.

7. Burton half strength again and 9m development time, but now with a 40 inversion pre-wash in sodium carbonate, followed by a water wash. BINGO – a decent result.

8. POTA again but with a 40 inversion pre-wash in sodium carbonate, followed by a water wash, continuous agitation for one minute at the start then as before. But now it’s all gone wrong – suddenly hugely over-developed with strong background fog. Development time and/or agitation and/or developer strength need to be reduced if the anti-halation layer is reduced. Was there contamination from the sodium carbonate making the developer far more active?

NOTE on the developers:

Adox Rodinal, 6 years old.
Burton 195: 1g metol, 10g sodium sulphite, 2g borax, 1g boric acid, 1l purified water; used fresh. This has the advantage that two solutions can be made up (metol/suphite and borax/acid) and will keep but once mixed about a 24 hour life.
POTA: 30g sodium sulphite, 1.5g phenidone, 1l purified water; used fresh. POTA has a shelf life of only one hour!
The quantities of developers (metol and phenidone) and the acidifyers are tiny so errors in measurement could amount to 5-10% of the weight – this would affect the results a little.

Sodium carbonate (washing soda) rapidly removes the anti-halation layer which seems to be the cause of the swirling pattern. Most developers are sufficiently alkaline to remove this quickly themselves but not Burton and POTA. On the other hand sufficient water washing should remove the layer on B&W film – maybe 5 minutes?

Conclusions:

Rodinal 400:1 was passable, probably fine on most images. Burton 195 half-strength with sodium carbonate pre-wash worked well.
If I use either Burton or POTA again I’ll skip the sodium pre-wash and simply use water for 5 minutes with regular agitation. For POTA I’d also try half strength and semi-stand development.

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