Fotospeed FD30 equivalent

[kev_lewis]

I have been taking photographs of the inside of a commerical reactor using Kodak Tech Pan 120 roll film in a heavily modified Mamiya 6x7 camera. Because the film becomes partially irradiated and fogged I have processed it in Fotospeed FD30 (1:19 dilution, 12 minutes at 20c) which gives the film a push and increase in contrast, resulting in very acceptable negatives.

Fotospeed no longer manufacture FD30, does anyone have some experience of alternative chemistry that will give me a similar negative, what dilution, processing times etc?

Additionally how much does the above FD30 dilution, temperature and time actually push the Tech Pan film as the fotospeed information only quotes push values using a 1:9 dilution.

Thanks for any thoughts, input or pointers that can be provided

 

[Tom Hoskinson]

Kev
The first thing I would try would be Kodak's D19, a favorite of astrophotographers with Kodak's Tech Pan. D19 should be available commercially, if not, it is easy to mix from "scratch."

Developer D-19: Formula


Water @ 125°F/50°C ...............................750millilitres
(boil the water first to remove dissolved oxygen)

KODAK ELON (Metol) Developing Agent ............. 2grams

KODAK Sodium Sulfite (Anhydrous)........... 90grams

KODAK Hydroquinone ................................8grams

KODAK Sodium Carbonate (1-Hydrate) ...52.5grams

KODAK Potassium Bromide (Anhydrous).....5grams

Water to make 1 liter

Check the Kodak Tech Pan data sheets for D19 dilution, time and temperature starting point recommendations.

A small amount of Benzotriazole can be added to the D19 if more fog reduction is desired.

 

[Tom Hoskinson]

Kev

Fotospeed FD 30 is described by the manufacturer as a “Fine Grain Push Process Developer.” Fotospeed rate Kodak Tech Pan 25 at an EI of 160 when developed for 10 minutes at 20 deg C in a 1:9 dilution of FD 30.

I suspect that Diafine would produce a result similar to the one produced by this "standard" time/temperature/dilution of FD 30.

I could find no data for a Fotospeed FD30 1:19 dilution, 12 minutes at 20c. However, I would expect that this time/temperature/dilution combination would lower the contrast index, lower the maximum density and possibly lower the fog level. The sharpness/acutance should increase also, but I doubt this would be noticeable with Tech Pan.

I would recommend getting densitometry done on Tech Pan films previously developed in FD 30 in order to establish a baseline for a choosing a alternative developer.