Rodinal Special & Studional

I understand that these are the same product. Rodinal Special in Europe and Studional in North America.

I have a few bottles of Rodinal Special so is it safe to use a dilution and time quoted for Studional?

I ask this becaue the massive dev chart on digitruth.com has lots of times for Studional but nothing for Rodinal Special.

Peter

Rodinal Special is Studional in small bottles !!!

It is GREAT STUFF. You might want to increase the dilution however.
Try 1+31 for double the suggested time.

Here is the data from Agfa ( It assumes agitation every 30 seconds. reducing the agitation to once per minute usually brings the contrast down to a slightly more common ? 0.58)

4.2 Rodinal Special

Developer concentrate ready for multiple use after dilution. It produces fine-grain sharp negatives with balanced contrast. Processing times are particularly short.

Mixing instructions

The concentrate is diluted with water 1 + 15 (= 1 part concentrate + 15 parts water).

Yield

• 10 –12 films 135-36 or rollfilms 120 per litre
• 50 – 70 sheet films 9 × 12 cm per litre (= 0.5 – 0.75 m²)
To ensure uniform speed yield and contrast, the developing time
must be lengthened for each successive batch (see page 4).

Life

The concentrate will keep for at least two years in the original pack. Developer mixed ready for use will keep for three months in brimful tightly capped bottles. Used developer should be stored separately from fresh.

Film speed (exposure index = ? 0.65)

Film type Time * Speed

Agfapan APX 100 4 min ISO 100/21°
Agfapan APX 400 6 min ISO 320/26°
Fuji Neopan 400 Prof. 3 min ISO 320/26°
Fuji Neopan 1600 Prof. 3 min ISO 800/30°
Ilford PAN-F Plus 3 min ISO 50/18°
Ilford FP 4 Plus 3.5 min ISO 100/21°
Ilford HP 5 Plus 4 min ISO 400/27°
Ilford Delta 100 3.5 min ISO 160/23°
Ilford Delta 400 4.5 min ISO 400/27°
Ilford Delta 3200 6 min ISO 1250/32°
Ilford SFX 200 4 min ISO 125/22°
Kodak Plus-X 5 min ISO 125/22°
Kodak Tri-X 3.5 min ISO 400/27°
Kodak T-MAX 100 5 min ISO 80/20°
Kodak T-MAX 400 5 min ISO 400/27°
Kodak T-MAX p3200 6 min ISO 1250/32°
Kodak Recording 2475 6 min ISO 640/29°
* Small tank or tray processing at 20 °C.
Developing times (at 20 °C) Small tank, tray

Yes I agree that a higher dilution is the way to go as the 1:15 times are very short.

Thanks for your help,
Peter

We list Rodinal Special as being equivalent to Studional on our Unlisted Data page which you can access via the left hand menu in the Massive Dev Chart. There are many products which are sold under different names, so it would be redundant to list them all in the chart. The simple answer is yes, you can use the times interchangeably. I can't comment on the advice to use 1+31, but it seems like this might be helpful. Studional/Rodinal Special is particularly useful when you have many different films to develop simultaneously, as the times are often very similar. A 5 minute time will produce good results with most emulsions regardless of speed.