While researching pyro developers, I ran across the following statement on a Flickr group dedicated to Pyro:
510-Pyro has the advantage that you can visually check for the optimal developing time after around 1/2 to 2/3 of the total developing time under red safe light - then the pyrogallole has de-sensitized the film so far.
- Is there truth to this statement?
- If so, would this be applicable to any other group of developers?
- If so, what is actually going on here to make this possible (please get at least a bit technical with the answer)
And finally - even if true, what would be the point? I can't imagine that one could tell if a negative is optimally developed without a loupe and with only the dimness of a safelight. The only thing that I can speculate is if developing sheet film in trays - turning the safelight on may aid the rest of the development process (by being able to see)...but given that the whole process can be done in the dark anyway, is the gain of sight here really all that much worth the risk?