Jono wrote:So, i was in a bit of a rush when loading film and shooting the other day and had forgotten to adjust my ISO from 400 to 125 while using Plus-X 125.
Long story short, I was looking to develop some of that film today only to discover that the Digital Truth as well as an extended search of the internet came up negative for helpful information regarding a developing time for Plus-X shot at 400.
I now ask you if you have ever stumbled upon a developing time that might work for this predicament.
(maybe using acufine or xtol? that's what i am working with at the moment.)
Thank you very much for any input.
Film comes in various rated speeds for a reason. Faster films are grainier, fine-grained films require more light. It is not really possible to salvage underexposed film through changes in processing time or special developers. Changes in processing time affect the contrast of the overall image, but cannot create density where insufficient exposure has been given.
Film speeds in use today call for the minimum exposure to produce acceptable results. This is by design, to keep exposure at the practical minimum.
exposure over this amount does little harm if it is less than three stops. There will be some loss of highlight detail but nothing disastrous. On the other hand, underexposure, even a little, cannot be tolerated. The film simply won't record anything in the deep shadows. The mid-tones will record where the shadows should be, and the highlights will be recorded where the mid-tones should be. In other words, almost all the 'margin for error' lies on the side of increased
You have under-exposed your film by about 1 2/3 stops. That simply cannot be remedied. My advice is to process the film is D-76 1:1 at the recommended time.
The popular notion that films can be uprated or down-rated is largely myth. Certain developers (fine-grain developers such as Perceptol or Microdol-X) can reduce
the sensitivity of an emulsion and thus require more exposure, but little can be done in the other direction. For many years developer companies touted speed-increasing properties of their products. Acufine boasted that you could get Tri-X to achieve speeds of 1200. This is a lie. These products used phenidone instead of metol but that in itself allows only a very small increase in speed, maybe 1/3-1/2 stop at most, and then only with the faster films. The speed of films such as Plus-X Pan will hardly be affected at all. This is a lost cause.