Quote Originally Posted by Tom Stanworth
just noticed something really weird...the image is positive! It hard to see the image within the emulsion but it is undoubtedly posistive. All the film information down the edges is also positive...clear on the neg (but largely obscured by the semi opaque base). I just devd a roll from the same camera from the same shoot in the same chems in the same way (APX400 this time) and it is 100% fine. This is one for the photographic X files!
Been watching this with interest.

As far as I know, there are only two ways this could have happened: there was some sort of exposure to light during development (old-time E6 reversal exposure) or some sort of chemical anomaly that caused the same effect
(see modern E6 reversal-exposure-less processing).
That would explain why additional fixing had no effect.

Is a contamination of chemicals possible?