Neg film + black line through several frames = scratch, hard to say when it occurred though. Dust whilst scanning will result in a spot not a black line through several frames.
You will have to excuse me if I am being thick, but, how?Dust in the calibration area will give a line on the whole strip of negatives.
On some flat bed scanners there is, as someone already mentioned, a small open area of the film holder just before the actual place that holds the film. This is scanned each time so that any variation in the light source or the sensor across the width of the film can be allowed for. Dust in that area will appear in the adjusted density of the film scan as a line running in the same direction as the scan.You will have to excuse me if I am being thick, but, how?
I think I understand now, so it is mapping out the pixel/s where the dust is? Thank you. It has been a long time since I used a scanner and then it was Flextight....On some flat bed scanners there is, as someone already mentioned, a small open area of the film holder just before the actual place that holds the film. This is scanned each time so that any variation in the light source or the sensor across the width of the film can be allowed for. Dust in that area will appear in the adjusted density of the film scan as a line running in the same direction as the scan.
Scratch on film is easy to see so that's quickly confirmed or........
Right, same as me. When you put the negative carrier in, there's a small gap at the top. Thats something to do with calibration, teeny bit of dust in that bit, whether its on the glass or the light, will result in what you've got there mate
On some flat bed scanners there is, as someone already mentioned, a small open area of the film holder just before the actual place that holds the film. This is scanned each time so that any variation in the light source or the sensor across the width of the film can be allowed for. Dust in that area will appear in the adjusted density of the film scan as a line running in the same direction as the scan.