Which is better to scan, film negatives or prints?
It is always best to scan the original negatives, provided that they are in good shape and the colors have not faded. The reasons for this are explained below.

To begin with, you have to realize that a photograph is merely a copy of the original, processed negative. In most cases, a copy is never as good as the original. Typically, photographs are printed out at 240-300 dpi when done at your local photo lab. That means that a 4x6 print is, at most, 1200x1800 dpi. This is why prints are typically scanned at 300 dpi as scanning at a higher resolution does not bring out any further detail other than what is on the original print. The only time that scanning a photograph at 600 dpi, or greater, would be if the original was either very small or if it is going to be edited at a later date.

The size of a typical 35mm negative is 24mm x 36mm or, roughly, 1.0in x 1.5in. This means that the film was essentially scanned at 1200 dpi in order to produce the 4x6 print in the above example.

Most 35mm film negatives are capable of being scanned at up to 4000 dpi. This is especially true for the slower speed films (100, 200). When scanning negatives the general rule of thumb is the higher the resolution, the greater the detail.

For example, a negative scanned at a lower resolution of 2000 dpi may not be able to clearly display the time on a clock in the background or the fine print on a paper or sign when the photograph is blown up. By simply rescanning the same image at 4000 dpi you are providing 4x the resolution of the original scan. This type of resolution can display these details much more easily and clearly, especially when a larger print is be made.

Another reason for choosing to scan the film negatives instead of the photographic print is that the original film contains much more contrast and detail as compared to a photographic print. This is because prints tend to fade over time due to exposure to sunlight, etc. Negatives, if they have been stored in a dry place, are much more immune to this behavior.
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