Photo Mural from Small Negs - Scanning Question

[slbowen]

I will be doing a photo-montage mural (5-1/2 feet high) and am not sure what the best approach is r.e. scanning. Most of the images were shot with 35mm (B&W); I will have access to the negatives (not my own). Usually I think that scanning from the negative rather than a print is the way to go, but there are obvious limitations to such a small negative when printing this large. I'm not sure at what point a higher resolution scan of the negative would be pointless, and I don't know if there might be some advantage to scanning from a print instead (or a combination of both techniques).

Anyway, any ideas appreciated.

[John Hoenstine]

You might want to check out http://www.interpolatethis.com/. An interesting article on upsizing.

[robc]

you just know that when someone needs to explain something in terms of rocket science that they haven't got a clue and are talking just plain bollocks!

[Bruce Watson]

I'm not sure at what point a higher resolution scan of the negative would be pointless, and I don't know if there might be some advantage to scanning from a print instead (or a combination of both techniques).

IMHO, there are few reasons to scan a print. One would be because the print is a significant departure from the negative and the changes would be difficult to reproduce (say, the artist isn't available). Another would be because you don't have access to the negatives. But when you scan a print you are stuck with the information on the print, and what information there is on the print has already been attenuated by the enlarging process.

The negative is the source, you should work from it if you can.

The question of how how high a scanner resolution is high enough is a good one. Think of it this way -- what you want to capture is the image information. You can typically capture nearly all of the image information at lower resolutions than are required to capture structural information (grain and other film artifacts). Once you've captured the image information, anything else is overkill.

Sadly for you, what resolution is appropriate is image dependent. It depends on the film and the skill of the photographer. If it was done on a tripod using mirror lockup at the sharpest aperature for the lens being used, there are some simple rules of thumb I use. Clearly, YMMV. For fast films (400 speed) you'll get just about everything there is to get at around 4000ppi from the scanner. Slow films (50 speed or less) around 5500ppi. Medium speed films are somewhere in between. These from drum scanners where the suggested resolutions above are close to the actual optical resolutions from the scanner.

Beyond this and you are adding data, yes, but you aren't really adding information. The concepts of data and information are related here, but they are different. If you recognize the difference, you can save yourself some time, money, and trouble.

BTW, if you take a 2.4cm negative and enlarge it to 168 cm (5.5 feet) that's a 70x enlargement. There's nothing you can do to make it sharp and smooth when viewed close up. Nothing. But when viewed from far enough away it's still doable.

[robc]

as bruce says thats upto 70x enalrgement except you haven't actually told us what you've got in the way of negatives to make the montage. i.e. is there one neg that needs to be printed at 5.5ft or is that made up of many negs or what?

[slbowen]

This will be a panoramic shaped montage (long horizontal thing) using many negatives; most will be full height (i.e. 1" negative being enlarged to 5.5' high). Overall it will be 48' wide.

I'll probably rent time using an Imacon scanner and then interpolate a lot I guess! Thanks.

Susan