[drissa]

Hi folks

Can you help me out with a scanning/resolution issue? It's one of those things I've never completely gotten my head around.

I'm working on a poster, so I guess I'll need to aim at 350dpi for the output. My friend has taken some shots and given me standard (6x4"?) prints, which I could scan with a Lide 50 (1200dpi). However, he could also scan the negatives at 2820dpi.

Obviously, I can produce more pixels by scanning the prints, but I have a feeling there may be a good reason for working from the original negatives. Does this give you a greater range to start from, because the film grain is still 'raw' and not fixed by processing?

Thanks

[art_director]

Originally posted by drissa:
Hi folks

Can you help me out with a scanning/resolution issue? It's one of those things I've never completely gotten my head around.

I'm working on a poster, so I guess I'll need to aim at 350dpi for the output. My friend has taken some shots and given me standard (6x4"?) prints, which I could scan with a Lide 50 (1200dpi). However, he could also scan the negatives at 2820dpi.

Obviously, I can produce more pixels by scanning the prints, but I have a feeling there may be a good reason for working from the original negatives. Does this give you a greater range to start from, because the film grain is still 'raw' and not fixed by processing?

Thanks

depends upon what sort of look / feel you're shooting for. what's the subject matter? that can be a determining factor. both routes have their pros and cons.

[bmmp]

Excellent Question Drissa!

Many people have problems dealing with this, and your first assumption is correct. You can be sure, that scanning in a 35mm neg would NEVER produce a better result on a flat bed.

Your question about range or film grain, is a moot point because there isn't enough space on that tiny tiny 35mm square to make a difference. (Now, if the negative was Medium or Large Format (3"+ negative) that's an Entirely different situation)

You confusion is also with your correlation between Photo detail and Resolution. Photo detail and resolution are not exactly the same thing. You can have a high res photo that is blurry, and a low res photo that is real sharp.

Your scaner will Always scan in at the highest quality detail possible. However, the resolution is up to you, and resolution deals with how the image will represent either onscreen or in print. (you need a higher resolution for images to print clearly, more so than onscreen/web etc.)

In a nutshell, always scan in the prints instead of the 35mm film on a flat bed.
The only exception is if you have a Separate, Independant 35mm FILM scanner. In this situation, you have to do a test. Here's how to conduct one.

1 - Scan in the print at any resolution, but as long as the final file size is 10 Megs.

2 - Scan in the 35mm neg on the film scanner and choose any resolution, but again make the file size 10 megs.

3 - Open both in photoshop and zoom in to compare!

[drissa]

Thanks for the replies so far.

I understand scanning/resolution, etc. Also, which I failed to mention, the negatives would be scanned on a high dynamic range film scanner, rather than a flatbed.

The film scanner is capable of capturing more information, in terms of pixels, than my flatbed. But the image I'd be feeding the flatbed, although a print, would be much bigger. On the face of it, assuming it's good quality, scanning the print would seem to be the way to go, in terms of resolution.

However, I wondered if there was anything to be gained by working with the original negative. Are there fundamental differences, such as film grain, etc between the original and 'second generation'? I've heard about this before and just wanted some clarification.

The images is a face shot and will be used for a theatrical poster, A3, possibly two colour.

[buchrob]

I ran a pre-press scanning department for a number of years and our rule of thumb was to ask the client to send a sample print as well and then we SENT THE NEG OUT TO BE PRINTED at 8 x 10 at a phoofinisher around the corner.

It cost us a few bucks per neg, but at least the customer got the color balance they were expecting. Enlarging the neg in an analog fashion also sidestepped the type of grain and artifact problems encountered when scanning small negs at ridiculous enlargements.

Originally posted by drissa:
Thanks for the replies so far.

I understand scanning/resolution, etc. Also, which I failed to mention, the negatives would be scanned on a high dynamic range film scanner, rather than a flatbed.

The film scanner is capable of capturing more information, in terms of pixels, than my flatbed. But the image I'd be feeding the flatbed, although a print, would be much bigger. On the face of it, assuming it's good quality, scanning the print would seem to be the way to go, in terms of resolution.

However, I wondered if there was anything to be gained by working with the original negative. Are there fundamental differences, such as film grain, etc between the original and 'second generation'? I've heard about this before and just wanted some clarification.

The images is a face shot and will be used for a theatrical poster, A3, possibly two colour.

[zigzag]

I don't have any personal experience with film scanners but everything I've read suggests that you'll normally get much more information from a negative than you will from a print. The print, after all, came from the negative, and has no more information than the negative, and probably a lot less. The fact that the print is larger than the negative doesn't mean it'll give you more information.

That's why film scanners typically scan at much higher resolutions than flatbeds - there's more information available from a negative. A print typically doesn't have more than 200-300dpi worth of information. The only reason to scan a print at a higher resolution than that is if you plan on blowing it up. If you want to make a poster, I would use the film scanner and scan at the highest optical resolution.

You could try scanning the negative with the flat-bed but they're not as precise as dedicated film scanners.

I recently read about an interesting technique for creating blow-ups in Photoshop if your image isn't high-resolution. Use Image>Resize to increase the image size by 10%. Repeat until you have the size you want. Apparently this will create pretty good blow-ups, much better than if you blow it up all at once. You might try this if you're not happy with the initial results.