Negative Scanning

[andrew vincent]

Please don't flame me for asking such a dumb question, but I've looked through the files and would like to get some new advice from the scanning experts on the forum.

Need to make a very big repro of a 4x5 negative. The new Fuji PRO 160C film. Image is blown out on the high end. I'm going to mainly leave it, but I'll need to do some corrections. Final prints will initially be done on an epson 9800 at 40x50in.

I use an Epson 4870 for initial proofs and generally have gotten 200mb tango drum scans of my velvia chromes at WCI. They're good - I know they could be better at higher resolution, but I just haven't wanted to spend that much yet.

For this, I'm willing to spend what it takes, and I don't want to end up with something where I've spent a good deal but still not quite enough. Penny wise/pound foolish sort of thing.

So questions:

1) 3200 dpi or 4000 dpi

2) 8 bit or 16 bit

3) what colorspace to use for negatives. I've been using EktaSpace for the chromes, but the new printer I'll be working with just uses Adobe98 and I just read a review saying that negatives should be done in ProPhoto because of their specific difficulties, so now I'm all confused.

A local place here can do a relatively inexpensive 4000 dpi scan on the creoiq3 which I think would be perfect, but I'm worried that for a negative, especially one that may need some work, requires 16 bit, which I've frankly never used, don't really like (because the file sizes just become unmanagable in PS at 1.4 gb+) and will basically double the price (the place is a lot cheaper than Calypso, and WCI's 16 bits are the same as Calypso anyway, so don't bother mentioning them.)

Any thoughts, pros?

[cotdt]

4000 dpi for 40x50 prints. printers are usually 360 dpi.

2400 dpi with your Epson, any more and you won't see any difference anyway.

for negatives i think 8-bit is fine.

[andrew vincent]

I will baldly admit to this being somewhat about economics. It's basically like

4000 dpi 8 bit scan
OR
pay 50% more for a 3200 dpi 16 bit scan
OR
pay twice as much for a 4000 dpi 16 bit scan

while admittedly, I'm sure the last is the best, I guess I want someone to say, YES, your negative will be ruined and you'll be forever sorry if you don't cough up the extra dough

[Ted Harris]

It's only partially a question of bit depth and resolution. It's also a question of how much time the scanner operator is willing to take to make the necessary adjustments required to salvage, as much as possible, your blown highlights.

You really want to go with 16 bit 4000 spi. See my PM.

[Bruce Watson]

You want to enlarge Pro 160 C about 10-11x yes? I wouldn't recommend a Tango for two reasons. First, the LinoColor/NewColor software reportedly doesn't make it easy to work with negatives. Second, the Tango's minimum aperture isn't small enough -- there are sharper drum scanners out there than a Tango for this work.

For negatives you definitely want 16 bit scans. No question.

For colorspace I use ProPhotoRGB. I want my working space to be bigger than my printer's ICC profile. Think about it -- what do you want to be your limiter? I always want my working space to exceed the gamut of the output device. And the modern inkjet printers already have gamuts that exceed AdobeRGB 1998. But this really means you want 16 bit scans. If you are going to stick with 8 bit scans there's not much point in going to a workspace larger than AdobeRGB 1998.

For resolution, that's a more interesting question. Some argue for scanning at "grain size" (hard to define), some argue for higher than grain size and downsampling to reduce noise (drum scanners typically have so little noise that this is of little value IMHO), and some argue for less than grain size to pick up image information but with grain.

What works for me is to scan at around 300 ppi at image size. That puts me at about 1.1GB (16 bits RGB) for a print this big. I've made some lovely big prints like this and did a lot of experimenting to find my optimum scan resolution. Then again, I've got my own drum scanner so this is easy for me to do.

If I were you, I'd talk to Danny Burk (a forum member here) for drum scanning, and Ted Harris for professional flat bed work. I don't have any connection to either of them but they both have excellent reputations for competence and both are straight shooters. Oh, and both are LF photographers. This would seem to be an advantage to me as they both will know "where you are coming from" as it were. Either of these guys will almost certainly give you a better value and a heck of a good scan.

BTW, it's nearly impossible to "blow out" highlights with a modern negative film like Pro 160 C. As either of these guys will tell you. I think you'll be surprised at how good a really good scan actually is.

[andrew vincent]

Bruce, everyone, thanks so much for this information - very helpful.

A follow-up regarding colorspace - it sounds like the info should be sent to the computer with ProPhotoRGB then? They're currently using Adobe98, as I said, but I can potentially get them to adjust their setup.

[Bruce Watson]

Bruce, everyone, thanks so much for this information - very helpful.

A follow-up regarding colorspace - it sounds like the info should be sent to the computer with ProPhotoRGB then? They're currently using Adobe98, as I said, but I can potentially get them to adjust their setup.

Might be easiest to get the file untagged -- in the scanner's native colorspace. Then assign it a colorspace like ProPhoto when you open the file the first time in Photoshop or some other image editor. Depending on the scanner software of course. Some software insists on assigning a colorspace; if that's the case the scanner operator would have to be willing to pick one that isn't his default (depending on what the scanner software has available).

But I'm certainly not an expert in this area. Talk to your service provider and see what they can do for you.

[Peter De Smidt]

The size of the colorspace to use is controversial. Ken Rockwell, for example, advocates using the sRGB color space with digital cameras. The bigger the colorspace, the larger the gaps between colors when represented by a finite number of samples. Bruce is advocating 16 bit, and this should lessen the problem. Using 8-bit per channel with a huge color space is asking for problem.

If I remember correctly, Ektaspace is colorspace designed by Joseph Holmes to contain every possible color capturable on ektachrome film. It's a pretty big color space, although it's smaller than ProPhoto.

[Bruce Watson]

The size of the colorspace to use is controversial.

Can't argue with you there! It can become a religious argument if the various parties aren't careful.

[Ted Harris]

Unless a client specifically asks I always scan for untagged output.