Where for Quality Color Neg Tango Scans?

[Bruce Watson]

Actually you can change the aperture size on the tango, and the smallest aperture is 10 microns.

I have used a DPL8000 with negative films and I saw no advantage to using apertures smaller then 10 microns. In fact, I would say that 10 microns it too small for color negative films. Also I found out that image quality is improved when you scan at a higher resolution then the one that corresponds to your selected aperture. This is due to the stochastic nature of film.

I've never been able to get to drive a Tango myself so all I know is what people who have, have told me. If I'm wrong I stand corrected.

As to which aperture to scan with, I think you paint with too broad a brush. Dye clouds are dye clouds whether from color negative or color positive film. And some films/images can make good use of 6 micron and smaller apertures. Much depends on what one is trying to accomplish. I for one don't believe in the one-size-fits-all school of scanning.

[8x10 user]

I haven’t been able to use a tango myself but I am in the process of purchasing a primescan so I had a good reason to learn this information. I'm not 100% sure on this, but from what I understand, the tango/primescan has 25 aperture selections but the operator is limited to using only the 10 apertures that are closest to your scanning resolution.

I tested three different film types on the DPL 8000 by scanning them at 8000 DPI using every aperture from 3 to 22 microns. The results lead me to believe that there is an optimal aperture size for each film type

I found that when you scan film with a too small of aperture that it introduces a large amount of color noise without any improvement in detail. I believe this is known as grain aliasing.

IMO these are the optimal apertures on the films that I tested.

Kodachrome - ~6 microns
Other slide films- 8-13 microns
Fuji NPS ~19 microns

I did not work with any black and white films yet but I would think that some of them would have small enough grain partials to warrant a scan with a 3-micron aperture.

Also, as I stated before there is IMO, a noticeable improvement in image quality when the scanning resolution is increased even when the aperture remains unchanged.

[neil poulsen]

I'm aware of one Tango that provides only provides 8-bit scans. Is this true of all Tangos?

[Jim Becia]

I'm aware of one Tango that provides only provides 8-bit scans. Is this true of all Tangos?

Neil,

While not an expert by any stretch of the imagination, some Tangos must be able to do 16 bit as I just got some 16 bit scans back from WCI. Jim

[Bruce Watson]

IMO these are the optimal apertures on the films that I tested.

Kodachrome - ~6 microns
Other slide films- 8-13 microns
Fuji NPS ~19 microns

I did not work with any black and white films yet but I would think that some of them would have small enough grain partials to warrant a scan with a 3-micron aperture.

The problem I have with this is that size and distribution of dye clouds / grain clumps is directly related to density. This is less important with tranny films because the density is in the shadows, so the graininess is often lost from view. Where it really matters then is in negative films, because there the density is in the highlights where all can see.

With a negative that is less dense one can often do better with a smaller aperture. With one that is more dense it may make a better scan to use a larger aperture. This is particularly true of B&W IMHO.

This is why I don't like blanket statements about what apertures go with what films. In my experience it's an image-by-image judgment.

[Don Hutton]

The problem I have with this is that size and distribution of dye clouds / grain clumps is directly related to density. This is less important with tranny films because the density is in the shadows, so the graininess is often lost from view. Where it really matters then is in negative films, because there the density is in the highlights where all can see.

With a negative that is less dense one can often do better with a smaller aperture. With one that is more dense it may make a better scan to use a larger aperture. This is particularly true of B&W IMHO.

This is why I don't like blanket statements about what apertures go with what films. In my experience it's an image-by-image judgment.

I'm by no means a scanning expert, but I own and operate a Howtek 4500. Over the past few years I have observed plenty of professionally done scans where it is clear that the operator used an aperture that was too small and as a result, there is very significant grain aliasing - in fact with very high resolution drum scans, most of the "professional" scans I have seen have this problem. While the type of emulsion is important in deciding on an optimal aperture for a drum scan, it is also too some extent image dependant. It appears to me that many drum scan operators presume that the smallest aperture is appropriate for the highest resolution their scanner can manage.

[Bruce Watson]

I'm by no means a scanning expert, but I own and operate a Howtek 4500. Over the past few years I have observed plenty of professionally done scans where it is clear that the operator used an aperture that was too small and as a result, there is very significant grain aliasing - in fact with very high resolution drum scans, most of the "professional" scans I have seen have this problem. While the type of emulsion is important in deciding on an optimal aperture for a drum scan, it is also too some extent image dependent. It appears to me that many drum scan operators presume that the smallest aperture is appropriate for the highest resolution their scanner can manage.

Indeed. I think we are in violent agreement. The art in scanning is to consider all these factors in setting up for a scan, and making the best use of the tools available, including but not limited to, aperture.

It's completely different from, yet somewhat similar to, selecting your taking aperture. I often find myself balancing demands of sharpness and DoF while also considering diffraction, motion blur, etc. I find that there aren't really any good rules that apply to every photograph. Instead of applying a blanket rule I have to evaluate every scene individually when I make photographs, and again I have to evaluate every film individually when I scan.