drum scanning black and white negatives are grainier?

[frdchang]

hello,

 

people seem to say that drum scanning c41 negatives (i'm also infering

black and white negatives as well) do not scan as well as E6 positives.

 

is this just an operator's fault, or is it the way the light source on

a drum scan enhances the grain on color/b&w negatives?

[bruce_watson1]

Oy. The urban legend continues to stagger about.

 

Drum scanning of negatives often results in *better* images than drum scanning chromes. The reason for this is that negatives are considerably less dense, and can have considerably more dynamic range, than chromes.

 

That said, scanning negatives (any scanner), or processing with a conventional darkroom enlarger, involves the Callier Effect. This is less evident with CCD scanners for two reasons. First, they aren't as sharp as PMTs. Second, their light source is diffuse. Unfortunately, with CCD scans, there's not a lot you can do about it - you are reduced to using software programs like Noise Ninja to "smooth out" the scan's grain.

 

With a drum scanner, a competent operator can open up the scanner's aperture a level. This lights the side of the grains making them appear smaller in the scan.

 

For context, I own my own drum scanner and do my own drum scans. Most of what I scan is 4x5 Tri-X. I also do some 4x5 160PortraVC. I've never had a problem with grain in my scans. I've printed some images at over 10x enlargement (1.0x1.25m prints) and they appear to me and everyone else who sees them (that my gallery owners and I have talked to) to be absolutely grainless.

 

One caveat. Some drum scanners, and some drum scanner software, do better with negatives than others. Some companies, and some scanner operators, do better than others. I have little doubt that YMMV, but there is nothing inherently evil about drum scanners and negatives.

[scott_eaton]

If it's an "urban legend", why did we just have a post a few days ago of someody claiming that two identical negs resulted in two different drums scans with different noise levels? I've been scanning negs a long time as well, and drums are a pain in the a$$ with negs. The PMT provides way too much dynamic range and you have to be aggresive about setting conservative black points, if not create a custom curve. I've got commercial Tango scans from 6x7 color negs that look like somebody used a 'add_party_glitter' filter to the image. The same neg scanned with a lowly Kodak PhotoCD system at the same rez is just as sharp, but lacks the increased grain.

 

That's really nice you have your own personal drum scanner and are able to tweak the B/W points and profiles to produce low D-min noise levels. Most of us don't, most labs won't, and the average neg shooter who wants quality scans is better off getting a non drum based scan when using a commercial source for negs, or get their own scanner.

 

I can print a tack sharp, totally sharp corner to corner optical print from 35mm up to 16x20 in my own darkroom. The odds of getting a razor sharp optical 16x20 print from 35mm film from a commercial source it like, 1 in 20. Hence, I don't advocate getting really big optical prints from 35mm even though I can do it.

[bruce_watson1]

Scott,

 

Urban legends continue on because people repeat them. But you know that, I'm sure.

 

The previous thread had one good scan and one poor one. IOW, that poster got a good drum scan from a negative. Which proves my point.

 

That he also got a poor scan on his second try doesn't invalidate the good scan he got on his first.

 

This argument of yours that the only thing worth scanning is a chrome seems to me to be similar to saying that because you can't get your car serviced to your satisfaction at the car dealership, you should abandon cars and drive a motorcycle. I'm suggesting that you should find a reputable independent mechanic who does good work and take your car there instead.

[roger krueger]

<i>That said, scanning negatives (any scanner), or processing with a conventional

darkroom enlarger, involves the Callier Effect. This is less evident with CCD scanners for

two reasons. First, they aren't as sharp as PMTs. Second, their light source is diffuse.

</i><br><br>

Many (most?) CCD film scanners do NOT have diffuse light sources. Nikons in

particular have a highly collimated light source. Callier effect + the

limited dynamic range of CCDs is why I got a drum--the difference on thick TMY is

amazing.

<br><br>

There's an inherent issue with scanning c41 on older drums--with 8-bit internals an

image that takes up a small fraction of the dynamic range ends up being effectively a 5- or

6-bit image by the time it's adjusted. This is the source of much of the "negs suck on

drums" urban legend. But even on a good scanner negs take more skill than

transparencies to get good results.

[tim parkin]

<p>Quite often the inbuilt sharpening (that some drum scanner operators don't know how to switch off and some drum scanner software doesn't let you) can cause huge problems. Also, inbuilt software inversion is typically 'shite' to use a British term. The best auto-neg inversions I have seen come from a Fuji Lanovia which uses Colorkit (the same software in Fuji Frontiers). <br>

Also, after lots and lost of testing, setting the black and white point in the scanner software doesn't produce better results than making a raw scan and setting the black and white point in Photoshop (tested on ICG, Fuji Celsis, Aztek Premier, Screen 8060 and Heidelberg scanners). The high bit depth of the scans and the 'dither' inherent in film means no visible data loss using this method. <br>

On top of this, Photoshop allows you to set the black and white point perfectly and then you can 'compress' the highlights and shadows, instead of clipping some of the 'grain' (which can make things noisier). <br>

Finally, the other test we ran on all of these scanners was to see how effective the aperture was at reducing grain/noise. The answer is 'fairly' but on further testing we realised that you get a better result using a film grain friendly noise reduction plugin (in our research Imagnomic Noiseware was the best). Larger apertures reduced detail at the same time as grain, noise reduction could be targeted to keep detail but reduce the prominence of grain in a way visually similar to aperture changes. <br>

we (http://www.drumscanning.co.uk/about/colour-negatives/) recently won a tender to scan a major fashion photographers images which was judged on visual quality alone. These were done using Photoshop inversion techniques we developed in-house (just ask if you want a quick guide) and noise reduction software instead of aperture control. </p>