Bit depth and banding (stepping)

George Collier · Aug 18, 2020

I've been using a V850 Pro with both Epson Scan and SilverFast, started with Epson until I got the time to explore SilverFast, which I really like.
However - In scanning some 4x5 negs, black and white, which have large open sky areas (no clouds, the yellow filter kind), which attempting to deepen in value, I get banding. Some info on what I'm doing:
I adjust the scan settings to very close to final tonal values
Saving in Tiff 8bit grayscale (SF doesn't allow 16bit, for some reason)
Open the Tiff in raw, if any other adjustments are needed.
Open in PShop and make edits if needed.
I'm working on one with a large sky area which I want to deepen just the sky, doing so with a gradient mask, in PShop, to the sky area only. When I saw the banding the first time, I reopened the Tiff in Raw, deepened the whole thing, opened a second copy of the file, copied the darker image, and pasted it into the original file as its own layer, applied a gradient mask to that image layer, just to hide the part I don't want to see. The effect is right, but the banding is there anyway, just because the sky has it's own gradation, I guess.
I haven't had this happen with smaller formats, maybe because grain masks or prevents the banding.
I'm thinking this banding would be minimized in a 16 bit file, but SF won't allo that (it's selection is 16->8bit).
Epson Scan allows a simple 16 bit choice in their popup menu. (I've used it before)
Any ideas about this?

shutterfinger · Aug 18, 2020

George Collier said:
Saving in Tiff 8bit grayscale (SF doesn't allow 16bit, for some reason)

Silverfast SE and SE Plus scan in 16 bit mode but saves in 8 bit. You have to upgrade to Ai to be able to save in 16 it.

George Collier said:
I adjust the scan settings to very close to final tonal values

Set the White and Black points, all other tonal adjustments are best done in post processing.

George Collier said:
However - In scanning some 4x5 negs, black and white, which have large open sky areas (no clouds, the yellow filter kind), which attempting to deepen in value, I get banding.

Please post an example of the "banding".
When I first started scanning B&W 4x5 I saw splotches and all kinds of weird tonal stuff. Some was slightly uneven developing barely detectable with excellent lighting and a very good loupe while the rest was due to particulate in the air at the time the exposure was made.

Kino · Aug 18, 2020

8 bit won't cut it for super smooth graduations; you'll need at least 10 bits to avoid.

An old trick to disrupt banding is to inject a bit of random noise into the smooth areas; it only takes a tiny bit.

You could also try this approach if you have photoshop:

https://www.slrlounge.com/an-effective-way-to-remove-banding-thats-not-adding-noise/

Alan Edward Klein · Aug 18, 2020

shutterfinger said:
Silverfast SE and SE Plus scan in 16 bit mode but saves in 8 bit. You have to upgrade to Ai to be able to save in 16 it.
....

Silverfast is playing a game to squeeze more money out of you. You spend so much extra for the V850 over the V800. Epson should include the right software not the version that doesn;t do the job.

grat · Aug 18, 2020

It's slightly galling to have to buy it, but the Epson version of silverfast can be upgraded to the AI version relatively cheaply (Under $100, if I recall).

It's a worthwhile upgrade for the greater depth and multi-exposure.

VueScan is also an option-- it seems to come down to personal taste between VueScan and SilverFast.

I agree the v850 should have come with SF AI studio.

PhilBurton · Aug 18, 2020

George Collier said:
I've been using a V850 Pro with both Epson Scan and SilverFast, started with Epson until I got the time to explore SilverFast, which I really like.
However - In scanning some 4x5 negs, black and white, which have large open sky areas (no clouds, the yellow filter kind), which attempting to deepen in value, I get banding. Some info on what I'm doing:
I adjust the scan settings to very close to final tonal values
Saving in Tiff 8bit grayscale (SF doesn't allow 16bit, for some reason)
Open the Tiff in raw, if any other adjustments are needed.
Open in PShop and make edits if needed.
I'm working on one with a large sky area which I want to deepen just the sky, doing so with a gradient mask, in PShop, to the sky area only. When I saw the banding the first time, I reopened the Tiff in Raw, deepened the whole thing, opened a second copy of the file, copied the darker image, and pasted it into the original file as its own layer, applied a gradient mask to that image layer, just to hide the part I don't want to see. The effect is right, but the banding is there anyway, just because the sky has it's own gradation, I guess.
I haven't had this happen with smaller formats, maybe because grain masks or prevents the banding.
I'm thinking this banding would be minimized in a 16 bit file, but SF won't allo that (it's selection is 16->8bit).
Epson Scan allows a simple 16 bit choice in their popup menu. (I've used it before)
Any ideas about this?

@George Collier Lots of people don't seem to like Silverfast. What is it about Silverfast that you like?

Phil

George Collier · Aug 19, 2020

Thanks for the responses.
Shutterfinger - I'm reluctant to spend more on SF, especially when Epson Scan offers 16 bit scanned files.
Making adjustments to an already digitized file contributes (if not causes) banding. This why I tweak the scan as much as possible to minimize post scan editing.
The link provided by Kino will show you banding. (Thanks Kino)
grat - doesn't SF SE Plus have the multiscan option? The manual seems to indicate that it does.
PhilBurton - I like SF controls and the stability of the histogram and curve pallets. Epson Scan has an annoying habit of changing settings every time you make any change before scanning and must be checked after all other adjustments (cropping, zooming in, etc).
I'm going to try doing a second darker scan immediately following the first scan to deepen the sky, then apply that second scan as a layer, masking the unneeded part. It's a pita workaround, though, at best. But it may prove that banding occurs only during post scan adjustments.

Alan Edward Klein · Aug 19, 2020

Scan to a tiff file not jpeg. That might help with reducing banding.

Kino · Aug 19, 2020

We really need a modern film scanner that has the capacity to scan in RAW format. The Viewscan option is a workaround, but it is not a true RAW file, but a TIFF file with a low contrast curve applied, so it doesn't preserve ALL data from the sensor.

Scans that are made very near desired results are inherently poor for making further adjustments, because they map data in the toe and shoulder (DMax and DMin) into very narrow regions of the total bandwidth, which then makes expanding or contracting this data almost impossible without causing breaks in the histogram.

As I have said repeatedly, there are those who scan for the finished product and those who scan to make a digital production negative (and by negative, I mean positive in this topsy-turvy World of Digital Nomenclature) for further manipulation. Don't expect a near properly adjusted scan to be very easy to work with...

Alan Edward Klein · Aug 19, 2020

George Collier said:
Thanks for the responses.
Shutterfinger - I'm reluctant to spend more on SF, especially when Epson Scan offers 16 bit scanned files.
Making adjustments to an already digitized file contributes (if not causes) banding. This why I tweak the scan as much as possible to minimize post scan editing.
The link provided by Kino will show you banding. (Thanks Kino)
grat - doesn't SF SE Plus have the multiscan option? The manual seems to indicate that it does.
PhilBurton - I like SF controls and the stability of the histogram and curve pallets. Epson Scan has an annoying habit of changing settings every time you make any change before scanning and must be checked after all other adjustments (cropping, zooming in, etc).
I'm going to try doing a second darker scan immediately following the first scan to deepen the sky, then apply that second scan as a layer, masking the unneeded part. It's a pita workaround, though, at best. But it may prove that banding occurs only during post scan adjustments.

George: If you check No Color Correction in the Epsonscan Configuration panel, there will be no settings and you scan flat. (I forget now whether the Sharpening box is checked or not). Then do all your adjustments in your post processing program. This would simplify your process. It would eliminate worrying about getting the settings right for the scan and having to scan numerous times. It would eliminate using similar adjustments on two different programs.

Alan Edward Klein · Aug 19, 2020

PS If the sharpening box is checked, un check it. Do that in post processing as well.

George Collier · Aug 19, 2020

Alan Edward Klein - I never scan to jpg, always psd or tiff. Lately tiff as you can open them in RAW, though I'm not sure yet as to any advantage in doing that. I'll try the NoCC idea. I don't care, though, how simple the process, only in the results. I'm scanning mostly only my best images, so not high production.

Wallendo · Aug 19, 2020

SilverFast does have a RAW option which should protect the complete bit depth , but requires more post-processing. I have only played around with it a few times. This file needs to be imported with a RAW converter and not simply opened in an editing program.

If you scan a lot it may be worthwhile just to upgrade SilverFast to allow 16-bit TIFF files.

PhilBurton · Aug 19, 2020

Wallendo said:
SilverFast does have a RAW option which should protect the complete bit depth , but requires more post-processing. I have only played around with it a few times. This file needs to be imported with a RAW converter and not simply opened in an editing program.

If you scan a lot it may be worthwhile just to upgrade SilverFast to allow 16-bit TIFF files.

It's my impression that a "scanner RAW" file isn't the same as a DSLR RAW file because the latter does capture the individual RGB pixel values, whereas the scanner has already merged those values into a single color, much like a TIFF or JPG. Is my impression right?

Either way, what additional info does a Silverfast RAW file contain? Is that additional data useful only within Silverfast, or in Lightroom or Photoshop?

Alan Edward Klein · Aug 19, 2020

PhilBurton said:
It's my impression that a "scanner RAW" file isn't the same as a DSLR RAW file because the latter does capture the individual RGB pixel values, whereas the scanner has already merged those values into a single color, much like a TIFF or JPG. Is my impression right?

Either way, what additional info does a Silverfast RAW file contain? Is that additional data useful only within Silverfast, or in Lightroom or Photoshop?

The scanner's dMax, lens, electronics, mechanics, define the quality of the scan not the software. You can't get blood from a turnip or make a silk purse from a sow's ear. Sort of like many of my photos.

Wallendo · Aug 19, 2020

PhilBurton said:
It's my impression that a "scanner RAW" file isn't the same as a DSLR RAW file because the latter does capture the individual RGB pixel values, whereas the scanner has already merged those values into a single color, much like a TIFF or JPG. Is my impression right?

Either way, what additional info does a Silverfast RAW file contain? Is that additional data useful only within Silverfast, or in Lightroom or Photoshop?

Yes, these aren't really RAW files.

The RAW files created by SilverFast and VueScan are really just 16-bit TIFF files inside of a RAW wrapper. Doing it this way allows the files to be imported via a RAW converter.

For SilverFast, this allows the entire bit depth to be preserved. None of the usual adjustments are made by SilverFast.
With VueScan, the "RAW" files can be imported and "scanning" adjustments made in the program as if a new scan were made - the image can be scanned once and processed multiple times.

With VueScan, I generally find it easier to just scan the image properly the first time. I have thought about trying to save RAW from SilverFast to get around it's 8/24 bit limit on my version, but in the end, it is generally easier to just switch to VueScan for that.

MattKing · Aug 19, 2020

Alan Edward Klein said:
The scanner's dMax, lens, electronics, mechanics, define the quality of the scan not the software.

I would suggest that the scanner's lens, other elements in the optical path, electronics, mechanics and firmware/software determine the dMax and define the quality of the scan.
The software also usually adds some additional functions which it would be nice to be able to easily dispense with, but the core functionality found in the firmware and software - the part that converts electrical information from a sensor into a file that can be used to create an image - is at least as important as the rest of the stuff.
The close matching of image algorithms with the output of the sensor is critical.

Alan Edward Klein · Aug 19, 2020

MattKing said:
I would suggest that the scanner's lens, other elements in the optical path, electronics, mechanics and firmware/software determine the dMax and define the quality of the scan.
The software also usually adds some additional functions which it would be nice to be able to easily dispense with, but the core functionality found in the firmware and software - the part that converts electrical information from a sensor into a file that can be used to create an image - is at least as important as the rest of the stuff.
The close matching of image algorithms with the output of the sensor is critical.

Other than multiple scanning, the value of which is debatable, Silverfast, Vuescan and Epsonscan applies post scanning processing edits on the basic scan that all three do. You can accomplish the same thing with your regular post scan editing software like Photoshop, Lightroom or whatever. This eliminates learning a second editing program other than using it for the basic scan. It also eliminates redoing scans because you screwed up the scanner settings. But everyone should do what works for them.

MattKing · Aug 19, 2020

Alan Edward Klein said:
Other than multiple scanning, the value of which is debatable, Silverfast, Vuescan and Epsonscan applies post scanning processing edits on the basic scan that all three do. You can accomplish the same thing with your regular post scan editing software like Photoshop, Lightroom or whatever. This eliminates learning a second editing program other than using it for the basic scan. It also eliminates redoing scans because you screwed up the scanner settings. But everyone should do what works for them.

You are talking about the editing functions - those are add-ons.
I am talking about what is essentially "under the hood".
Sort of like the core of a computer operating system, or the image processing chip built into digital cameras.
Without firmware/software - and the interpretive algorithms built into them - scanners don't give you anything that you could make any use of in any editing program.
In many ways the rapid improvements we have seen in digital cameras have been more to do with the built in image processing than any other component in the camera.

PhilBurton · Aug 19, 2020

Wallendo said:
Yes, these aren't really RAW files.

The RAW files created by SilverFast and VueScan are really just 16-bit TIFF files inside of a RAW wrapper. Doing it this way allows the files to be imported via a RAW converter.

For SilverFast, this allows the entire bit depth to be preserved. None of the usual adjustments are made by SilverFast.
With VueScan, the "RAW" files can be imported and "scanning" adjustments made in the program as if a new scan were made - the image can be scanned once and processed multiple times.

With VueScan, I generally find it easier to just scan the image properly the first time. I have thought about trying to save RAW from SilverFast to get around it's 8/24 bit limit on my version, but in the end, it is generally easier to just switch to VueScan for that.

@Wallendo I use Lightroom, which can import any sort of file for processing. Unlike "toy" programs that just do JPGs, Lightroom (in case you aren't familiar with it) can also use a TIFF as the "master" and also does RAW conversion. But a RAW file input is not required by Lightroom.

So, aside from working with a RAW convertor, what advantage is there with a scanner RAW in Silverfast. With Vuescan are the scanning adjustments equivalent to what I could do in Lightroom, for example. I'm hardly an Adobe "fanboy" but I like the idea of all my post work being done by the same piece of software.

Phil

Wallendo · Aug 19, 2020

PhilBurton said:
@Wallendo I use Lightroom, which can import any sort of file for processing. Unlike "toy" programs that just do JPGs, Lightroom (in case you aren't familiar with it) can also use a TIFF as the "master" and also does RAW conversion. But a RAW file input is not required by Lightroom.

So, aside from working with a RAW convertor, what advantage is there with a scanner RAW in Silverfast. With Vuescan are the scanning adjustments equivalent to what I could do in Lightroom, for example. I'm hardly an Adobe "fanboy" but I like the idea of all my post work being done by the same piece of software.

Phil

I use Lightroom extensively - I just need to figure out why it won't sync my photos properly . The reason for saving RAW from SilverFast is that the less expensive versions of SilverFast do not allow you to save as 16-bit TIFF files. Scanning in RAW is a work-around for this problem.

Alan Edward Klein · Aug 19, 2020

MattKing said:
You are talking about the editing functions - those are add-ons.
I am talking about what is essentially "under the hood".
Sort of like the core of a computer operating system, or the image processing chip built into digital cameras.
Without firmware/software - and the interpretive algorithms built into them - scanners don't give you anything that you could make any use of in any editing program.
In many ways the rapid improvements we have seen in digital cameras have been more to do with the built in image processing than any other component in the camera.

Your post isn't clear. Silverfast or Vuescan scan no better than Epsonscan. All their bells and whistles are editing functions that can be done after the scan just as well or better with Lightroom or Photoshop.

MattKing · Aug 19, 2020

Alan Edward Klein said:
Your post isn't clear. Silverfast or Vuescan scan no better than Epsonscan. All their bells and whistles are editing functions that can be done after the scan just as well or better with Lightroom or Photoshop.

I am not talking about Silverfast or Vuescan or Epsonscan, save and except to the extent that they are designed to interface between the built-in firmware and software that comes with the scanner.
I am talking about that built-in, nameless firmware and software, that does a whole bunch of processing before anything in Silverfast or Vuescan or Epsonscan gets their hands on it.
Some of that software may be found in the connectivity driver that allows you to connect the scanner to your computer, but most of it isn't seen by the user.

Kino · Aug 19, 2020

The answers are in color management; scanner LUTs (which are never truly defined by the manufacturer), operating system color space and gamma, display color space and gamma and the computer application you are using to view the scanned image (managed or not?).

In any event, most people just poke around until it satisfies them, so it's a thankless rabbit hole to go down...

grat · Aug 19, 2020

Alan Edward Klein said:
Your post isn't clear. Silverfast or Vuescan scan no better than Epsonscan. All their bells and whistles are editing functions that can be done after the scan just as well or better with Lightroom or Photoshop.

So your belief is that general purpose software is just as good as purpose-written, optimized software?

That's an... interesting viewpoint.

Yes, you probably can do the same sort of editing with Lightroom or Photoshop-- but you'll work considerably harder at it.

Bit depth and banding (stepping)

George Collier

shutterfinger

Kino

Alan Edward Klein

grat

PhilBurton

George Collier

Alan Edward Klein

Kino

Alan Edward Klein

Alan Edward Klein

George Collier

Wallendo

PhilBurton

Alan Edward Klein

Wallendo

MattKing

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Bit depth and banding (stepping)

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