Epson V700 and Silverfast 16 bit scanning

[feppe]

Is the V700 a native 16-bit machine which can actually pull 16 bits of clean data and not just claim to be a 16-bit machine like digital cameras advertising 16-bits? I'd be fine with 14 clean bits, or any significant increase over 8.

I tried two bit depths with SilverFast SE. There is an 8 bit (which SilverFast calls 48->24 bit), and 16-bit (first time I've heard anyone call 16-bit HDR, as some marketer decided to name it 48 bit HDR). The 8-bit output can be tweaked nicely to pull shadows up. But when I scanned the same chrome with 16-bit, I had no chance to do it when scanning, and I ended up with severely clipped shadows.

Is tweaking of 16-bit files a missing feature in the SE version? According to their complicated product offerings, Ai version looks like it might allow adjusting the image hi-lowlights before 16-bit scanning, or am I missing something?

[Tyler Boley]

Silverfast was calling that mode HDR long before there were digital cameras and digital processing. It's basically right off the sensors, like Vuescan's "Raw", also before digital capture and also not the same as what we now call raw.
So no software controls are operational in Silverfast's HDR mode. If you want Silverfast image editing tools use the "48 bit color" or "16 bit grayscale" modes, not the HDR modes.
I don't know the native bit depth off the CCD of your Epson...
Tyler

[Ken Lee]

If you mention getting useable data out of the shadows, aren't you asking more about the actual dMax of the scanner ?

One could have 2 different scanners, both of which divide their respective ranges into 2^16 slices, but the scanner with greater dynamic range, will have more useful data, no ?

[feppe]

Silverfast was calling that mode HDR long before there were digital cameras and digital processing. It's basically right off the sensors, like Vuescan's "Raw", also before digital capture and also not the same as what we now call raw.
So no software controls are operational in Silverfast's HDR mode. If you want Silverfast image editing tools use the "48 bit color" or "16 bit grayscale" modes, not the HDR modes.
I don't know the native bit depth off the CCD of your Epson...
Tyler

So you're saying SilverFast doesn't do 16-bit color scanning, only the unadjustable "HDR" mode? And that I'm stuck with 8-bit regardless of what my scanner is capable of?

[feppe]

If you mention getting useable data out of the shadows, aren't you asking more about the actual dMax of the scanner ?

One could have 2 different scanners, both of which divide their respective ranges into 2^16 slices, but the scanner with greater dynamic range, will have more useful data, no ?

I'm talking about getting the additional levels from going to 16 (or more likely 14) bits from 8. I've moved to 16-bit editing in my digital workflow, and while the benefits of going beyond 8 bits can be argued, I'd like to squeeze as much data from the chrome as possible.

Shadow detail was just an example to illustrate that the "HDR" mode doesn't allow tweaking of the output file (levels adjustment, grey point, etc). The data apparently is there somewhere as the 8-bit mode pulls it just fine. I checked the HDR output file, and it does include the same data in very dark shadows which would be much easier to pull during scanning rather than in PS.

According to the product comparison on SilverFast website the Ai version includes "48 Bit RGB TIFF: with SilverFast adjustments" which is not explained further - I'd assume that this means level adjustments, but Tyler's earlier comment suggests it can't be done. I'll ask them.

[Kirk Gittings]

I'm thinking a 48 bit tiff is another way of referring to a normal 16 bits per channel tiff file, 16 bits per channel with 3 channels=48 bit tiff. Nothing unusual there. In PS when you select 16 bits in IMAGE>Mode>16 bit. It is 16 bits/channel or 48 bits altogether.

and

and while the benefits of going beyond 8 bits can be argued

Is there still any argument? I thought the benefits of a 16 bit workflow were settled years ago?

[feppe]

I'm thinking a 48 bit tiff is another way of referring to a normal 16 bits per channel tiff file, 16 bits per channel with 3 channels=48 bit tiff. Nothing unusual there. In PS when you select 16 bits in IMAGE>Mode>16 bit. It is 16 bits/channel or 48 bits altogether.

Yeah, that's the case, and have no problem with that. I'm used to referring to it as 16 bits which seems to be the convention - it's not like there's a standard which has odd bits on Red channel, for example :P

[Tyler Boley]

So you're saying SilverFast doesn't do 16-bit color scanning, only the unadjustable "HDR" mode? And that I'm stuck with 8-bit regardless of what my scanner is capable of?

no, the oposite. Perhaps the confusion here is that what you call 16 bit color they call 48 bit color. RGB is 3 channels, 3 channels of 16 bit each is 48 bit.

"16-bit color scanning" is available to you 2 different ways-
48 bit color- which gives you all the normal controls the 8 bit has, seems to be what you want.
48 bit HDR color, which is raw data off the heads, no controls available.

Additionally, no matter the native bit depth of any scanner, 8, 10, 12, 14, 16, it will be remapped down or up to 8 or 16 bit per channel depending on settings in any scanner software I know of...

Make sense?
Tyler

[feppe]

no, the oposite. Perhaps the confusion here is that what you call 16 bit color they call 48 bit color. RGB is 3 channels, 3 channels of 16 bit each is 48 bit.

"16-bit color scanning" is available to you 2 different ways-
48 bit color- which gives you all the normal controls the 8 bit has, seems to be what you want.
48 bit HDR color, which is raw data off the heads, no controls available.

Additionally, no matter the native bit depth of any scanner, 8, 10, 12, 14, 16, it will be remapped down or up to 8 or 16 bit per channel depending on settings in any scanner software I know of...

Make sense?
Tyler

I think the confusion is due to my crippled SilverFast version (SE) which came with the scanner. It only has the following two color options for scanning slides:
48->24 bit color (outputs files with 8 bits per channel)
48 bit HDR color (outputs 16 bits per channel)

There is a 48 bit color option, but it's greyed out, which I assume will be available with an upgrade.

Thanks for the explanation on the HDR option, it seems the non-HDR 48 bit color is what I'm looking for, and need to upgrade. It's still unclear from SilverFast's feature comparison whether I need SE Plus or Ai, but hopefully they'll respond to my query faster than Gitzo does...

[Ken Lee]

The Epson driver supports 48-bit color, doesn't it ?

I'm not familiar with the 700, but on my 4990, I prefer it to Silverfast and VueScan.