Digital BW, The Print

Martin,

This is probably not of great interest to the other readers of this list,
but it always seems the backroom conversations turn out to be interesting.
Also, it fits right in with some of the gamma space conversions Dan C. has
been sharing with us...

I know that like me, you scan in RAW highbit mode (you with a Polaroid 120,
and me with a Leafscan 45), and then post-scan "develop" the file, thus
retaining a toned 16-bit file. I know that you use Silverfast to do this,
and are quite pleased with that program. I've only tested it with a Demo
version, and it'd be a costly add-on purchase for me.

Bruce Fraser shared a gem with me regarding doing the toning in Photoshop.
This pleases me because of the cost savings, but also because I'm familiar
with the interface, and I can zoom in to 100% magnification or more. Anyway,
I thought you might like to try it and see if it works for you.

One thing to note. The directions I post below work very well as-is for me
for transparency materials, short of perhaps a color balance tweak and some
contrast. But since I shoot my negatives routinely to be a stop or so "over
exposed" I still have to make a significant gamma move on them. Not a big
deal, just letting you know that's probably normal if it arises for you too.

From Bruce:

************
(snip)

Your problem stems from the way the Leaf software writes out 16-bit files --
as you've noticed, all the data is bunched up in the shadow end.

Here's what I do with my legacy Leaf 16-bit images: it works fairly well.

1.) Create a linear-gamma profile. I use Adobe RGB as a starting point. With
Adobe RGB set as the working space, in Color Settings, choose Custom RGB,
set the gamma to 1.0, call it something sensible, then save it using Save
RGB. Then restore your working space of choice.

2.) when you open the Leaf image, assign the linear gamma profile.

3.) Go into Curves, set the input value to 4, and the output value to 14.

4.) Use Convert to Profile to convert the image to working RGB.

5.) Edit as necessary.

It's a bit of a kludge, but it works quite well.

************

If you get a chance to try it let me know how it works. I'm still not ruling
out Silverfast for myself, but if this does as well, for free.....

Todd

PS, I did find it tricky to save the custom gamma profile at first but I did
stumble my way through it eventually. I think one of Dan's posts was a bit
more explicit on how to do that than Bruce's if you get stuck.

> Bruce Fraser shared a gem with me regarding doing the toning in
> Photoshop.

So this handles the "tree" problem you were having?

Tim
--
Tim Spragens
http://www.borderless-photos.com

Martin,

From what I have seen, most scanners that have a RAW mode will produce dark scans with the data "bunched" up at the shadow end.  Silverfast has a fairly easy solution to the problem. They have  a gamma gradient that is applied to the raw scan before exporting it out for use by other programs or Silverfast HDR.

Under the Frames tab select Option/General and put a check in the "for HDR output" box. Set the Gamma Gradation to 1.5, 1.8, or 2.2 depending on your working space. Basically the program distributes the data across the histogram allowing for easier adjustments later.

I find that I can do the adjustments in SIlverfast HDR or in Photoshop. Of course Photoshop converts my 48bit RAW HDR file to a 16 bit file.

Basically your "kludge" is doing the same thing.
Regards,

Michael J. Kravit, AIA
Architect/Photographer
www.kravit.net/photography


[Non-text portions of this message have been removed]

>> Bruce Fraser shared a gem with me regarding doing the toning in
>> Photoshop.
> 
> So this handles the "tree" problem you were having?

Sorry Tim, refresh my memory.

Todd

Todd,

Basically all Silverfast is doing is a mathematical adjustment to the 
raw data and I don't see any reason why it could not be done a number 
of ways in Photoshop or other software.

Now if you really could adjust the brightness of the lamp and/or the 
sensitivity of the CCD array, it would be another story.

Bruce's suggestion sounds workable for the problem we discussed. 
Namely you wind up with a raw scan of 12 or 14 bits of data mapped 
into a 16-bit space but off to one end. Moving it to center in 16-bit 
shouldn't be that difficult.

I need to play with the scanner and software quite a bit more before 
I know it has (or may not have) to offer. A lot of it may just be 
ease of use and speed. I am afraid I just don't know enough about it 
to give you a good answer. Maybe George would jump in here. I know he 
uses it and has lots of experience with it.

Martin

--- In DigitalBlackandWhiteThePrint@y..., Todd Flashner <tflash@e...> 
wrote:
> Martin,
> 
> This is probably not of great interest to the other readers of this 
list,
> but it always seems the backroom conversations turn out to be 
interesting.
> Also, it fits right in with some of the gamma space conversions Dan 
C. has
> been sharing with us...
> 
> I know that like me, you scan in RAW highbit mode (you with a 
Polaroid 120,
> and me with a Leafscan 45), and then post-scan "develop" the file, 
thus
> retaining a toned 16-bit file. I know that you use Silverfast to do 
this,
> and are quite pleased with that program. I've only tested it with a 
Demo
> version, and it'd be a costly add-on purchase for me.
> 
> Bruce Fraser shared a gem with me regarding doing the toning in 
Photoshop.
> This pleases me because of the cost savings, but also because I'm 
familiar
> with the interface, and I can zoom in to 100% magnification or 
more. Anyway,
> I thought you might like to try it and see if it works for you.
> 
> One thing to note. The directions I post below work very well as-is 
for me
> for transparency materials, short of perhaps a color balance tweak 
and some
> contrast. But since I shoot my negatives routinely to be a stop or 
so "over
> exposed" I still have to make a significant gamma move on them. Not 
a big
> deal, just letting you know that's probably normal if it arises for 
you too.
> 
> From Bruce:
> 
> ************
> (snip)
> 
> Your problem stems from the way the Leaf software writes out 16-bit 
files --
> as you've noticed, all the data is bunched up in the shadow end.
> 
> Here's what I do with my legacy Leaf 16-bit images: it works fairly 
well.
> 
> 1.) Create a linear-gamma profile. I use Adobe RGB as a starting 
point. With
> Adobe RGB set as the working space, in Color Settings, choose 
Custom RGB,
> set the gamma to 1.0, call it something sensible, then save it 
using Save
> RGB. Then restore your working space of choice.
> 
> 2.) when you open the Leaf image, assign the linear gamma profile.
> 
> 3.) Go into Curves, set the input value to 4, and the output value 
to 14.
> 
> 4.) Use Convert to Profile to convert the image to working RGB.
> 
> 5.) Edit as necessary.
> 
> It's a bit of a kludge, but it works quite well.
> 
> ************
> 
> If you get a chance to try it let me know how it works. I'm still 
not ruling
> out Silverfast for myself, but if this does as well, for free.....
> 
> Todd
> 
> PS, I did find it tricky to save the custom gamma profile at first 
but I did
> stumble my way through it eventually. I think one of Dan's posts 
was a bit
> more explicit on how to do that than Bruce's if you get stuck.

Michael,

I have used Silverfast just as you say. The gamma adjustment brings 
the raw file more to center making adjustments easier. George DeWolfe 
recommends using gamma set to 3.00 as I recall. I have also been 
using Polacolor Insight (waiting for Silverfast to fix a Win 
2000/Firewire bug) for my raw scans. In this software you can make 
full screen levels, curves, etc adjustments then specify a raw scan 
to file. Insight then does the raw scan and applies the changes to 
the file after the scan is complete. Slower but the results seem 
similar.

I believe Silverfast's 48-bit Color is the same as Photoshop's 16-bit 
color. One is looking at the total bits and the other is just 
considering the count on one channel but the data set is the same.

Anyone wanting to know more about Silverfast (or who has Silverfast!) 
should check out Ian Lyon's tutorials 

http://welcome.to/computerdarkroom

Martin

--- In DigitalBlackandWhiteThePrint@y..., "Michael J. Kravit" 
<kravit@b...> wrote:
> Martin,
> 
> From what I have seen, most scanners that have a RAW mode will 
produce dark scans with the data "bunched" up at the shadow end.  
Silverfast has a fairly easy solution to the problem. They have  a 
gamma gradient that is applied to the raw scan before exporting it 
out for use by other programs or Silverfast HDR.
> 
> Under the Frames tab select Option/General and put a check in 
the "for HDR output" box. Set the Gamma Gradation to 1.5, 1.8, or 2.2 
depending on your working space. Basically the program distributes 
the data across the histogram allowing for easier adjustments later.
> 
> I find that I can do the adjustments in SIlverfast HDR or in 
Photoshop. Of course Photoshop converts my 48bit RAW HDR file to a 16 
bit file.

> 
> Basically your "kludge" is doing the same thing.
> Regards,
> 
> Michael J. Kravit, AIA
> Architect/Photographer
> www.kravit.net/photography
> 
> 
> [Non-text portions of this message have been removed]

Todd,

Tree. That would be the discussion we had about adjusting an 8-bit 
image to the point of histogram meltdown vs. doing the same 
adjustments in 16-bit where a smooth histogram is maintained but when 
they are printed you can't tell the difference between the prints. In 
other words maintain a smooth 8-bit histogram is not a requirement 
for a good print and working in 16-bit space may not offer an 
advantage to adjusting your average neg.

Martin



--- In DigitalBlackandWhiteThePrint@y..., Todd Flashner <tflash@e...> 
wrote:

> 
> >> Bruce Fraser shared a gem with me regarding doing the toning in
> >> Photoshop.
> > 
> > So this handles the "tree" problem you were having?
> 
> Sorry Tim, refresh my memory.
> 
> Todd

> Todd,
> 
> Tree. That would be the discussion we had about adjusting an 8-bit
> image to the point of histogram meltdown vs. doing the same
> adjustments in 16-bit where a smooth histogram is maintained but when
> they are printed you can't tell the difference between the prints. In
> other words maintain a smooth 8-bit histogram is not a requirement
> for a good print and working in 16-bit space may not offer an
> advantage to adjusting your average neg.
> 
> Martin

I remember that conversation, but where was the tree? Never mind, I just
remembered. I've got to stop keeping these hours....

Todd

PS, Tim, I don't think I was having the tree problem. I liked my tree.
Martin was having a sky problem, but that came off a different scanner. That
tip from Bruce I actually found more useful for my color images than BW, but
I have no idea why that should be.

> 
> 
> 
> --- In DigitalBlackandWhiteThePrint@y..., Todd Flashner <tflash@e...>
> wrote:
>> 
>>>> Bruce Fraser shared a gem with me regarding doing the toning in
>>>> Photoshop.
>>> 
>>> So this handles the "tree" problem you were having?
>> 
>> Sorry Tim, refresh my memory.
>> 
>> Todd
> 
> 
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> 
> 
> 
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> 
>

> >> Bruce Fraser shared a gem with me regarding doing the toning in
> >> Photoshop.
> > 
> > So this handles the "tree" problem you were having?
> 
> Sorry Tim, refresh my memory.

Offlist, you sent two images, one the raw scan, the other 
processed. It was intended to demonstrate the histogram combing 
that you were getting when processing the image scanned with the 
Leaf scanner.

Tim
--
Tim Spragens
http://www.borderless-photos.com

> PS, Tim, I don't think I was having the tree problem. I liked my tree.
> Martin was having a sky problem, but that came off a different scanner.
> That
> tip from Bruce I actually found more useful for my color images than BW,
> but
> I have no idea why that should be.

No, you were happy with your tree, even with the combing, though 
Bruce's tip may have helped to prevent the combing nonetheless, 
and lessen problems like Martin's sky should you ever run across 
one. Sorry for the confusion.

Tim.
--
Tim Spragens
http://www.borderless-photos.com