48 Bit Output from SilverFast Ai

[Guest]

Dear SilverFast Team,

I have a Nikon Ls-40 scanner and have been using Nikon Scan to do all my scanning (mostly of negatives). Due to the release of Negafix and general good reviews for SilverFast, I have been investigating the package and have downloaded the demo.

One thing that disappoints me about the package is that it is not possible to output colour-corrected 48-bit colour images from SilverFast for further high-bit manipulation in Photoshop. It seems as though the only 48 bit output intended for HDR, another expensive package which I'm afraid is beyond my budget.

If SilverFast were able to output corrected 48 bit scans I would certainly invest in the software but as things stand I cannot justify the cost of Ai + HDR and will have to stick with Nikon Scan.

This point has been mentioned a few times before in other posts -- any chance of this feature being added to SilverFast?

Thanks,
Adrian

[LSI_Wolff]

Dear Adrian,

48 bit output with or without any corrections is a big point of discussion.
LaserSoft Imaging developed SilverFast Ai and SilverFast HDR long times before Photoshop was able to work accuratly with 48 bit raw data. SilverFast philosophy was to keep the full dynamic range of the scanner, without any manipulation or correction. This enables each following operator to work with the scanned images in his own way, for his specific solution, but without changing (or even destroying) the sorce data. Anyone should be able to produce a scan, even a machine (e.g. a slide feeder for the Nikon LS2000), even a novice user, without mistakes!
The intention was to solve problems occuring in big (e.g. colour management) workflows. At the beginning of the workflow it's very often not clear which images when and where will be used. The process of scanning itself is very time intensive. A second, third, ? scan of the same slide or picture is completely superfluous ?? If you produced a high-res real raw data scan without any correction!

By the way: The latest (October 12th, 2001) CD-ROM versions of SilverFast Ai 5.5.x for LS2000 and LS4000 include a full version of SilverFast HDR !!!


Best regards
Gerhard Wolff
LaserSoft Imaging

[Guest]

DearMr Wolff

I accept the validity of your point with respect to Silverfast Ai.

It is indeed a valuable feature to be able to scan the image only once and to have pure raw data to work on.

HOWEVER, Silverfast HDR would benefit a lot from the ability to edit in AND output 48bit colour. Silverfast is a strong color editor, but with more and more plugins comming out for 16 bit editing, Silverfast HDR could lose some attractiveness if it can not COOPERATE with those. I don't think it's an either or situation.

Example: People might want to do some correction in HDR, output to Photoshop. Apply Mask Pro masking program , do some more work in 16 bit, return to HDR etc. The losses working in 8bit color are just too great.

Looking forward to hear your response.

[Guest]

Gerhard,

Thanks for the reply.

I realise the value in separating the scanning and correction steps so that they be performed by people with different skills. However, this is of more value to a graphics studio than to a non-pro photographer. I also realise that enabling SilverFast Ai to output 48 bit colour may to some extent cannibalise sales of HDR. Perhaps this is the real reason this functionality has not been implemented.

I want to get the best out of my scanning hardware without unnecessary (for me) steps in the workflow and without additional expense.

The last post makes another good point -- I'm using the iCorrect Professional plug-in to make automatic colour corrections on some scans. I'd really like to use all the tools together in high-bit mode in the following workflow:

1. Scan using the SilverFast Ai plug-in, using SilverFast tools to get the best possible data out of the scanner.

2. Output 48 bit data to Photoshop.

3. Save what is (for me) my archive scan for future use.

4. Optionally use iCorrect Professional for colour correction.

5. Perform other high-bit correction in Photoshop (and more and more tools will work in high bit mode).

6. Convert to 24 bit and target for the application.

Ai provides all the correction tools I need, it just lacks the ability to output 48 bit data. If Nikon Scan can output 48 bit data, why not SilverFast?

I'd really like to use SilverFast. It's the best scanner interface out there and I'm really impressed by NegaFix. If it could output 48 bit data I'd buy it tomorrow. However, as things stand I just cannot justify the expense of HDR.

It looks as though I'll have to stick with Nikon Scan.

Thanks,
Adrian

[tolsen]

Hi Adrian.

You can output 48bit data from Silverfast Ai. You just cannot correct color within Silverfast IF you opt to output 48bit data.

Then you can do 48bit colorcorrection in iCorrect professional. You can read how to use silverfast for 48bit output at http://www.computer-darkroom.co.uk (go to Photoshop tutorials, then bottom of page: Silverfast, then tutorial 2 HDR - this will tell you how to use Silver fast Ai in conjunction with Silverfast HDR OR Ai directly with Photoshop).

But it would be great to be able to do some color correction in Ai and then more in Photoshop - all in 48bit color. Now it's an either or situation - you correct in 48bit in Silverfast and output 24 bit OR you do no correction and output 48 bit from Silverfast leaving all the 48bit editing to be done in Photoshop and other plugins. That's too bad.

[ilyons]

Allowing some form of colour adjustment within either Ai or HDR and then outputting in 48bit colour is in my view essential for SilverFast to gain even more users.

There are a few products already on the market that allow editing and output of 48bit images and next week will see a further Photoshop Plugin that will allow selective colours to be edited in 48bit mode.

However, and to b fair NONE of these products has the range of features available in Ai or HDR. They do little bits of this or that but not everything. It's also the case that we make a lot of the need for 48bit images but forget that Ai and HDR allow us to take an image to virtual completion before we export into Photoshop - what is there left to do ? That said I want colour corrected 48 bit output (says he leaping up down in a infantile tantrum I leave the sharpening and masks for next year )



<font size=-1>[ This Message was edited by: ilyons on 2001-10-18 00:23 ]</font>

[Adrian]

Tolsen,

Thanks for pointing this out. I should have made myself clearer -- I want to have my cake and eat it . I'd like to output colour corrected 48 bit images from Ai to Photoshop.

Ian, I agree. The SilverFast strategy has to now accommodate the growing number of high bit editing tools in order to attract the growing number of non-pro users for whom a high speed production workflow is not a big issue. Or, position the product as a professional tool but potentially miss out on a big market segment.

Any comments, LaserSoft?

Adrian

[ilyons]

Any comments, LaserSoft?

To be fair and reading beteen the lines of a post made by one of the LaserSoft folk a few weeks back - I think they are looking at some colour features being made available for 48bit output. Which and when we will have to wait and see.

Ian

[LSI_Wolff]

Thanks Ian!

Yes, we are thinking (and still working) on further developing of 48 bit- or HDR-tools! Our internal whislist is long, but everything needs some time and developing capacity!

Does anyone need a job?? :-,,
http://silverfast.com/jobs-de.htm

Gerhard Wolff
LaserSoft Imaging AG

[President_LSI]

SilverFast 48 bit output with colour correction, etc

Just a little more patience and the new feature with 48 bit output of all SilverFast controls will be there!

We are already very close! Just a few more weeks and some testing and the release will be there!

[ilyons]

Not all of us are impatient as some and some of us also realise that the 48bit mountain is as awkward to climb as Everest once was. If it was easy it would have been done by now.

Ian

PS don't go breaking anything on the way up that mountain

<font size=-1>[ This Message was edited by: ilyons on 2002-01-22 01:43 ]</font>

[ilyons]

Not all of us are impatient as some and some of us also realise that the 48bit mountain is as awkward to climb as Everest once was. If it was easy it would have been done by now.

Ian

PS don't go breaking anyhting on the way up that mountain

[nmoss]

As a non-graphical person I think I need a little enlightenment about the 48 bit issue. Maybe someone can help me.
The human eye can detect 200 hues with 20 levels of saturation and 500 brightness levels, which makes 2 million gradations of color. 48 bit color allows 280 billion different gradations of color (I think!), which seems like overkill. Why then is 48 bit so useful?

nmoss

[ilyons]

On 2002-01-23 15:47, nmoss wrote:
As a non-graphical person I think I need a little enlightenment about the 48 bit issue. Maybe someone can help me.
The human eye can detect 200 hues with 20 levels of saturation and 500 brightness levels, which makes 2 million gradations of color. 48 bit color allows 280 billion different gradations of color (I think!), which seems like overkill. Why then is 48 bit so useful?

nmoss

Forget 48bits and think 16bits per colour channel - it's easier to think that way. An 8 bit scanner can give you 256 shades, but apply a gamma shift of 2.2 and you trash something like 30% of those shades. Your 8bit scanner therefore delivers significantly less than 256 shades per channel. Typically modern scanners are 12 or 14 bit per colour channel so we can get 4096 and 16384 shades respectively. However, gamma adjustments, etc means that we again trash a proportion of these shades as we get the raw scan into a useable state. The more bits you have to start with the more ruthless you can be with the adjustments before the image begins to fall apart (posterise). The idea being start with 12/14 bits, edit and then get the best possible 8bits for your final image.

The above deals with your theory/query! The following is of more significance:

Dynamic Range of the scanner is a function of the number of bits used in the CCD sensor. More usually we talk of the Optical Denisty, i.e how deep into the shadows the scanner can see without flooding them with noise. A 12 bit per channel scanner gives a theoretical value of O.D = Log 2^12= 3.6 (theoretical) 3.2 is more realistic. For a 14 bit scanner the acual is usually closer to 3.8. Typically a consumer slide film will require at least a 12bit scanner to get all info and for something like Fuji Velvia at least 3.6 and probably better.

Not convinced?

Go to http://www.creativepro.com and search for material by Bruce Fraser. You can read on-line or download for printing. When you have finished reading it you will realise just how simplistic the above decription is and why we all seem to jump up and down asking for the feature!

Ian

[nmoss]

Thank you, that is really helpful, I had not thought about the channel issue. Now I should look into gamma correction. It must be one of the most misunderstood issues around.

nmoss