LaserSoft Imaging

Hi! Am a newbie and I have some questions on this subject.

I have Reflecta Proscan 4000 and SilverFast SE Plus. I want to use them to digitize my collection of about 200 peaces of 35mm film negatives in order to save them from the whims of time :-). Most of them are shot with an ordinary pocket camera and are developed sometimes with not the best quality that one can expect. This implies unfortunately the need of some post-processing, especially when it comes to colors and grain... I intent to print the pictures with a maximum size of 10x15 cm but in some rare cases maybe I will need to be able to print in 13x18 cm. Anyway I would like not to loose much detail but in the same time to be in the range of 10-20 MB for a TIF file.

I don't want to invest much more money in this project and I don't want to spend more than the apropriate minimum of time on it, so I came to the idea to batch-scan all of the negatives somehow in a RAW format and to do the postprocessing later when I want to print a particular foto. Is that feasible. How would you proceed if you were me? I need an advice for the best practise!

BTW. I have on my desk the "Official guide", but at a first glance I didn't find the Answare of my question....

TIA!

Dear evgeninikolov

raw procession in SilverFast means using an HDR scan mode. However, this basically sets gamma to unmodified 1.0, so the images come up quite darkish e.g. in a gamma 2.2 Photoshop environment.
Therefore I suggest you want to set > Options > General > Gamma for HDR output: Activated.

Best regards
Sonny Noack
- Manager Technical Support, LaserSoft Imaging AG -

Thank you for the answer Sonny!

What workflow would you suggest in order to scan pictures in batch mode (a film stripe at once)? I intend to process the pictures later in Photoshop.

I'm not a very experienced when it comes to color management. Should I visually control at least one picture before I set some gamma value or I need just to set the option "Gamma for HDR output" and not take care about gamma value itself? Would this option taken into accoun when I use Photoshop for the postprocessing or it would be used only if I use Silverfast HDR?

Best regards,

Evgeni

Dear Evgeni

if you're doing your scans with the HDR scan modes in SilverFast, you cannot influence the scan, so there's no need for previewing the image.

Also, with HDR scans no colour management is used, but a scanner profile can be embedded if you want to do so.

The "gamma for HDR output" option tells SilverFast to use the gamma value set before this checkbox, even when scanning in HDR modes.
Else a scan at gamma 1.0 will be done.

This is no necessary for SilverFast HDR (/DCPro), as you can set these programmes to use one gamma value for displaying on the monitor, but expecting another when reading information from 48 bits of colour image files.
As you cannot set Photoshop equivalently, you can tell SF Ai (the scanning software) to already apply a gamma curve with you HDR scan.

Best regards
Sonny Noack
- Manager Technical Support, LaserSoft Imaging AG -

Dear Sonny,

Sorry for the annoying questions - I just try to protect myself from doing silly things.

I'm afraid I didn't understand what value should I set for the gamma correction. Does this value depend on the film being scanned or is it a characteristic of the scanner itself?

If I don't set this value properly, would I loose some information or it's just a question of better presentation on the screen of the scanned pictures?

Could you please explain me what do you mean with the following "...a scanner profile can be embedded if you want to do so"?

Best regards,

Evgeni

If you are scanning negatives ( not slides or positive film) then the "embed profile" will not apply. You will also have to invert (black becomes white and vice versa) and correct for the orange mask present on negatives.

Gamma is used to make the image lighter and viewable on your CRT or LCD. Otherwise it will look vary dark in the midtones of the image. Many PC users set gamma to about 2.2.

Yes, I'm scanning negatives. This is another subject, but is there a guide how can I process them in Photoshop CS. To invert them is not a problem, but how can I correct the orange mask? Should I first correct the orange mask and then invert or the opposite?

degrub wrote:Gamma is used to make the image lighter and viewable on your CRT or LCD. Otherwise it will look vary dark in the midtones of the image. Many PC users set gamma to about 2.2.

So it means (please if possible answer with yes or no :-) ) that it doesn't matter what value I will set for the gamma correction? Is 2.2 the right value? On what does it depend? Or let me put it another way - does gamma correction change the data about pixels or it instructs the programs how to represent this data ?

Ian's tutorial on scanning negs will help:

http://www.computer-darkroom.com/sf5-ne ... egafix.htm

He also addresses most issues you will face with SF in other tutorials on his website.

for HDR - there is also a link in the tutorial for use with Negafix and CMS:

http://www.computer-darkroom.com/sf5-ne ... _cms_2.htm

Quick test is to scan a a file to HDR with gamma set to 1 and another with gamma set to 2.2

The value you use depends on how much you want to spread the mid tone values for editing with your CRT or LCD. An excellent explanation and a method to optimize gamma selection is here:

http://www.computer-darkroom.com/gamma/gamma_1.htm

regards,

Dear evgeninikolov

the gamma value adjusts the general brightness of the image for mid-tone
and shadow. You will want to check that your monitor is set to the
correct gamma in order for the tonal values to be displayed evenly.
For best results scan a grey calibration strip and adjust your gamma accordingly.

You can start learning about gamma correctiong with the corresponding Wikipedia entry or the article "What is gamma correction and why do I care?" from the CDSG group.
The are numerous grey strips out on the internet, I liked the circle approach from Ken Turkowski. Unfortunately, the scale is somewhat rough. The webserver of the university of Utah holds an <a href="http://www.cs.utah.edu/~lavanyat/ip/report1/report.htm">article</a> that shows with example images the influence of gamma correction.

I'm afraid I didn't understand what value should I set for the gamma correction. Does this value depend on the film being scanned or is it a characteristic of the scanner itself?

No, it's based on your working environment / software (e.g. if "Adobe Gamma" or somthing similar also running) / monitor / room lighting condition.

If I don't set this value properly, would I loose some information or it's just a question of better presentation on the screen of the scanned pictures?

The discussion if one could do lossless recalculation of gamma curves on a given image bears highly theoretical traits and simply is beyond me.
I tend to that wouldn't say you really loose anything, but will have practical problems if you work on the image and can really see what you're doing to it.

Could you please explain me what do you mean with the following "...a scanner profile can be embedded if you want to do so"?

Well, it is up to you if you want to embed this information.

Best regards
Sonny Noack
- Manager Technical Support, LaserSoft Imaging AG -