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Problem with ME-function

PostPosted: Sat May 14, 2011 9:25 pm
by artroxx
Hello,

I just tried out my new Silverfast SE Plus on my canon 8800F.
But unfortunately when I used the multi-exposue-function for a color-negative, the result was a scan with strange colors.
Here you see:
Pic02.jpg
multi exposure
Pic02.jpg (142.43 KiB) Viewed 2314 times


...compared to the original picture in one-shot:
Pic01.jpg
on shot exposure
Pic01.jpg (177.08 KiB) Viewed 2314 times


Question: What may corse this mistake?


Thanks for your response!

Moritz Leick

Re: Problem with ME-function

PostPosted: Mon May 16, 2011 4:17 pm
by LSI_Morales
Dear Moritz

artroxx wrote:Question: What may corse this mistake?


The NegaFix profiles were not created to work with Multi-Exposure.

Cheers

Re: Problem with ME-function

PostPosted: Mon May 16, 2011 5:27 pm
by artroxx
So how can I do the ME-function on negatives? Or can I not do it at all?

It´s funny: I achieve the same strange results, scanning transparencies in ME

Re: Problem with ME-function

PostPosted: Tue May 17, 2011 7:33 am
by LSI_Morales
Dear Moritz,

The Negafix profiles were created for the normal scan (without Multi-Exposure). Slides on the other hand should not have any problem with Multi-Exposure. Especially the color shift should not be present when scanning slides.

Greetings

Re: Problem with ME-function

PostPosted: Wed May 18, 2011 3:24 pm
by artroxx
Here I got an example for the color shift, at Slides scanned in ME-mode.

This one is scanned one-shot ....
DIA_OS.jpg
Slide normal
DIA_OS.jpg (72.82 KiB) Viewed 2286 times


... and this came out at ME.
DIA_me.jpg
Slide with ME
DIA_me.jpg (74.11 KiB) Viewed 2286 times


Maybe there´s anything wrong in the adjustment?
The only thing, I did, was pressing the auto-adjustment-button before scanning but it even comes out like this, when I did nothing at all.

I've my back to the wall!!!

Re: Problem with ME-function

PostPosted: Thu May 19, 2011 2:20 pm
by LSI_Morales
Hi artroxx,

It seems strange indeed. It is way too early to say Multi-Exposure alone as the cause for this change.
This might be a hardware problem as well.

Which version of SilverFast are you using?

Re: Problem with ME-function

PostPosted: Thu May 19, 2011 11:27 pm
by artroxx
I´m using Silferfast SE Plus (6.6.2r4a)

Re: Problem with ME-function

PostPosted: Fri May 20, 2011 7:42 am
by LSI_Morales
Dear Moritz

Are these pictures screenshots of the resulting picture opened with a second application?
Which program are you using to open the resulting picture?

Cheers

Re: Problem with ME-function

PostPosted: Fri May 20, 2011 12:49 pm
by artroxx
they are no screen shoots.
they are the the jpg copies from original tiff file and look absolutly the same.
If watched them by the common preview application on my apple macbook.

Re: Problem with ME-function

PostPosted: Fri May 20, 2011 1:32 pm
by LSI_Morales
Hi Moritz

How are you creating those jpg copies?
Are the originals scanned in 16 bit mode per channel?
Do you have color management active in the Apple viewer?

If not, please make sure you activate this option. Also bear in mind, screens (as well as jpg files) are only capable of displaying 8 bit images (per channel) if you images are scanned in 16 bits TIFF they might not be correctly displayed. In such cases is imperative to use an application with color management (like photoshop) and perform the 16->8 bit per channel conversion (compression) there.

Kind regards

Re: Problem with ME-function

PostPosted: Mon Jul 11, 2011 5:44 pm
by Mustavio Fantastico
LSI_Morales wrote:
The NegaFix profiles were not created to work with Multi-Exposure.

Cheers


But this is a contradiction to what is written on the SilverFast website
at: http://www.silverfast.com/highlights/mu ... re/en.html

There it says:

"Multi-Exposure® is one of the most popular SilverFast features.
Experience here how your slide and negative scans can benefit from it."

Further down it also says:

"The original to be scanned has to be transparent like slides or negatives."

So which information is correct?
Should Multi-Exposure always be disabled when scanning negatives with SilverFast and NegaFix?

Re: Problem with ME-function

PostPosted: Thu Jul 14, 2011 12:57 pm
by LSI_Morales
Dear Mustavio,

Thank you for the notice.

Both are correct to a certain extent.

Multi-Exposure was created for enhancing the dynamic range while scanning transparencies, and it does so by combining two different exposures. One with the normal scan speed and a second exposure at a slower speed (longer exposure).

So far so good...

However, color negatives have an orange mask which must be detected to make the inversion to positive. Some scanners with led as light sources produce a color shift on the orange mask while using Multi-Exposure which in change can not be properly detected by NegaFix.

Black and white negatives do not present this problem cause they do not have an orange mask.

Hence my statement.

Cheers

Re: Problem with ME-function

PostPosted: Thu Jul 14, 2011 1:12 pm
by Mustavio Fantastico
Hi,
Ok, thanks for the information.

So would you recommend to always turn off Multi-Exposure when scanning
negatives with my Plustek OpticFilm 7600i scanner?

So far I always used Multi-Exposure when I scanned negatives and I never got
any strange color problems. Usually the only problem I have with negatives
is low contrast and low color saturation, but that can quickly be fixed with software.