IT8 and Negafix problem? (Epson V700)

[ksah]

Hi all,

I'm confused by the effectiveness of the IT8 calibration process; and also whether it can have a negative effect on what the Negafix profiles do to a scan.


-when doing an automated IT8 calibration using the small transparency chart, the IT8 calibration button in the toolbar remains greyed out, even when I do get a message saying the calibration was succesful, with a delta of 1.X. If my understanding is correct, that button becomes "active" after the automatic calibration. If the button is greyed out, does this indicate that the scanner has not been profiled successfully?

-This is where I'm even more confused: it seems that NO Negafix profile gives me a good color match with ANY of the films I am scanning. I have scanned Fuji pro800Z, velvia50, provia100F, reala100, superia200, superia 100, pro400H, provia400X, Agfa Ultra 100, Optima200, vista400, portrait160. With every single one of those film types, I selected the correct Negafix profile, yet, I'm absolutely unable to get a good color match. For me, it never ever works. In some cases, the color looks like a bad joke and is way way way off. Does Negafix work at all for anyone?

-Logically then, I am assuming that if the IT8 calibration isn't actually working on my scanner (assumption based on the fact that the IT8 button remains greyed out even after the calibration process completes), the Negafix profiles will be way way off. Is there a foolproof way of obtaining a very close match of any particular film's color palette using IT8 and Negafix?

I'd like to take an example: Agfa Ultra 100- which is a very saturated film - comes out cool/bluish on my Epson V700. The same film scanned at a local lab, on a Fujifilm Frontier, comes out the way I expect it to: Very saturated, cyans are punchy, reds are deep, etc... Why can't I get the same color response from my film when I scan it on the Epson V700 with Silverfast Ai, with IT8, Negafix, blablabla? Is there somethign I'm missing when it comes to calibration? Are the Negafix profiles a gimmick?

Thank you for any help/hint you can provide.

KS

[LSI_Luebker]

Dear KS,

the IT8 calibration or to be more specific the ICC profile created by the IT8 calibration is not being used when you use NegaFix.
The Problem that you seem not to get the correct colors is due to the fact that negs are not that stable so after a while they change depending on how you store them. Therefore we created some tools to get rid of the colorcast and to adjust the NegaFix profiles individually. Please have a look at this Quicktime movies to untap the full potential of NegaFix:
http://www.silverfast.com/download/movi ... -08-09.mov
http://www.silverfast.com/download/movi ... -08-12.mov
http://www.silverfast.com/download/movi ... -11-28.mov
http://www.silverfast.com/download/movi ... -05-13.mov

Here is also a link to our NegaFix feature page:
http://www.silverfast.com/show/negafix/en.html

I hope this helps you

[ksah]

Dear Thomas,

many thanks for your reply.

the IT8 calibration or to be more specific the ICC profile created by the IT8 calibration is not being used when you use NegaFix.

Is the IT8 calibration then only used when scanning slide film? Does this also mean that the ICC profile for the scanner is ignored when scanning negatives? Both options seem quite illogical to me and would mean that doing IT8 calibration on a scanner is a waste of time. Can you please clarify what you mean by "the IT8 calibration is not being used when you use NegaFix"?



Also, you haven't commented on my question regarding the IT8 calibration process itself: Once that process has been run for the scanner I use (Epson V700), the IT8 button in the toolbar should become "active", correct? By "active", I mean not greyed out. Is this correct? The problem here is that even after performing an IT8 calibration, this button remains GREYED OUT. Is this normal? How can I verify that the IT8 calibration has been carried out succesfully? Earlier you are saying that the ICC profile generated by the IT8 calibration process isn't used when using Negafix... So, if that's the case, how does Silverfast know how to correctly apply the necessary corrections to the scanned image??

The Problem that you seem not to get the correct colors is due to the fact that negs are not that stable so after a while they change depending on how you store them.

I'm sure this is the case with film that was exposed many years ago. But in my case, all the film I'm scanning at the moment has only recently been exposed. And so, I am not expecting huge variations in the processed negatives and slides. Besides, even if the colors had somewhat changed a bit, I would still expect the relevant Negafix profiles to offer a close enough color rendition for any particular film. In my case, the Negafix profiles are so wrong, and that for any kind of film that I scan. They are not wrong by a little bit. They are wrong by a very large margin. I mean low contrast films like Agfa Portrait are rendered very contrasty (crushed blacks) when the Negafix profile is selected. How can this be explained?

Therefore we created some tools to get rid of the colorcast and to adjust the NegaFix profiles individually. Please have a look at this Quicktime movies to untap the full potential of NegaFix:
http://www.silverfast.com/download/movi ... -08-09.mov
http://www.silverfast.com/download/movi ... -08-12.mov
http://www.silverfast.com/download/movi ... -11-28.mov
http://www.silverfast.com/download/movi ... -05-13.mov

Thank you for those. But they are not really really illustrating the problem I'm having.

KS

[LSI_Luebker]

Dear Thomas,

many thanks for your reply.

the IT8 calibration or to be more specific the ICC profile created by the IT8 calibration is not being used when you use NegaFix.

Is the IT8 calibration then only used when scanning slide film? Does this also mean that the ICC profile for the scanner is ignored when scanning negatives? Both options seem quite illogical to me and would mean that doing IT8 calibration on a scanner is a waste of time. Can you please clarify what you mean by "the IT8 calibration is not being used when you use NegaFix"?

It means that rather than the ICC profiles you use with Slides and Reflectives the NegaFix Profile is used as the chemical process C41 is widely variable as you have to take different labs and chemicals into account.

Also, you haven't commented on my question regarding the IT8 calibration process itself: Once that process has been run for the scanner I use (Epson V700), the IT8 button in the toolbar should become "active", correct? By "active", I mean not greyed out. Is this correct? The problem here is that even after performing an IT8 calibration, this button remains GREYED OUT. Is this normal? How can I verify that the IT8 calibration has been carried out succesfully? Earlier you are saying that the ICC profile generated by the IT8 calibration process isn't used when using Negafix... So, if that's the case, how does Silverfast know how to correctly apply the necessary corrections to the scanned image??

As I already wrote in my last post it is using the NegaFix profile to apply the corrections

The Problem that you seem not to get the correct colors is due to the fact that negs are not that stable so after a while they change depending on how you store them.

I'm sure this is the case with film that was exposed many years ago. But in my case, all the film I'm scanning at the moment has only recently been exposed. And so, I am not expecting huge variations in the processed negatives and slides. Besides, even if the colors had somewhat changed a bit, I would still expect the relevant Negafix profiles to offer a close enough color rendition for any particular film. In my case, the Negafix profiles are so wrong, and that for any kind of film that I scan. They are not wrong by a little bit. They are wrong by a very large margin. I mean low contrast films like Agfa Portrait are rendered very contrasty (crushed blacks) when the Negafix profile is selected. How can this be explained?

As In my first answer this relates to the instability of the C41 process.
You should ensure that you are using the latest version of SilverFast 6.6.0r6 as we did some improvements of the NegaFix profiles here .

Therefore we created some tools to get rid of the colorcast and to adjust the NegaFix profiles individually. Please have a look at this Quicktime movies to untap the full potential of NegaFix:
http://www.silverfast.com/download/movi ... -08-09.mov
http://www.silverfast.com/download/movi ... -08-12.mov
http://www.silverfast.com/download/movi ... -11-28.mov
http://www.silverfast.com/download/movi ... -05-13.mov

Thank you for those. But they are not really really illustrating the problem I'm having.
KS

I really hope my explanations helped you further

[ksah]

Thank you...

let's try this again, as I'm only getting partial answer to my questions:

Also, you haven't commented on my question regarding the IT8 calibration process itself: Once that process has been run for the scanner I use (Epson V700), the IT8 button in the toolbar should become "active", correct? By "active", I mean not greyed out. Is this correct? The problem here is that even after performing an IT8 calibration, this button remains GREYED OUT. Is this normal?

[LSI_Luebker]

Dear KS,

after a successful calibration the scale icon should appear blue when you are in the mode you calibrated your scanner in(transparency or reflective).
If this is nit the case it could be some corrupted preference file that is causing this behaviour, so I would recommend deleting the prefs(please note that this will delte all of your settings).