Variation in prescan and procesed image in Archive suite

[dbcar]

In Archive suite, on a Coolscan 9000, is it normal for the pre-scan and the RAW image to differ significantly?

What I mean is, the image looks well-exposed and colourful initially, as it is captured slowly, moving left to right; but at the end of the pre-scan, when the right edge of the image is reached, and before saving it, it suddenly changes, appearing in relative terms much more exposed and less saturated in colours. It is this second version that is saved in the processing.

I haven't had this problem so much with slides but I have batches of Portra 160 and Ektar 100 with which this is currently happening.

[LSI_Ketelhohn]

Dear customer,

Yes, the HDR(i) RAW image is being saved without any adjustments or gamma corrections. So it will look very dark.
All adjustments are done when the image is bing processed in the SilverFast HDR Studio software where it will look normal again.

Kind regards,
Arne

[dbcar]

Hi Arne,

Thanks. What puzzles me is not that they are different; its that the dark version looks almost normal and the lighter version looks very over-exposed, on nearly 20 rolls of Portra 160. I don't think the films are over-exposed and I am trying to understand if there is anything in the scanning process that may explain this.

[LSI_Ketelhohn]

For the preview to work correctly make sure the red scanframe is set correctly around the image.
Unexposed material inside the frame will disturb the histogram and will cause issues when the calculation takes place.
That can cause wrong brightness and colors.

Kind regards,
Arne