Microtek F1 - cast in shadows?

[Matus Kalisky]

(posted also to hybridphoto.com - M1/F1 users are scarce)

Hello,

just a few days ago I received a refurbished Microtek F1 (I am in Germany) and now I slowly learn how to use it. As it came along with a SilverFast Ai Studio 6.5 (which I upgraded to 6.6) I am using this software for scanning.

I also calibrated the scanner with IT8 target (Kodak Ektachrome)

Question:
- I am scanning a 4x5 Kodak E100G slide that looks very reasonable to start with. The preview of the scan at default scan setting looks OK too, but the final scan (48 bit color) has a very strong magenta cast - but only in shadows! The middle tones and the high values look very reasonable!

Do you have any idea what could be the reason and how to fix this? Please see below for a example:

ou have any idea what could be the reason and how to fix this? Please see below for a example:

Whole 4x5 image


Crop 1:


Crop 2:

[Ken Lee]

Even when calibrated, the scanner won't be perfect. Better, but not perfect.

In addition, every brand of film has its own color curves. Films are not linear, in spite of the Chemists' best efforts. You will probably notice variations, as you change from one processing lab to another.

You may need to learn how to balance colors in your editing tool. If it's Photoshop or GIMP, there are many tutorials freely available on the web.

[Martin Miksch]

IMO the film should show the emulsion side to the glass.
BTW, where did you get the refurbished scanner from in Germany and how much did you pay?
Regards
Martin

[bob carnie]

I see blue overall not magenta , not as strong in the mid and highlight , but present .
I am not familiar with the software you are using but some work in the blue channel will definately help.

[Matus Kalisky]

Thank you.

Yes - there is some slight cast to the image - I did not process it before posting. I agree on the post processing - but I would like to get as good scans as possible of course.

The film was with the emulsion down (there is no glass - I used the glassless holders. The film has quite a sag on one side, the the scanners AF seems to be able to handle this)

There was a suggestion over at hybridphoto that this the cast in the shade is caused by the color of the noise - so I went back and did 100% crops and pushed by tuning the leves up to 2.0. See bellow for the result.

I got this scanner off the evilBay - a larger electronic company was selling one refurbished with return warranty and full original warranty. The scanner was undistinguishable from new. The starting bid was 450 euro and I was the only bidder ...

Org 100% crop from 2400 spi scan:


The same crop with Levels pushed to 2.0 - a lot of red pixels there ... :

[percepts]

Looks like overall blue cast to the image not just shadows. Correction is uncertain as we don't know true colour of the car. If it wa white then attached image may be what you are looking for. But if it was a cream colour then different correction would do it.

I selected just the blue sky then inverted selection and applied -100 on the blues in hue/saturation tool. I did this twice to get rid of most blue in whole image. Then applied a little brightness to bring back luminosity.

I'd say scanner settings need adjusting to decrease blue sensitivity. Maybe you need to build a profile/settings file for this film type. Doesn't that film have very high saturation anyway? With a very blue sky you always have a lot of blue in shadows and maybe a warming filter is required at capture time with those conditions and that film.

Attachment 32187

[bob carnie]

Pretty decent correction Mr Percepts

Looks like overall blue cast to the image not just shadows. Correction is uncertain as we don't know true colour of the car. If it wa white then attached image may be what you are looking for. But if it was a cream colour then different correction would do it.

I selected just the blue sky then inverted selection and applied -100 on the blues in hue/saturation tool. I did this twice to get rid of most blue in whole image. Then applied a little brightness to bring back luminosity.

I'd say scanner settings need adjusting to decrease blue sensitivity. Maybe you need to build a profile/settings file for this film type. Doesn't that film have very high saturation anyway? With a very blue sky you always have a lot of blue in shadows and maybe a warming filter is required at capture time with those conditions and that film.

Attachment 32187

[Matus Kalisky]

Well, that is a bit on the heavy side - the bottom part of the image got a bit scary grey. The car was indeed very close to white, but the direct sun reflection altered the color in the worm direction and at the same time the shady parts are indeed somewhat blue-magenta. The stone ground has some warmer tones there too. But I get the point.

Using the eye dropper for shadows in the Leves worked too, but it is a bit of hit-or-miss approach.

The film is E100G which one can compare to Fuji Astia saturation wise.

I posted some more checks HERE and currently I am trying to figure out how to scan the image with different brightness of the lamp. There should be this option in the SilverFast Ai Studio (6.6.1r2) in the Option->Special. but I just do not see it there ... any ideas?

I would like to try to make two scans - one with "normal" exposure and one overexposed and blend them - to improve the shadow detail and to be able then to cut the problematic part of the levels without loosing the information in the shadows.

[rugenius]

I've been archiving 6x6 cm Velvia and B&W negs.
My current routine is to produce a raw file from the 48bit HDR scan.
There is a multiple frame mode hat increases scan time enourmously... I'm still playing with it...
Then I open these files in Photoshop or Silverfast versus trying to create the final output in Silverfast from the initial scan sequence.
Take a close look at the difference between applying UM in the scans opposed to taking the expanded dynamic image and post processing in either SW.
The unsharp mask combined with lower resolution can create undesirable effects like what you posted.
FYI, I have found that the resolution is optimized somewhere near 3200 versus 2400.

My 2 cents.

[Matus Kalisky]

Rugenius, is the HDR the only method one can use to increase the shadow detail and to suppress the noise? I still hope to find out how to adjust the lightness of the bulb in the hardware to get physical higher exposure. Have you ever tried such an approach?

I am just looking at the HDR and feel like I am in the mercy of the scanner software as I do not see any possibility to tune something there ...