Help with flat field correction

Software RawTherapee
1

I’m trying to use flat field correction, but it doesn’t seem to do anything. Whether I select the flat field file specifically, or through auto matching, there is no update to the history panel and no change I can see to the image. What else do I need to do to apply the correction?

I am shooting with a Kodak DCS460c, which requires a fair amount of correction to make up for the color cast of its sensor.

Ideally, what I’d like is an easy way to apply a saved flat field shot to all images taken with this camera. Kodak apparently did this with their Photo Desk software, but this required a per-camera calibration file which I do not have for mine.

Thanks,
Paul

2

For which application are you requesting help?

3

Sorry, it’s for Raw Therapee. I did not realize there were other applications also being discussed here.

4

Hi, would it be possible to share both raws (i.e. the image and the flat-field one)?

5

Just for the sake of completion, have you also enabled the tool or just specified the flat file location and settings?

6

I right-clicked on the thumbnail image and selected Flat Field, then Select Flat Field… or Auto Flat Field.

I was trying to follow direction from here: Flat-Field - RawPedia

How do I enable the tool?

7

Flat Field is not applied on the thumbnail iirc

8

IIUC, it is not applied on the thumbnail, but should be applied in the main preview, and I would expect to see something added to my History pane.

9

Please provide a raw file the flat field shot should be applied on and also the flat field raw file. A screenshot of what you’re doing would also help.

10

Here you go.

DCS00850.TIF (6.1 MB) DCS00850-Edit.tif (35.7 MB) DCS00800-2.dng (3.0 MB)

11

Flat field correction only works with raw files, not with tif

12

TIF is the RAW format of the Kodak DCS460c

13

Opening DCS00850-Edit.tif in RawTherapee does not enable the raw tab, which is a clear indicator, that the file is not raw (it’s already demosaiced)

grafik
grafik1920×1080 1.15 MB

14

And the OOC non-edited one?

15

That one does not open at all in my RT version.

16

And that’s the true RAW file. So, hmm… what to do with it? Export as DNG?

17

Yes, if I first export it as a DNG from LightRoom, then I can load the file into RT. I now have things in the raw tab, but applying the flat field still doesn’t make a change to the editor preview.DCS00850.dng (3.5 MB)

18

This is not a common modern camera at all, so I guess that also makes proper support a bit rarer :slight_smile:

19

Are the dimensions (width and height of original file and flat file) the same? Flat field correction needs same dimensions for both

20

No. It’s a very old digital camera (1995), but a lot of early cameras used TIF for raw. Same with my EOS 1D.