(Raw) Black & White Point

[jchnkl (Jochen Keil)]

Hi!

I have a couple of images from a timelapse sequence. Unfortunately some images show a noticable color cast [1]. After some experimentation, thinking and google consultation I came to the conclusion that it’s not the white balance as I first suspected. After all I was able to fix the color cast using the raw black/white point module in darktable. [2, 3]

However, I would like to do this in a more automated (scriptable) and deterministic / reproducible manner since I have plenty of images to fix here. I toyed around with dcraw (I’d be happy to get some baseline 16bit TIFFs that I can process further in darktable) but apart from white balance I couldn’t figure out how to adjust black/white point with it.

I also played a bit with masking and clipping the red values below a certain threshold using ImageMagick but that did not lead to satisfying result. The idea was that the red channel is quite off as some people on dpreview suggested [4, 5]. One can also observe this on the histogram before adjusting the black points.

Any ideas or suggestions or more insights on the color science behind this? Thank you!

[1]

[2]

[3]

[Claes]

Hallo @jchnkl!

I may be utterly wrong — but the first thing that popped up
in my mind was Retinex, here is some basic info Retinex - RawPedia

Have fun!
Claes in Lund. Schweden

[Peter]

What camera model and what is exif saying about black level?
Take a look at this thread Measure black and white levels?

[rvietor]

Raw black and white levels should be at fixed values for a given sensor and ISO setting. So, you should not need to set them per image. If the default values are wrong, you can use automatic user presets to apply the correct values, taken from the raw metadata (assuming the camera manufacturer knows what he’s doing…).

Note that you may have to look in the makernote data (exiftool can read most of those).

[jchnkl (Jochen Keil)]

@Claes Thank you for the hint! However, I need more time to look at this since I’m not very familiar with RawTherapee. But I’ll check out!

@Peter It’s an A6300 with the 10-18mm. One file was taken at ISO 320 and the other at 400. However, I’ve noticed this effect also on files with same ISO values.

exiftool says:

$ exiftool -e 2022-09-22T19:13:31+0200_00608.arw | grep -i black
Black Level                     : 512 512 512 512

$ exiftool -e 2022-09-22T19:14:06+0200_00609.arw | grep -i black
Black Level                     : 512 512 512 512

I did look at the thread you linked but I think I need some more time to follow through and comprehend.

@rvietor It could well be that I’m using the wrong tool to adjust the color shift and it’s not really the black levels that need to be fixed. I looked at histogram modifications with ImageMagick and gimp (basically levels) and got decent results.

Fixing the black points in darktable & copying the history stack to affected files sounds like a still tedious but probably the best approach for now. However I’m still curious what’s the root cause here.

I also tried to adjust the -BlackLevel exif entry with exiftool -BlackLevel="500 500 500 500" but that did not work, at least for the MakerNote tag and I couldn’t get a user defined writable tag entry working yet. Something like:

exiftool custom config

%Image::ExifTool::UserDefined = (
    'Image::ExifTool::Sony::SR2SubIFD' => {
        0x7310 => {
            Name => 'BlackLevel',
            Writable => 'int16u[4]',
            WriteGroup => 'MakerNotes',
            Count => 4,
            Protected => 1,
        },
    },
);

Any help appreciated!

For the curious I’ve uploaded the files here: WeTransfer - Send Large Files & Share Photos Online - Up to 2GB Free (link valid for one week, I can reupload if necessary)

I’ve also attached the output from exiftool -e for each file:

2022-09-22T19:13:31+0200_00608.arw

ExifTool Version Number         : 12.40
File Name                       : 2022-09-22T19:13:31+0200_00608.arw
Directory                       : .
File Size                       : 24 MiB
File Modification Date/Time     : 2023:09:12 16:04:50+02:00
File Access Date/Time           : 2023:09:14 17:23:49+02:00
File Inode Change Date/Time     : 2023:09:12 16:04:50+02:00
File Permissions                : -r--r--r--
File Type                       : ARW
File Type Extension             : arw
MIME Type                       : image/x-sony-arw
Exif Byte Order                 : Little-endian (Intel, II)
Image Description               : 
Orientation                     : Horizontal (normal)
Image Width                     : 6048
Image Height                    : 4024
Bits Per Sample                 : 12
Compression                     : Sony ARW Compressed
Photometric Interpretation      : Color Filter Array
Samples Per Pixel               : 1
Planar Configuration            : Chunky
X Resolution                    : 350
Y Resolution                    : 350
Resolution Unit                 : inches
CFA Repeat Pattern Dim          : 2 2
CFA Pattern 2                   : 0 1 1 2
Sony Raw File Type              : Sony Compressed RAW
Sony Tone Curve                 : 8000 10400 12900 14100
Strip Offsets                   : 684544
Rows Per Strip                  : 4024
Strip Byte Counts               : 24337152
Chromatic Aberration Correction : Auto
Distortion Correction           : Off
Preview Image Start             : 139938
Preview Image Length            : 543828
Y Cb Cr Positioning             : Co-sited
Exposure Time                   : 30
F Number                        : 4.0
ISO                             : 320
Sensitivity Type                : Recommended Exposure Index
Recommended Exposure Index      : 320
Exif Version                    : 0230
Date/Time Original              : 2022:09:22 19:13:31
Create Date                     : 2022:09:22 19:13:31
Components Configuration        : Y, Cb, Cr, -
Compressed Bits Per Pixel       : 8
Brightness Value                : -8.6078125
Exposure Compensation           : -0.7
Max Aperture Value              : 4.0
Metering Mode                   : Multi-segment
Light Source                    : Unknown
Flash                           : Off, Did not fire
Focal Length                    : 10.0 mm
Rating                          : 0
Brightness                      : 0
Long Exposure Noise Reduction   : Off
High ISO Noise Reduction        : Off
HDR                             : Off; Uncorrected image
WB Shift AB GM                  : 0 0
WB Shift AB GM Precise          : 0.00 0.00
Face Info Offset                : 94
Sony Date Time                  : 2022:09:22 19:13:31
Sony Image Width                : 3008
Faces Detected                  : 0
Face Info Length                : 37
Meta Version                    : DC7303320222000
Creative Style                  : Standard
Color Temperature               : Auto
Color Compensation Filter       : 0
Scene Mode                      : Standard
Zone Matching                   : ISO Setting Used
Dynamic Range Optimizer         : Lv5
Image Stabilization             : Off
Color Mode                      : Standard
Full Image Size                 : 6000x4000
Preview Image Size              : 1616x1080
File Format                     : ARW 2.3.2
Quality                         : RAW
Flash Exposure Compensation     : 0
White Balance Fine Tune         : 0
White Balance                   : Auto
Sony Model ID                   : ILCE-6300
Multi Frame Noise Reduction     : Off
Picture Effect                  : Off
Soft Skin Effect                : Off
Vignetting Correction           : Auto
Lateral Chromatic Aberration    : Auto
Distortion Correction Setting   : Off
Lens Type                       : E-Mount, T-Mount, Other Lens or no lens
Lens Spec                       : E 10-18mm F4 OSS
Auto Portrait Framed            : No
Flash Action                    : Did not fire
Electronic Front Curtain Shutter: On
Focus Mode                      : Manual
AF Area Mode Setting            : Flexible Spot
Flexible Spot Position          : 391 340
AF Point Selected               : n/a
AF Points Used                  : (none)
AF Tracking                     : Off
Focal Plane AF Points Used      : 0
Multi Frame NR Effect           : Normal
Focus Location                  : 3008 2000 1504 1000
Variable Low Pass Filter        : n/a
Flash Level                     : Normal
Release Mode                    : Normal
Sequence Number                 : Single
Anti-Blur                       : Off
Shot Number Since Power Up      : 607
Sequence Image Number           : 1
Sequence File Number            : 1
Sequence Length                 : 1 file
Camera Orientation              : Horizontal (normal)
Quality 2                       : RAW
Sony Image Height               : n.a.
Model Release Year              : 2015
ISO Setting                     : Auto
ISO Auto Min                    : 100
ISO Auto Max                    : 1600
Ambient Temperature             : 8 C
AF Area Mode                    : Manual
Focus Position 2                : 236
Exposure Program                : Aperture-priority AE
Intelligent Auto                : Off
Sony ISO                        : 312
Base ISO                        : 100
Stops Above Base ISO            : 1.6
Sony Exposure Time 2            : 32
Sony Max Aperture Value         : 4.1
Sony Image Width Max            : 6024
Sony Image Height Max           : 4024
Picture Effect 2                : Off
Battery Temperature             : 39.4 C
Battery Level                   : 33%
Lens Mount 2                    : E-mount
Lens Type 3                     : Sony E 10-18mm F4 OSS
Camera E-mount Version          : 1.60
Lens E-mount Version            : 1.20
Lens Firmware Version           : Ver.01.001
Tiff Metering Image Width       : 44
Tiff Metering Image Height      : 30
Tiff Metering Image             : (Binary data 2640 bytes, use -b option to extract)
Release Mode 3                  : Normal
Self Timer                      : Off
Flash Mode                      : Flash Off
HDR Setting                     : Off
Picture Profile                 : Gamma Still - Standard/Neutral (PP2)
WB RGB Levels                   : 833 256 367
Min Focal Length                : 10.0 mm
Max Focal Length                : 18.0 mm
Distortion Corr Params Number   : 11 (APS-C)
Shutter                         : Silent / Electronic (0 0 0)
Flash Status                    : Built-in Flash present
Shutter Count                   : 1993
Sony Exposure Time              : 32
Sony F Number                   : 4.1
Shutter Count 2                 : 1993
Sony Time Min Sec               : 12:59
Release Mode 2                  : Normal
Internal Serial Number          : 9d000000f70b
Lens Mount                      : E-mount
Lens Format                     : APS-C
Lens Type 2                     : Sony E 10-18mm F4 OSS
Distortion Corr Params Present  : Yes
Lens Spec Features              : E OSS
Shutter Count 3                 : 1993
User Comment                    : 
Flashpix Version                : 0100
Color Space                     : sRGB
Exif Image Width                : 6000
Exif Image Height               : 4000
Interoperability Index          : R98 - DCF basic file (sRGB)
Interoperability Version        : 0100
File Source                     : Digital Camera
Scene Type                      : Directly photographed
Custom Rendered                 : Normal
Exposure Mode                   : Auto
Digital Zoom Ratio              : 1
Focal Length In 35mm Format     : 15 mm
Scene Capture Type              : Standard
Contrast                        : Normal
Saturation                      : Normal
Sharpness                       : Normal
Lens Info                       : 10-18mm f/4
Lens Model                      : E 10-18mm F4 OSS
PrintIM Version                 : 0300
SR2 Sub IFD Offset              : 45230
SR2 Sub IFD Length              : 56958
SR2 Sub IFD Key                 : 0x44332211
Black Level                     : 512 512 512 512
WB RGGB Levels Auto             : 3196 1024 1024 1588
WB RGGB Levels                  : 3196 1024 1024 1588
Color Matrix                    : 1377 -205 -148 -56 1183 -102 -17 -27 1068
WB RGB Levels Daylight          : 2636 1024 1900
WB RGB Levels Cloudy            : 2840 1024 1740
WB RGB Levels Tungsten          : 1648 1024 3468
WB RGB Levels Flash             : 2964 1024 1736
WB RGB Levels 4500K             : 2384 1024 2144
WB RGB Levels Shade             : 3116 1024 1560
WB RGB Levels Fluorescent       : 2456 1024 2808
WB RGB Levels Fluorescent P1    : 2560 1024 2008
WB RGB Levels Fluorescent P2    : 2856 1024 1820
WB RGB Levels Fluorescent M1    : 1920 1024 3416
WB RGB Levels 8500K             : 3272 1024 1480
WB RGB Levels 6000K             : 2816 1024 1756
WB RGB Levels 3200K             : 1836 1024 2992
WB RGB Levels 2500K             : 1436 1024 4208
White Level                     : 15360 15360 15360
Vignetting Corr Params          : 11 0 192 736 1568 2592 3776 5088 6464 8000 9824 12032 0 0 0 0 0
Chromatic Aberration Corr Params: 22 -512 -256 -128 0 256 384 640 768 896 1152 1408 2048 1664 1280 1024 768 640 512 384 384 256 384 0 0 0 0 0 0 0 0 0 0
Distortion Corr Params          : 11 79 22 -50 -133 -234 -352 -471 -561 -622 -629 -582 0 0 0 0 0
Subfile Type                    : Reduced-resolution image
Make                            : SONY
Camera Model Name               : ILCE-6300
Software                        : ILCE-6300 v2.01
Modify Date                     : 2022:09:22 19:13:31
Thumbnail Offset                : 38836
Thumbnail Length                : 4695

2022-09-22T19:14:06+0200_00609.arw

ExifTool Version Number         : 12.40
File Name                       : 2022-09-22T19:14:06+0200_00609.arw
Directory                       : .
File Size                       : 24 MiB
File Modification Date/Time     : 2023:09:12 16:04:50+02:00
File Access Date/Time           : 2023:09:14 17:03:14+02:00
File Inode Change Date/Time     : 2023:09:12 16:04:50+02:00
File Permissions                : -r--r--r--
File Type                       : ARW
File Type Extension             : arw
MIME Type                       : image/x-sony-arw
Exif Byte Order                 : Little-endian (Intel, II)
Image Description               : 
Orientation                     : Horizontal (normal)
Image Width                     : 6048
Image Height                    : 4024
Bits Per Sample                 : 12
Compression                     : Sony ARW Compressed
Photometric Interpretation      : Color Filter Array
Samples Per Pixel               : 1
Planar Configuration            : Chunky
X Resolution                    : 350
Y Resolution                    : 350
Resolution Unit                 : inches
CFA Repeat Pattern Dim          : 2 2
CFA Pattern 2                   : 0 1 1 2
Sony Raw File Type              : Sony Compressed RAW
Sony Tone Curve                 : 8000 10400 12900 14100
Strip Offsets                   : 635392
Rows Per Strip                  : 4024
Strip Byte Counts               : 24337152
Chromatic Aberration Correction : Auto
Distortion Correction           : Off
Preview Image Start             : 139938
Preview Image Length            : 493318
Y Cb Cr Positioning             : Co-sited
Exposure Time                   : 30
F Number                        : 4.0
ISO                             : 400
Sensitivity Type                : Recommended Exposure Index
Recommended Exposure Index      : 400
Exif Version                    : 0230
Date/Time Original              : 2022:09:22 19:14:06
Create Date                     : 2022:09:22 19:14:06
Components Configuration        : Y, Cb, Cr, -
Compressed Bits Per Pixel       : 8
Brightness Value                : -8.83046875
Exposure Compensation           : -0.7
Max Aperture Value              : 4.0
Metering Mode                   : Multi-segment
Light Source                    : Unknown
Flash                           : Off, Did not fire
Focal Length                    : 10.0 mm
Rating                          : 0
Brightness                      : 0
Long Exposure Noise Reduction   : Off
High ISO Noise Reduction        : Off
HDR                             : Off; Uncorrected image
WB Shift AB GM                  : 0 0
WB Shift AB GM Precise          : 0.00 0.00
Face Info Offset                : 94
Sony Date Time                  : 2022:09:22 19:14:06
Sony Image Width                : 3008
Faces Detected                  : 0
Face Info Length                : 37
Meta Version                    : DC7303320222000
Creative Style                  : Standard
Color Temperature               : Auto
Color Compensation Filter       : 0
Scene Mode                      : Standard
Zone Matching                   : ISO Setting Used
Dynamic Range Optimizer         : Lv5
Image Stabilization             : Off
Color Mode                      : Standard
Full Image Size                 : 6000x4000
Preview Image Size              : 1616x1080
File Format                     : ARW 2.3.2
Quality                         : RAW
Flash Exposure Compensation     : 0
White Balance Fine Tune         : 0
White Balance                   : Auto
Sony Model ID                   : ILCE-6300
Multi Frame Noise Reduction     : Off
Picture Effect                  : Off
Soft Skin Effect                : Off
Vignetting Correction           : Auto
Lateral Chromatic Aberration    : Auto
Distortion Correction Setting   : Off
Lens Type                       : E-Mount, T-Mount, Other Lens or no lens
Lens Spec                       : E 10-18mm F4 OSS
Auto Portrait Framed            : No
Flash Action                    : Did not fire
Electronic Front Curtain Shutter: On
Focus Mode                      : Manual
AF Area Mode Setting            : Flexible Spot
Flexible Spot Position          : 391 340
AF Point Selected               : n/a
AF Points Used                  : (none)
AF Tracking                     : Off
Focal Plane AF Points Used      : 0
Multi Frame NR Effect           : Normal
Focus Location                  : 3008 2000 1504 1000
Variable Low Pass Filter        : n/a
Flash Level                     : Normal
Release Mode                    : Normal
Sequence Number                 : Single
Anti-Blur                       : Off
Shot Number Since Power Up      : 608
Sequence Image Number           : 1
Sequence File Number            : 1
Sequence Length                 : 1 file
Camera Orientation              : Horizontal (normal)
Quality 2                       : RAW
Sony Image Height               : n.a.
Model Release Year              : 2015
ISO Setting                     : Auto
ISO Auto Min                    : 100
ISO Auto Max                    : 1600
Ambient Temperature             : 8 C
AF Area Mode                    : Manual
Focus Position 2                : 236
Exposure Program                : Aperture-priority AE
Intelligent Auto                : Off
Sony ISO                        : 361
Base ISO                        : 100
Stops Above Base ISO            : 1.9
Sony Exposure Time 2            : 32
Sony Max Aperture Value         : 4.1
Sony Image Width Max            : 6024
Sony Image Height Max           : 4024
Picture Effect 2                : Off
Battery Temperature             : 39.4 C
Battery Level                   : 33%
Lens Mount 2                    : E-mount
Lens Type 3                     : Sony E 10-18mm F4 OSS
Camera E-mount Version          : 1.60
Lens E-mount Version            : 1.20
Lens Firmware Version           : Ver.01.001
Tiff Metering Image Width       : 44
Tiff Metering Image Height      : 30
Tiff Metering Image             : (Binary data 2640 bytes, use -b option to extract)
Release Mode 3                  : Normal
Self Timer                      : Off
Flash Mode                      : Flash Off
HDR Setting                     : Off
Picture Profile                 : Gamma Still - Standard/Neutral (PP2)
WB RGB Levels                   : 829 256 369
Min Focal Length                : 10.0 mm
Max Focal Length                : 18.0 mm
Distortion Corr Params Number   : 11 (APS-C)
Shutter                         : Silent / Electronic (0 0 0)
Flash Status                    : Built-in Flash present
Shutter Count                   : 1993
Sony Exposure Time              : 32
Sony F Number                   : 4.1
Shutter Count 2                 : 1993
Sony Time Min Sec               : 13:34
Release Mode 2                  : Normal
Internal Serial Number          : 9d000000f70b
Lens Mount                      : E-mount
Lens Format                     : APS-C
Lens Type 2                     : Sony E 10-18mm F4 OSS
Distortion Corr Params Present  : Yes
Lens Spec Features              : E OSS
Shutter Count 3                 : 1993
User Comment                    : 
Flashpix Version                : 0100
Color Space                     : sRGB
Exif Image Width                : 6000
Exif Image Height               : 4000
Interoperability Index          : R98 - DCF basic file (sRGB)
Interoperability Version        : 0100
File Source                     : Digital Camera
Scene Type                      : Directly photographed
Custom Rendered                 : Normal
Exposure Mode                   : Auto
Digital Zoom Ratio              : 1
Focal Length In 35mm Format     : 15 mm
Scene Capture Type              : Standard
Contrast                        : Normal
Saturation                      : Normal
Sharpness                       : Normal
Lens Info                       : 10-18mm f/4
Lens Model                      : E 10-18mm F4 OSS
PrintIM Version                 : 0300
SR2 Sub IFD Offset              : 45142
SR2 Sub IFD Length              : 56958
SR2 Sub IFD Key                 : 0x44332211
Black Level                     : 512 512 512 512
WB RGGB Levels Auto             : 3168 1024 1024 1600
WB RGGB Levels                  : 3168 1024 1024 1600
Color Matrix                    : 1377 -205 -148 -56 1183 -102 -17 -27 1068
WB RGB Levels Daylight          : 2636 1024 1900
WB RGB Levels Cloudy            : 2840 1024 1740
WB RGB Levels Tungsten          : 1648 1024 3468
WB RGB Levels Flash             : 2964 1024 1736
WB RGB Levels 4500K             : 2384 1024 2144
WB RGB Levels Shade             : 3116 1024 1560
WB RGB Levels Fluorescent       : 2456 1024 2808
WB RGB Levels Fluorescent P1    : 2560 1024 2008
WB RGB Levels Fluorescent P2    : 2856 1024 1820
WB RGB Levels Fluorescent M1    : 1920 1024 3416
WB RGB Levels 8500K             : 3272 1024 1480
WB RGB Levels 6000K             : 2816 1024 1756
WB RGB Levels 3200K             : 1836 1024 2992
WB RGB Levels 2500K             : 1436 1024 4208
White Level                     : 15360 15360 15360
Vignetting Corr Params          : 11 0 192 736 1568 2592 3776 5088 6464 8000 9824 12032 0 0 0 0 0
Chromatic Aberration Corr Params: 22 -512 -256 -128 0 256 384 640 768 896 1152 1408 2048 1664 1280 1024 768 640 512 384 384 256 384 0 0 0 0 0 0 0 0 0 0
Distortion Corr Params          : 11 79 22 -50 -133 -234 -352 -471 -561 -622 -629 -582 0 0 0 0 0
Subfile Type                    : Reduced-resolution image
Make                            : SONY
Camera Model Name               : ILCE-6300
Software                        : ILCE-6300 v2.01
Modify Date                     : 2022:09:22 19:14:06
Thumbnail Offset                : 38836
Thumbnail Length                : 4608

Here’s another screenshot to highlight the issue:

The ISO values are varying but there are images with different ISO values that look alike and images with same ISO values that differ, thus I’d rule out an ISO issue here.

[jchnkl (Jochen Keil)]

So I did some basic editing in darktable and used the color calibration module with the spot color mapping mode as described in the color calibration manual.

And what should I say, it turned out really really nice. From the mess above I went to this:

I’m very happy with this now. The only other sequence-related module I used was the exposure module in automatic mode. Looking forward to get my timelapses finally done

Also I don’t really understand the how, I’m happy that there’s such a great piece of free & open software out there.

(Pinging @AxelG maybe that’s interesting for you as well )

[Edit]

What a shame, there’s still a slight color cast that’s only noticeable when you scroll through or create a video

[123sg (Steven)]

It does look like a black point issue. I downloaded the files, (curious to have a look) but for some reason can’t un-zip the .zip file. Any idea why? You can upload the files here, btw (if you want)

Edit: got them now. 7zip worked

[123sg (Steven)]

Hopefully others can tell me if this is a silly idea - but it looks to me rather as if the picture with the reddish cast didn’t have the in-camera dark frame subtraction done. (called long exposure noise reduction or similar)

I don’t know about this camera, but most of mine have a switchable feature to automatically take a dark frame after the shot which is used to reduce noise.

If you were using an intervalometer, I wonder if triggering the shutter for the next frame, while the dark frame is still being processed would make the camera cancel it? If your timing was borderline, slight timing variations could account for the unpredictable nature of the issue.

In any case, I notice the problem is also present on the embedded jpg preview, ruling out a development issue (I think).

[ggbutcher (Glenn Butcher)]

It’s definitely a black subtract problem, I duplicated the render in rawproc by taking the EXIF number (512) and incrementally reducing that number until it matched:

Note in the bottom-left params pane for the subtract tool, the camera-supplied value in the EXIF is 512, converted to 0.0-1.0 floating point for rawproc is 0.007812. The number that approximates your render is about 484 (rawproc: 0.0074), so the question becomes, where is darktable getting it’s black subtract number?

This is not a nominal output that compels correcting with a color tool, it’s a wrong number used in basic raw processing.

[Peter]

For Sony Rawspeed reads Exif. For Canon Rawspeed measures optical black area if it is specified in cameras.xml

ARW: Get black level and white point from EXIF

[123sg (Steven)]

But Glen, DT is using the same number (512) on both files, with very different results…

[ggbutcher (Glenn Butcher)]

Well, I use 512 in rawproc and it looks just fine. The OP’s render in the first post is definitely not using that number…

[123sg (Steven)]

Here’s a screenshot from dt, with identical history stacks (copy paste) one image on the left, the other on the right. Both have the black point set to default at 512.

The only difference between the images is the ISO - which looks like the culprit… but against that, the OP said he’s seen the issue on matching images too.

[Peter]

Black level at high ISO and Sony [ARW] Fix incorrect white levels and black levels on high iso by koolfy · Pull Request #349 · darktable-org/rawspeed · GitHub

[123sg (Steven)]

Isn’t that pull request only for ISOs above 102400? This case is iso 320 and 400.

[123sg (Steven)]

And as I said above, the problem is obvious in the embedded jpg preview - if Sony can’t develop it’s own file correctly I don’t see how metadata related changes are going to help…?

Edit sorry didn’t mean to sound grumpy…

[Peter]

So the JPEG also was affected? Then a manual measurement of a black raw file with same temperature, ISO and shutter speed should help.

[123sg (Steven)]

Good idea. This is getting a little out of my depth - what would one use to measure it?

[Peter]

I used Hraw before Measure black and white levels? - #6 by Peter

G for green channel
G2 for the second green channel
R for red channel
B for blue channel

Because Sony doesn’t have optical black area, the size of the left and top in pixels don’t matter.

Hraw works in Windows also.

True RAW highlights clipping in a snap: Open Talk Forum: Digital Photography...

[123sg (Steven)]

@Peter

I used Hraw before Measure black and white levels? - #6 by Peter

Thank you! Now all we need (maybe!) is an all-black file - under the same conditions…