Cause of green/purple concentric rings in fog photo?

Started Sep 29, 2017 | Questions thread
sharkmelley Senior Member • Posts: 2,631
Re: It's the firmware

bokesan wrote:

bokesan wrote:

sharkmelley wrote:

Is it possible that the camera is still applying some kind of crudely implemented "correction" algorithm even when all the user settings are switched off?

Yes, that's it. I already have some "proof" images obtained by disabling the electronic contacts of the Voigtländer. Will upload them later this day when I have a faster connection.

Here they are. I just rotated the lens a bit in the mount to disable the electronic contacts. Impossible with a focus-by-wire lens, so the Voigtländer is all I have:

The above images were produced with dcraw -w -h and ImageMagic -modulate 100,10000,100. If anyone wants a look at the raw files, here they are: (436 MB).

Out of curiosity, I switched the shading compensation on (settings tab 7 / lens comp / shading comp.: on). And got an indistinguishable result:

I'll have to repeat this test with the Sony 1.8/55, but for the Voigtländer, this setting has no effect on raw files.


Excellent piece of analysis!

It's conclusive then - just like the "star eater" spatial filtering, Sony is once again tampering with the data in a badly implemented manner to camouflage a perceived problem.

I wonder what the reason is? Is it a badly designed fix to the corner colour cast issue discussed here, I wonder:


 sharkmelley's gear list:sharkmelley's gear list
Sony a7S Nikon Z6 +1 more
Post (hide subjects) Posted by
(unknown member)
(unknown member)
(unknown member)
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow