RAW Artifacts on Sigma X3F (sd Quattro) files

[brianandcamera]

Onedrive collection of files - X3F, TIF, JPG

 

First, when I open a .X3F that I shot portrait orientation, it's opening landscape. When I open a TIF generated from Sigma's software, it opens up correctly as portrait. 

 

 

 

 

 

Second, I am seeing some artifacts. It almost looks like noise but it's too uniform. The picture is muddy and has purple dots. 

 

 

 

 

Here's the tif for comparison:

 

 

I did a JPEG export out of Affinity and it has the artifacts as well (But muddied further by jpeg compression/etc)

 

Rotation/artifact screenshots are here:
http://imgur.com/a/X23uN

 

Onedrive is here:

https://1drv.ms/f/s!ArciU0vVYB2QiWmyBYHTBFZ60Ee4

[brianandcamera]

After checking a few other files, it's not just the artifacts - the images look muddy/unsharp. 

[brianandcamera]

Updated the onedrive link to include a DNG

I used x3f tools (x3f_extract) to create a DNG 

 

Interestingly enough, it was sharp in photoshop - but had black dots where affinity shows the purple dots. 

 

When I open the DNG in affinity, it's just a black and white scramble. Looks like the cable is out :)

 

 

edit: Ah, I guess they make adobe do some of the heavy lifting, and affinity isn't prepared for that. Either way, there's a chance someone could get a DNG file that opens in photoshop but not in affinity. 

"The DNG output of our converter is actually quite cool. We let Lightroom and ACR do the conversion for us. We only construct the color conversion matrices and do some noise reduction.

 

This means that we avoid the clipping problem that you get if you make a TIFF, e.g. from SPP. Nothing is lost. The data is still RAW (minus noise)."

 

 

 

 

And here's what they said about the dots, if it helps:

"We know about the dots. It is AF dots. We will fix it."

 

[brianandcamera]

Any word on this? Affinity is useless as part of my Sigma workflow right now (Then again, so is lightroom...)

[jbed2005]

I have tried the x3f support from Sigma DP2 Merrill.

1) The built-in raw engine does a very poor job with the colors messed up and noise. Needs some serious attention.

2) I also use the x3f_extract tool but Affinity crashes when I try to load them, it must be something in the file format because if I load the DNG in lightroom then export as DNG then Affinity can accept the file. Even after this DNGs looks like they have a green radient discoloration, which could of course be compensated with a purple radial gradient filter ...

 

In practice the development persona does not work for x3f files as it is now.

[Pauls]

Yes the Sigma files are notorious for causing problems - we have this logged to investigate.