Mike Chaney's Tech Corner

This is my 'edit photos' day I think - hence the questions!

I mentioned before that the RAW conversions in Qimage for my new Sony RX100 M3 are really good. Almost all are processed perfectly and don't need any adjustment.

There are a few photos (out of >300) where things don't quite work out. These few photos tend to be ones with lots blue sky and I can get some significant blue posterization in the corners. I can't seem to deal with this issue in RAW refine or the image editor - the conversions already applied to the photo have 'done their work' and I can't unwind them. What are my options when it comes to dealing with such photos - is this a case where Qimage won't work so well and I can't recover the quality photo I need?

These problem images I can deal with better in Lightroom or Sony Image Data Converter (but neither do as well by default on the vast bulk of my images as Qimage).

Thanks again,

David

This is one of the situations where words do not suffice.  Posterization in the corners???
In order to help and to answer, I need one of the offending images.
If too large to email, you can use the free file transfer on line system called WE TRANSFER
https://www.wetransfer.com/
My email address is wathree.ssz@verizon.net

I will flip it to Mike in a second for scrutiny
Did you try turning off SC in refine?
Fred

Thanks. It put it on my work server http://www.erg.kcl.ac.uk/downloads/Policy_Reports/ (the ARW file)...

David

I must be doing something wrong. I click on the ARW  file and I get a website
 http://www.erg.kcl.ac.uk/downloads/Policy_Reports/ (the ARW file)...

Sorry.
There's one arw file dated 8-19

Fred

Yes, there does seem to be a problem (some download restriction on teh site I think). I have emailed it via WeTransfer as you suggested....

Thanks

David

ps, links is http://we.tl/XRAx7eJjsM if anyone else wants to take a look...

OK got it/

The image is full of Chroma noise!

Open in the editor, Click on ULTRA, then select Chroma from the drop down, and Poof! All cleaned up.

143 and 1144 are magnified
Fred

Thanks Fred. That does reduce the posterization, which was important. The downside is loss of sharpness across the photo and there is significant vignetting that I don't see in other processors (LR, Sony Image Data Converter). I can live with the odd 'rogue' photo that doesn't work as well in Qimage as the vast bulk are spot on.

David

Hi David,
I did and had a different approach.
Your camera has a small sensor so more prone to noise in images. Also the dark corners in the sky are due to lens vignetting at that focal length, nothing to do with QU.
I started with raw preferences and for your camera set the Noise Reduction slider to near maximum so 100 iso was included. I then saved that setting for your camera by making sure the thumbnail was selected at the same time.
The blue sky in that image was nothing like a normal UK sky (I live in Rugby) so in raw refine I did a custom white balance using the upper part of the central cloud (catching the direct sunlight). This made the sky more true to life and pepped up the field colours.
In the editor I could see sky noise levels were better and to improve them further used TTS from the sky, near a corner. TTS/DFS values were -100%, 4 radius and Tone + set. This softens the blue and sharpens the cornfield area - you may prefer a lower radius. An additional improvement can be made using Ultra NR where the "low" setting is adequate.
Finally, I would crop off the top part of the sky to remove the lens vignetting  :o  ;) This last step will probably avoid the Ultra NR being used.
See attached below, my version and original.

... and David, Terry has a number of well earned trophies and certificates of merit to back uo the fact that he knows what he is doing!!

Fred

Thanks Terry - yes, that does improve matters a lot. I know there is some vignetting, but the other two RAW converters do a much better job of controlling it. Having said that, this photo was one of very few troublesome ones and I was interested to see what Qimage could do; and how to approach editing it. Many thanks for you time and suggestions - it has helped a lot.

All the best

David

The other converters aren't controlling it.  They are just not applying the contrast that QU is applying so you don't see it as much.  QU automatically levels both black and white so in a photo that doesn't have much black, there will be more contrast.  In raw refine, draw an exposure box over most of the image and choose the red exposure box (camera black level) and you'll see what I mean.  The image will be more dull (like the other converters show it) and the vignetting will be much more subdued due to the reduced contrast.

Mike

Well, I'm still learning about QU after all these years  ::) I was aware of the red rectangle but rarely used it; blue or magenta get used most.
I tried this on David's image and and used levels in the editor to pep up the contrast. The histogram was concentrated in the middle of the scale so adjusting to bottom end to just meet the curve and the top end to clip a little produced a nice contrast. The overall result had reduced noise (virtually none) and disguised vignetting.  :)
Terry

That's great - I wasn't aware of that; very useful. That gives me a much better starting position from which to make any adjustments. That deals with (all) the few tricky ones I have...

Great stuff - thanks all!

David