A custom raw tone curve for EOS 80D needed


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Jacal
A custom raw tone curve for EOS 80D needed

If anybody has already done this, I would be happy to test it.

I only made a few lazy, through the window shots with this camera and an older stock lens. (I'll try to provide more useful samples in the near future.) An I am not happy with the provided tone curve. (Made by the book, I'm sure.)

In some recent discussions (1, 2) I have "learned", that some "abrupt" tone curves, with some very stretched zones, and some strongly compressed in-between, can produce unwanted results (like posterization/banding, lost details and colours ...). And the 80D curve doesn't look "natural" to me, neither do the results.

Here is the curve, compared to my loyal 600D and the 760D (I have added this one, since it has a newer and, possibly, more similar sensor.)

Here is my snapshot's detail, as rendered with default settings in Canon's DPP, darktable, LightZone (here I have added sharpening, since the other editors do this) and RawTherapee. (1, 2, 3)

And here is, just for "fun", LightZone's rendering with the default tone curve and two others, borrowed from the mentioned "Rebel" cameras. No sharpening here.

"I'll be back," hopefully with a simplified, less accurate and nicer curve, but would appreciate some opinions and experiences.

Link to the filebin folder with all the files, including the raw sample.

Have all a nice day!

Mart

sfink16
DPP Wins in Default settings, Not sure why

One question though, why does your 80D tone curve have luminousity instead of RGB like the others?  

 

The LZ default tone curve for my Canon 7D Mark II looks like your 760D tone curve, lots of points.  I didn't like the results of that so I created my own using Doug's video.  My curve looks closer to your 600D, with a few less points at the top end, but those results aren't great either.  Not sure where to go from there.

 

Steve

 

Jacal
Luminousity instead of RGB:

I remember Masahiro has done this before, for Panasonic G7, to avoid some colour related problems. (But this can introduce some desaturation etc.) I guess this was also the case with 80D.

I'll make some better samples during the weekend. Sometimes slightly overexposed photos make such issues more visible.

Mart

 

Edit: Here is a Panasonic example that shows the problem in RGB mode, and actually also some unsolved issues in luminosity mode.

The similar picture from 80D behaves better, but I'll try to tweak the curve to improve it.

Jacal
"DPP Wins in Default settings"

DPP's version is actually far from default, it is using proprietary camera settings from metadata, like lighting optimizer (standard), picture style (standard), sharpness, NR, CA, peripheral illumination ..., so this picture is much more processed than other examples. Even disabling, what can be disabled, produces images that look quite different than, for instance, with RawTherapee's neutral profile, or with LightZone's tone curve and colour NR disabled.

Jacal
My first attempt

is here, and comparison of settings here.

In Doug's test it gives results 229 150 91 48 21 7.

My first impression is, it might be slightly better than the original tone curve, at least as much I have tried it.

Jacal
My first attempt II

To make this at least slightly interesting, some funny birds I am adding: jpeg, original.

Have a nice day!

Mart

sfink16
Hey Mart

I'm not sure if I was supposed to process the images or not.  What I did is bring up your original in LZ and than go directly to Browse mode with no further edits.  Then I used the same original, this time bringing in your J1 LZT RTC, again going to browse mode with no further edits.  I was left with two saved LZN images, the original and your new one.  The original looks brighter (rather odd spike in the histogram) while yours seems to have more detail in the histogram.  Each look as if they can be work with.

 

Steve

Jacal
Thank you, Steve,

for your valuable time and opinion!

(And, of course, you can do with my images, whatever you wish.)

Perhaps I'll try to tweak the curve a little more, but a different camera will also require slightly different approaches, adaptation of my usual "styles" and some practise.

Be well!

Mart