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Canon vs CHDK histograms

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Re: Canon vs CHDK histograms
« Reply #70 on: 02 / June / 2021, 01:20:41 »
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@reyalp

Just had a quick look before I go off to work.

No change I'm afraid.

RGB, linear with auto scale on or off shows a CHDK histo that is erratic, ie constantly jumping about, and doesn't match the Canon histo.

Bottom line: looks the same as before - sorry.

Re: Canon vs CHDK histograms
« Reply #71 on: 02 / June / 2021, 02:05:04 »
@reyalp

The following may help.

The CHDK live histo looks the same in the LCD and the EVF. Neither map to the Canon histo.

My script has an auto ETTR function that calls get_live_histo(). Yes I know get_live_histo() is broken but it still kind of works for me  ;)

Although my ETTR function 'works' in LCD mode, when I switch to the EVF it doesn't work. That is the over exposed shutter setting gets adjusted down and stops in the LCD mode, as expected, but the same function in the EVF doesn't stop.

BTW the script I'm using is here: https://gist.github.com/pigeonhill/cdf25239bae6a4343e6431fb4c10c849


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Offline reyalp

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Re: Canon vs CHDK histograms
« Reply #72 on: 02 / June / 2021, 23:46:39 »
Just had a quick look before I go off to work.

No change I'm afraid.

RGB, linear with auto scale on or off shows a CHDK histo that is erratic, ie constantly jumping about, and doesn't match the Canon histo.
Thanks for checking, this remains a puzzle. Rather than testing a bunch of permutations, I'd suggest sticking with Y, linear, no automag. If it's working, it should recognizably match the canon histogram like the attached g7x example.

When you are testing, are you checking in half press, or do you have it set to show in rec or always? (not asking you to test different permutations, just checking)

Also, do you have CHDK zebra enabled at all?
Although my ETTR function 'works' in LCD mode, when I switch to the EVF it doesn't work. That is the over exposed shutter setting gets adjusted down and stops in the LCD mode, as expected, but the same function in the EVF doesn't stop.
If you can get a screen dump of with and without EVF, that might be informative. The screen dump module is now in the trunk and ximr builds. It's under "Miscellaneous -> Tools -> Screen Record". When you chose "Schedule dump" it will record after the time given in "Dump start delay" (details)
Don't forget what the H stands for.

Re: Canon vs CHDK histograms
« Reply #73 on: 03 / June / 2021, 02:32:45 »
@reyalp

Zebras off

PMed you

Cheers

Garry
« Last Edit: 03 / June / 2021, 02:34:22 by pigeonhill »


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Offline reyalp

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Re: Canon vs CHDK histograms
« Reply #74 on: 26 / June / 2021, 17:31:45 »
@pigeonhill
Here's a new test build. The issue spotted by caefix in https://chdk.setepontos.com/index.php?topic=12542.690 was m3 ximr build specific, and should explain at least some of the problems with both the OSD histogram and script get_live_hosto
Don't forget what the H stands for.

Re: Canon vs CHDK histograms
« Reply #75 on: 27 / June / 2021, 03:35:04 »
@reyalp

Just had time for a quick test.

'Looks' better ;-)

Only got time for a quick feedback.

The histogram doesn't seem to work when camera starts, but if I press EVF a few times, the histgram kicks in.

The structure looks much better, ie mapping CHDK to Canon: but there are differences.

Bottom line: progress :-)

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Offline reyalp

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Re: Canon vs CHDK histograms
« Reply #76 on: 27 / June / 2021, 17:07:50 »
Just had time for a quick test.
Thanks for testing. I was reluctant to apply my other fixes while your camera still showed unexplained issue.
Quote
The histogram doesn't seem to work when camera starts, but if I press EVF a few times, the histgram kicks in.
"Doesn't work" meaning it doesn't appear at all on the screen, or shows incorrect data, or something else?
Do you observe the same problem if you only use the camera LCD?
Quote
The structure looks much better, ie mapping CHDK to Canon: but there are differences.
Some differences are expected. The CHDK histogram attempts to auto-scale so the highest value fits, optionally modified by auto-magnify, which if I've followed the code correctly tries to boost the average level up to 20%. I'm not clear what the Canon histogram does, but it's almost certainly different. On g7x, my impression is that it clips, keeping the overall scale constant.

When you have time, can you confirm whether get_live_histo still shows the spurious peaks you saw before?
Don't forget what the H stands for.

Re: Canon vs CHDK histograms
« Reply #77 on: 28 / June / 2021, 15:11:09 »
Quote
"Doesn't work" meaning it doesn't appear at all on the screen, or shows incorrect data, or something else?
Do you observe the same problem if you only use the camera LCD?

Here is what consistently happens:
1. Switch on camera, with CHDK histo showing, as well as Canon
2. CHDK histo exhibits 'random noise' like histogram across the spectrum, ie dark to light
3. Put hand in front of camera and Canon histo changes as expected, but CHDK continues exhibiting random noise like response, ie doesn't react to the scene changing
4. Switch to EVF and CHDK hist continues to exhibit random noise spectrum
5. Switch back to LCD and CHDK histogram changes to looking like the Canon and behaving well
6. Switch to EVF and the random spectrum reappears
7. Back to LCD and 'good' historgram returns.

Quote
When you have time, can you confirm whether get_live_histo still shows the spurious peaks you saw before?

Will do.


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Offline reyalp

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Re: Canon vs CHDK histograms
« Reply #78 on: 28 / June / 2021, 15:43:30 »
Here is what consistently happens:
1. Switch on camera, with CHDK histo showing, as well as Canon
2. CHDK histo exhibits 'random noise' like histogram across the spectrum, ie dark to light
3. Put hand in front of camera and Canon histo changes as expected, but CHDK continues exhibiting random noise like response, ie doesn't react to the scene changing
4. Switch to EVF and CHDK hist continues to exhibit random noise spectrum
5. Switch back to LCD and CHDK histogram changes to looking like the Canon and behaving well
6. Switch to EVF and the random spectrum reappears
7. Back to LCD and 'good' historgram returns.
Thanks. Sounds like there's still something extremely broken in this port.

Does CHDK histogram *never* work when EVF is active?

FWIW, CHDK histogram takes a noticeable amount of time to update, it may take ~1 sec a few hundred ms to fully respond to changes. So seeing garbage *immediately* after switching output is expected. On a non-broken port it settles down very quickly though.

edit:
Oops, looks like I attached the wrong build to the last post  :-[

Please try this one (and thank you for your patience testing)
« Last Edit: 28 / June / 2021, 20:49:28 by reyalp »
Don't forget what the H stands for.

Re: Canon vs CHDK histograms
« Reply #79 on: 29 / June / 2021, 11:17:54 »
@reyalp

Haven't had a chance to spend a lot of time checking but have looked at the liveview histo data and it looks ok, ie no strange peaks.

Also, using the Y option, the CHDK histogram looks well matched to the Canon one in both EVF and LCD modes.

Looking good :-)

Well done!

Cheers

Garry

Ps forgot to say that the under and over warnings looks off and might need ‘calibrating’.
« Last Edit: 29 / June / 2021, 13:38:24 by pigeonhill »

 

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