Howdy Gunther,

Hope all's well.
I come across this problem every now and then since shooting Av more and can't seem to replicate it reliably.
Shot on a 6DMkII in Av mode.
For some of the exposure steps the orange curve goes up and down according to the shutter speed changes that the camera decided on.
But then on other changes the orange line doesn't create these jumps.
They can be deflickered but it needs a lot of refining and even then it can sometimes not be accurate enough.

Screenshot: https://ibb.co/4jdqJ9c

Am I missing something?

Danke,
Matthew

Hi Matthew,
What exactly do you mean with orange curve?

Sent mobile...

This post was last modified: 2020-11-04, 22:13 by Gunther.

Do you mean the pink curve in your screenshot? It shows the luminance of the visual previews. If you shoot in AV mode, it's the camera metering that causes this. I never shoot holy grail in AV mode, and one of the reasons is, that I cannot control at all what the camera is doing. I just need to rely on the metering - and that's not really deterministic. You can find the other reasons for not shooting day-to-night in Aperture Priority (or any other automatic Mode) in my faq: http://forum.lrtimelapse.com/Thread-why-...ority-mode
Better use qDslrDashboard, it's the best solution that I know and really easy. I've explained it in my tutorial: https://lrtimelapse.com/dslrdashboard/

I understand why you wouldn't shoot Av (I only started shooting it recently myself) but in some cases it's the only way to go. I guess it might be more of an observation as opposed to a question then, anyway...

Annotated reference image: https://ibb.co/KWjKZMz

The red oval marks where exposure changes have happened because of the camera's metering of the scene, where it adjusts the exposure with 1/3rd of a stop. These exposure changes have clearly caused the orange line to go up and down like that.

However, further down the sequence the camera has done the same thing (near the arrow) where it changed 1/3rd of a stop however there for some reason these step like changes do not appear in in the orange line.
When you look at this sequence straight out of camera there is just the normal amount of flickering (reflected usually as the blue line which would be the mirrored version of the orange line if I'm not mistaken), but I'm wondering why these circled steps appear.

In short: I'm trying to get a better understanding of why these steps happen there but not on other places. I've been able to fix it all using multiple deflicker and refining passes, but it seems like they shouldn't be there from the start, and I'm wondering if LRT could be improved so that these steps do not appear to begin with.

I understand there might not be a need for you to investigate or develop this further as Av is my (and I assume yours and others) least favourite way to shoot HG shots, but still, thought I'd send it over to hear your thoughts!

Sorry about the wall of text, it's late and it's been a stupid long day.

Cheers,
Matt

Hi Matt, ok, I see, you mean the red curve with the deflicker corrections. Could you please show me a screenshot with the camera preview and the blue luminance line? (Just turn off the visual previews by clicking on the Visual Previews button, then make a screenshot of the preview, after the blue curve has completely loaded.
On the blue curve we'll see, if those flicker effects are already in the original files, or if it's lightroom that's introducing them.
More about that, after I've seen the screenshot :-)

Hi Gunther,

Sorry about the delay.
Here is a sequence shot on the EOS R6 in the same way (Av mode, auto iso).
1: sequence initialised https://ibb.co/TKRsKKh
2: visual previews on https://ibb.co/WBfRh6K
3: visual deflicker result https://ibb.co/D7wRGK7

Here is the sequence rendered right after initialising in LRT: https://gfycat.com/fondficklecaiman (for some reason part of the end is at the front..)
As you can see that flickering isn't there but gets introduced at some point in the editing process later.

Hope this is useful!

Matt

Hi Matt,
in that case the "flicker" has definitely been intruduced by Lightroom. That's one of the major anoyances of the "smarter" tools in Lightroom, like Dehaze, Clarity, Whites, Blacks and also Shadows/Highlights which act in a non linear way to a certain extend.
If you exaggerate using those tools you might get strange effects.
We already discussed this many times here - just use the search feature for "non linear"
For sequences where this happens, I'd recommend to do the basic contrast grading via the tone curve and use the basic tools only to little extend. Especially avoid too much Dehaze, there is also an faq: https://lrtimelapse.com/news/use-dehaze-...imelapses/

Thanks, I never use shadows/highlights/clarity etc for those exact reasons, worth noting that the only edits applied to this shot were exposure, contrast, vibrance and saturation. So maybe it's the contrast slider that's now adding this new flicker?