Hi, I've been trying to deflicker my image sequence with LRTimelapse 3.1 but I have some strange results. Now I'm going to list all steps I do and also attach screenshots of graphics I see in LRTL so that you could see this strange deflickering behaviour of LRTL.

1. I changed my raw files and exported them into JPEG for 2-nd deflickering pass.
2. I open the sequence in LRTimelapse. I initialise it, define static reference area which is not changed during the whole sequence and use default diflickering options (actually I used different option - but it doesn't help me). By the way - I have slight flicker which is not connected with color balance but only with exposure.

So here is the part of the image that I mark as reference area
   

Here is what deflicker suggests
   

Here is what happens after saving XMP metadata to jpeg files
   

3. I reload medadata in Lightroom and to be sure that's I'm not wrong - I check several pictures to be properly corrected (exposure) with what I can see in LRTimelapse in Exposure 2012 column after deflickering - it's ok - the metadata is really loaded.

4. I export my sequence into new another jpeg sequence (let's say seq2) hoping it will be at least less flickering. But it's not.

5. I open seq2 in LRTImelapse (I was exporting with no metadata, only with copyright).

6. I try to set the same reference area and see - how the mean values changed for the sequence.
   

7. What I see is that now I have reversed flicker! The mean values seem to have the same form as my exposuree correction graphic has for seq1! Why does it happen?? I tryied to use as less deflicker as I could (close to 0) but the result does not change much - I still have reverse flicker! And actually it's still as strong as it were on source sequence (maybe just slightly weaker) but reversed: images that were overexposed became underexposed!
   

Can you help with any advice? What's happening? Is it a LRTimelapse's bug or my misunderstanding of deflicker workflow and LRTimelapse's abilities?

What kind of flicker is this? Doesn't look like Aperture flicker - did you shoot in Automatic mode?
Especially when working with jpgs if the camera applies in camera editing like dynamic corrections etc. you will have a hard time deflickering.
For good deflicker results, your previews must be as flat as possible (when working with raw files turn off all in camera editing - set it to neutral).

A better place for a reference area would be the tar on the bottom, but I don't know if there are any cars passing by there.

What do you mean with "as less delicker as you could (close to 0)" - you can't set the amount of deflicker, you can only set the smoothing, and if you set that to 0, you won't get any deflicker at all. Set the smoothing so that the green curve looks smooth, resembling how the blue curve should look like.

I suggest you try the whole workflow again. For the second pass you can use the intermediate sequence (LRT_xxxx) that the LRTExport plugin generates when rendering.

This post was last modified: 2013-09-16, 03:16 by rrock.

What kind of flicker is this? Doesn't look like Aperture flicker - did you shoot in Automatic mode?

It was shoot in manual mode. I can not see flicker visually on source images - it seems to become more strong after post-processing in Lightroom. That's why I export them to jpeg sequence and I deflicker that sequence.

Especially when working with jpgs if the camera applies in camera editing like dynamic corrections etc. you will have a hard time deflickering.
For good deflicker results, your previews must be as flat as possible (when working with raw files turn off all in camera editing - set it to neutral).

I understand this advice but there was no any dynamic corrections in the sequence above.

A better place for a reference area would be the tar on the bottom, but I don't know if there are any cars passing by there.

Unfortunately there are many cars during the sequence at the bottom.

What do you mean with "as less delicker as you could (close to 0)" - you can't set the amount of deflicker, you can only set the smoothing, and if you set that to 0, you won't get any deflicker at all. Set the smoothing so that the green curve looks smooth, resembling how the blue curve should look like.

Saying "as less delicker as I could" in this case I meant "as unsmooth as I could but not 0". I understand what all the curves mean, but I think you haven't got my idea. Please, watch my curves again. What does green curve mean? It shows how the reference area will look like after applying deflicker, doesn't it? So I though that if I apply the deflicker, reexport the sequence into another one, load on LRtimelapse and reset the reference area the same as it were on the first one - so I could see blue ("mean brightlness values") are the same as they were in previous green curve - right? But instead of it my blue curve is similar to previous yellow one (which was exposure correction for the whole sequence). Why can it happen? Bug?

I suggest you try the whole workflow again.

Actually, I tried it several times every time initializing the sequence - but all in vain.

P.S. I can send you a portion of my timelapse sequence if you have time to test LRTL on it.

Currently I'm tavelling until end of month and only have really weak internet so I will not be able to have a look at the sequence, sorry. If you can wait 2 weeks, I'm certainly willing to have a look.

I can not see flicker visually on source images - it seems to become more strong after post-processing in Lightroom.

You should always apply deflicker on the source material (RAW files), not on already processed sequences since the processing in Lightroom will behave non-linear and change dynamics of your sequence, this might "reverse" the effect.
The two-pass deflicker always includes a deflickering of the source material and only fine tuning on the jpgs later.

This post was last modified: 2013-09-22, 00:32 by rrock.

Currently I'm tavelling until end of month and only have really weak internet so I will not be able to have a look at the sequence, sorry. If you can wait 2 weeks, I'm certainly willing to have a look.

I think I don't hurry right now. I wanna make two two-lapses about my city and almost all the source material I want - I already shot. Now I gonna spend much time for it to post-edit (especially for motion time-lapse sequences - it's difficult to stabilize them). And I would also like to help you to improve your program if I can - so we can test it when you come home.

You should always apply deflicker on the source material (RAW files), not on already processed sequences since the processing in Lightroom will behave non-linear and change dynamics of your sequence, this might "reverse" the effect.
The two-pass deflicker always includes a deflickering of the source material and only fine tuning on the jpgs later.

The problem is that there is no flicker on source image. The flicker appears only after my editing of source image but LRTimelapse does not take into account this edit so I have to firstly export to jpeg.

Could you please tell more about "since the processing in Lightroom will behave non-linear and change dynamics of your sequence, this might "reverse" the effect"? Does it mean that this problem often occurs when deflickering jpeg sequence?

The problem is that in my case the result of deflickering is really reversive. For example - when I apply deflicker, export and then apply it once again - I get almost the kind of source flicker (the second correction reverses the first). and so I can do it almost infinetly times with no much result (there is some difference but it's too much small). I decided to investigate the deflicker effect on the images of the sequence going one by one like this: lightest-darker-darkest. After applying deflicker with value 10 I get this result: darkest-lighter-lightest. I decided to try to match the last two images exposure manually in Lightroom and compare it with the LRTimekapse result. So I found exposure correction as 0,11 but LRTimelapse makes much more correction which obviously leads to reversed deflicker. Even when I set smoothing value to the least I can (there is no really value, there are just 0, 10 and 20 but I mean as close to 0 as possible but not 0) I still get a little bit of overdeflickering which still leads to reverse deflickering (the smallest exposure correction I mamage to get in LRTL is 0,17 which is much more than 0,11 wich I found manually in Lightroom). I want to mention that I talk about a really static part of the image with sky and no changes between two frames. I'm also sure that the overdeflickering comes to EACH and EVERY pixel of my deflicker rectangle - so there is no just darker or brighter PARTS of it - the whole reference area really becomes more lighter or darker - if you understand what I'm talking about.

Trying to understand where is the bug I came to this. All the graphs in LRTimelapse seem to be shown correctly - the problem is in VALUES. It seems to me that there is some misunderstanding with how LRTimelapse wants to correct exposure and how Lightroom corrects it in real. You told about issues with deflickering jpegs. I would like hear more about that - maybe that will be the key.

Only a short answer for now: The more you process the JPGs, the more difficulties you will have to deflicker. If you do strong dynamic changes in the images, compressing dynamics by pullig down lights and increasing shadows etc. those changes will not be linear. The exposure however that is used for deflickering acts linear. So this does not go well together.
LRTimelape's deflicker ist a function meant to be used to compensate for Aperture and/or Shutter flicker. But it neads linear (flat) previews without any edits and in best case RAW files.

What you are trying to do ist first make strong edits, that will introduce some kind of "flickering" <- not really flickering but some weird effects - and LRT will then probably apply some deflicker to the mid tones but intorduce other kinds of flicker in the shadows and highlights because the do not correlate anymore with the midtones after your edits.

Trust me, if the source material does not have flicker, and your edited material has, you are just overediting your sequences. You won't be able to correct that with LRTimelapse's deflicker.