I'm seeing something that doesn't look right to me...

I'm processing a 1550-frame sequence, and when I got to the visual deflicker stage I noticed that the pink curve still took the shape characteristic of the HG transitions, so I wondered whether I had forgotten to save earlier in the process. I started from scratch, first removing the XMP files to make sure nothing was 'dirty'.

However, after applying the HG wizard and saving the sequence, this time I loaded the metadata for the full sequence in Lr, then I found a pair of HG frames and had a look at them. If I've understood the process, I think they should have already looked the same brightness, yes? But there was a noticeable difference.

Here's the HG curve after running the wizard:

   

Should the vertical lines in the curves be the same height??

Here are the frames in the list:

   

And here is how it looked in LR:

   

It's probably hard to tell from the comparison view, but if I switch back and forth I can see that the second frame is brighter than the first.

Have I misunderstood how this works? Maybe I need to use the 'stretch' slider in the HG wizard... but I never had to before.

You have a made a huge adjustment there, it's quite normal that the holy gail compensation might not be 100% perfect in the first step. This has to do with the way the camera writes exif data for example. But don't worry, those residual effects will be easily smoothened out when using the visual deflicker later, just don't worry about them, follow the workflow like I explained in my tutorials.

BTW: The curves look good, the vertical lines are fine, they show how big the adjustment was that you did on the camera.

Thank you for the quick reply Gunther

Yes, I understand that it was a big change. However, that's the reason I highlighted it so that it was easy to see. There were many other changes that were not so large, and I was still seeing their effects in the deflicker curve...

But you are right: I will wait until I have applied the deflicker. Hopefully it will work OK!

Possibly my camera doesn't report accurate exposure information. I've noticed other people having that issue. Mine is a Sony Alpha 77, by the way. I'll finish the sequence and report back when I have the deflickered version.

Thanks!

That worked out OK, thanks! My visual luminance curve is perfect

That's how it's supposed to be :-)

This post was last modified: 2015-05-05, 11:44 by aversis.

Hi Gunther,

First of all, version 4 is great, the visual previews make the whole process so much faster and easier!

I have the same problem as macronencer. Maybe also the jump was too big. Attached are 2 screenshots. I would expect the HG compensation curve to match the height of the luminance gap?

Second screenshot shows the visual preview luminance. Still a big gap left, and indeed after lots of refining the deflicker it gets better, but not 100%. There is also a jump in whitebalance, can spot it easily in lightroom when I switch back and forth between the 2 HG keyframes.

So I have several questions:
1. What are your recommendations when shooting HG timelapse for when to adjust the camera? Do you wait until the metering says you're for example 1 stop too low and then go up by one stop?
2. Does the deflicker adjust only the exposure, or will it alter other settings like white balance too?
3. Can we manually do something to get these 2 HG keyframes to match better before trying to solve the problem with deflicker? I tried the match exposure technique in lightroom but this completely fails, it makes the second HG keyframe much darker, there is no match at all. I also edited the 2 keyframes manually to match them, tried to reload in LRT but the gap still existed for some reason.

Thanks,

Wouter

   

Hi,

After some more tests, in fact it got really good. Noticed other people have similar issues, but always the same, can be easily solved with deflicker (or the flicker is just natural because of clouds rapidly passing by).

Thanks!!

Glad you've got a good result now.
Will still answer your questions:
1) I'd suggest using 1/3 stop when automatically ramping with qDslrDashboard or similar, otherwise 2/3 stops when manually ramping. While the sun is in the frame, you should do smaller steps (1/3) afterwards you can go to 2/3. Make sure to check the RGB-Histogram to prevent single channels to blow, not the exposure metering. Try to avoid clipping when shooting!
2) It will adjust brightness but not user the exposure tool for this anymore in LRT4.
3) If you really need to do manual adjustments between adjacent frames, just use regular (blue) keyframes for this on that adjacent frames.