• 2 Vote(s) - 5 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Deflicker like workflow for Color Temperature

Offline
#1 Delrious
Use the color temperature stored in the Exif data as a guide for making a smooth color temperature curve. So if the user shoots in AWB mode, it reads each color temperature that get's stored and then creates a smooth color temperature curve to follow. This will allow for a much more precise color temperature ramp rather than trying to key frame it and guessing where the color temperature should be. Workflow could be similar to the deflicker workflow.

Thanks!
Ben
Offline
#2 Delrious
I should add that this should work regardless of what the WB preset it. Even if it is set to "Custom", it should still be able to use the WB value stored in the exif.
Offline
#3 Gunther
The Idea sounds doable - but - do you really think automatic whitebalancing makes any sense when shooting time lapse? Why not set the white balance in post processing? I don't even use automatic WB when shooting stills because in my opinion the camera is wrong in 90% of all cases...
Subscribe to: LRTimelapse Newsletter, Youtube Channel, Instagram, Facebook.
Offline
#4 hamishniven
(2012-09-25, 21:27)gwegner Wrote: The Idea sounds doable - but - do you really think automatic whitebalancing makes any sense when shooting time lapse? Why not set the white balance in post processing? I don't even use automatic WB when shooting stills because in my opinion the camera is wrong in 90% of all cases...

So what do you select for you white balance?
Daylight is not correct on the coast - 5,600K is too cold with all the sea?
Tungsten is too cold 2,900 looks horrible for most incandescent lighting.

When shooting RAW the colour balance is only to show the colour on the camera as every balance is captured, post processing allows you to make that choice.

Back on topic, on the time-lapse I posted a week ago, Toprope - A Unique Project I had some people working on the leg of the oil rig as the sun began to set.
I set the initial colour balance at the start of the clip to be 6,800, and the last point to be 4,500 as the colour was too orange for the final, and LRTimelapse did a smooth render of the colour balance through the whole clip.


LR4.2 / LRT2.01

Hamish
Offline
#5 Gunther
Hi Hamish, I always set my WB in the camera to "Cloudy" and shoot RAW. Later in Lightroom I adjust the WB to my liking. Make sure to have your Monitor calibrated!
Subscribe to: LRTimelapse Newsletter, Youtube Channel, Instagram, Facebook.
Offline
#6 zzyzx
Is eleven years too soon to reconsider this?

It may be that the camera is always wrong when it computes white balance, but it is very close to an optimal value. It is better than I could do by entering temperature and tint numbers from scratch. When shooting stills I start with the camera's estimate (using Canon's Auto White Balance/White Priority setting) and only need small adjustments in post-processing (usually <500K for temperature, and <5 in whatever the tint scale is in Lightroom). The camera's algorithm gives more consistent results on wide shots than narrow shots, so I'll pick the best white balance from a wide shot then copy that setting to neighboring images that were shot in the same light.

Moving on to time-lapse sequences, I shoot a lot of day-night and night-day landscapes with a wide field of view. During a sunset or sunrise the white balance changes rapidly. I can't guess and type in temperature and tint values on enough keyframes to capture those changes accurately. Camera AWB results are pretty good, though jittery.

To handle this, I dump out the temperature and tint numbers from the Lightroom catalog file, plot them, and use the plot to find local minima and maxima. In Lightroom I mark those points as keyframes, set White Balance to "Custom" individually for each keyframe, then send the sequence back to LRTimelapse for interpolation.

The attachments show plots from a day-night-day sequence. The first has readings from my initial import of RAW files to Lightroom. The second is the same sequence after manual keyframing, processing in LRTimelapse, and return to Lightroom. The shapes of the curves might not be ideal but they are pretty good. Most important is that they don't flicker. Second most import is that I didn't have to think about the numbers.

My next step in this project is to write more code to apply some kind of best-fit curve to the data and push that into the XMP… but I'd rather not spend more time on it. So my feature request is for LRTimelapse to have a tool to smooth these two curves, as it does for the exposure curve. Just like OP said Smile
Attached Files
Thumbnail(s)
       
Offline
#7 Gunther
I understand what you are trying to do, however I still think there is a misunderstanding what exactly the white balance is and how to think about the "right" white balance.
What you are referring to as "right" white balance is what your camera tells you in Auto White Balance mode. But this is only a guess by the camera. This guess will be different depending on the camera brand and model and also the AWB settings (for example with Nikon you can set different Auto White Balance profiles which would deliver different interpretations of how to balance the color. Bottom line: there is no "right" white balance, even if the camera auto white balance algorithms have gotten better over the years. It is highly subjective.

Even more, I think the whitebalance is a way to express a mood in a picture. People would edit Snow picture a little bit to the blue, even if Snow is not blue. This is only an example. The same goes for the Sunset/Sunrise. In fact Cameras would tend to level out the Orange tint in such situations in the past - more modern Auto White Balance algorithms will now try to detect this and try no to ruin the mood by removing the warm tint.

The initial idea of white balance editing in LRTimelapse still applies: LRTimelapse allows you to keyframe the white balance - this is a great artistic tool because it allows you to really create great an impressive transitions especially from sunset over blue hour to the darkness. This will be much more pleasant than any auto white balance of a camera can do it. That's why I still find this is the best way to do it.

Of course, since the initial post here, a lot has been done in LRTimelapse and also the camera auto white balance improved. Therefore, now you can just leave the White balance on "As Shot", if you want, on all keyframes. Then LRTimelapse will not make any transitions on the White Balance and you will be working with the white balance from the camera.

Technically, there is no way for LRTimelapse to know the Temp and Tint settings (the actual numbers) from an image, before Lightroom developed it. That's why the White Balance will always be initialized as "As Shot" by LRTimelapse. Only, if you change it to "Custom" in the visual editor in LRTimelapse, you will get initial numbers, but those are static defaults that you need to change.

All that being said: a way to accomplish what you are trying to do would be to initialize the sequence in LRT, create keyframes wherever you want to pin the camera whitebalance to an image. If you don't know where to set the keyframes, just create a fairly high number of even spaced keyframes.
Then go to Lightroom and change the Whitebalance treatment on all keyframes to custom. This will make those values available to LRTimelapse. Save Metadata. Back in LRT you can now do an auto transition over those values and get smooth curves over the pinned whitebalance values that your camera calculated.
Subscribe to: LRTimelapse Newsletter, Youtube Channel, Instagram, Facebook.
Offline
#8 zzyzx
> initialize the sequence in LRT, create keyframes wherever you want to pin the camera whitebalance to an image.
> Then go to Lightroom and change the Whitebalance treatment on all keyframes to custom.

Yes, that is what I do now, except that I don't use even spaced keyframes. I take the additional step of charting the camera's white balance settings so that I can make a better choice about which keyframes to use.

...also check out: