Author Topic: Flicker Free ETTR Timelapse: - -Beginners Guide & Basic Post Processing --  (Read 367133 times)

Audionut

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 3657
  • Blunt and to the point
1.  Depends on the "RAW EV indicator" setting in the histogram settings.  Will either be ETTR hint, or Dynamic Range.
2.  Well, Intervalometer doesn't care, nor Deflick.  ETTR shouldn't care either when working alone, just take longer to settle on correct exposure settings I guess.  ETTR/Intervalometer working together, not sure.  It shouldn't affect things, did you get any error messages, or log files on the card?

If you can find a way to consistently reproduce the problem, please file a bug report here.

CreativeEndeavor

  • New to the forum
  • *
  • Posts: 24
Thanks for the feedback Audionut,

Upon reflection, I think I caused ML to crash/stop because I hit the review button right after the people passed in front of my frame to check the image.  This evening I went to the same location and did another timelapse without interruption using a much lower Highlight ignore, which I could see was reflected in the Histogram.  Pretty cool!  I will attempt post processing tomorrow, and am certain to have more questions.

If my understanding is correct, ETTR captures as much data as possible by making the exposure as far as possible to the right without blowing out the highlights.  From there I can use the XMP Adobe Bridge script to manipulate the exposure to gradually get darker towards the end of the time-lapse when the sun is set.  I will be figuring it out tomorrow and the next day and will have a few questions.

Audionut

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 3657
  • Blunt and to the point
Upon reflection, I think I caused ML to crash/stop because I hit the review button right after the people passed in front of my frame to check the image.

Yeah, that will do it.

CreativeEndeavor

  • New to the forum
  • *
  • Posts: 24
I think I am getting the hang of this!  Thanks!

garry23

  • Contributor
  • Hero Member
  • *****
  • Posts: 2218
I have been continuing my ETTR, silent DNG timelapses, and have a suggestion/idea.

As is recommend in the first post, ETTR needs greater than 10 seconds or so to 'kick in'.

My results today confirm that a 10 second interval is marginal, ie I got strange results and frames with 1/8000 shutter, when the base shutter was about 1/250. Going to a 15 second interval stopped the frame 'dropping', but I still had a step in exposure about halfway through a 300 image capture.

I really only need ETTR for sunrises and sunsets, as at other times exposure, front to end, doesn't change that much, and is recoverable through LR/LRT.

I will wait for an EXIF enabled silent DNG before attempting a holy grail sequence, however, my thought is this. In the timelapse area, rather than only be able to ETTR every frame, how about an ability to carry out an ETTR every nth frame. Thus over a 60 min sunset sequence, you would, say, enable an ETTR 'reset' every n images.

Also the timelapse would only start AFTER the ETTR had reached a solution, ie the timelapse could tolerate the extra delay between the ETTR frames. This approach would also allow any timelapse interval, ie less than the ETTR solution time.

To LRT these steps will clearly trigger the auto key framer.

Bottom line: I wonder if an extra user variable of carrying out an ETTR every nth frame, and allowing for an ETTR solution, would be a useful addition?

Audionut

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 3657
  • Blunt and to the point
If you're using silent DNG, I assume you have liveview on consistently?  Set the trigger mode in AETTR to always on.

garry23

  • Contributor
  • Hero Member
  • *****
  • Posts: 2218
Yes, I do that.

Audionut

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 3657
  • Blunt and to the point
I don't understand these "frame drops" you are describing then.

In liveview with always on, AETTR is always adjusting the exposure as necessary.  Since you describe a sunset/sunrise, the exposure doesn't change that often, and is consistent.  This is easy for AETTR to calculate.

As far as I know, the initial "kick in" period, is simply for AETTR to make the initial exposure adjustment.  ie:  You have the camera at ISO 3200 - 1/10s - f/1.4 (for example), and the scene requires some exposure values darker then that.

CreativeEndeavor

  • New to the forum
  • *
  • Posts: 24
Question about Ramping and Aesthetics:  When reviewing my test time-lapses of Kerry Park, Seattle, I noticed the sky gets a bit lighter/bluer when the pollution in the air is no longer being reflected back to the image sensor by the setting sun.  This time-lapse transition looks unnatural to me (Go figure RIGHT?!.)  Should I add a Keyframe as soon as the light reflected back to the camera by the pollution is no longer visible to darken the rest of the images from that point forward?

What tips and tricks do fellow photographers here have for shots like the Kerry Park, Seattle timelapses I have posted?

Constructive Criticism very much appreciated.

P.S.  I do not know what silent DNG is.  Can you provide me a link to a summary of it on Magic Lantern?


garry23

  • Contributor
  • Hero Member
  • *****
  • Posts: 2218
Audionut

I plan to carry out a few more experiments with my 5DIii, silent DNG, AETTR pandora timelapse, to see if I get any 'strange' behavior.

Regarding the option to request an AETTR every nth frame in a timelapse sequence, I believe if someone could add this it would be a worthwhile feature, ie it would allow any interval, as you could tolerate the nth and nth + 1 interval being longer to ensure an AETTR fix.

Audionut

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 3657
  • Blunt and to the point
You should confirm the existing functionality is broken first, before considering yamlmo

garry23

  • Contributor
  • Hero Member
  • *****
  • Posts: 2218
Sorry, it's not a case of being broken. It was a suggested enhancement, as if you use ETTR my understanding was you need an interval of, say, 10 seconds or more to allow ETTR to settle on a solution.

If following a holy grail strategy, 'all' you need is to adjust the exposure through the change at regular intervals., eg every 1-2 Ev change in the scene.

Of course you could BRAMP as well, however, like others I see ETTR as the way to go.

At the moment we can only ETTR continuously, ie every frame, with the inherent interval restriction.

Of course I could be totally wrong and thus I will defer to my betters.

dmilligan

  • Developer
  • Hero Member
  • *****
  • Posts: 3218
  • 60Da / 1100D / EOSM
Sorry, it's not a case of being broken. It was a suggested enhancement, as if you use ETTR my understanding was you need an interval of, say, 10 seconds or more to allow ETTR to settle on a solution.
If your exposure is way off (like when you start), possible it could take that long, but once your sequence is going, it should be much shorter, as the exposure is not changing that much from frame to frame (only minor adjustments are needed). I've never used ETTR for timelapse in LV mode though (too much heat and battery usage). In regular photo mode, it just analyzes QR data after each pic, and it only takes a second or two (I recently did a timelapse with slowest shutter 16", interval 18"), and I think most of that time is just waiting for the QR data.

garry23

  • Contributor
  • Hero Member
  • *****
  • Posts: 2218
Good points.

However, I've made a decision to only use silent dng mode, ie save shutter life for other work.

Will keep practicing and reporting.

Cheers

Garry

barepixels

  • Member
  • ***
  • Posts: 134
@ Garry23, do you get any corrupted DNG in your silence time lapse?  Last time I tried I got 3 bad frames in a batch of 400+ frames.  Wondering if I had some settings wrong?

PS can't wait to play with full size silence pictures...  Exciting time.
5D2 + nightly ML

garry23

  • Contributor
  • Hero Member
  • *****
  • Posts: 2218
@barepixels

I tried another AETTR + silent-DNG timelapse at an interval of 15 seconds this morning, deliberately with a boring (no clouds) sky.

The captured images appeared stable, ie the overall exposure frame to frame looks contiguous.

Without any EXIF it is difficult to really see how things are changing.

As for settings I use the following:

- AETTR = Always On
- Dual-ISO = OFF
- Global Draw = On, all modes
- Histogram = RAW HistBar
- Video = all off
- Intervalometer = ON, 15s
- Silent Picture = Simple

BTW I know that many/most use 'normal' shutter mode when taking timelapses; however, I have decided to only do timelapses with shutterless silent-DNGs. Of course, if the full size silent experiments that Alex is leading work out, this will mean we will have a FF silent timelapse capability, which, with embedded EXIF will mean ML, once again, has a killer feature!

dmilligan

  • Developer
  • Hero Member
  • *****
  • Posts: 3218
  • 60Da / 1100D / EOSM
I'm not convinced that silent picture timelapses are somehow inherently better for your camera. Shutters last for a very long time and are fairly cheap and easy to replace (esp. if you think about the cost in terms of per picture, or per timelapse sequence). By the time you wear out a shutter it might be time for a new camera anyway (and it's great excuse to tell the wife).

garry23

  • Contributor
  • Hero Member
  • *****
  • Posts: 2218
I'm sure you are not wrong, however; maybe naively, as a mechanical engineer, I think of all those mechanical movements occurring when I 'take an image', it just feels right that it is 'better' to achieve the same thing electronically.

I will likely not worry too much about this as I will not likely be taking lots of timelapses.

BTW this slowmo of a shutter and mirror working is fun to watch:


jimmyD30

  • Senior
  • ****
  • Posts: 386
I think I am getting the hang of this!  Thanks!

Nice time-lapse! The POV is awesome with that mountain in the background.

garry23

  • Contributor
  • Hero Member
  • *****
  • Posts: 2218
Have trawled the web and it seems what I am 'logically' looking for is not available...unless of course I'm wrong!

I know I can keep the mirror up in LV mode, but having LV on all the time burns my battery.

Does anyone know if there is a way, using ML, to undertake a normal timelapse sequence, ie .CR2s and not using silent DNG, and keep the mirror up from the start to the end, ie only actuating the shutter each shot.

Audionut

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 3657
  • Blunt and to the point
In LV with AETTR set to always on, naturally it has a constant stream of data to analyze, so by the time the intervalometer activates, there is no delay.

I'm off to find any mention of this 10 second delay nonsense in the OP, and erase it!

garry23

  • Contributor
  • Hero Member
  • *****
  • Posts: 2218
@Audionut

Any insight into my non-LV mirror always up during timelapse question. Is it possible?