Flicker Free ETTR Timelapse: - -Beginners Guide & Basic Post Processing --

[a1ex]

if you set a short interval, it should do that.

[andyshon]

I'll give it a try. I'd been erring on the side of caution, not wanting to risk dropped frames.

[andyshon]

I tried this last night on 5D2 using 5th August build (ad21e3450a3c). 5 sec interval, 2 sec max exposure. All other ettr setting default. Shot started at 0.3 secs, 100 iso and all seemed fine. When the exposure time reached 0.6 secs it started dropping the odd .xmp file, about 1 every 10. As the exposure increased more .xmp files got skipped though the frame timing seemed to stay tight. At 1.3 secs it was skipping every other .xmp and after six frames it locked up, battery out to get it restarted.

Guessing that this was due to pushing the timings, I restarted it with a 10 sec interval, all other settings the same, but this time it crashed out after only twenty or so frames. This is odd as I've run with these settings for hours before with no problem at all, so maybe the previous crash had left some mess behind. My previous tests were with an older build, July 21st I think.

[andyshon]

PS. If you add

-ext .xmp

to the end of the exifttool command from a couple of posts back, it makes it run much quicker.

[andyshon]

Here's the shot. It seems something was going wrong with the deflicker before it started skipping. Several frames had exposure gain inexplicably set 0.05EV-ish higher than those around them, enough to flicker. And these got more frequent towards the end.

[a1ex]

The latest algorithm uses a fast (but less accurate) estimation if timing is tight. A complete estimation takes 2-3 seconds IIRC. I'll try to reproduce the crashes (if you can give more info about them, it will help).

[andyshon]

I'm not sure where in the cycle the crash happened. When I came to the camera the rear screen was blank. Trash, play and menu buttons did nothing. The top lcd was as if the camera was metering, number of shots left (999) was flashing, cf light was off, not sure about blue led. Turning off the power cleared most of the display but left the meter and the 999 displays flashing, so I pulled out the battery.

The second crash was at 1.6 secs, with the 10 sec interval (2 sec max shutter), after several missed .xmps. As I say, I've shot with these settings for hours before, with no skipped frames and no flicker.

I was using a fairly slow card, a 64GB ProSpec 420x. The same card I've used before and freshly formatted. Part-twisted EF lens (@f/11 with nd0.9 and nd0.6 grad), full battery. ETTR set to always on with the 2 sec max shutter but all other settings default. Globaldraw on with raw histogram and zebras. 2 sec preview. Deflicker set to .xmp but otherwise default.

Anything else?

[sletts02]

5D3 & 17-40mm
Magic Lantern
Auto ETTR
Intervalometer @ 7sec
Post Deflicker - XMP
Import Lightroom to Export Slideshow @ 1080p 24fps

Cheers for all the work guys! Love it!

[Audionut]

Cheers for all the work guys! Love it!

Nice work agent 86 

[sletts02]

Nice work agent 86 

[Canon eos m]

I've had quite a few tries with ETTR timelapse now and I'm very, very impressed. It's the best ramping solution I've tried, and I've tried a fair few. Most of what I've shot has ended up in the bin due to my crappy photography, or the rebellious British weather, but the two shots bellow have worked out ok. Besides the fly on the lens in the first one, and the motion control going tits up towards the end. But ETTR has performed admirably in all.

These have been shot essentially with default ETTR settings, bar increasing the max exposure time and setting the sidecar to XMP. Processing is limited to static white balance and curves, plus ML deflicker. Ramping over a 13 stop range in the first shot!

I've got a few questions/requests if you don't mind.

Is it possible to process these same files through dcraw, using the deflicker in the xmp files? I'd like to compare results but I'm a bit wet behind the ears when it comes to the command line.

Am I right in thinking that if I tweak the deflicker target down a stop, this will offset the post gain applied by the same value? Would it be possible for this to be a slightly more intuitive scale? Not knowing how the algorithm works setting -4EV to get essentially unity makes no sense to me. And could it be adjustable in finer increments, half or third stops?

A utility that allowed you to offset exposure gain in post, whilst maintaining deflicker, would be very handy. Does anyone know of a way to do this?

I've had a few dropped exposures. Not many but enough to be a concern. Am I pushing it to do a shot every 12 secs with a max exposure of 4 secs on a 5D2? They seem to happen when the exposure is on the long side, but that's an impression, not carefully tested fact.

The resultant RAW files sometimes seem to lack lens correction data, but not always. Easily rectified but I thought worth pointing out.

Is there any way that starting the intervalometer could automatically turn the LCD brightness right down? Be a really handy power saving feature.

My biggest request is the obvious one, speed. The amount of time it takes to process is a limiting factor in these day-to-night type situations. Any little optimisations here would make a big difference.

Once again, I tip my hat to you chaps. And I think Canon ought to send you a very nice christmas card, with a very big cheque inside!

The second video is awesome.

[sletts02]

Not that exciting, but another test using the Auto ETTR & Post Deflicker (loaded in to LR exported using LRTimelapse 24p 1080p template).

[finges]

what setting for post deflicker should i use for a sunrise timelapse?

with the default -4ev setting i'm getting overexposed nightshots.

if i adjust the deflicker so that the nightshots are well exposed i get overexposed daytime shots.

i'm using xmp as sidecar file.

anyone tried a combination of auto ettr and expo ramping?

[a1ex]

Looks like you need some sort of ramping.

I've also shot some sunrise and moonrise timelapse this week, but didn't develop it yet, so stay tuned. I think I'll move post deflicker back to a PC-based tool, so you can play with options.

[finges]

cool ... maybe if the results are any good you can upload something + your settings

a pc based tool for post-deflicker would also be great!

[glubber]

I might offer some help with the ramping:

Andyshon brought up the idea of changing the expo-Level of the xmps in post by using "exiftool".
Based on that idea i'm working on a way to write out the metadata to a spreadsheet, manipulate it in Excel or "OO Calc" to write it back to the xmps again.

Exiftool can handle that by writing/reading an csv file.

##READOUT to CSV
exiftool -csv -exposure2012 -ext xmp c:\timelapse > list.csv   
exiftool -csv -exposure2012 -ext xmp  . > list.csv                  #### xmp/ exiftool/ csv in same directory

##WRITE BACK TO XMP
exiftool -csv=list.csv c:\timelapse
exiftool -csv=list.csv .            #### xmp/ exiftool/ csv in same directory


A rough workflow (for Windows):

Software needed: exiftool/ MS Excel, Openoffice calc or sim./ Notepad++ or other editor (only in special cases, see descr. below)
skills needed: medium in all upper three, exiftool is a commandline tool!

1. Read out the Xmps from ML-deflicker to a csv-file
   exiftool -csv -exposure2012 -ext xmp  . > list.csv

   opened in a texteditor the csv looks like this:
   SourceFile,Exposure2012
   ./IMG_4060.XMP,+2.30553
 
2. open the csv with Excel so you can calculate with it.
   (In my country f.e. excel needs a comma instead of point as decimal seperator)
   It should look like this:



3. copy the second column with the exposure data to a second sheet for doing the ramping calculation.

4. Open your timelapse in LR or ACR and choose your keyframes i.e. first and last frame.
   Adjust "Exposure" to your liking and write the value next to appropriate frame in the calc sheet.
   for example:  first frame  -> orig value = 2.30553, chosen exposure: 1.45  -> ramping difference: -0.85533
                         last frame  -> orig value = 0.82060, chosen exposure: 2.11  -> ramping difference: +1.2894

5. Do the math for the ramping values inbetween: ramping diffence first to last frame divided by frame numbers (or sth like this )
   
6. Add the ramping difference to the orig Exposure and copy that column to the second column of your original spreadsheet.

7. Save Excelsheet as csv-File. Open in notepad++ to check if the csv looks like in step 1: comma"," for value separation, point "." for decimal.

8. Write csv file to xmps.
   exiftool -csv=list.csv .       ("." point is important!)

9. If my workflow is doing right you should have now a flickerfree exposureramping timelapse.

Good Luck


edit: thx finges

[finges]

thanks for your post glubber, thats a clever way to do the exporamping.
i think i'll try your solution after my next shooting when the weather is better -.-

just to be sure, please have a look at my correction in your text below (marked bold)

4. Open your timelapse in LR or ACR and choose your keyframes i.e. first and last frame.
   Adjust "Exposure" to your liking and write the value next to appropriate frame in the calc sheet.
   for example:  first frame  -> orig value = 2.30553, chosen exposure: 1.45  -> ramping difference: -0.85533
                 last frame  -> orig value = 0.82060, chosen exposure: 2.11  -> ramping difference: +1.2894

[andyshon]

Nice one glubber. Great idea. Not being a fan of Excel I've pinched your idea and tried to put it into a shell script. Seems to work in brief tests but I aint used it in anger yet.

Code: [Select]

#!/bin/sh
# Script to ramp XMP exposure values
# expramp [total ramp] [path/to/sequence]

ramp=$1
path=$2
cd $path
seq_total=$(ls -1 *.XMP| wc -l)
steps=$(expr $seq_total - 1)
inc=$(echo "scale=8; $ramp / $steps" | bc)

n=0
gain=$(echo "scale=8; 0 - $inc" | bc)

while [ $n -lt $seq_total ]
do
n=$(expr $n + 1)
gain=$(echo "scale=8; $gain + $inc" | bc)
xmp_file=$(ls -1 *.XMP | sed -n "$n"p)
echo ""
echo "Processing frame $n: $xmp_file"
echo "The gain to be added is $gain"
exiftool -Exposure2012+="$gain" "$xmp_file"
done
So expramp -1.2 ~/Desktop/ETTR_Sequence should ramp ETTR_Sequence down by a total of 1.2 stops. The numbers it produces look right but I haven't actually watched a sequence processed with it yet.

I've been trying to pin down the crashes mentioned above but I aint got that far yet. Now on the 21st August build. It seems all is well at 10 sec intervals, 2 sec or 4 sec max shutter. At 5 sec intervals with a 2 sec max shutter it will reliably crash, but not predictably. I've had it shoot for a while at 2 sec exposure and then crash after the exposure has dropped to 1.3. But it will crash sooner or later. With these settings I've never managed more than about 50 shots. I am forcing fairly rapid exposure changes on it, but then I'm doing the same at 10/4.

The crash seems to be directly after the frame is taken, before any lcd action or beeb. On one occasion I thought I saw it change exposure settings essentially as it crashed, but this has never happened again and I might have imagined it. If I find out anything else out I'll post.

Deflicker on the computer sounds good, if time consuming. Would it speed the shooting cycle up much?

[zuzukasuma]

can anyone share their screenshots about sunrise-sunset timelapse, "intervalometer, deflicker and ettr" tab settings on their cameras?

[dalanz]

Hi colleagues,

I am an amateur who is trying to make a timelapse video of my city Santander (Spain). Yesterday I first tried a day to night timelapse, and I have to repeat it again because my lens got fogged at the end.

Anyway, I have a doubt with the ETTR tool. I took overexposed photos at the end. I configured my Canon 650D camera this way:

• Aperture: 5.6
• Trigger Mode: Press Set
• Exposure target: -0.5 EV
• Slowest shutter: 11"
• Post Deflicker: UFRaw -4EV/50%

Can I set a highest ISO? Because when my camera changed from 3200 to 6400 with a 10" shutter, it was a complete disaster, since the lights of the city were overexposed.

Regards,

Daniel

[finges]

I took overexposed photos at the end.

i also ran into this problem, see above (http://www.magiclantern.fm/forum/index.php?topic=5705.msg70401#msg70401) for a suggested solution.
good thing is you can do it even after you took the photos.

Can I set a highest ISO?

you can set the max iso in the normal canon menu.

[dalanz]

you can set the max iso in the normal canon menu.

Thank you very much. It works. I will limit the ISO value to avoid the exposure of the lights :-)

[Doyle4]

Hi there,

I use a mac and wondered if anyone could help me? when i import all my images into ACR there are times i would like to drop exposure etc so i select them all but not press synchronise, when i move the slider the rest of the images apply the same amount as the image im tweaking instead of creeping down or up, Eg: Exposure on one image is say +1 and under it is +0.9 if i move the slider on the +1 up a notch instead of the +0.9 been +1 it matches the one i tweaked identically.

Bit of info would be great thanks

[a1ex]

From previous page:

exiftool -Exposure2012+=-0.5 /path/to/ettr_sequence_folder will knock half a stop off all the exposures.

[Doyle4]

Ah excellent that makes it more clear.