Time Lapse technique

MikeA · #1 12-10-2007, 06:26 PM

Hi.

I've been getting interested in Time Lapse sequences of natural events, and to that end, I have the canon intervalometer to play with.

We've had a few bushfires in our area, so I've been getting ready for the super sunset. (something good has to come out of all that destruction!) This is the best so far:

Not sure how or if a movie can be embedded here, so it's a link to the gallery. 1mb file if you are on dialup.

I'm taking an image every 15 seconds and creating the movie at 24fps. It's not bad, but I'm getting a bit of flicker which I'd guess is the micro variations in exposure between images. Not sure how to tune that out, it's not possible to capture the dynamic range of full sun to twilight on a single exposure setting - the sequence starts at 1/8000 (F8) and finishes at 1/6th or so.

Any suggestions for improvements?

Mike

MikeA · #2 12-19-2007, 03:07 AM

Well, looks like no-one is into this then?

I've done some more since, and fluked a great lightning shot as a storm went through the sequence.

Here's the sequence, 1.2mb click the picture to view it. Needs quicktime:

And the frame with lightning happening:

Still interested in any technique hints for this process...

Regards,

Mike

PatrickFordham · #3 12-19-2007, 12:47 PM

Quote:

Originally Posted by MikeA

Still interested in any technique hints for this process...

Mike,
Besides the capturing, What is the process?

Martin_Kristiansen · #4 12-19-2007, 01:59 PM

I am not into movies but these clips are fantastic and I am tempted to give it a try in Namibia next week. Thanks for the inspiration.

michaelnotar · #5 12-19-2007, 05:10 PM

personally cant see any differance from about 12-15fps and above. the flicker is small object moving, but characteristic of the technique.

what camera are you using?

i reccommend the time machine device, from Mumford Micro Systems - The Crackpot Inventor. it can also time lapse, and has a sensor to turn off during night, so if you want to do muli day time lapses, such as construction time lapse. im also made high speed time lapses with it, with is complex, i did a water drop sequence.

MikeA · #6 12-21-2007, 03:25 AM

Hi Michael,

I'm using a Canon 5D and a TC-80N3 timer remote controller. I have had a look at the Time Machine and it's a pretty clever piece of kit. Maybe one day

Maybe we are looking at different flickering, or maybe it's not as obvious in the small movie. I'm pretty sure it's due to variations in the exposure caused by the scenery moving through the frame and the variability of the lighting. The camera does it's best to record these variations, but it means that constant patches of sky (for instance) suffer small variations in exposure.

It's a big ask, but some sort of lag exposure or averaging between frames might help the end result. Post processing these variations out is a bit of a headache, at the rate I take them, an hour real-time is 240 exposures.

Mike

michaelnotar · #7 12-21-2007, 04:07 AM

hopefully you did or will now, shoot only Sjpgs. i set it on auto exp too.

i think you are being too hard on yourself about the flickering, exposures many seconds apart rang at many FPS will probably do it. just a characteristic of the process.

i always overshoot, then i can edit 1/2 or so out to make the movie.