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-   -   Time Lapse Recording on GL2 (interval recording feature) (https://www.dvinfo.net/forum/canon-gl-series-dv-camcorders/2762-time-lapse-recording-gl2-interval-recording-feature.html)

cocobutt July 19th, 2002 03:52 PM

Time Lapse Recording on GL2 (interval recording feature)
 
Just a short observation of the time lapse feature on the GL2.. It has odd time settings.. you can choose to shoot between .5 seconds to 2 seconds (at 4 intervals, .5, 1, 1.5, and 2 seconds) of footage from every thirty seconds to every 10 minutes (at 4 intervals, 30 sec, 1 min, 5 min., 10 min.) This seems odd to me and the practice shots of live motion seem very jerky.. Perhaps its good to set up and tape the decomposition of a banana peel over 24 hours, but it does not allow one to shoot live motion at rapid speed with good results.. The only way I can think to accomplish that is to shoot a full 60 minutes of footage, then speed it up to an equivalent 1 frame/sec, but that takes a good deal of effort and hard disk space. I had planned on shooting a game of pool using the interval record feature, but am confident it won't come out as smooth motion fast-forwarded a great deal (as was shown excellently in Requiem for a Dream).

I had also planned to shoot the night sky using a tripod, but it also seems as though it may be jerky.. even at the lowest recording time (0.5 seconds) it is clear that things are jerking around on the screen and is essentially equivalent to a frame rate of 2 frames/sec. Thus, even if I were shooting all night, the footage would look as if the stars hop across the sky as opposed to smoothly gliding across.. Perhaps an After Effects script could be written to extract one or two frames from each of the 0.5 second intervals and compile them to make a smooth video.. I do not know how to write such a script and would appreciate people's ideas on how to accomplish such a task as I would like to do some smooth time lapse with the GL2 without require 8 DV tapes an all-nighter to catch the footage.

Hope someone finds this useful and/or someone has an idea of how to solve my conundrum.

-Cocobutt

Don Palomaki July 20th, 2002 07:33 PM

What you see is the typical camcorder interval recording, as was on the old Canon A1 Digital Hi8 camcorder, and perhaps the L1.

The reason for the .5 sec minimum is to advance the tape off the spinning head while in pause mode (to avoid tape wear-through).

For true time lapse you need a recorder specifically designed for time lapse, or perhaps use your NLE to grab every n-th frame from the data on the tape.

normbaits July 20th, 2002 09:11 PM

why not experiementing with speeding up the footage in your NLE to about 1/15th of its original time, something like that.

Jason Bagby August 7th, 2002 11:47 AM

thyme laps
 
learn from my pitfall!
if you get the bright idea to use interval recording to do time lapse by extracting a single frame from each interval, i would suggest setting it even intervals (short ones, mind you) like 2seconds on, two seconds off, then in your nle take the first and last frame of each interval, so you get two frames for each interval you spend recording.
this math breaks down very quiclky, if you do 1 minute shots then you only get 4 seconds of footage from an hour tape
if you are doing a 24 hour banana peel tho, you need the shortest intervals possible i'd say, and divide this number into the number of seconds in the tape you are using (e.g. 1 second goes into an hour tape 3600 times.) use this number to divide the period of time you are shooting (eg 24 hrs= 86,400 seconds), the resulting answer should be the minimum interval needed to make your tape last for 24 hours at 1 second intervals- and i think the answer is every 24 seconds. but i don't claim to be a math guy.
also, a good trick to strecth it out is to use two of each frame instead of one, thats how animation is done, so you actually see 12 fps instead of 24.

Chris Hurd August 7th, 2002 01:52 PM

Don is quite right; the time-lapse settings on the GL2 work in the same manner as the XL1S, VX2000 or any other video camcorder with the intervalomater feature, for the reasons he gave. We'll never see true single-frame recording in a DV camcorder due to the limitations of the tape transport mechanisms. Hope this helps,

Mark Austin November 16th, 2002 10:05 AM

Time Lapse at night
 
About shooting the night sky with the GL2 in time lapse mode. I know were some coments about stars jumping across the sky, and my take was that it's not worth trying. As some of you know there is going to be a meteor shower (at lease visible in Texas) from the Leonid trail in the next few days, and I thought it may be an opportunity to try some different settings. I have only had the GL2 for a few months so any advise on where to start would be greatly apprecieted. Or should I just go out (not shoot) and enjoy it?
THANKS!

Tom Christensen November 16th, 2002 11:27 AM

I had the same idea and was thinking the same thing.

From the comments above though, it sounds like you would get stars moving across the sky, but probalby miss the shower unless you just got extremely lucky that the shutter would be open when a streak occurred. Even then, you would not get movement, just a quick couple of frames.

From MSNBC:

"The Leonids actually began as a trickle on Thursday, and the hourly rate will increase each morning. In addition to a background rate of about 20 random shooting stars per hour (meteors not associated with the Leonids) here’s what you can expect from the Leonids, according to Robert Lunsford of the American Meteor Society:
Saturday morning: 5 per hour
Sunday morning: 10 per hour
Monday morning: 20 per hour
Some Monday morning math: 20+20=40, and 40 per hour means nearly one every minute!"


Let us know if you try it.

Tom

Mark Austin November 16th, 2002 11:37 AM

Leonids -
 
The local news here in Houston reported that at the peak showers would produce 500 to 2000 events per hour. I have tried to find a link on their web site http://www.khou.com for the best times but as of yet have been unable to find the info. I'll post it for anyone who is interest when (and if) I find it. I'm probably going to try to shoot it anyway, I guess I'll get a night of star gazing either way.
Mark


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