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Denis OKeefe August 10th, 2009 10:04 AM

Timelapse questions
 
Pardon me for not aggregating all the previous threads on this, but my head is swimming; maybe I'm trying too many variables at the same time.
When shooting dusk to night timelapse I set the camera in manual and started at 1/8 sec at f4 - with the ISO set to A, and using an intervalometer remote. Once I started the sequence the ISO did not change as I expected it would.
So question #1 - when shooting a radical expose chance such as this, what is the best way to compensate for the darkening skies? I'm working with old Nikkors so auto iris doesn't come into play.
Question # 2 - is there a "best" combo for building an image sequence? I set the interval to every 4 seconds and manually fiddled with the shutter speed after realizing the ISO was not changing (you can imagine how well that worked - but I am learning). After a while the shutter speed was getting longer than the interval, time to shut down and rethink this.
Question # 3 - when I imported all the images and put them on a timeline I set the duration of each image to half a second, and still got a bit choppy playback - should I be setting that as a quicker duration (with more images) or is there a method of "blending" the exposures together ( I don't quite mean dissolving between all the images - but something similar that smooths the clip out).
I'm trying this with a mylapse head, and sooner or later I'll have to deal with the motion of the camera/head versus the slow shutter - any thoughts on that?
ALl suggestions that will tighten the learning curve will be appreciated!
Surprisingly I did catch two shooting stars that I didn't see by eye, and one apparently drunken lightening bug in close to the lens.

Jon Fairhurst August 10th, 2009 12:38 PM

I have yet to try it, but you should be able to do a three shot exposure compensation. I'd choose a set ISO and vary the shutter speed, so on each trigger you'd shoot long, medium and short durations.

One trick that I've read about is to make three timelines, each with it's own exposure, and to blend between them, so by the time one blows out, the next exposure takes over.

Alternatively, you could process everything with HDR software and go with that. If you output 16-bit TIFFs (assuming your NLE handles them), you will have lots of control over the gain in the video domain.

Denis OKeefe August 10th, 2009 01:13 PM

Sorry Jon, I think bringing HDR into the mix at this point will insure cranial overload (someday though). There are some amazing time lapse sequences, I'd like to be able to replicate them - you've probably seen the timescape.org stuff, if not it is a treat.

Chris Barcellos August 10th, 2009 02:16 PM

This was my first experience with time lapse with this camera. Shot all of it in a 24 hour period.

Light Cycle on Vimeo

I shot night scene on bulb, using my the cheap Chinese timer. I used the timer to set the exposure duration. I wanted the sky to darken as night went on, so I did not want exposure adjusted. As I recall, I think my wide lense was at something like F8, the ISO was at around 800 to 1200, and my exposure duration was 10 seconds. In an earlier test I did 20 second exposures at a lower ISO, but I think camera shake caused a softer pic.

I shot the day time scenes on Manual. I locked ISO there to. I believe one of the keys to timelapse is showing changes in lighting as day goes by, so I don't allow exposure to change.

However, I think if you put your camera in manual mode, and put your ISO in Auto position, you may get the desired exposure compensations.

Jon Fairhurst August 10th, 2009 02:26 PM

The 3 exposure, 3 timeline approach is a lower processing approach than HDR. It would even work with JPEGs. It's just a matter of blending the opacity of the timelines as they approach blowing out. I think the only challenge is to group the photos correctly, without needing to write a custom software program or having to do it by hand.

Of course, this triples the shutter use. I believe that if you shoot in "Live View - silent mode", it cuts the shutter triggers in half, so that could help.

Another approach is to change things manually (ISO, shutter speed or ND filtering) between shots after some number of minutes, by monitoring the results on the LCD screen. I've done this. The problem is that the exposure change is not linear, so you'll get a jump, unless, you're really good at color correction. Of course, you need a really solid tripod, so you don't accidentally jar the camera. Of course, you can always reframe in post, if needed.

Chris Barcellos August 10th, 2009 02:33 PM

Oh, one other thing, as I recall I hadto go into live view, and put the camera in stills only mode, to make it react like I thought it should.

Denis OKeefe August 10th, 2009 03:04 PM

nice star shots Chris - I live in an area too built up to see the stars like that at night, but I'd like to try that one day soon.

WHen I had the camera on the timer with the ISO set at "A" it did not change as expected, I'll have to play with it a bit to find a better way.

Jon Fairhurst August 10th, 2009 03:38 PM

Quote:

Originally Posted by Denis OKeefe (Post 1205783)
WHen I had the camera on the timer with the ISO set at "A" it did not change as expected, I'll have to play with it a bit to find a better way.

If it did change, you'd risk it jumping back and forth when it gets right between two levels. It would be better to manually change it, if you have a solid enough tripod.

Chris Barcellos August 10th, 2009 04:39 PM

Quote:

Originally Posted by Denis OKeefe (Post 1205783)
nice star shots Chris - I live in an area too built up to see the stars like that at night, but I'd like to try that one day soon.

This is Northern California, in my back yard. Suburbs of sacramento. Those trees in shot are in school yard with permanent lights blaring, and street light reflection off tips. The shot was also toward Sacramento, into light polution of the City of Sacramento. I really couldn't see many of the stars and was relying on camera to pick them up with long exposure.

Charles W. Hull August 10th, 2009 07:30 PM

Timelapse power?
 
Chris, how did you power the camera? I can only get a couple of hours of battery life doing timelapse.

Chris Barcellos August 11th, 2009 01:21 AM

I bought the Canon AC adapter.


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