Rodney Campbell's Blog

Something new to try 🙂 – I decided to make a timelapse movie with my D-SLR – it’s not fabulous but it’s given me a start to work from 🙂

Firstly what do I mean by a Timelapse movie… Time-lapse photography is a cinematography technique whereby the frequency at which film frames are captured (the frame rate) is much lower than that which will be used to play the sequence back. When replayed at normal speed, time appears to be moving faster and thus lapsing. Processes that would normally appear subtle to the human eye, such as the motion of the sun and stars in the sky, become very pronounced.

My aim at the outset was to try and capture motion in the moonrise and in the clouds in the sky, in then end the very heavy cloudcover obscured much of the moonrise but after the moon was high in the sky the moonlight lighting the clouds from above made for interesting pulsating cloud formations.

NB: I don’t know why the encoder (Quicktime or iMovie) or YouTube have corrupted the first few seconds of the movie (the source movie works fine here and I have retried the encoding & youtube upload a few times with the same results)…

For those who are interested the techniques I used to create this first attempt is as follows:

1. Tripod – I’m going to be taking lots of exposures over time and I need them all to be taken from the same position (plus in this case they are going to be long exposures so I need a stable platform)
2. Turn all the Auto functions on my camera off – this means:
• Frame the scene and set the focus and then set the Lens to Manual Focus and turn off VR – I don’t want the focus to change between shots and I don’t want the power drain of VR for every shot
• Turn off Auto White Balance and set the White Balance manually – you don’t want it to change drastically between frames – in my case I chose Cloudy
• Turn off AutoISO and set the exposure manually – in my case I tried a few test shots and opted to use 13 second exposures at f/8 with ISO 400 – in reality you want the Aperture to stay constant (so DoF doesn’t fluctuate) and you want the shutter speed to remain relatively constant (stay shorter than the interval time but not so short as to create blippy effects with moving objects) – if the scene had a large change in exposure over time (e.g. start during the day and then move into night) I’m wondering how to achieve this with more subtle changes in exposure over time (if you used auto exposure you could have radical shifts in overall frame brightness/exposure from frame to frame (e.g sun or moon move in and out from behind clouds)
3. Set the camera to shoot JPEGs – whilst you can shoot RAWs since I was going to take many hundreds of images I didn’t want to waste storage space or bother post processing them so I simply chose JPEG Normal at Small Size (which is still massive resolution for a video)
4. Turn off the Image Review function – to conserve battery
5. Use an Intervalometer – this allows you to program a sequence of images to take – in my case I simply set it to take an image every 20 seconds for a unlimited number of images (till the battery drains, the card fills or I turn it or the camera off). My Nikon D7000 has an intervalometer function built right into the camera but as I shot this with my D90 I used my $20 eBay programmable wired remote

Some other tips include:

• The factors which relate say the (S)hutter speed, (I)nterval between shots in seconds, (O)verall time in seconds, movie (F)rame rate in frames per second, movie (L)ength in seconds, etc are that… S should be less than I, and O = L * F * I, and the number of shots required to be taken will be L * F, and the apparent time speed increase will be I * F
• in my case the just over 30 second movie (L) at 25 frames per second (F) required 770 images which when taken at 20 second intervals (I) took just over four and a quarter hours to complete with an apparent time speed increase of 500x
• Use an Interval suitable for the type of thing you are shooting – object which change/move slowly over time (e.g. stars, moon, clouds, etc) can be shot with longer intervals but scenes with faster moving objects (people, vehicles, etc) will need much shorter intervals
• Drag the shutter – basically don’t use really short (e.g. much shorter than 1 sec) shutter speeds when there are moving objects expected in the frame – this is because shooting with short shutter speeds will lead to objects appearing as blips in the movie rather than smoothly or blurily moving through it
• Battery – make sure it is fully charged before starting – you’re taking a lot of images which will chew up a lot of juice
• Card Space – make sure you’ve got enough memory card space to store all these sequential images

I then just loaded all the images into QuickTime Pro (the older version) and used the Open Image Sequence… function and selected the first image from the sequence which created the Quicktime movie at the frame rate I selected in the wizard.

Don't forget to Share...

Google

Facebook

Twitter

Linkedin

Pinterest

Email

Print