Shooting time-lapse footage is a lot of fun and a great way to compress time into short video clips but it's not without it's challenges. We've spent a lot of time shooting time-lapse and made plenty of mistakes in the process. For example, it took three separate trips to the Christmas in the Park event to get the footage you see above. To get the best possible quality from our footage we also tried four different workflow methods to finally find the best solution. If you're interested in shooting time-lapse footage, here are our recommendations on getting the best quality out of your workflow.
THE BASICS
If you're new to time-lapse we suggest you head over to our friends at
Photojojo who've created a nice
guide to get you started. Once you're comfortable with the basic steps needed to shoot a time-lapse and you've purchased your
Intervalometer, we've created a
time chart to help you determine your interval time. The next step is to determine your image format.
CAPTURE FORMAT
Determining your image capture format can be a tricky decision because your image format may affect your interval time. We ran into this problem quite a few times with frustrating results. Your choices are basically RAW or JPG. We always prefer to shoot RAW because it gives us the full resolution of our sensor which in turn gives us the greater quality final image. The problem with RAW however is that some cameras cannot process a RAW file quickly enough to allow a 2 second interval time for example. We found that our Canon 1Ds could only shoot 1 RAW image every 4 seconds without filling the buffer. Remember we need to shoot 100's of frames to create one 24fps video clip so if your camera buffer fills up after 24 frames then you won't be able to complete your entire sequence. RAW files are also much larger and will quickly fill your storage card which cause a lot of headaches. We choose not to shoot JPG, even though our camera will process a JPG image much faster and the file sizes are significantly smaller, because it doesn't give us the quality or latitude in post-production. A JPG image is rendered in-camera and cannot be adjusted later without degrading the image. We found the perfect solution in the sRAW format. sRAW is a relatively new image format which is based on RAW. The file is identical to RAW only 1/4 the resolution and 1/2 the file size. To produce 1080p time-lapse videos, sRAW is the way to go!
DETERMINING EXPOSURE
This step is the most crucial and most difficult step of the entire process. Because of the fact that a time-lapse sequence takes place over a certain duration of time, you will have to deal with the fact that your ambient light and color will change. What you're trying to do here is reduce the amount of flicker you get when you assemble your footage. If your camera settings change (even slightly) during the image capture, you'll get a really annoying flicker effect when you playback the video sequence. The first thing we recommend using is a custom white balance. Pull out your neutral gray or white card and take the time to create a custom white balance for your sequence. This is even more important for night sequences. We found the WB presets in Canon cameras to really suck at night so we always use a custom WB setting when shooting at night. Setting your exposure will be a creative choice so while we can't help you determine your exposure, we can give you some tips.
- We suggest setting your camera to Manual mode but if you choose to use an automatic meter, use Aperture priority so that the camera changes shutter speed and not your aperture.
- If you can tie your spot meter mode to your auto-focus point, do it! Then set your AF point to a fixed position of your scene that the camera can meter on without too much interference. This will hopefully provide a consistent exposure and not have your exposure jumping around to much during the sequence.
- When shooting at night be sure to shield your eyepiece from any stray light that might enter from say your LCD monitor. This stray light can throw off your meter reading slightly and give you a wrong exposure setting.
Our last tip has to do with focus. ALWAYS set your camera to shoot in manual focus. This is the first thing that will severely screw up your sequence as your images have a different focus point from image to image. Remember the MOST important thing to keep in mind is to create a consistent environment that changes as little as possible from shot to shot.
POST PROCESSING
Here's another area where we learned quite a bit from trial and error. Again, our goal was the absolute BEST quality output we could get published to Vimeo.com. There are a lot of moving pieces and a lot of little decisions that play a part in the final output quality. On one side of the spectrum you could easily shoot a sequence of JPG's, assemble them in Quicktime 7 Pro and export them using a simple preset and be perfectly happy with the results. To get the best quality output however takes a little more work. Our workflow goes something like this:
- Import sRAW files into Lightroom for processing. This step can be optional, but we find that processing RAW is easier in Lightroom than in Camera RAW.
- Import the original RAW files into Adobe After Effects as an "image sequence". When you do this, you will be shown the Camera RAW interface where you can choose to adjust your images using the standard RAW adjustment controls. If you previously edited the images in Lightroom, you will see your adjustments in the Camera RAW dialog. Once you are done with the Camera RAW adjustments the images, After Effects will automatically assemble them into one "camera raw sequence".
- Use After Effects to apply any motion, titles, or effects to your sequence. We like to add music to our clips and we'll be honest, After Effects sucks at this! We've tried to export our edited sequences into other programs that better handle music tracks and would always loose quality no matter what setting we used so we just live with After Effects and suffer through it.
- Export your final composition using the following guidelines from Vimeo. If you're using another site to host your video you should google what their compression guidelines are. If you can't find their guidelines posted than switch to Vimeo!
The best advice we can give here is to keep working with your source files in the same application if possible. Every time you have to export/import footage or convert footage to a different format you loose quality. Keep your source footage as high resolution as possible during the workflow and only compress or convert it at the very last stage. After Effects was the best application we found for their video compression algorithms. We've heard good things about using Quicktime 7 Pro for compression as well.
MORE RESOURCES
We hope you've learned a thing or two from our real-world failures and wasted hours of experimentation. If you're looking for more information here are some resources that can help.
. These filters attach to the front of your lens and reduce amount of light that enters your camera which allows you to shoot with a larger aperture. If you're metering through your lens then you don't have to change a thing, simply screw the filter on your lens and enjoy an extra 1-3 stops. If you use an external or handheld meter than don't forget to compensate your exposure depending on the filter you're using.
