Time lapse photography
The process of shooting hundreds of photographs over a period of time and compressing them into a short video which gives the effect of speeding up time.
I know you all have seen these fascinating videos out there on YouTube or Facebook that seemingly look like clouds moving abnormally fast or stars at night moving slowly across the sky which you would not normally see in real-time. This is the world of time-lapse photography. I am mesmerized by these time-lapse videos and decided to put one together myself. I would like to share with you my experiences and show you how to shoot your own time-lapse video. First will start off with a few basic steps on how to set up your camera and shoot a time-lapse sequence. Then i will go into how to process and put these videos together in my next article with several software packages that make time-lapse photography a whole lot easier these days.
To start with you will need a DSLR or any camera that will accept an inexpensive external wired interval timing unit and a sturdy tripod. The main piece of equipment you may not have will be the interval timer . You can find the one that connects to your particular camera Here at ebay.
Time lapse photography is a fairly advanced topic. I assume you have a good understanding of photography and how to set up your camera.
- Use a tripod a must.
- Use an interval timing device – Make sure you read the manual and understand how this device works before you start.
- Set the camera to the raw file format.
- use a White balance card for raw shooters.
- If you must use JPEG make sure you set to the appropriate white balance settings (do not use auto white balance).
- Set your camera to manual exposure mode (M)
- Disabled auto ISO.
- Disabled autofocus.
- Disable image stabilizer if equipped.
- Use and understand your cameras histogram.
- Use a neutral density filter in daylight applications. I recommend B&W brand.
- Bring a small notebook to take notes of your process and calculations.
- bring a kitchen timer or you can use your watch to keep track of time.
- Bring a chair and a good book
I recommend you use a the widest wide-angle lens you have to start with for two reasons the depth of field is much greater and the look and feel of the final video clip is much more dramatic. but try your telephoto lenses as well. There are other settings you may want to consider but for now this will get you started.
Picking an Interval Time
1 second intervals – traffic, people moving, fast-moving clouds
2 – 5 seconds intervals – sunrises, sunsets, slow-moving clouds
15 -30 seconds intervals – Stars in the night sky, Sun or moon moving across the sky with no clouds, Moving shadows in buildings or the forest.
90 – 120 seconds intervals – growing plants in a studio setting (indoors only)
Make a note of the interval time you have selected for your subject.
The frame rate we are going to use is 24 frames per second. There are many other frame rates out there but for simplicity sake. Each frame rate has its advantages and disadvantages. Here is a list of the most common frame rates. 12, 15, 24, 25, 30, 50,60. Of these frame rates the most compatible frame rates that can be mixed and matched our 12 and 24, 15 and 30 and 60, 25 and 50.
How many exposures
Number of exposures required for a video clip. We are to start off assuming our end movie is going to be 24 frames per second. As this is the framework that the motion picture industry uses and produces the most aesthetically pleasing results. At 24 frames per second you will need 360 photographs to produce a 15 second time-lapse video clip. for a 30 second 720 photographs. Time required to shoot a 15 second time-lapse sequence. This is the minimum recommended amount of time you should use for a time-lapse clip. for different lengths and frame rates the formula is as follows: frame rate multiplied by number of seconds in clip equals number of exposures required.
Make a note of how many exposures in your time-lapse clip.
How long will it take
Once you have figured out how many photographs you will need for your 15 second time-lapse clip. you can determine how long it is going to take to shoot that sequence. The formula to calculate this is: Intervals time multiplied by number of exposures divided by 60 equals number of minutes required or divide by 3600 equals number of hours required.
below are examples of several scenarios with different interval times using the formula above.
At a 1 second interval – Your 15 second time-lapse sequence will take 6 minutes.
At a 2 second interval – Your 15 second time-lapse sequence will take 12 minutes.
At a 5 second interval – Your 15 second time-lapse sequence will take 30 minutes.
At a 10 second interval – Your 15 second time-lapse sequence will take 1 Hour.
At a 30 second interval – Your 15 second time-lapse sequence will take 3 Hours.
At a 90 second interval – Your 15 second time-lapse sequence will take 9 Hours.
Make a note of how long it will take to shoot your sequence. (This is important)
Set your ISO as low as possible to prevent noise. Night shots may require a higher ISO.
You want to have a shutter speed around 1/30 of a second or longer if possible. You can use a neutral density filter for daytime shooting to get a longer shutter speed. This will minimize the Flickr effect after you put the movie together. The less than 1/30 of a second or longer rule seems sort of counterintuitive to photography in getting sharp images. But the little bit of blur you get in the moving objects allow the final project to have a more natural smooth look.
Some say to use a wide open aperture. looking at this scenario it works great for low light or evening photography but during the bright sunny day it is nearly impossible to achieve these settings without using a neutral density filter. I use a ND 1.8 which i already have that subtracts 6 f-stops. But a better choice might be the 3.0 which will subtract 10 f-stops. I like to set mine to around F8 or F11 to get the best image quality and increase the depth of field in my subject.
In raw file format white balance will be set in post processing. I use a white balance card and photograph the first photograph in the sequence and last photograph in the sequence for a white balance reference in post processing. If you use the JPEG format you will have to set your white balance to the appropriate setting for your light conditions. Do not use auto white balance.
Take a test exposure and use your histogram to determine whether you have a properly exposed photograph. the histogram should be as far to the left as possible without clipping on the left. Adjust exposure if required and take another test exposure until your exposure is correct. This step is important because you spending a lot of time shooting a sequence and you want the best exposure you can get. here is an article on using your histogram tools for better exposure.
Time to shoot
Now it’s time to shoot your sequence. With your camera firmly supported on a tripod and connected to your interval timer, set up your interval time, compose your subject, set your ISO, shutter speed and aperture to a proper exposure, focus your camera. raw format shooters should hold up your white balance card on the first and last shots in your sequence as a white balance reference. You can remove them later in post processing. Set your kitchen timer or stopwatch to the amount of time required to shoot your entire sequence. Now start your sequence and start your timer. do not disturb your camera or tripod during the entire sequence of shots. Sit down in your chair and be patient. Read a good book or just enjoy the scenery. When the timer goes off your sequences complete.
It may take 8 to 10 or more sequences of different subjects to put together a short 3 minute time-lapse video.
Star time-lapse photography
If you are shooting stars and do not want to see the star trails or streaks you see in many long exposed photographs. You can use the rule of 600 to determine the maximum exposure time for your particular focal length of your lens. To calculate this. take the number 600 and divided by the focal length of the lens you’re going to use. example: 600/12mm = 50 seconds or less To get stars without tails, A 24mm lens would be 25 seconds or less and 50mm lens would be 12 seconds or less.
I hope this helps you in your pursuit of time-lapse photography. Even if you never shoot a time-lapse video. I hope this article gives you a great appreciation of the time and effort it takes to put one of these videos together. It can take many hours or even days of shooting and processing just to create a short 3 minute video. In my next article I will be discussing how to processing these individual photographs into a video clip and how to assemble them into a short video. The Software I used to produce my time lapse video is Adobe Lightroom 4, LRtimelapse 3 and Photodex Proshow gold. I highly recommend the e-book LRtimelapse listed below as a comprehensive and complete resource to learn more about how to shoot and process time-lapse videos.