Reader Q: 3D photography of moving subjects

Occasionally I get email or comments or Flickr messages that I think might be best answered via a blog post. Other people may be interested in the question and my best efforts at an answer. I received this question through Flickr the other day, and asked Pepe’s permission to answer it here. As part of 3D month, here’s a query about moving subjects in 3D photography:

The Question

I have just read your discussions on ‘How to see’ and ‘How to take ‘3D photos. My sincere congratulations. I am going to recommend then in my site at Flickr.

Only one thing I don’t quite understand: you said, apparently wihout exceptions, that nothing can move between shots in ‘Disadvantages’ in ‘How to take 3D photos’, but evidently, in your examples you have many shots even of people practicing sports. Perhaps this is a contradiction or I didn’t understand you well. I suppose a pair of cameras with synchronized shots are used. I would like and appreciate very much to have your comments about this type of 3D shots with moving people or objects.

Please, take a look at http://www.flickr.com/photos/joserodmon/sets/72157603505323290/. Your comments will be very valuable to me.

Thank very much for your time and effort. Sorry for my poor English.

Best regards, Pepe

The Answer

Thank you for your question Pepe! First of all, your English is excellent.

Your confusion is entirely my fault. It is certainly true that subjects which move while taking 3D photos are problematic, but only if you are using a single camera to take two separate shots. The most accessible way to take 3D photos is using the cha-cha method, as I described in How to Take 3D Photos.

There are a number of other ways to take 3D photos that eliminate this problem by capturing both the left and right eye views at the same time. These include:

• A 3D lens or attachment, such as the Loreo 3D Lens in a Cap.
• A specialist 3D camera which has two lenses built in and records an image through both of them at the same time.
• A twin-camera system, which mounts two cameras side-by-side, and takes 3D photos by triggering the two cameras simultaneously.

For the 3D photos to which you refer, for example the one at the top of this post, I used my Loreo 3D Lens in a Cap. This used a mirror and dual-lens arrangement to capture left and right views simultaneously on a single exposure, thus allowing me to freeze movement.

I’m sorry I didn’t make it clearer that I take 3D photos using both methods. I will go back to the posts in question and make a note of the fact. I have updated all of my 3D images in Flickr so that they are tagged either “cha-cha” or “loreo” to specify what method I used to capture the image.

More Information

So what can you do if you want to capture 3D images of potentially moving subjects using the cha-cha method? Here are some suggestions:

• If shooting people, explain to them that remaining motionless is critical. Motionless includes breathing, where they are looking, shifting their weight, ANY movement.
• Be quick! Plan your shot and rehearse it in your head before you shoot, so you can get both shots withing a very short period. You increase your chances of capturing slow or infrequently moving subjects.
• Take the same pair of shots several times. You might be lucky and find a pair where movement is minimised
• If shooting plants outdoors, shoot on still days and wait for a lull in the wind. Small breezes will change lots of the smallest leaves, so calm weather will help a lot.
• Accept that some things are impossible. Any kind of moving water is impossible, windblown vegetation, people whom you are unable to instruct etc will likely be forever impossible with the cha-cha technique.

I probably overstated the problem of shooting cha-cha 3D photos of moving subjects, and a little practice and experimentation may open up new possibilities, but there will always be a limit.

Send in Your Own Question

If you have any questions about my photography, any of the posts or photography in general, please don’t hesitate to get in touch with me, either via the blog comments, email, or via the contact form that I’ve just decided needs to go on my Profile page (look for it soon!). If I think your question would make a suitable topic for a blog post, I’ll write one up and share the answer with blog readers.

Hope to hear from you soon!