July 17, 2010 at 11:33 PM by Dr. Drang
Now that I have a phone with a camera that focuses, I’ve been taken more cameraphone photos. I got the AutoStitch app and have tried to shoot a few panoramas. This involves taking a series of photos looking in different directions from the same point and having AutoStitch combine them into a single image. AutoStitch is good, but I’ve found that I can help it out by holding and rotating the phone in a particular way.
Serious panorama photographers use a tripod with a head that rotates the camera about its lens’s entrance pupil to eliminate parallax. That’s obviously not a possibility with the iPhone, but it can be roughly approximated by gripping the phone with the thumb and index finger above and below the lens, holding that hand steady, and rotating the phone about the axis that runs between the two fingers.
This works better than standing in one spot and rotating your body around as you shoot because it minimizes the parallax that AutoStitch has to deal with. You probably won’t see much difference if you’re taking a panorama in which everything is about the same distance from the camera. But if you’re taking a panorama with distinct foreground and background objects, the difference can be striking.
Here’s a panorama with a foreground object, stitched together from five photos taken by rotating my body.
And here’s the same subject matter, stitched together from photos taken by rotating about the two-finger grip.
Note the nasty ghost image of the foam finger in the first panorama, the result of parallax that AutoStitch just couldn’t compensate for. The ghost is gone in the second panorama. The two-finger grip certainly can’t eliminate parallax, but it can reduce it to a point where AutoStitch can handle it.
There’s certainly nothing new about what I’m doing here, but apps like AutoStitch are bringing panorama photography to people who’ve never done it before (like me), so I thought it was worth a mention.
You can click on the images to see larger versions. I apologize for the poor lighting, but I didn’t have a well-lit example.