Aaron Adams’s Blowhard Blog

Long ago, I talked about using an Apple iSight camera to take pictures through a telescope. I promised some pictures and a sort of how-to. And then I told everyone to wait. And wait some more. And then, finally, Tim and I actually found an evening with clear weather where we could get away from the city and test out the camera and take some pictures, so I could write about the experience. Just as I was about to write everything down, I became seriously ill, so I was out of action for a week or so. But now… now I’m going to write about it! After months of waiting, you’re finally going to have the opportunity to read the most semi-climactic of all possible outcomes in this mildly interesting project.

The goal, for those of you who can’t remember that far back, was to couple an iSight camera to our telescope and see what happened. We tried a preliminary run and got a video of Saturn, which I was able to make into a semi-decent still image. The fly in all of this ointment was that the camera had to be held still to get a decent picture, and neither Tim nor I (or probably any person for that matter) can hold it steady enough. So we decided to build a mount.

Mounting the iSight to an eyepiece is simpler than you might think, assuming you have the kinds of eyepieces we do. I took some pictures because describing the mount without the pictures would probably be pointless.

The parts:

Clockwise from the top left, the black thing is our 8mm eyepiece with the rubber eye cup removed, exposing a convenient indented edge which nylon screws can grip. Next to that is the iSight camera. Below the camera is the inner aluminum cylinder which houses the iSight, with nylon screws to hold the camera steady. The other aluminum cylinder goes on the outside of the first, as you’ll see shortly in another shot. Tim machined both of these cylinders and the screw holes to fit both the iSight and the eyepiece. Finally, there’s a rubber ring to prevent the iSight from slipping into the barrel, again, illustrated in pictures just below.

Here’s a step-by-step illustration of how these parts fit together:

And here’s the finished product mounted on the scope:

And the scope, plugged into my PowerBook, running Starry Night Pro, ready for action:

The mount worked very well. The camera was held as still as we could expect. The problem we ran into was the software. To make a long explanation short, we needed to focus both the telescope and the camera, and after that, we had to adjust the camera’s settings so that details from Jupiter, made bright by the telescope’s 12-inch aperture, wouldn’t be washed out in the resulting image. The only software I could find that would allow me to control the iSight in that way was Quicktime Broadcaster, and frankly, it’s not great for astronomy. QTB is intended for what I assume most people would call normal shots, in a room, of maybe a person or a scene, not of tiny planets through a telescope. That being said and understood, QTB’s preview window is too small, and it’s hard to see whether the object you’re viewing, in this case, Jupiter, is in focus, and what level of detail is available. Also, the interface for controlling the camera’s settings is idiosyncratic and frustrating until you get the hang of it. The only way to tell if we were in focus was to take movie after movie, and then guess whether we should tweak it anymore or just leave it.

With some patience, Tim and I managed to get a decent movie of Jupiter, ready for processing by Keith’s Image Stacker into a sharp still:

It was a long way to go, and admittedly Tim and I were climbing a bit of a learning curve, but the iSight turns out to be fairly good for planetary imaging. If there were a better piece of software other than QTB available, the task probably would have been 1/2 as hard.

Having done about as well as we could with planets, we decided to turn the camera towards some relatively bright deep sky objects. M13 is a giant globular cluster that looks great to the eye, but didn’t even register on the iSight. M57, the Ring Nebula, didn’t show either. Neither of these no-shows is surprising - the iSight is intended to photograph humans in a lit room, not faint fuzzies of the night sky.

Our next target is the moon. It’s large and bright with a lot of little details and seems like it would be the perfect object for an iSight-equipped telescope.

Smile Tim!