Jahdakine recently opened a thread at the Long Exposure Group about Double Exposures. Interested in it I asked him to write up a tutorial and give some examples. Here is his post.
I'm calling this technique the Blind or Black Pan/Zoom. It came to me while experimenting with moon zoom blurs. I'm sure it's been done before and will afford possibilities other than moon superimposition, but these are a few of my first attempts. My objective was to make these appear like a single image, unlike the obvious overlap in the top left example. For that, it requires little to no cloud cover around the moon.
The process: zoom in on the moon and take as many shots as needed to understand where your exposure time needs to be to keep from "blowing it out" (losing the detail).
Then do the same for the second exposure and make sure you have some kind of reference so you can know where to aim.
Finally, point back at the moon and lock the shutter release. After the determined exposure time, cover the lens and then re-aim to the second spot. Zoom out and uncover the lens for the determined second exposure. Release the lock. Pray. Repeat as needed.
I'm considering a scope to get a better view of the second part of the exposure, and possibly a digiscope to create even more unbelievable moon size. The ultimate trick – get the sun and the moon or even two moons for that crazy other worldly effect.
Thanks Jah! I am fascinated by this and will have to go out and try it myself. If anyone else has examples please post the links in the comment sections!