The planetarium show packages we distribute were originally designed for classic, slide-projector-based theaters. Single-shot projectors, dissolver pairs, horizon panoramas, all-skies, zooms, slews, special effects projectors -- these are the tools we expect most planetarians to use when presenting our shows.

We provide the images in our show packages on data CDs, ready to be made into 35mm slides. Most customers will find it easy to slip the disc in their computer and view the images. The challenge will come in getting the images off the data disc and onto slide film.

Perhaps the most common method of digital-to-film transfer is through the use of a film recorder. If your planetarium already has one, you're all set. Otherwise, you will need to locate a photo lab or graphics imaging bureau that offers the service.

Alternatively, if you already have a calibrated camera and copystand, you could simply print the images on an inkjet printer, and photograph the resulting printout. This is the method we used to use, and we've written an article describing it, and discussing its relative costs vs. the film recorder/service bureau methods -- read it here.

A show package's single panel images should require no reworking. They're in the usual 3:2 ratio. (Actually, they're 1056 x 712 pixels, which conforms to the Wess 002 aperture; a true 3:2 ratio frame would require a Wess 001 mount. Most people use 002s.) We use Targa .TGA as our image format for easy importing into most dome image processing software. The bottom-up Targa frames use lossless RLE compression for more efficient disk storage.

For images that are not full-frame, we provide two masks (white/clear image area on black background). An exact size mask is stored as an alpha channel in the color Targa image; this is useful for compositing in programs such as Adobe After Effects. The other mask is provided as a separate Targa file, similar to the alpha channel mask but with a skosh more room in the image area. These can be used to make the traditional planetarium-style masks, to be sandwiched in the Wess slide mounts along with the color film chip during final assembly. If you're like us, one of the dying breed who still use Kodalith to make masks, it's a simple keystroke in Photoshop to invert the mask image to black-on-white.

The multi-panel images will require some reworking. You will want to run both the color and mask images through DigiDome -- to slice and dice the chords, horizon panoramas, and all-skies to custom-fit the specific needs of your planetarium's projector systems.

Eventually, you'll have all the images in single frames, ready to output. They'll come out one of your computer's ports -- either the printer port, to an attached inkjet printer or film recorder; the comm port (to FTP the images to the service bureau via the Internet); or the removable disk drive, to deliver to the service bureau.

In any event, you'll end up with images on 35mm slide film -- and once the images are on film, the rest of the light-table procedure of mounting slides (cutting, cleaning, labeling, etc.) should be a familiar, time-worn routine to most planetarians.

In theory, it should be that simple.

But what does all this cost?

The answer is, "there's no easy answer, so grab your calculator."

Time is money, and it is true that someone on the staff will be spending time seeing the process through.

If you use our inkjet printer method or your own film recorder to output the images, there will be the cost for your camera's film stock. Costs for processing the film, for Wess mounts, and the labor for mounting, cleaning, etc. will factor in too.

If you're going the service bureau route, the lowest price film lab we've found that does this sort of work is GammaTech, in Albuquerque, New Mexico. As we write this (August 2003), they have a special rate for planetarium customers of $1 per film chip. They'll also mount your film in a Wess 002 slide mount for another $1. So if a slide has a color chip, mask, and mount, it would cost $3 (plus shipping). $5 to $10 per slide is more typical of larger commercial film labs.

Good luck!