I took 10 overlapping digital photos (1.4-1.8 MB each) and combined them into a panorama with Photomerge automated action in Photoshop CS3. This was the first time I'd ever attempted this, and I was very pleased with the result.

However, the completed panorama was huge—about 570 MB (18311 pixels wide x 2430 pixels high, 155 w x 21 h cm, 300 pixels/in).

Should I have processed the photos in some way before combining them? If not, how should I reduce it now?

Thanks.

Barry

Barry, believe it or not, 570MB is not all that large for a Photoshop image.
Firstly I would recommend that you save the 570MB file on a CD, DVD, or backup storage drive, because you may find it useful in that format later.
Now as for re-sizing it, decide what size you want you print to be and multiply by 300 ppi to give you the pixel dimensions. If you are downsizing then select Bicubic Sharper from the Interpolation pull down window. If you are saving as a jpg, be sure to use setting 12 to preserve as much quality as you can - or save it as a .psd or .tiff.
Regards, Murray

you can reduce the resolution down to 200 ppi and still be able to use that file up to a 175 line screen ruling, i did some testing years ago on our crosfield film output units but i've yet to redo the same tests with an inkjet proffer...