I need the font for the old Polaroid logo

Not so old—it appears to be Gotham (released in 2000), by Hoefler & Co.:
http://www.typography.com/fonts/gotham/styles/

Gotham appears to me only as a very good ready-to-go option but I don't think it's the one. I comes very close for all letters except /a but I assume it would be not so hard to customize it. A geometric sans like ITC Avant-Garde Gothic Demi-Bold may work for everything but /a (plus a slight edition on /P). /a is something completely different reminding me of the approach of Frutiger's one. Something like Neue Frutiger or FreeSet could work. My best option here would probably be Avenir which combines the geometry of AVG and a double storey /a close to Polaroid.

I stand corrected, Ryuk (obviously, my eyes aren’t what they used to be).

To add to your list of options, I’ll add Basic Commercial:
http://www.myfonts.com/fonts/linotype/basic-commercial-lt/

With a bit of widening and flattening of the letterforms, and editing the |a|, it comes awfully close.

If you want to make a closer comparison of the letters with various fonts you can download a vector version of the logo from brands of the world http://www.brandsoftheworld.com/logo/polaroid-3 You should not use the logo for anything else without obtaining the express permission of the copyright/trademark holder.
Don