[Aavso-photometry] Used CCDs

[cspratt]

Thanks for the replies on my previous question about new or used CCDs 
for photometry. I was looking at a used  SBIG 237A CCD which is light in 
weight but doesn't have a guiding chip (do I need one?) . My old 
computer has a parallel port so that isn't a problem. I have an AP600E 
GOTO mount which can handle up to a 9.25" SCT. But this is a portable 
setup and takes time to calibrate the guiding chip, thus I wouldn't use 
the guiding chip in any case. The are aslo some older Starlight Xpress 
CCDs on the used market at a reasonable price. I'm looking at the HX516 
or MX512 as an alternative to the SBIG 237A. Both of these use a 
parallel port interface and are small and lightweight. Again, I don't 
know if either of these are suitable for photometry.

I could also mount a Canon DSLR on the scope and use a telephoto lens or 
small refractor instead of a regular CCD through the main scope, Is this 
the way to go?

I also have a Schuler green 1.25" filter marked "1.25"V bvri VISIBLE". 
Is this the correct V one for photometry?

Thanks again,

Chris. Spratt
Victoria, BC