What do you mean by photo capture software? You mean for taking pictures with the built-in camera? You could use Photo Booth for that. If you mean for transferring data from a camera, use Image Capture. Both are already in your Applications folder. If you mean something else, you'll need to be more specific.
Do you have the image-sensing eyepiece now? If so, install it in the microscope, connect it to your Mac, and see whether the Image Capture application recognizes it as a camera or scanner. If it does, you're in business. If it doesn't, ask Celestron (or the sensor's maker, if it isn't Celestron) what software they recommend to Mac users.
If you haven't yet bought the sensor, don't buy it until its maker tells you what software will work with it on a Mac. If they down't know, it's high time they did the research to find out, so they can support customers like you.
I just purchased a Celestron product, which is a mini USB microscope.
The Package says it compatible with OSX 10.49 and up.
The camera DOES NOT WORK with my macs (i tried 4).
When I called Celestron support today, the woman said " I wish they would stop saying it works with mac, as I get so many calls from mac users".
Basically, they don't provide any mac software, they want you to use Photobooth instead, which might be ok IF IT WORKED.
I attached the device to a windows box and installed the provided windows software, and it works fine.
I would say DON"T buy any Celestron product until they get the mac support thing happening. It's 2012 and the Mac is a big deal now, they need to wake up and smell the coffee.
I have the same microscope with mini digital camera. It works fine under Snow Leopard and Mountain Liion, using PhotoBooth. It is not, however, recognised by ImageCapture or Preview.
You might like to download the free ImageJ software from http://rsbweb.nih.gov/ij/download.html if you would like to process your captured images further.