I have a Skywatcher-127 telescope and would like to take some deep space images e.g. globular clusters etc. I have had recommendations about what webcam to use for planetary photography but not deep space as such. Is a webcam the way to go here too? What do people recommend?
What you want to do is head over to cloudynights.com, get an account, and start reading FAQs.
A webcam isn't going to cut for DSO (deep space objects) but a decent DSLR will. However, without removing the infrared filter from your DSLR you'll not get the deep reds that you're used to seeing in other astrophotography photos. (See Happ Griffin's page for more info, he does the mods but so do others and you can also do it yourself. Note, once you've done it you can't go back.)
You're also going to want a decent mount for the telescope, I'm not sure what you're mounted on, but a Celestron CG-5 class is about the bare minimum you'll want. The CG-5 can give great images but it can also be difficult to setup correct. If you buy one used, make sure you have upgradable firmware, which so you can get the awesome polar alignment code.
Then you'll need stacking software... Once you get all your gear together you'll be able to turn out shots like this:
That was taken with a Canon 40D with the infrared filter removed, attached to a Burgess 1278 refractor mounted on a Celestron ASGT mount. It is a stack of 9 exposure, each 2 minutes long. There was significant post processing.
Astrophotography is a lot of fun but it is also a lot of work, you're heading down a wonderful path that is full of joy and full of curses and can really empty your pocketbook. Keep your goals simple and you'll be fine.
I have a clone of that scope. Webcam is the way to go for bright objects. You'll want a cam that can do subframes to limit data to just the area of interest. Another feature would be one that polls the whole ccd at once, rather than one that does interlacing. Several are reasonably priced and appear on the second hand market.
Bright objects like the moon and planets are quite rewarding and will let you get your feet wet. It's fun to watch the differences on the moon even in the course of a single night.
The advantage of a webcam is readily apparent when sharing the view with lots of people as they can cluster around a screen. Also, it's easy on aging eyes. It's great for instant gratification.
Once you have a few video clips saved (usually less than 60 seconds long) you can throw them at stacking software which uses the principle of "lucky seeing" to grab the best frames from the 1000 or more of the video stream. A stack of the good frames with moderate sharpening will produce very nice results.
Globular clusters and even the brightest stars will not do well in the consumer grade webcams. However, there are some video cameras that are built to see the dimmest of objects -- Mallincam is a big name -- and can show good detail and color.
It all depends on the quality you want to achieve. The best quality is going to be achieved with a DSLR with a mount for your telescope. A good mount should basically turn your telescope in to a giant lens for your DSLR. You can then also do things like long exposure photography to see things that normally wouldn't be visible and the quality will be MUCH higher than any webcam. Looks like what you would need for that camera is a T-Ring and an adapter from some quick searching.