Reddit mentions of Neewer Timer Remote Control RS-60E3 For Canon 550D / T2i

You can do it either way.

If you shoot video you can bring it into an editing program and speed it up as much as you like. Turning 3 hours into 30 seconds would be a 360x increase in speed. You need a video camera that has the memory and battery power to shoot continuously for 3 hours (in this example).

If you have a DSLR camera like the Canon EOS Rebel you can shoot a sequence of still images. You can pick up an inexpensive timer/intervelometer that will take a still picture once every x seconds.

Another way to shoot a time lapse sequence with a Canon DSLR is to install Magic Lantern firmware.

There is also the Canon Hack Development Kit (CHDK) another firmware project that enables time lapse functionality in a wide variety of Canon Powershot cameras.

Once you have your image sequence you use software to convert it into a video. On the Mac you can use Quicktime or iMovie.

When calculating how many seconds to delay between pictures know that video plays back at 30 frames per second (fps). So if you want the resulting video to last 30 seconds that will be a total of 900 frames. If the project takes 3 hours (10,800 seconds) then you would take one picture every 12 seconds (10,800 / 900).

One thing you can do with an image sequence that you can't do by shooting video is to make each still picture a "long exposure." This is where you leave the shutter open for a relatively long amount of time, let's say each exposure is 2 seconds long. Use a small ISO and aperture to get the exposure right. By leaving the shutter open for a relatively long time the workers and anything that moves will appear as a blur, but everything that remains stationary will still be in focus. This might be an interesting effect, or not, just FYI. A video camera shoots 30 fps and cannot do long exposures like this.

yt1300 has some great advice.

Regarding cameras:yes it exists. I know a used Canon Rebel XSi, T1i, T2i will be very good, the XS will be ok as well. You can read more about camera bodies here. You can get a cheap interval timer like this. It will allow you to take as many and as long of pictures as you want. If you want star trails you can use exposures of several minutes. If you don't want trails, the use deep sky stacker and exposures that are shorter. This is a nifty tool to help with exposures. Astro photography can be very hard and frustrating. It will take several attempts. Don't give up! You can PM me with specific questions. You said you didn't want an equatorial mount. If you change your mind you can get a cheap motorized one for $150 from Orion telescopes. You can also build a barn-door mount that's manual very cheaply. That might be a next step if you like this.

I was able to do this with my Canon Rebel t2i and kit lens. Do not expect this on your first night!

The Pentax K-x and K-r should work fine. I think the Nikon D3100, D5000, 5100, and D90 will all work well. I'm not a Nikon guy. As a general rule, older DSLR's will not work as well as newer ones because the sensor technology has improved a lot. It can be done, but not as easily or as well. Getting a camera with live-view is very very nice and will make this much easier. All the Canon's I suggested have live-view.

One of these should work fine for you. (this is what I use for astrophotography on Canon gear) https://www.amazon.co.uk/Neewer-Shutter-Release-Hasselblad-PowerShot-x/dp/B004FKYBJM/ref=sr_1_2?ie=UTF8&qid=1482778814&sr=8-2

If you have an Android phone you can also connect it via an OTG cable and use the android device to trigger it: http://petapixel.com/2013/03/21/give-your-dslr-a-brain-by-connecting-an-android-phone/

I'd spend $14 and get this. It's a remote and intervalometer.