This is a 200mm reflector, which is to say it has a 200mm diameter mirror at one end of the tube. The focal length is 1000m, so the tube is about a metre long. The two counterbalances are very heavy, and the whole thing is so awkward that I need to take the tube assembly off to move it.
The primary mirror reflects light back up the tube as shown on the right, where it bounces off a flat mirror at 45° to reach the eyepiece. The secondary mirror blocks the light slightly, but only distorts the image if the eyepiece is out of focus.
Many of the star photos on this site were taken with a camera mounted on the telescope tripod so I could take advantage of the motor to move the camera in time with the rotation of the Earth. This is called "piggy-backing". The camera is mounted on the tube rings and points the same way as the telescope, but doesn't use any of the optics. Often I don't actually have the telescope tube mounted at all. This means I have less heavy equipment to move, especially as only one of the counterbalances is required. Also, on windy nights the camera is more likely to pan correctly. An additional advantage is that the pictures are always aligned exactly the same way.
Here the camera is mounted in place of the eyepiece. The light from the primary mirror is focused directly onto the film, at "prime focus". The total length of the light path from the primary mirror to the film is 1000mm, and this gives the same magnification as using a 1000mm camera lens. The aperture is a bit bigger, though. Pictures are rotated according to how I mount the telescope in the rings, although screws in the adapter can be loosened off to let it be rotated.
This picture shows the same method used with my home-made CCD camera. This gives more magnification as the CCD sensor is rather smaller than a 35mm negative, namely 1/3" diagonal instead of 36mm*24mm.
This picture shows my cheap CMOS digital camera being used to take a picture, just by holding it up to the eyepiece. I was surprised that this worked at all! It's good for taking pictures of the moon, except that a full moon can't fit into the picture. I found that better results could be achieved by using part of an old film cannister as a spacer, so that the camera could be held steady a centimeter or so away from the eyepiece. It's kept in place with blue sticky tape. You can buy a bracket for this, with adjustable sliders to get the camera in the right place.
Here my CCD camera is attached with the eyepiece still in place, giving more magnification. This is called "eyepiece projection". The further away the sensor is from the eyepiece, the larger the image, but with a corresponding reduction in the brightness.
Lastly, you can buy a supplementary lens called a Barlow, which can double the magnification. I've had some success with using my CCD camera with my most powerful eyepiece and the Barlow to get maximum magnification with Venus and Jupiter.
The picture on the right shows what happens if the camera is mounted on an ordinary tripod. The stars appear to spin around the Earth's axis as the planet rotates. The North star, Polaris, is almost exactly aligned with the axis of rotation, so the telescope is set up with its own axis pointing at it. There's a small telescope built into the hub for sighting Polaris. This needs to be done every time the telescope is moved. Many of my pictures fail due to not having the alignment correct.
Now, you might think that the planet isn't spinning fast enough to have an effect - only 360° per day. Well as a general rule for 35mm cameras, the maximum exposure possible without trailling is 1000 seconds divided by the focal length. So, for a standard 50mm lens, an exposure of less than 20 seconds in necessary. Many of my pictures require an exposure of about 5 minutes, which is why the camera is attached to the telescope mount. If the camera is at prime focus, the maximum exposure is 1 second as the focal length is 1000mm. This isn't a problem for the Moon as 1/400s is often enough.
My new digital camera can have the effective film speed cranked up to 1600ASA, so shorter exposures are required. However, the sensor is 2/3 the size of a 35mm negative, so magnification is 50% more with a corresponding increase in the potential trailling problem.
If the telescope is set up correctly the pictures show the stars stationary while the buildings are spinning round.