There is not a specific cleanser that you need to use on your sony camera lens. You can use any that is made to clean camera lens' As long as they say that they are camera lens safe and that is what they were made for then you can use it!
That is a tricky question, but it would be best to use two cameras, at the very least. Use one with long lens, something within the range of 70-200mm. Partner that with another camera with a wide angle lens, since this one would be great for candid shots and tight spaces.
I've used a 200 mm lens on a 35 mm camera for track events and football. It is a little long for portrait work, but may work OK for random candid people shots.
The telescope has an object lens at the top, which is a large lens with a long focal length. It produces an inverted image of a distant obect at the focal point. The eyepiece is a smaller lens, and you look through the eyepice at the image formed by the object lens. The image is formed in space, it does not need a screen, and you can see it with the eyepiece. The ratio of the focal lengths of the two lenses is the linear magnification.
Yes as long as it's not pre AI
It means the zoom power, i.e. how much magnification is possible at the long end of the zoom.
Infinite, with a suitable lens. In theory, a pinhole camera (which has no lens at all) will have a nearly infinite depth of field, but at the expense of extremely long exposure time.
It's possible there is corrosion to the mainboard (PCB) of the camera; it's like a computer motherboard. If so then it is shorting out the camera and the part will need to be replaced. Yes, if there is sand in the lens then the lens will be jammed and the camera may not turn on. The lens will need to be removed, opened, cleaned and checked for damage. This is a long process and usually difficult to do. If you don't want to try and repair it yourself, try the Related Link below that says "digital camera repair", its an online business that has affordable lens and LCD screen repairs.
Yes you should not expose your camera lens to direct sunlight for a long time when you are cleaning it.
The Hobby-Eberly Telescope works by refracting light through 1 meter long frames of glass, put together to form the lens, and uses the light to project images of what that light is coming from.
I would at least try the lense on a few pictures and see what the quality is. Depending on the price of a new one, you could even remove the front lense and clean it, or have it done by a professional.
Mass. A refracting telescope needs to be either really long, or have really thick lenses. In either case, the mass of the telescope limits how large you can make it, if you want to be able to change its direction.