Telescope + HD Webcam. What Am I Looking For
I'm looking for some insight.
Here,
Telescope:
Refracting VS reflector
Instrument will be used in daylight ONLY. Goal is great focus for up to 10 miles. Not sure what the bandwidth is on a reflector & a refracting telescope, but I assume it varies greatly due to their uses in astromony. Sooo..... up to 15 miles:P
Is that what you call it, bandwidth? I am speaking in terms of distance. Bandwidth doesn't sound right. I assume it's because the term is more associated with acoustics
HD Webcam:
What am I looking for?
Lense doesn't matter as it will be taken off. I assume lux won't either given the daytime application
Any way to get wireless? I know they have AV wireless recievers. All the webcams I've seen are connected via USB. -The AV wireless recievers I've seen are connected via RCA (red, white, yellow). I don't need sound, but video yes. Do they make RCA to USB adapters? Btw, are the cables balanced or unbalanced?
No telescopes dont have bandwidth
for daytime use a refractor will be nuch easier to use and set up. You wanna get one with a elevation-azimuth El-Az mount as for looking around teresterially a German Equatorial would be a nightmare.
OK you have 2 mounting choices,
1) prime focus --- no eyepiece in the telescope and no lens on the camera, the telescope is basically a large telephoto lens
2) eyepiece projection --- eyepiece in the telescope and no lens on the camera
either way you will be mating the 2 units together with a short length of tubing that you can adj. back and foreward to get the camera into the focal point.
Prime focus will be the easiest way
There are plenty of wireless video senders on the market, usually 2.4 GHz or 5.8GHz they work well over ~50 metres
look on ebay, they are pretty cheap
coax and screened leads are an unbalanced transmission line
cheers
Dave
There are radio-control pilots who put a camera on their airplane. It sends back live video. I'll bet such a system is expensive.
I have held my digital camera at the low power eyepiece of my telescope (reflecting type). It works but I have to experiment by moving the tube in and out, to find a good position so my camera can capture a sharp image.
I can take still pictures or video.
I don't know if it can work without an eyepiece. A camera (or webcam) is able to focus close or far. I'm not sure it will focus on the converging light cone in a telescope. Can't be sure what magnification you'll get without an eyepiece.
I could get sharper pictures if I made some kind of rigid adapter to fit the camera to the tube. Tele-photographers have something called a T-adapter. You may be able to simply tape a webcam to the tube.
Ohhh a couple of additional comments
( may clear up your "bandwidth" comment :)
the distance a scope can see is dependant on how bright that object at distance is.
the clarity that the scope can see an object at a given distance is a function of its resolution.
the larger the optical elements... mainly the primary mirror (a reflector) or the objective lens (a refractor)
the better the resolution, resolution is measures in seconds of arc or parts there of.
Dave
- - - Updated - - -
really cheap usually less than S50
as said above, not using an eyepiece in the scope is called prime focus photography us astronomers use it all the time.
the magnification is approx the focal length of the scope / 50
T-Ring Adaptor
cheers
Dave
Lumens: Measure of total light output emitted by source
What happens when I take 10 steps back & the intensity decreases? Would that be lumens or can lumocity change. In other words, is "lumens" relative to OR not?
Light like other electromagnetic radiation falls off in strength by the inverse square law ( google it :) )
over relatively short distances, say 100metres or so, thats not going to be an issue in your case
the luminosity of the emitter doesnt change, just the amount of light you receive changes
you hold a square metre sheet of paper, as you move away from the light source there are fewer photons hitting that sheet of paper
as they are spreading out over a larger and larger area ... ripples on a pond is another analogy
Dave
I agree with Dave's comments.
If you have binoculars you may find they are usable. It works when I hold my camera up to my binoculars. A firm grip is necessary. Experimentation is needed to find the right focus.
Common magnifications for inexpensive binoculars are from 6 to 8. Much greater than that and it becomes difficult to get a steady image.
For a single webcam you would get a monocular (half a binoculars). But 10 or 20 dollar binoculars should be readily available. And binoculars often get more use than a telescope.
Also a spotting scope could be suitable. Easy to transport and set up.