Saturday, February 27, 2010

How to produce bigger and clearer image from a telescope?

based on your physics knowledge,related with light and prismsHow to produce bigger and clearer image from a telescope?
Bigger is usually the opposite of ';clearer'; for ground-based telescopes. The more you boost the magnification, the more you exaggerate defects in the optics and in the atmosphere.





Your question doesn't specify how the knowledge is to be applied. One could get a clearer image at high magnification by blasting the thing into outer space like Hubble.





Staying on Earth, you can get clear image and higher magnification with imaging equipment. Web cams are excellent ways to get more out of a telescope, becuase they take 30 frames a second and you can throw out the 28 pictures that are bad and keep only the two pictures that are good. This gives powerful results on planets such as Jupiter and Saturn.





Most telescopes require optical alignment called COLLIMATION, so one way to get clearer and more useful magnification is by tuning the optics so everything precisely lines up. This is usually done with a set of adjustment screws typically in the rear (on a Newtonian) or up front (on an SCT like the c8).





Telescopes are also prone to thermal interference as they cool. The most powerful single technique is to put fans on the main mirror and break the boundary layer of air directly over the optics. This is done by many owners of amateur telescopes.





If you push magnification too far your telescope starts to ';dim out.'; You spread the image too wide with the eyepiece--the magnification--and you'll get a dark not very useful image. By contrast low magnification always seems very clear and razor sharp, even when the upper atmosphere isn't helping.





But the #1 simple answer is if you want a bigger image swap out the eyepiece for one of shorter focal length. In most scopes swapping a 25mm eyepiece for a 10mm will provide an increase in magnification (bigger) without a huge degradation of clarity.





Hope that helps,





GN


How to produce bigger and clearer image from a telescope?
There are two ways to get resolution better than the diffraction limit. Interferometry is one. The idea here is to combine light from telescopes that are some distance from each other. The VLT and the Keck telescopes are large examples of this. The Keck has twin telescopes at 100 meters apart, and can get the effect of a telescope that is 100 meters in diameter. This has also been done with radio with baselines over 1000 miles. Space based optical telscopes with interferometry and long baselines should allow us to image continents on planets orbiting other stars.





The other way to do this is with optical surfaces that have a negative index of refraction. This has not been accomplished in visible light as yet, but has been demonstrated at longer wavelenths of light.






A telescope is limited by the size and quality of its main objective or mirror. That defines how much light it can collect and resolve. However, by using photography you can collect that light over time and perhaps use electronics to resolve detail which is beyond the eye's ability to see.
I have to agree with the first answer %26amp; will add the more money you have at your disposal to spend on instruments, the better resulting images should be achieved. It might also be a benefit to do some trial %26amp; error to try %26amp; find the best results as this usually works. The 4th answer by gn is also very good %26amp; should help you with your problem.





Cheers !

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