| Telescopes Questions and Answers |
Q. How well will I see the planets? Will I see Saturn's rings? A. Depending on the scope you have, you should see most of the planets pretty good. Mercury and Pluto will be real tough because Mercury "hugs" the sunrise and sunset. Pluto has a very dim magnitude. You can see detail on Mars, Jupiter, and Saturn's rings. Uranus & Neptune can be seen, but they also have dim magnitudes (5 to 7).Back to Top Q. What is the aperture on a telescope mean? A. Aperture is the diameter of the lens or mirror. In a reflector, the larger the aperture the more light is collected for better viewing. A mirror that is 8" in dia. is 3 or 4 times better in light gathering than a 4.5" mirror. In other words bigger is better.Back to Top Q. What is better: A Reflector or Refractor? A. I hate this question. A reflector can be very large and collect quite a bit of light but sometimes suffers in the resolution department. A reflector with at least a 3.75" lens or larger gives a sharper image and is great for astrophotography. I have seen refractors beat reflectors in overall viewing of some deep sky objects, and then I've seen reflectors beat refractors in really deep space viewing. It's really up to you what you want in viewing. Never buy department store scopes. They're crap!Back to Top Q. How do I know where to find stuff in the sky?A. Simple, buy a star chart. There are many good star charts out there that help you locate objects by using the "star hopping" method. Learn where the constellations are and certain star names in relation to the sky. If you have a star chart and let's say you study one area; then go outside to find that area and look for the stars from the chart. You can use these stars to help navigate to points in the sky to help find nebulas & galaxies. It is essential that you know the night sky to enjoy the sights above.Back to Top A. There are a couple of reasons. First of all if you just went outside with the scope you need to wait for the Telescope tube to cool off inside. Need to match the ambient air temperature from outside to the inside of the tube. The heat causes light to waver in the tube which effects the view. So in other words wait about 15 minutes to an hour to let things cool. Another reason could be optics. Your eyepiece could be dirty or too tight. On Plossel type pieces, the lens elements are stacked on top of each other. If they are too tight, they will cause the lens to warp. To fix this, just loosen the focus stop underneath the eyepiece. Also another reason for the rotten view is the mirror needs collimation. In which you'll have to re-align the focus. To do this there are at least 3 adjustment screws on the back of a reflector that pivots the mirror to align the focus in the center diagonal mirror and the eyepiece. There are a few ways to do this, either you use a collimating tool or use the "dead eye" method of putting a dot in the middle of the mirror and use a peep hole at the focuser end and line the dot on your eyeball.Back to Top A. Filters are glass elements that screw on your eyepieces. There are several types. Lunar, Broadband, narrowband, Oxygen III, Nitrogen II. The most common and the most recommended is a lunar filter. If you look at the moon without one, the glare will kill your night vision. The filter dims the glare and makes seeing detail more clearer. Broadband filters use special coating to filter out certain light like street lights and close city lights. These are used in light to medium light pollution areas and help bring out certain planetary nebulas. Narrowband is for heavily light polluted areas. O-III are used for photography and helps bring out the emission & diffuse nebulas. There are also color filters for planetary viewing. I use a light blue filter to see the bands and the red spot on Jupiter.Back to Top A. Yes. But you must use a screen type filter. In reflectors, you must use a Mylar type cap on the scope. Never use a eyepiece solar filter. If you do, that mirror in the reflector will ignite your scope! I know, I saw that happen once at a star party. Very dangerous. On refractors, you should also use a a Mylar type. Never, never ever look into a telescope without a filter or sun-screen. You will go blind!Back to Top Q. What's the difference between an Alt-Azimuth and a Equatorial mount for telescopes? A. The Alt-Azimuth is a very simple mount that turns left and right and up and down which enables it to go to anywhere in the sky. Though zenith positions are somewhat difficult, especially for Dobs. These mounts are popular with homemade and store bought Dobsonians. There are a few designed for refractors. Equatorials are very different that Alt-Azimuth because they are designed for tracking. The mount when moved is following the sky, or trailing the objects because the center (equatorial hinge) is centered on the North Star (Polaris). By doing this, you may adjust the dial that have the positions RA/Dec to a point in the sky. Very handy if you are into astrophotography.Back to Top Q. Can I see colors in my scope? A. No. Not really anyhow. Our eyes cannot pick up on the color spectrum that flows through space because of the dimness of the light. Using filters on CCD cameras or regular cameras after a long exposure will pick up the color. It takes time for the color to imprint on film. Basically when viewing through a scope, almost all objects except planets are whitish, gray hues. One exception though is the Orion Nebula (M42). Because of it's size, and distance to us, it does have a hint of color. It will have a slight bluish tinge. Planets are a lot closer and with certain color filters you can see colors like Mars and Jupiter.Back to Top A. Means Schmidt-Cassagrain Telescope. These are scopes that utilizes a corrector lens and folds the focal length. They are very good for Imaging.Back to Top A. The focal length is the distance from the face of the mirror to the point of focus. The focal ratio is the number that determines the focal length by multiplying the diameter of the mirror and the known focal ratio. Example: 8" mirror with a focal ratio of 6 (f/6) will have a 48" focal length. (8x6=48).Back to Top A. The focus point is where the image being seen through the telescope fo
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