Telescope question???

Question

I have a Bausch & Lomb telescope. I believe its an RV-5+. It says on it "D 130mm" & "F 715mm". I know it's probably an older scope, but does anyone know if its a decent telescope or not? Would I be able to see Saturn's rings with it, for instance, or anything else of interest, other than the moon? Thanks!

Answer 1

Based on the information you have provided about that telescope, I can infer that it is likely of at least decent quality and should be more then adiquite to show you the rings of Saturn. The marking that says "D 130" means that the telescope has an objective diamter of 130mm. thats how big the front lens is. "F 715" is refering to the focal length of the telescope in millemeters. Focal length determins how much magnification the telescope will give you. in order to determin magnifcation, you divide the focal length of the scope by the focal length of the eyepiece you using. So if you had an eyepiece with the common focal length of 25mm it would give you a magnification of 28.6. thats a great magnifcation for sweeping the milky way on a dark night. in order to see the rings of saturn you need about 20 magnifcation, but to see them in detail, 90 power is much beter. a 7, 8, or 9 mm eyepiece would get you into the 90 power neighborhood. the scope likely came with 2 eyepieces that were somewhere arround 25mm and 10mm.

Your scope was likely purchased at an upper-end department store, and if thats the case its quality is not excellent, but i would say closer to the decent catigory but maybe good or excellent. It really depends. One way to get a feel for it is to look at the reflections in the main lens. are they green, purple or blue? purple or green is beter, every lens being purple or green is the best. When you move the focuser is the motion smooth or jagged? posting a picture would help.

Some highlights of things you can see with your scope are: The Orion Nebula, The Ring Nubula, Andromida Galaxy, Pleadis Star Cluster, the Hurcules globular cluster M13, The Whirlpool Galaxy, and hundreds upon hundreds of other Deep sky objects, and every planet but Pluto. My suggestion would be to buy a good astronomy guide like Night Watch by Terence Dickison. Its a great beginer guide. If you have any more questions feel free to contact me. A picture and/or addition information on your scope would be helpful

UPDATE

I have done a little bit of research on your scope. Its is a newtonian reflector on an equitorial mount and was imported in the year 1986. standard equipment for this scope was a set of 20mm, 12mm, and 6mm Kellner eyepieces. The Kellner eyepiece is fairly simple design by todays standards but is still of decent quality. With those three eyepieces your scope will give you 36, 60 and 120 power. Thats a very good range of magnifaction. your scope originaly retailed for arround 600 dollars with the optional drive. Based on this information I'd say your scope falls into the decent to good catigory of quality because in telescopes, you tend to get what you pay for. Current prices of these scope being sold used range from $300 to $75 depending on condition. Ignore the thing i said earlier about the collor of the reflections, as I incorectly assumed it was refractor.

If you were to buy some more modern eypieces, like the cheap but high quality ones avialable from orion telescopes, you will improve your over all optical quality. you may also want to consider haveing the mirrors recoated for a cost of about $75 as over time the coating degrade.

Answer 2

Bausch & Lomb is a decent maker, should work fine on things like Saturn, Cassini's division on a good night!

If it has been kicking around storage for a while, it may need some TLC, a careful cleaning likely as well a collimation, very likely.  Probably worth about $200 - $300 these days.