Quote:
Originally Posted by Screwdriverone
Hi Chucky,
I am a bit intrigued when you say your dob cant do high mag?? most dobs have a focal length over 1000mm, generally 1200mm or 1500mm. Now with a refractor, the focal length is usually 900mm or lower, so in both cases, you will only get about 300x mag on a planet with say a 10mm eyepiece and a 3x barlow.....
As for a relatively simple EQ mount with clock drive, take a look at say Andrews comms for an EQ2 or EQ3 with RA motor as this will be enough for basic tracking...my Eq2 is quite portable, but still heavy with the counterweights. Pop a refractor on that or a short tube reflector (parabolic mirror only) and you have a niceish grab and go.
Refractors are more expensive per mm of aperture so if its details on planets you want, aperture rules and price per mm, dobs cant be beaten. What size is your dob? If it is 200mm or more, you should be able to get in close around 300x depending on the seeing for details on Mars, Jupiter and Saturn, but only get discs looking at Venus, Neptune and Uranus due to the cloud tops on these ones.
Cheers
Chris
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Hi! My dobby is f/5, 8" so yeah, not really a planetary machine but i can see the cassini division around the edges now that its well collimated. I am very interested in the planets and would like to do some huge magnifications. I like to draw what i see and it's annoying to do what when i have to move the scope lol. The planets are so dynamic and changing every day ever so slightly whereas the much larger heavens move slower so I want something planetary and good. i have an idea what i have in mind but telescope selection is one of life's dilemmas.
I just bought a planetary eyepiece as well, 6.3mm, before i never went above 100x except with a shocking barlow through which I saw apparitions of the Virgin Mary.
I have seen some detail on Venus stopping it down to 2" a few mornings ago. I believe they correspond to Lowell's spoke arrangement on that planet, but they looked slightly curved as well so they might have been clouds. I also believe I can see in ultraviolet or some wavelength which does not register on cameras so well as I see these wierd features in the Saturn hemisphere pointing towards us currently and others say nay.