apaulo

thank you everyone for the feed back.  its much appreciated. i never thought of the light dispersion and the low altitude. will do a star to check things anyway. clear skies to you all. 

ive just been viewing venus, i am seeing a disc made up of 3 colours, red, yellow, and greeny blue. i am using a 200p on a homemade dob. eyepieces are vixen slv 25 and 12mm. also bst  8 and 5 barlowed. seeing the disc of venus in these colours, id like to ask have i got a collimation problem, or is it seeing conditions. or something else. or possably normal. any help and advice from you guys would be much appreciated. thanks in advance.  paul

nice job, im jealous lol.  the sheets make a great roof. the only problem could be quite serious condensation. ive had it with sheds and vans.  I found the easiest and cheapest solution was to use cheap chord carpet and carpet glue spray. just make sure you cover the whole surface and try to tuck it behind the wood beams. hopefully your observatory will stay bone dry.  clear skies. paul.

personally i use 7x 50 binos on the boat. steadier view.  i have russian zomz i got on ebay. dont let the price or the name put you off. very good indeed.

hi ian, i would suggest a little smear of vaseline, petroleum jelly, as some might call it these days should do the trick. not a blob, just a coating on the threads will be ample.