Quote:
Originally Posted by ausastronomer
I am currently in the process of building a 10"/F5.3 truss newtonian with a Mark Suchting mirror. The scope will have a premium everything, including a Protostar quartz secondary, a Feathertouch dual speed focuser, Argo Navis and Servocat jnr. When I am finished building it, I will happily let anyone throw their 6" refractor of any manufacture up against it. In actual fact, I haven't yet seen a 6" refractor that gets close to my present 10" tubed newtonian. Which has a very good mirror, but most importantly, has been carefully baffled. FWIW I have used 6" APOS from Takahashi, Astrophysics and TMB.
That all having been said, at some point in the future I am likely to try my hand at "digital" astrophotography. My previous attempt at astrophotography (prior to the introduction of running water and electricity) ended up with countless wasted rolls of Kodak Ektachrome and a very big bunch of frustration. For my introduction to digital astrophotography I will be purchasing a premium 4" or 5" Takahashi APO. Will I put an eyepiece in it? Not very often 
Cheers,
John B |
Do you think the truss rather than a baffled tube will loose a fair bit of the contrast you would have otherwise ?
That's the reason why I've not opted at this stage in my 10" f4.66 newt OTA rebuild not to go to a truss. Even though the potential to save on OTA mass is attractive , but not as important with my new GEM , the Atlux will hand the 10" OTA handily I think with capacity to spare no matter how I load up the 10".
I was bit shocked when I took the mirror out of the storage / shipping box last night and examined it with a magnifying glass and saw what looked like a lot of minute pin holes all over the surface .... never noticed them before and they are too small to see without a magnifying glass.
I don't think they have had any effect on the images I was able to see before I demolished the old OTA it was in. I am however wondering now if I should ship the mirror off for a recoat - I'd like one of those superduper Ti02 overcoated dialectric ultra high reflectivity coatings (would be like adding an inch diam to the mirror) .... what do you think ?