Quote:
Originally Posted by Satchmo
I would ad that the return from a larger telescope is very much up to your experience and expectation and that ease of transport and setup are significant issues.
Big bright objects such as Omega Centauri and Eta Carinae look brighter but do not look substantially different in comparing views between a 30" and an 18" scope -new owners of larger scopes are often quietly disappointed by this: the differences are more subtle and clear when trying to find faint objects .
If you are not obsessed about faint fuzzies and and not prepared to house or travel to a dark sky once a month , the advantages of a larger dob may become swamped by the practicalities of trying to cool a large mirror , a large structure , and the inevitable woolly soft images that come with poor seeing and large scopes ( or is it heat from my structure or mirror ? or is it the quality of the seeing ? or is it the quality of my mirror ? )
Many large scope owners just get overwhelmed by the portability issues and never get to the bottom of these questions before their enthusiasm runs out. I know of a number of large telescopes that rarely see starlight - they are status symbols of one having reached a financial peak in ones involvement in the hobby and not much more. Theres a simple maxim - if you need help to pack or unpack your scope before and after travelling your telescope will get used much less.
I would hazard a guess that a high quality 16"-18" scope is in a sweetspot as far as all factors concerned- up until 30 years ago would have been considered a very large telescope to be in amateur hands.
If you are in the market for a large telescope do try and get a look through one and really evaluate if the images are going to be worth your while in the long run when you factor in transportation and cooling time . How are your energy levels ?
Just keepin' it real  |
Cannot agree more with Mark's comments...
An 18" is perfect for me. I can load everything in the ute by myself, unload it and set it up in 10 minutes max. I have looked through a 25" Obsession but my gut feeling is that it was only marginally better than my 18" under similar skies with a majority of common DSOs. Yes the larger aperture did bring out some extra detail on the occasional faint fuzzy. But I walked away totally satisfied for my 18" 4.5.
I did considered an Obsession but after factoring in the shipping options it was cheaper to buy from SDM - SDM also have supplied no end of free advice and support. I also heard of a disappointing story in regards to their (Obsession's) customer service which really made me nervous.