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Looking for a 12" DOB (or larger) which can be transported to Prestwick, Ayrshire. Any brand, as long as the telescope is optically sound and in good working order. I'm a reliable buyer who has bought and sold on this site before.
So I picked up a classic... a 1970's - 80's edmund optics f6 150mm newtonian...
... like this one but mine has a different mount. It was cheap. Very good condition. The focuser is pants. The mechanics of the secondary holder is (IMHO) brilliant and apparently the primary is 1/10th wave.
But its f6 and I trhink I'd rather swap it out for a faster synta f5 mirror. . The thing is its a one shot job bc to make the f5 mirror work I will have to saw off a good few cm from the barrel of the scope.
So the question is: Is a high quality f6 mirror better than a faster synta f5 mirror for wide deep space astrophotograhy?
All comments gratefully received. 😉
Skywatcher 150/1200 f8 planetary Newtonian.
Bought this originally intending to set up a planetary rig but circumstances call for sale.
Will come with eyepieces and a collimation eyepiece. Not used by myself and has seen very little use. Mirrors in good condition
By Ships and Stars
Last night was the best night of astronomy I've had in my short time delving into this passion. It was simply incredible. Fortunately my dear friends the midgies have departed Scotland for another season. This means I can now stand at the scope without ingesting a lungful of tiny biting insects and concentrate on what I am observing. Always a plus!
Two nights ago I went to my local dark spot with my 200p SW reflector. It was wonderful. LP map shows Bortle 4, but I would actually say it was a 3 or possibly a 'bright 2' when the lights go down a bit in the wee hours.
Last night, I took the 20" dob and parked up. I am finding it easier and easier to move this beast around, but it's still a little bit of work to set up at the end of the day (literally). It can't all be so easy!
I'm fairly new to astronomy and my scopes haven't seen a huge amount of use. After several failed attempts to get the GOTO working, I finally sussed it last night. It was just a few simple things really - small errors on my part such as a misplaced washer which blocked the azimuth from using its full range of motion, combined with a limited view at home which prevented me from doing a successful align. A huge relief to get the GOTO up and running, but I now feel a bit like I'm cheating!
I don't feel guilty enough to not use the GOTO however😁 Frankly, it's brilliant and was putting objects bang in the centre of the EP.
I arrived about 6pm yesterday so plenty of time to set up. I left my counterweights at home and thus ended up strapping a small vinyl bag of tools and tyre jack to the underside of the mirror box with a tie-down. Worked really well actually! Can fine tune by removing a spanner or two.
A few drops of rain blew through just before dusk but then rapidly cleared off, so all systems go.
I tripped over the power cord after my first successful align. And then did it again a minute later after my second align! Will need to tidy that arrangement up or put some of my glow tape on the cable. Plenty of practice then doing an alignment, haha.
M57 Ring Nebula for starters, I've been playing with my Baader 36mm aspheric quite a lot lately, I like the wide views. The Ring was fairly small through the 36mm but bright and crisply defined with an apparent faint blue tint. I then swapped to the 21mm Ethos and OIII which stayed in the focuser most of the night.
Next stop was NGC6960, Western Veil Nebula or 'Witch's Broom Nebula' which was mind-blowing. It appeared as a silvery apparition which threaded right across the sky and extended well past the FOV from the 21mm Ethos. Scanning along its wispy tentacles was amazing. There's something unnerving about viewing it, it gives me goose-pimples, just otherworldly. The Eastern Veil and Pickering's Triangle in the central area were also clearly prominent, albeit slightly less luminous than 6960. The Veil was also clearly visible without the OIII, but with much more 'background noise', i.e. stars competing for attention.
Following this, I slewed over to the Cocoon Nebula, but only saw a very dark lane practically void of stars. That was interesting in itself as it was so apparent by virtue of its darkness.. I don't know if I bumped the scope alignment of if I was just too impatient to punch another object in to the handset, but didn't spend a huge amount of time chasing it. In hindsight, I think I slewed to the wrong end of the dark lane. I'll find it next go.
I then lined up on the Crescent Nebula which was easily visible, lots of fine filamentary details observable after some time studying it. A beauty.
Next was Dumbbell Nebula which practically looked 3D through the big dob, just jumped right out at me. Another simply amazing sight. I spent quite a long time staring at it and could easily see the entire shape and structure extending from the 'Apple Core'. I remarked last night it looked like it was hanging inches in front of the scope. That's sheer aperture working I suppose!
At the end, I spent some time just slewing around and having a mesmerising look across the sky, just taking in the depth and variable magnitude of stars that a big scope can display. I was already running on three hours' sleep from the previous night and by this time, I was starting to crash but was on a natural high. I crashed into the bed happily.
Can't wait for another clear night with the big dob. I was a bit worried a few weeks ago that I'd bought something I didn't have the time or skill to fully appreciate, but getting the GOTO up and running and being able to rapidly slew to various objects really put things into perspective. My 200p is a wonderful, portable scope, but in comparison, 20" of aperture is simply a completely different level. It is like the difference between a small grainy 640px video and high definition 4k with the brightness cranked right up.
Tonight I shall stay in, sleep well and dream about how much discarded glass is needed to cast a 36" mirror blank and how many years it would take me to figure it...
Clear skies all