Orion Optics UK 12" F4 Dob

[webboid]

I purchased this used scope yesterday & was fortunate to have a chance for a brief first light late last night.

Firstly it fits easily on the back seat of our small car & the mount in the boot. It is also very light weight meaning I can move it around the garden on the mount with ease. Despite being a fast scope & having travelled a reasonable distance from the seller, the collimation only needed a small adjustment on the primary.

This is my first dob & it seems to be very smooth in its movement. It has a crayford single speed focuser with a baffled 2" extension tube. The focuser seems nice to operate too. It also has a Rigel Quikfinder plus another shoe for a traditional finder. Generally it looks very well made. The mirror cell is very open so hopefully this will help with cool down. It also has two dust caps, one for either end. For those wishing to know the Zygo report states it is Strehl 0.989 PV wavefront 0.122, Astmag 0.006. Just numbers to me & it is hilux coated.

Excited is an understatement as the sky was clear last night so i could have a go straight away. A bit impatient I started observing only 10 minutes after I had set it up at 11pm. This was extremely easy, taking it out in two bits. I really had no plan so decided to revisit targets I know from using my 200P. The rigel needed a small adjustment & I was ready to go. First up M57 easy to find with the rigel. I tried 66x first then upped the mag to 108x with a Nagler. This looked so much brighter than in the 200P. My skies were less than ideal at around mag 4 last night & I was racing the rising moon. Very distinct ring with maybe a hint of colour, but I cant be sure. I next tried out M13. This was not in such a favourable position now as it was affected by skyglow but still very impressive. Trying my 32mm e.p. which really has too large an exit pupil, I viewed the double cluster. This looked better than I had ever seen from my garden. Once I upped the mag even more stars became visible as the background darkened. I was captivated for a while staring at this beauty. A quick look at Andromeda revealed a very bright core & M32 but the moon was beginning to wash things out. Rushing now I aimed at M71. This had always just looked like a faint patch in the 200P but I could see that it was indeed a loose glob of faint stars & with averted vision many more. M27 at 108x showed the apple core & surrounding nebulosity very well defined & huge in the e.p. Finally on to M15 which revealed many stars as well.

To close I checked out the moon using up to 170x & a variable polarizing filter. The detail, resolution & crispness of the view was breath taking.

Although the scope had undoubtedly not cooled properly I am extremely pleased with my new scope.

[John]

Congratulations on a great scope aquisition Paul

I have the F/5.3 version with similar quality optics on a custom dobsonian mount and it's a superb instrument. I'm sure you will have great fun with the scope as the darker nights draw in

[Laurie61]

Hi Paul, nice first review and welcome to the OO owners club

If you want to delve deeper into the mystery's of a Zygo report have a look here

http://www.rfroyce.com/standards.htm

[paulastro]

If I'm right you bought this scope from 'AA' - I saw it advertised and anything you buy form him is always in very good order. I enjoyed reading your observing report. Congratulations on securing such a good buy.

[John]

If I'm right you bought this scope from 'AA' - I saw it advertised and anything you buy form him is always in very good order. I enjoyed reading your observing report. Congratulations on securing such a good buy.

I think I know who AA is and I agree. Top chap

[webboid]

If I'm right you bought this scope from 'AA' - I saw it advertised and anything you buy form him is always in very good order. I enjoyed reading your observing report. Congratulations on securing such a good buy.

I think I know who AA is and I agree. Top chap

Quite agree very nice chap & thanks for your comments.

[Moonshane]

hi Paul - told you that you'd like it and that it was a good buy ;0)

another OOUK dob goes to a good home. light weight, retaining collimation well and fast cooling are the trade marks of an OOUK scope - the optics speak for themselves!

[estwing]

welcome to the dob mob Paul...you'll be left open-mouthed more than once with that light bucket

[webboid]

Still smiling & feeling very fortunate to own this scope. Just anticipating viewing from a dark sky where I really can test it leaves me giddy with expectation.

[webboid]

hi Paul - told you that you'd like it and that it was a good buy ;0)

another OOUK dob goes to a good home. light weight, retaining collimation well and fast cooling are the trade marks of an OOUK scope - the optics speak for themselves!

Shane Thanks for your advice certainly contributed to me deciding to buy.

Lucky with first light as now clouds for the foreseeable future.

Can any one offer any recommendations on oculars. I suspect they will probably be premium ones.

Thanks

[Moonshane]

just try what you have and see what's missing / could be improved upon. personally I find a paracorr makes a massive difference - rare used though. I got mine for about £170

[webboid]

Thanks Shane

I have a paracorr on my wish list but want to get some observing done first to see how noticeable or annoying it is.

[Moonshane]

good policy I think. I tried a 32mm TV plossl and the coma was quite bad but in a 15mm it was hardly there so it will depend on your observing preferences too. try what you have first and then decide - if you can get together with someone that has a coma corrector then even better!

[Mr Spock]

Sounds like you have a great scope. At f4 you will need quality eyepieces to get the best out of it. You already have two Naglers, I'd be tempted to add a T4 17mm

[Moonshane]

or if OK with the eye relief of the 7mm, watch out for a used 16mm T2. I have one and it's excellent and a bargain at around £100.

[webboid]

I am very happy using the 7mm so looks like the wish list is growing. I had thought maybe a 24mm Panoptic, for low power? Could get expensive but I think the scope deserves the best

[estwing]

I am very happy using the 7mm so looks like the wish list is growing. I had thought maybe a 24mm Panoptic, for low power? Could get expensive but I think the scope deserves the best

...plenty of second-hand bargins about...now where was that slippery slope!

[Stu]

I may be moving a 24mm Panoptic and some other goodies on soon so watch this space.......or rather watch the classifieds :-)

Stu

[webboid]

I may be moving a 24mm Panoptic and some other goodies on soon so watch this space.......or rather watch the classifieds :-)

Stu

That is interesting Stu. Hope my bank balance can cope.

[NGC 1502]

You have a great scope, could very easily sustain a lifetime of astronomy.

Don't want to drain your bank balance, but your scope needs and deserves the best eyepieces. I'd sooner have 2 or 3 excellent EPs than a shedload of cheaper options. It's actually less expensive in the long run to get top ones than buy cheap, be disappointed, then upgrade. Guess how I found that out

Regards, Ed.

[webboid]

Appreciate the comments chaps.

Beginning to get the impression that I may well have to get saving a bit harder.

"could very easily sustain a lifetime of astronomy"

I think you may be right Ed just from my brief first light I'm very pleased & will not get more aperture fever any time soon.

Honest!