It's official. I have ordered an f/5 20" Obsession-style dob from Peter Read of SDM Telescopes.
If you haven't checked out their website, it is at sdmtelescopes.com.au
From all I have read, heard and seen, SDM scopes are as good or better than Obsessions. They use the same mirrors (if you want), the same alt azimuth bearings, and the finish of the scopes is so professional as to put any furniture you may have to shame.
My scope will have an OMI Torus mirror, and will be fitted with a CR2 moonlight focuser. It will have a powerboard, digital encoders, and have Kendrick dew heaters fitted for primary, second and the EP holder, and a fan for the primary. Also, as standard inclusions, it has a light shroud and removable wheelbarrow handles.
One aspect of Peter's service which I find quite extraordinary is that he is going to deliver the scope to my door (in NSW, he is based in Victoria) without charge. The plan is that it will be delivered for New Moon in November.
Thanks guys. I am looking forward to revisiting some of those close doubles, and driving a proverbial Mack Truck between them!
Geoff, I actually investigated ladders before settling on the f/5. I wanted to be sure that I could find something that I would be comfortable observing with. I have found a product which consists of two or three steps leading up to a platform which is at the perfect height for zenith. It folds flat for easy transportation. Google Grahams Ladders, and you will see what I am talking about.
Congratulations Rod....I'm not in the least bit jealous
I haven't really considered any of these big dobs, but having looked through some of the websites of the big American companies, it's certainly got me interested.
I see SDM only make 18" as their smallest size. Does anyone know of any manufacturers in Australia making truss dobs in the 14" - 16" range? I tried googling, and searching here, but couldn't find anything.
Sometime down the road I could be interested. Has anyone ever ordered a large scope from overseas? I just find it hard to imagine the cost after transerring to Aussie dollars, then adding shipping, GST, customs etc. Will make a very expensive scope out of range for most people. Shame really, cause they look very nice.
Anyway, well done Rod. And great to hear about the excellent service you are receiving too.
Has anyone ever ordered a large scope from overseas? I just find it hard to imagine the cost after transerring to Aussie dollars, then adding shipping, GST, customs etc. Will make a very expensive scope out of range for most people. Shame really, cause they look very nice.
Thanks Ziggy.
FYI, the freight cost quoted to me by Obsession for a 20" f/5 was $US1,400, which, by my reckoning, equates to about $AUD1,850.
By ordering locally, you can rely on post sale support, which, with a purchase of this size, is a must IMHO.
Peter is only a short distance from where we live. So he should stop by here on his way to you, so we can make sure it is in excellent operating order.
I see SDM only make 18" as their smallest size. Does anyone know of any manufacturers in Australia making truss dobs in the 14" - 16" range? I tried googling, and searching here, but couldn't find anything.
I'm after exactly the same thing, but have yet to find anyone in Oz doing it commercially. I did ask SDM about making a smaller one, but they were not interested.
Congratulations Rod Please keep us informed on the performance of the "Beast"
We're (my club) hopefully (on funding) going to purchase a 30" SDM in the not too distant future.
Thanks everyone. I suspect I won't be able to quietly observe "in a corner" at star parties ever again with the size of this baby!
Scott, I will see how the performance is at f/5 without a paracorr, and if I am unhappy with coma (which is likely to be a lot less than f/4.5 would have been) then I will probably invest in a paracorr. I have pushed my budget to its limit already without a paracorr.....and I would rather buy a Nagler or Pentax EP rather than a paracorr next time I have a spare $560 lying around....
Congrats Rod
Thought I would include a pic of the 24" thats on its way to us , I hope to have the mirror from Steve Kennedy in October , if its as shinny as the mirror box we'll be doing well.
Apparently the specs are exactly the same as per Obsession scopes, so based on the Obsession specs, the 20" f/5 has a focal length of 100", ie 254cm, which is EXACTLY the same as was my LX200. In other words, same magnification as before.
HOWEVER, as the 20" will be able to handle up to 1000x on a regular basis, I will, as you suggest, have to get some shorter focal length Ep's. I might have to start by making Matt an offer for the return of my 13mm T6 Nagler.
Other specs:
2" thick primary mirror, with 96% reflectivity
3.1 inch secondary mirror, with 98% reflectivity
11 lbs upper assembly
100 lbs lower assembly (25 lbs with wheelbarrow handles)
Height at zenith 8 feet
limiting stellar magnitude 16.5
Rayleigh Resolution limit 0.27 arc seconds
Lower assembly dimensions: 31"x29"x25"x27" (huge!)
I'm not happy - I bought one eyepiece and it rained for 2 weeks - imagine what a 20" Dob will do guys..... would you mind moving from the Central Coast before you take delivery?
Seriously - sounds fantastic, hope you don't get vertigo mate....
Congrats Rod
Thought I would include a pic of the 24" thats on its way to us , I hope to have the mirror from Steve Kennedy in October , if its as shinny as the mirror box we'll be doing well.
Zane
Very nice Zane.
Peter Read was telling me this morning that the glossy finish can tend to show the finger marks. I for one don't mind...I am happy to have any excuse I need to polish my baby...
I would love to visit when you have taken delivery. Maybe we can compare scopes after mine arrives?? I am sure I could find a few other people who would like to play, too!
What are you going to call your scope? I am going to give mine a name...I am open to suggestions.
20 inch SDM Telescope Ordered
Congratulations Rod!
