[SOLD] 25" / F5 Obsession Telescope

[ausastronomer (John Bambury)]

Good Afternoon All,

I am offering for sale on behalf of a friend of mine an original 25”/F5 Obsession Telescope with Nova Optics primary. The scope is just over 10 years old and belongs to a friend of mine who previously worked at the Compact Array Radio Telescope facility at Narrabri, but is now based in Sydney and has nowhere to store the scope. The scope is still located on site at the Compact Array facility at Narrabri and would need to be picked up from Narrabri. Given enough notice the owner could arrange for transport to Sydney (after sale only as he has no way to store the telescope in Sydney). The telescope can be inspected at Narrabri by prior arrangement.

There is some slight surface damage to the finish on the front face of the mirror box. This is cosmetic only. Two of the split blocks will be in need of repair soon, but are currently serviceable. This would be a minor repair by simply ordering two new blocks from Dave Kreige at Obsession telescopes. Apart from the two damaged split blocks and the deteriorated cosmetic finish on one face of the mirror box the structural integrity of the scope is very good and solid. The primary and secondary mirrors are in very good condition as they are usually stored in their shipping boxes, when the scope is not in use. This is a bare bones scope fitted with a JMI single speed focuser. If you’re not worried about looks two new split blocks and the scope is good to go for many more years. If you are worried about looks two new split blocks and some sanding and varnishing has it is good as new. If you did want to refinish the woodwork this would be a perfect time to retrofit accessories like Argonavis and Servocat.

Included with the telescope is:-

- Primary mirror (engraved): Nova FL 121.5" Serial # 400-1075
- 3.5" Astrosystems secondary mirror
- Telrad finder
- Brand new light shroud (not in the pictures)
- Meade 8.8mm 2"/1.25” Ultra Wide Angle Eyepiece
- Meade 40mm 2" Super Wide Angle Eyepiece
- 2" Lumicon OIII Filter
- 2" Nebula Line Transmission Filter (OIII 496nm, OIII 501nm, Hbeta 486nm)
- 12V fan for mirror cooling

The asking price of the Scope is $10,000 including all eyepieces and accessories, or $9,750 for the scope only without eyepieces and filters. The price is negotiable. Keep in mind that a 25”/F5 primary mirror alone will cost $10,000 shipped to Australia.

The filters and eyepieces are in excellent condition.

Anyone interested should contact me and I will put you in touch with the scopes’ owner.

Cheers,
John B

[ausastronomer (John Bambury)]

More scope images

[ausastronomer (John Bambury)]

Images showing the parts of the scope requiring a little TLC

[ausastronomer (John Bambury)]

Images of the filters and eyepieces

[hector (Andrew)]

Hi All
For those people interested in maybe owning a 25" scope I can let you know I have observed with this instrument and the optics are great. Views through a 25" scope are amazing.

[DCM (David)]

Hi
I noted the ad for the 25" Obsession. Can you send me some more information on it? Can it be retro fitted to make it a GoTo and to track? Can it be used for astrophotography? I presently have a Meade LX90 10" but have been interested in larger apertures. I live in Tamworth. My email is dmoore@northnet.com.au. I look forward to hearing from you

[ausastronomer (John Bambury)]

Originally Posted by DCM

Hi
I noted the ad for the 25" Obsession. Can you send me some more information on it? Can it be retro fitted to make it a GoTo and to track?

Hi,

It can certainly be retrofitted with a GOTO and tracking system. For a scope of this size, style and aperture the best system to retrofit the scope with is the Argo Navis Digital Telescope Computer and the Servocat Drive System

These two systems are fitted as the standard drive and computer systems by Obsession Telescopes when ordered with GOTO and tracking from Obsession, as a new telescope. All the components you need can be ordered from Wildcard in Australia and Stellarcat in the USA. The all up cost would be around ~$3,000 including encoders and mounting hardware. For someone reasonably handy with wood working tools and a screwdriver, it is about a 2hr to 3 hr job to install. The Servocat comes with a handy instructional DVD. I would also recommend you purchase the Catstalk System from Markless Astronomics which allows you to easily mount the controllers at the scope.

Owning two Obsession type dobs both fitted with Argo Navis/Servocat/Catstalk I think a scope of this aperture really benefits from all 3 components.

Can it be used for astrophotography?

Yes it can. However it is far from an ideal astrophotography setup due to the limitations imposed by field rotation and the tracking alt/az mount. It is designed for visual observation, not astrophotography.

In the hands of someone skilled it can do good astrophotography.

These are deep space images taken by Alex Cherney with a 22"/F3.6 Obsession Style dob fitted with Argo Navis/Servocat

I presently have a Meade LX90 10" but have been interested in larger apertures. I live in Tamworth. My email is dmoore@northnet.com.au. I look forward to hearing from you

As a visual instrument there is no comparison between the two. One is a serious amateur telescope and the other is a medium/small aperture mass produced telescope.

If your primary goal is visual astronomy it doesn't get much better than a 25" Obsession. If your primary goal is serious astrophotography it's probably not a good choice. If you want a great visual telescope that you can have a dabble at astrophotography with, you will probably be very happy.

Cheers,
John B

[DCM (David)]

Hi John
thankyou for your reply. I would be interested to talk to you in person re the scope. Could you call me of an evening on 0427 663899? I go to Narrabri for work every fortnight or so, so it would be possible to see it. Thankyou

[ausastronomer (John Bambury)]

Hi David,

I am currently away observing at Coonabarabran with some American observers. Unforunately I have very limited phone service out here and only get a signal from town when I go in there mid morning each day.

I will give you a call hopefully over the weekend when I get back to civilisation.

Cheers,
John B

[DCM (David)]

Hi John. That is no problem. Try me any time over the weekend.
regards
David

[ausastronomer (John Bambury)]

Sale of scope is pending. The transaction should settle over the weekend. This is a serious visual telescope going to a good home.

Cheers,
John B