oldham optical

[rl]

Hi people;

I've got the option on a 18" big dob for sale on ABS which looks good for the price. The mirror is by Oldham Optical; it comes with a maker's test certificate for 1/9 wavelength, Strehl 0.94 at 550 nm. All looks good superficially but I wondered what the collective experience was with Oldham. I don't think the testing was done with an interferometer but I might be wrong on that one. There are a few negatives on this site; are they representative or is it a case of the majority of satisfied customers remaining silent while the dissatisfied ones complain?

Comments appreciated. RL

[estwing]

Not had any experience with them but it's a cheap big Dob...hope you like ladders!!your not confusing Orion Optics with Oldham Optics are you?

[faulksy]

as estwing says hope you like ladders, great big scope for the money though

[Tinker1947]

Your generally only hear the bad stuff about people, web sites, shops, ect ect ,,,the good stuff doesn't get into print to often.....

[rl]

No..it's definitely Oldham..I wouldn't think twice about OO...I've owned enough of theirs to trust the zygo.

RL

[John]

I think I've seen the scope in question advertised. It's an 18.5 inch F/5.8 I believe - you will need a ladder !

The mirror specs look OK for a large aperture light bucket. A lot of scope for the asking price.

[nightfisher]

I know of an 8" f7 oldham optical mirrored dob for sale, but im not buying at the mo

[Peter Drew]

I've purchased some optics from Norman Oldham in the past and have been satisfied with the quality, I've also used telescopes with Norman's optics in and have been impressed with some of the larger ones. I seem to recall a short period in the past when Norman changed testing procedures to a null test and got the rig a little out of spec (think Hubble), once rectified quality was back to normal. Norman is a decent chap and would address problems if they arose. As mentioned, a lot of telescope for the money, couldn't see the azimuth base in the photos, could it be extra?    

[ollypenrice]

I have what I consider to be a rather rustic 20 inch Dob. I never make any claims for it other than that it is big - and there I'm on safe ground! However, lots of big Newt and Dob buffs come and use it and their consesus in favourable. 'It's fine,' they say. 'Let's get on with it.' The thing is, most people don't use a big Dob for finessing on the planets. They use it for pulling out the little faint fellas. Double star buffs might be different but, on faint fuzzies, how much difference does a killer mirror make?

I bought mine for a very low price in Oldham - but it doesn't have an Oldham mirror.   It has a Beacon Hill. It cost what you'd pay for a sub-premium 80mm Apo OTA. It has to be the most productive £1400 I ever spent and twelve years later it is marching on. I thnk that, in the UK, people dream about big Dobs but don't buy them so the used prices are low.

Olly

[perfrej]

Not experienced in visual, but Olly's beast is a blast to look through. Even after considerable quantities of various French stuff, the faint stuff can be seen. Have to be careful with the ladder, though

/p

[rl]

Thanks for the input guys...will add a comment after I've seen it.

RL