Anyone collimated a Tele Vue scope?

[MortonH]

My recently acquired Pronto appears to be out of collimation, showing coma in star images at 60x. I contacted Bintel and Astronomy Alive and they both said the scope would need to be sent back to Tele Vue for re-collimation. However, the cost of doing this would be more than the scope is worth.

I've seen a handful of threads on CN suggesting that DIY collimation is possible although way beyond my own (non-existent) skills. So I thought I'd see if anyone here has ever done this successfully with a TV scope and might be willing to have a go at this one.

[Profiler]

You can try:


https://www.rogersopticsrestoration.com.au/

[MortonH]

Thanks. I've left a message. I do note, however, that Tele Vue is conspicuously absent from the list of supported brands on their website!

[Fox]

Morton, I think it’s Roger Davies most recently from Bintel in Melbourne, unfortunately now closed. He’s really knowledgeable and should give you a straight answer, Fox

[N1]

Morton, have you seen this thread?
https://stargazerslounge.com/topic/305223-tele-vue-prontos/

I'd probably just ring TV. Good old phone is still a highly effective way to get answers quickly (unless it's a govt dept or something).

[Ukastronomer]

Is this true

" Whereas the TV76 has a 76mm full APO objective, the Pronto is a 70mm achromat. Read that again. No, it’s not a “semi-APO”, it’s an achromat! From what I have read (by a certain person who almost certainly knows), TeleVue used a cheap ED glass in the objective which has little or no effect on correction for chromatic aberration, but did allow them to use the letters “ED” when marketing it!"

[Ukastronomer]

I would be interested in a thread about collimating refractors or web site please

[Oddity]

Roger is brilliant. I found a visit to his workshop and a nice long chat with him to be a privilege and that alone was well worth the drive to padstow. He’s got spare parts and bits of every kind too.

[MortonH]

Roger replied and isn't put off by tackling a Tele Vue scope so I may pay him a visit.

I also discovered tonight that the retaining ring on the front of the lens was a bit loose. Tightening this by hand (and breaking several nails in the process) has made a dramatic improvement and the coma seems to be gone. It's not quite perfect but then the seeing is awful so it's hard to tell. Once I get a better night I'll do a proper star test but things are looking up.

[Profiler]

Roger is probably the best person going in Sydney so you have certaionly made the right choice when you consider/balance up the variables of cost vs value of the scope etc

[MortonH]

In better seeing tonight things are looking pretty good! Might take it to Roger for inspection anyway but I'm getting nice tight stars and good contrast. Just need to find a way to balance it better.

[GrahamL]

I took my new one out for a spin last night , pretty poor seeing at the moment i believe, and a bit of smoke around and was happy enough at around 90 x , I dont expect it to be more than a nice compact widefield .
Though on the moon I found CA to really be minimal like its there but nothing like a any of the short achros I've looked through .


Over 2k when new in aus .

[MortonH]

Yes, the CA is well controlled. On Jupiter it's more evident but not objectionable, and this is hardly a planetary scope anyway.