Solar telescope

[Podger]

Hi folks,
Have become interested in solar viewing and photography. Many pluses - don't have to freeze in the night, the only star we can see details of, always something new happening (might even have something to do with global warming!), easy to find etc. Question - has anyone seen a Lunt solar telescope yet or reports/reviews? Ads suggest a 60mm scope for about same price as a 40mm Coronado Solarmax. I have been reading up a lot and find a lot of stuff but not always very clear ( eg double pass/ double stacked) so any advice on equipment choice for viewing and photo work appreciated. Prepared to spend ca $2000.
Rog

[Podger]

Done some reading in the archives. Seems the PST does a reasonable job and the next step is quite expensive - ie adding a second filter (double stacking).I see that HOughy is taking delivery of a Lunt 60mm double pass unit in October. Think I'll wait to see how that goes before investing. I guess with a double pass the amount of light transmitted is very much reduced but there is plenty anyway? I've been trying to find out how this works without success - is it by internal reflection, mirrors or what?
(Might be silly questions but best way to learn).
Rog

[iceman (Mike)]

Hi Rog
I believe it's the filters that cut only to a very specific wavelength of light which gives you the extra detail on the sun. The sun is so bright that there's obviously still enough light transmitted.

What camera will you be using to photograph with, and what will you mount the scope on?

[Merlin66 (Ken)]

The etalon filters in the PST and the Solarmax SM40/60/90 front end Ha filters have a bandwidth of about 0.7 Angstrom. This means that the distribution of the light getting through is a Poisson distribution ( bell curve) about 0.7 A across the base. If two filters are used, slightly out of phase (the Tmax adaptor does this) then the combination of the two curves gives a narrow bandwidth of approx 0.5 Angstrom; this gives the improved contrast.
The trick is to be able to do this two stage "tuning" to maximise the contrast. After a few trials, you quickly get the hang of it.
Throughput is reduced by about 20%; not an issue with the Sun.
Colin wrote an article on the subject; explains it much better than me!
http://www.designerinlight.com/solar...ArticlePt1.pdf
Hope this helps.

[MikeyB (Michael)]

The Lunt Yahoo group is very active and a good source of info, comments, etc:

luntsolar

I believe the "double pass" Lunt design has been axed and replaced with a more conventional double stack. Also, I understand that Lunt prices have risen recently.

[MikeyB (Michael)]

There's a brief 'first light' Lunt double stack review on Cloudy Nights at:

First "decent" Light for Lunt 60 doublestack!

[Podger]

Hi again,
Thanks Mike and Merlin for the links. More reading and interesting. Boy one can spend some time on these chat sites! The review on Cloudy Nights seems to have sparked a lot of movement in the Lunt world - I hope the guy isn't on the Lunt payroll. Anyhow I've bitten the bullet and ordered a Lunt LS60HaDS50/BF1200/C. The bad news is the price is now$2995 from Bintel and delivery is May 2009!
I can mount it on a EQ3 and thought I'd buy a DSI III camera which I'm assured by Bintel will be fine. I guess it should be as long as the magnification isn't too high and it can be focussed. Anyone know if this is so? If not a DSLR.
In order to fill in the time until next May I have also decided to proceed with the purchase of a GoTo SCT. I am tossing up between a Meade LX90ACF 8"/10", Meade LX200ACF 8" or Celestron CPC9.25" depending on which I can lift. I just have to go to the showrooms now and try picking them up. Due to age and lack of firmity it will probably be the the LX90 8"!
Any comments much appreciated.
Rog.

[lloydysun]

Hi Mate, I have looked at a review of the LUNT 0.5ANGS SOLAR TELESCOPE DOUBLE STACKED on Cloudy Nights. there is a bloke there with the name of JIM ROSENSTOCK he gives an exellent review on this scope,plus a bloke called STEVEN W RAMSDEN, he is going to check the scope for me, he should get back to me pretty soon. i will let you know what he say's when i find out. Bottom Line is, i think this scope is a great great buy, especially for this price. cyou..Lloydysun....

[Peter Ward]

Originally Posted by Merlin66

......This means that the distribution of the light getting through is a Poisson distribution ( bell curve) ........

Moot point, but I think the curve is Gaussian (there is no statistical spread happening here)

[Merlin66 (Ken)]

Peter,
Stand corrected!