TOA for SUN

Use this section to discuss "standard" Baader/Coronado/ Lunt SolarView/ Daystar, etc… filters, cameras and scopes. No mods, just questions/ answers and reviews.
Post Reply
fedele
Ohhhhhh My!
Ohhhhhh My!
Posts: 78
Joined: Thu May 27, 2021 10:34 am
Has thanked: 24 times
Been thanked: 133 times

TOA for SUN

Post by fedele »

A technical question
i want to buy a TOA 130. I have seen that it has 3 groups of lenses ( 2 ED) that are very far apart. This creates larger air chambers than a TSA or other telescopes. On the one hand this is the particularity of the TOA, on the other hand, however, two doubts arise:
1) acclimatizes more slowly
2) For the Solar this could be a problem, due to the heating of the air between the interstices. Even using DERFs.
What can you tell me about point 2?
thank you


User avatar
marktownley
Librarian
Librarian
Posts: 42272
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Has thanked: 20435 times
Been thanked: 10243 times
Contact:

Re: TOA for SUN

Post by marktownley »

The TOA130 is one of the best corrected scopes you can buy for certainly CaK... You won't have any problem with heating using an ERF.


Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!
User avatar
rsfoto
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 6159
Joined: Mon Jun 18, 2012 8:30 pm
Location: San Luis Potosi, México
Has thanked: 9401 times
Been thanked: 5568 times

Re: TOA for SUN

Post by rsfoto »

Hi,

I am using a FSQ 85ED (Petzval 4 elements) with a double stacked Coronado SM 60 and have observed that there is a difference if I start immediately or if I start 30 minutes later always pointing to the Sun but I have attributed this to an acclimatization of the etalons and not the telescope itself because I need to adjust the sweet spot changing the etalon angle.

Maybe I am wrong ¿?


regards Rainer

Observatorio Real de 14
San Luis Potosi Mexico

North 22° West 101°
User avatar
Merlin66
Librarian
Librarian
Posts: 3970
Joined: Tue Dec 13, 2011 1:23 pm
Location: Junortoun, Australia
Has thanked: 173 times
Been thanked: 615 times
Contact:

Re: TOA for SUN

Post by Merlin66 »

I use the Genesis 100/ 500 Petzval design for white light imaging with the Baader cool wedge. No issues.
I have it in writing from Televue, Takahashi and Williams Optics that all their telescopes (including the multi element Petzval etc.) are 100% safe to use for solar observing without an ERF eg white light observing with a Herschel wedge.


"Astronomical Spectroscopy - The Final Frontier" - to boldly go where few amateurs have gone before
https://groups.io/g/astronomicalspectroscopy  
http://astronomicalspectroscopy.com
"Astronomical Spectroscopy for Amateurs" and
"Imaging Sunlight - using a digital spectroheliograph" - Springer
christian viladrich
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 2150
Joined: Sun Jun 14, 2015 4:46 pm
Location: France
Has thanked: 1 time
Been thanked: 2713 times
Contact:

Re: TOA for SUN

Post by christian viladrich »

Hello,
I have been using my TOA 150 for solar imaging for years. There is no question this is the best refractor you can have for solar imaging from Ca II to Ha.
There is no issue about using it with / without ERF.
- For Ha, I use a 160 mm ERF,
- For G-band or continuum, I usea Baader Hershel,
- For Ca K, I use no ERF but a sub-aperture 50 mm ERF.
No issue at all about internal current, thermal stabilisation or acclimatization.

Peztval quadruplets are a different beats. I also have a Taka FSQ106. Because of its optical design, the focal position is much more sensitive to temperature change.


Christian Viladrich
Co-author of "Planetary Astronomy"
http://planetary-astronomy.com/
Editor of "Solar Astronomy"
http://www.astronomiesolaire.com/
User avatar
DeepSolar64
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 18823
Joined: Thu Sep 05, 2019 12:19 am
Location: Lowndesville S.C.
Has thanked: 17572 times
Been thanked: 16693 times

Re: TOA for SUN

Post by DeepSolar64 »

It looks like to me if the lenses are clean and transparent as the air between them should be, they should pass the infrared heat through them and not absorb any to heat up. That's why heat doesn't damage the lenses before it hits a solar wedge and the inside of the scope does not heat up from that light's passage. it doesn't look like the design would matter, at least in most designs.

A Petzval has two of the elements far back in the optical train, right? Towards the rear of the scope. If so they may have to deal with a tighter focus of the light beam from the front two elements. This could cause uneven heating of them. But even then if the optics are clean and IR transparent is should be very minimum to none.

If I ever win the lotto I am gonna have a TOA 150 equipped observatory!

James


Lunt 8x32 SUNoculars
Orion 70mm Solar Telescope
Celestron AstroMaster Alt/Az Mount
Meade Coronado SolarMax II 60 DS
Meade Coronado SolarMax II 90 DS
Meade Coronado AZS Alt/Az Mount
Astro-Tech AT72EDII with Altair solar wedge
Celestron NexStar 102GT with Altair solar wedge
Losmandy AZ8 Alt/Az Mount
Sky-Watcher AZGTI Alt-Az GoTo mount
Cameras: ZWO ASI178MM, PGR Grasshopper, PGR Flea
Lunt, Coronado, TeleVue, Orion and Meade eyepieces

Image Visual Observer
" Way more fun to see it! "
Post Reply