whats the best scope to use ith a SM90II etalon and BF30?

[Houghy]

As i said in the topic title, i am interested in what people have to say on what the best scope/etalon combination for this?

[pedro]

I used a pre-meade SM90 with a TV101 F/5.4.

This Etalon is now sold but I will have a SM60 (also pre-meade) soon that I will use with the same scope for FD imaging. I will use it with a Coronado BF10 and a LUNT B1200

Pedro

[solarchat]

well, the best scope to use with that etalon/BF combination would be a single etalon Coronado 90mm internal etalon scope, in my opinion.

[Houghy]

well, the best scope to use with that etalon/BF combination would be a single etalon Coronado 90mm internal etalon scope, in my opinion.

ok so you are suggesting that I purchase a Coronado 90? well here in Australia they are a small fortune - that's why i jumped at the chance of getting the etalon for 3.5k. a dedicated 90mm scope with bf15 is 5k, with a 30BF its 6k and DS is 9k. I was thinking i could have mounted it on another scope or my existing large refractor but i take the point

[solarchat]

maybe I didn't understand the question..

If you already have an external Coronado 90 filter and want to put it on the "best" scope possible, I suggested the Coronado 90mm internal etalon scope. Then you would end up with a doublestacked 90.

Do you mean which of your current scopes would be best? What are your current scopes?

[swisswalter]

Hi David

I would mount it on a TAK102

[Houghy]

maybe I didn't understand the question..

If you already have an external Coronado 90 filter and want to put it on the "best" scope possible, I suggested the Coronado 90mm internal etalon scope. Then you would end up with a doublestacked 90.

Do you mean which of your current scopes would be best? What are your current scopes?

far too many scopes all at the low end, 127ed ed80's 14" meade acf, 11 celestron, 8 inch meade ACF

[Houghy]

Hi David

I would mount it on a TAK102

thanks Walter, do you see these 2nd hand much?

[swisswalter]

Hi David

from time to time ther is one up on astromart or Astronomie de or astro inof

[Valery]

The best telescope for using a Ha 90mm external etalon is a telescope with minimal spherical aberration at this wave length.

Among compact telescopes are:

1. Synta or Made 102mm F/10 simple achromat. Any of them. Will work better than any TAK doublet apochromat.

2. Meade AR 129mm F=1200mm will work even better. But it much less compact than the scopes above.

Valery.

[Houghy]

The best telescope for using a Ha 90mm external etalon is a telescope with minimal spherical aberration at this wave length.

Among compact telescopes are:

1. Synta or Made 102mm F/10 simple achromat. Any of them. Will work better than any TAK doublet apochromat.

2. Meade AR 129mm F=1200mm will work even better. But it much less compact than the scopes above.

Valery.

well I am learning stuff all the time, thanks. i was thinking of and extra scope to image with , you know when the sun goes down

[Houghy]

well i went ahead and visited my local machine shop - $300 later and i will have within 2 weeks an adapter for the 127ED to take the SM90. mind you though for the chunk of metal its a very expensive adapter

HOU-LA-001.pdf

(146.81 KiB) Downloaded 160 times

[swisswalter]

well i went ahead and visited my local machine shop - $300 later and i will have within 2 weeks an adapter for the 127ED to take the SM90. mind you though for the chunk of metal its a very expensive adapter

Hi Dave


yes I wonder too. 1 KG of my stuff is sold for maybe 30 $, 250 g of formed metall is sold for 300 $. Next time I come down to earth . I'll get me some metal and a lathe

[Houghy]

i updated the above post to include the design of the plate

[marktownley]

i updated the above post to include the design of the plate

Nice plan!

[Houghy]

i updated the above post to include the design of the plate

Nice plan!

well i hope it works - and functions as it should. so should i paint the outside white?

[Rybak]

Hi
Will your adapter plate be thread into dew shield?

[Houghy]

Hi
Will your adapter plate be thread into dew shield?

yes directly into the shield

[gbealnz]

Hi
Will your adapter plate be thread into dew shield?

yes directly into the shield

Hate to say it Huff mate, but if I understand your "yes directly into the dew-shield" I reckon you'll be disappointed.
The SM90 x 2 is huge, and more to the point HEAVY, it will tilt the dew-shield depending on the orientation.
The SM60 setup I had worked on the FS78 scope, and it meant removing the dew-shield completely, and attaching directly to the "ring" that the dew-shield screwed onto. This was rock solid, and introduced no tipping/tilting whatsoever. (I still have the SM69-FS78 fitting if there is anyone out there that wants one).
One way to find out though, expensive way, but you'll know soon enough.
Gary

[Houghy]

Hi
Will your adapter plate be thread into dew shield?

yes directly into the shield

Hate to say it Huff mate, but if I understand your "yes directly into the dew-shield" I reckon you'll be disappointed.
The SM90 x 2 is huge, and more to the point HEAVY, it will tilt the dew-shield depending on the orientation.
The SM60 setup I had worked on the FS78 scope, and it meant removing the dew-shield completely, and attaching directly to the "ring" that the dew-shield screwed onto. This was rock solid, and introduced no tipping/tilting whatsoever. (I still have the SM69-FS78 fitting if there is anyone out there that wants one).
One way to find out though, expensive way, but you'll know soon enough.
Gary

I only have one Sm90?

[marktownley]

I screwed mine straight into the lens cell on my skywatcher 102mm f5

sky by Mark Townley, on Flickr

[Rybak]

I use DIY adapter plate on my Skywatcher 102 mm f5. And I control the tilt of adapter plate by GMK collimator.

[axlefoley]

2. Meade AR 129mm F=1200mm will work even better. But it much less compact than the scopes above.

Valery.

Correct me if I'm wrong but aren't the Meade the same as a Bresser for $795 looks good to me and no way would I hang a SM90 off a dew shield.

http://www.astroshop.com.au/products/de ... d=MAS-031B

Or a 152mm for $1175

http://www.astroshop.com.au/products/de ... d=MAS-031C

[axlefoley]

Only paid $180 for this adapter, your machinist is very expensive David.

[marktownley]

Nice setups chaps!

[axlefoley]

Nice setups chaps!

Thanks Mark.

[axlefoley]

And this looks ok to

http://www.walmart.com/ip/Explore-Scien ... e/33595793