Cold weather etalon performance

Use this section to discuss "standard" Baader/Coronado/ Lunt SolarView/ Daystar, etc… filters, cameras and scopes. No mods, just questions/ answers and reviews.
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jetstream
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Cold weather etalon performance

Post by jetstream »

I'm still tossing around another Ha set up besides my Quark and have a few questions. My weather here is extreme- right now its -26c with a bright sunny sky and with some VG seeing around here.

Will a Lunt 60mm-internal air spaced etalon come on band from the factory? I'm at 1100ft with temps from +30c to -40c, summer to winter. What are the chances of both internal and external etalons working together at this cold temp? Will a pressure tuner (s) O ring hold its air? Would tilt tuning be better here?

One more...does etalon temp sensitivity go up with increasing etalon size ie the 60mm's internal vs the 80mm internal, Lunt that is. I can afford a scope, just not a mistake :shock:

Thanks,Gerry


Gerry
SW 120ED Pro,90mm Stellarvue
Baader Cool wedge, Quark Chrom
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MapleRidge
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Re: Cold weather etalon performance

Post by MapleRidge »

Hi Gerry...

I have operated my Lunt solar filters in the same temperature range that you describe with no issues. I have both presume (PT) and tilt tuned (TT) etalons in use. The LS80 in single stack mode (PT), double stacked with a LS75FHa front mount etalon (TT), and usually use the DSII module (PT) in a modded 150mm, f8 refractor.

The pressure tuning can be easily rest for you altitude by completely unscrewing the PT cap, remove it, and then thread it back on and tune. I do not move my equipment so I'm fixed at about 920 ft above sea-level, so this isn't too different form your elevation. I see a slight shift in tuning on the PT units if there is a considerable change in temps from one session to the next, but overall the units are very stable.

BTW...where are you located? I'm pretty sure that we know each other...Perceptor perhaps?
Brian
Last edited by MapleRidge on Sun Jan 10, 2016 4:29 pm, edited 1 time in total.


Brian Colville

Maple Ridge Observatory
Cambray, ON Canada

Photos: https://www.flickr.com/photos/185395281@N08/albums

10'x15 Roll-off Roof Observatory
Takahashi EM400 Mount carrying:
C14 + Lunt 80ED
Deep Sky Work - ASI294MM Pro+EFW 7x36/Canon 60D (Ha mod), ONAG
Planetary Work - SBIG CFW10, ASI462MM

2.2m Diameter Dome
iOptron CEM70G Mount carrying:
Orion EON 130ED, f7 OTA for Day & Night Use
Ha Setup: Lunt LS80PT/LS75FHa/B1200Ha + Home Brew Lunt Double Stack/B1800Ha on the Orion OTA + Daystar Quantum
WL, G-Band & CaK Setup: Lunt Wedge & Lunt B1800CaK, Baader K-Line and Altair 2nm G-Band filter
ASI1600MM, ASI432MM, ASI294MM Pro, ASI174MM, ASI462MM
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jetstream
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Re: Cold weather etalon performance

Post by jetstream »

Thanks Brian, I'm near Fort Frances, in between Thunder Bay and Winnipeg. We moved to a lake home that has some great skies, but there are temp extremes. So if I ordered a Lunt 60mm say, there is a VG chance it will work right out of the box? My Quark had to be tuned for my set up and temps...we'll see if it works today, unreal skies atm :)


Gerry
SW 120ED Pro,90mm Stellarvue
Baader Cool wedge, Quark Chrom
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