That's really quite a nice image Dan, welcome to the forum. What scope did you use?

Yes spotted these had appeared recently. We've been doing this for years here on solar chat using plastic bags. I wonder if when people complain about the unevenness of their quarks for imaging Daystar will tell them they need one of these...

You can use the fov calculator here https://astronomy.tools/calculators/field_of_view/ to get an idea of what you'll get. I use a 50mm etalon on the front of a 60mm f6 scope, followed by a Quark and then the Baader 0.7x telecompressor which gives me a full disk on a PGR GH3 with a 3376 x 2704 pixel ...

You got any pictures you can show with the 174? Dont forget with this camera you are hugely undersampling and so will have a loss of resolution which may be what you are seeing?

AndiesHandyHandies wrote: ↑

Thu Dec 03, 2020 9:42 am

All the pictures of the inside of PSTs I have seen have the penta prism at a slight angle so seem to be made that way.

Indeed, but the glue is gloopy and this sag generally increases over time. After a certain point the sag introduces astigmatism which is what the issue could be here.

That's very good indeed Alfred¬!

That's very good indeed Alfred¬!

You sure it's not the prism out of alignment in the PST? Sounds like it to me... The glue that holds it in place flows over time and the prism sags.

SJohnson wrote: ↑

Wed Dec 02, 2020 9:01 pm

I struggle with it having a band across the center of the disk when using it double stacked

This is because you have too much tilt on the etalon. Nice pic btw.

Really nice shots Stu, glad you got some sun!

Very good images Paul!

Sounds a positive session Andrew

Nice disk!

Keep in mind what Christian pointed out, you need a big aperture and his seeing was sustained 0.7~0.8 arc-seconds, and as good as 0.3 arc-seconds. This isn't anyone's backyard seeing. This was at a specific location with exceptional seeing conditions. Professional observatory location class. G-band...

Excellent images Christian. The difference between single and double stack is both subtle and dramatic at the same time. How do you find it affects exposure time between the two methods?

Good shot Stu!

A very good set of images indeed Marty. You would have got away with the 8" for Ha first thing looking at the seeing chart. Long may your good seeing prevail!

Hi there and welcome to the forum. I would suggest you are unable to get the external etalon to tune as it is the 'double stack' etalon, it is designed to be used for this only. If you want to use an etalon on another scope you need to use the inner (or primary) etalon as this is the one designed to...

Great data Stu, thanks for sharing.

Impressive data chaps! Welcome to Les also

Thx Montana, Met Mark and Stephen as a Panelist on AstroRadio.Earth a couple of weeks ago, just getting into Solar but after hearing about how Mark got into solar observing I get it. I am a Slooh.com remote imaging user and Ambassador, and a member of the Milwaukee Astronomical Society; http://milw...

Incredibly impressive images Phil

Hot off the press, the running order as follows: Solarsphere Day 19th December 2020 ( FREE ON-LINE EVENT ) 11am – 12:50 pm JD Quenzer - Solarsphere Music Show ( Radio Event ) Zoom and YouTube 1pm – Introduction 1:10pm Emma Wride AstroCymru with Space Crafts & Projects for Children 2pm – 2:30pm – Fun...

That's a good disk Robert. It's all goin' on darn sarf'...

MapleRidge wrote: ↑

Sun Nov 29, 2020 9:42 pm

Sounds good Mark...thanks for the heads up!

Just want to check if it isn't the 19th...that is the Saturday?

Brian

Sorry, yes, good spot, it's the saturday...