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Saturday Sun 11th Aug

Posted: Sat Aug 11, 2018 3:16 pm
by Carbon60
I was expecting it to be cloudy this morning....and I was right, but miracles happen and the sky cleared at around 7:30 am through to about 9:00 am when white contrails started to spoil the fun, spreading, merging and creating a milky hazy mess. Before then the sky conditions were quite good with reasonable clarity and very few clouds, but the seeing was really highly variable and for the most part pretty darn poor. However, I thought it time to try the big gun (to please Valery). This is my 250mm RCT fitted with a Lunt 35 at the back end and an internal plano-concave paralleling lens to pull the light-waves pretty much normal to the Lunt's objective fitted etalon. On the front was a full size Aries ERF.

I used a 2.5x TV Powermate for a higher magnification image on the Basler acA1920-155um IMX74 sensor. Really the seeing conditions were JUST about manageable, at least for one reasonable image of the active region. Most of my data ended up in the bin.

Images were captured using Genika Astro, stacked with AS!3 and deconvoluted using ImPPG with final finessing and colouring using PixInsight. The SER files were captured as 10s bursts and I stacked 1% of the 1650 frames contained therein.

I should have made the final images a bit brighter as they can look a little dark (depending on which machine I look at them with).

Image20180811_Ha1 by Stuart Green, on Flickr

and in colour.....

Image20180811_Ha1_colour by Stuart Green, on Flickr

The session was cut short with worsening sky conditions and the usual weekend 'things to do'......

Thanks for looking.

Stu.

Re: Saturday Sun 11th Aug

Posted: Sat Aug 11, 2018 4:09 pm
by MalVeauX
Nice resolution!

Would love to see how you fitted that Lunt 35mm to the RC!

Very best,

Re: Saturday Sun 11th Aug

Posted: Sat Aug 11, 2018 4:28 pm
by Carbon60
A couple more, processed slightly differently to try to preserve some of the fine detail, but not as 'sharp'

Image20180811_Ha2_Mono by Stuart Green, on Flickr

Image20180811_Ha2_Colour by Stuart Green, on Flickr

Stu.

Re: Saturday Sun 11th Aug

Posted: Sat Aug 11, 2018 4:31 pm
by Carbon60
MalVeauX wrote:
Sat Aug 11, 2018 4:09 pm
Nice resolution!

Would love to see how you fitted that Lunt 35mm to the RC!

Very best,
Hi, I did post an image of the set up. I'll try to find the reference.

Found it.... viewtopic.php?f=4&t=24562&p=220910&hilit=RCT#p220910

Cheers

Stu.

Re: Saturday Sun 11th Aug

Posted: Sat Aug 11, 2018 6:10 pm
by MalVeauX
Carbon60 wrote:
Sat Aug 11, 2018 4:31 pm
MalVeauX wrote:
Sat Aug 11, 2018 4:09 pm
Nice resolution!

Would love to see how you fitted that Lunt 35mm to the RC!

Very best,
Hi, I did post an image of the set up. I'll try to find the reference.

Found it.... viewtopic.php?f=4&t=24562&p=220910&hilit=RCT#p220910

Cheers

Stu.
Ahh yes, I remember that now. I always wondered what the components were. And that Lunt is just inserted right into another scope, kind of like a PST stage I mod? That cell that holds the scope is super interesting. I imagine custom machined?

Forgive my non-stop questions, I'm trying to piece together a potential 8 inch HA scope setup, using a C8 and a crayford focuser on the back and I'm trying to find better options than just using a PST etalon, such as the 35mm Lunt option, or a SolarMax II 40mm cell in some way. Not sure yet.

Thanks!

Very best,

Re: Saturday Sun 11th Aug

Posted: Sat Aug 11, 2018 7:49 pm
by Carbon60
MalVeauX wrote:
Sat Aug 11, 2018 6:10 pm
Carbon60 wrote:
Sat Aug 11, 2018 4:31 pm
MalVeauX wrote:
Sat Aug 11, 2018 4:09 pm
Nice resolution!

Would love to see how you fitted that Lunt 35mm to the RC!

Very best,
Hi, I did post an image of the set up. I'll try to find the reference.

Found it.... viewtopic.php?f=4&t=24562&p=220910&hilit=RCT#p220910

Cheers

Stu.
Ahh yes, I remember that now. I always wondered what the components were. And that Lunt is just inserted right into another scope, kind of like a PST stage I mod? That cell that holds the scope is super interesting. I imagine custom machined?

Forgive my non-stop questions, I'm trying to piece together a potential 8 inch HA scope setup, using a C8 and a crayford focuser on the back and I'm trying to find better options than just using a PST etalon, such as the 35mm Lunt option, or a SolarMax II 40mm cell in some way. Not sure yet.

Thanks!

Very best,
No probs with the questions. Just thought I'd point out that the Lunt is not simply connected to the rear of the RCT. There has to be a negative focus lens (correction lens) in place ahead of the Lunt in order to diverge the light cone from the donor scope such that is enters the Lunt etalon substantially normal to it.

The focal ratio and position of this lens will depend on the donor scope.

The 'cell' is indeed custom made, including the extension element on the front which carries the correction lens.
Lunt35 adapter (3).jpg
Lunt35 adapter (3).jpg (792.01 KiB) Viewed 357 times
I hope this helps.

Stu.

Re: Saturday Sun 11th Aug

Posted: Sun Aug 12, 2018 12:43 am
by ffellah
Great results for such a close-up image, Stu ! I also like your "soft" processing of the image, without too much hard contrast.

Your big gun is definitely working: I hope you will have excellent seeing conditions in the future to use it more.

Franco :bow

Re: Saturday Sun 11th Aug

Posted: Sun Aug 12, 2018 12:59 am
by rsfoto
Great Close-Up

Re: Saturday Sun 11th Aug

Posted: Sun Aug 12, 2018 12:01 pm
by Derek Klepp
Well done Stu you really are getting some good results.

Re: Saturday Sun 11th Aug

Posted: Sun Aug 12, 2018 1:03 pm
by marktownley
Super closeups there Stu!

Re: Saturday Sun 11th Aug

Posted: Sun Aug 12, 2018 1:20 pm
by Ibbo
nicely done Stu

Re: Saturday Sun 11th Aug

Posted: Sun Aug 12, 2018 4:22 pm
by krakatoa1883
Fantastic resolution and very good processing. The Lunt 35 is a really fine scope.

Re: Saturday Sun 11th Aug

Posted: Sun Aug 12, 2018 11:38 pm
by eroel
Stu:
A very nice big gun setup, at least you have tried your 250mm ERF, I have not yet used my 265mm Aries ERF for my 250mm Maksutov. :oops:
Bad weather and remodelation have not let me. :(
Best regards,
Eric.

Re: Saturday Sun 11th Aug

Posted: Mon Aug 13, 2018 2:09 pm
by Montana
I really like version 2 the best, nice work Stu :hamster: :bow
Alexandra

Re: Saturday Sun 11th Aug

Posted: Mon Aug 13, 2018 9:34 pm
by Carbon60
Many thanks, everyone. I really appreciate your comments.

Eric, I hope you get to set up yours sometime soon.

Stu.

Re: Saturday Sun 11th Aug

Posted: Mon Aug 13, 2018 9:38 pm
by Carbon60
Montana wrote:
Mon Aug 13, 2018 2:09 pm
I really like version 2 the best, nice work Stu :hamster: :bow
Alexandra
Thanks, Alexandra. I agree with you, but it really took quite some effort to squeeze out every drop of data with minimal noise. It's so difficult when the seeing conditions don't cooperate.

Stu.