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Possibly one of the last active regions of cycle 24? AR12757 ends january with decent activity for solar minimum. Taken by Marty Wise with his 8" SCT, Aries ERF and PST mod.

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by bart1805
Tue Jan 28, 2020 9:08 am
Forum: This is SolarChat !!
Topic: AR2757 January 26th, 2020
Replies: 16
Views: 195

Re: AR2757 January 26th, 2020

Hi Franco, looking at your images it works! I used the PST etalon with the lenses straight on my 7 inch Intes. AOK made an adapter to mount it directly to the back of the telescope. A PST etalon at f/27 is maybe a bit less narrow than in the original configuration with the lenses at f/10. Christian ...
by bart1805
Mon Jan 27, 2020 9:16 pm
Forum: This is SolarChat !!
Topic: AR2757 January 26th, 2020
Replies: 16
Views: 195

Re: AR2757 January 26th, 2020

Hi Franco,
Nice set-up. Second image is a big improvement!
Why do you choose to use the PST etalon in a Telecentric beam? You could choose to use it with the collimating lenses, the Celestron is f/10.
CS! Bart.
by bart1805
Sun Jan 26, 2020 11:42 am
Forum: This is SolarChat !!
Topic: PST MODs
Replies: 7
Views: 232

Re: PST MODs

Good to see the Denkmeier mod in the Portugese sun Pedro! Good luck with it.
by bart1805
Sun Jan 19, 2020 4:07 pm
Forum: Solar Scope Modifications
Topic: Baader 1.25x GPC with PST Mod, How to Mount the GPC?
Replies: 12
Views: 254

Re: Baader 1.25x GPC with PST Mod, How to Mount the GPC?

If your telescope you are using it with has 16cm backfocus or more, why would you put the glasspath more to the front? Just mount it in the nosepiece of and right before the etalon.
by bart1805
Mon Jan 13, 2020 9:13 pm
Forum: Solar Astronomy Shop and Swap
Topic: Astrosolar, SM40, doublestack your pst etalons etc.
Replies: 6
Views: 400

Re: Astrosolar, SM40, doublestack your pst etalons etc.

BF30, Skybender and Spectrum upgrade (plus one of the adapters for the SM40) are sold, so updated the first post.
by bart1805
Mon Jan 13, 2020 9:05 pm
Forum: Solar Scope Modifications
Topic: PST modification - idiots guide
Replies: 38
Views: 1721

Re: PST modification - idiots guide

Yes Alexandra, that is no problem. A bit further back could be nice to see more of the sun (when the BF is small), but for HR imaging it is fine.
by bart1805
Mon Jan 13, 2020 8:55 pm
Forum: Solar Scope Modifications
Topic: How close to F10 must a PST mod truly be?
Replies: 14
Views: 290

Re: How close to F10 must a PST mod truly be?

Yes Andy, that is how it works. Here is an example of a result with a 150mm f/8 Skywatcher, mounted in the nosepiece of the etalon was the glass path. https://solarchatforum.com/viewtopic.php?f=4&t=25937&p=233583#p233583 Idea comes from banjo, he produces a steady stream of beautiful images with (I ...
by bart1805
Sun Jan 12, 2020 9:30 am
Forum: Solar Scope Modifications
Topic: How close to F10 must a PST mod truly be?
Replies: 14
Views: 290

Re: How close to F10 must a PST mod truly be?

When a telescope is f/8 you place the glasspath (mounted right before the etalon) at minus 160mm. More about this in this thread:
viewtopic.php?f=9&t=26808
by bart1805
Tue Jan 07, 2020 10:27 am
Forum: Solar Astronomy Shop and Swap
Topic: Astrosolar, SM40, doublestack your pst etalons etc.
Replies: 6
Views: 400

Re: BF30 (sold), Spectrum60 upgrade, doublestack your pst etalons etc.

pedro wrote:
Tue Jan 07, 2020 9:03 am
I'm interested in the Upgrade for Coronado PST
You have got mail Pedro and the upgrade is reserved for you.
CS! Bart.
by bart1805
Wed Dec 25, 2019 4:54 pm
Forum: Solar Astronomy Shop and Swap
Topic: Astrosolar, SM40, doublestack your pst etalons etc.
Replies: 6
Views: 400

Astrosolar, SM40, doublestack your pst etalons etc.

Merry christmas for everyone and a beautiful, healthy, sunny and active 2020! Some pieces for sale. Will miss them but need the funds after buying a secondhand SolarSpectrum. CS! Bart. Baader Astrosolar 3.8. BDSF 180mm. https://www.baader-planetarium.com/en/solar-observation/baader-solar-filter/bdsf...
by bart1805
Mon Dec 23, 2019 8:16 pm
Forum: This is SolarChat !!
Topic: Solar Analemma 2016-2019
Replies: 20
Views: 317

Re: Solar Analemma 2016-2019

Congratulations Alexandra, beautiful piece of work!!
by bart1805
Sun Nov 24, 2019 7:08 pm
Forum: Solar Scope Modifications
Topic: Took my Lunt LS50T apart to measure stuff - interesting results...
Replies: 12
Views: 518

Re: Took my Lunt LS50T apart to measure stuff - interesting results...

Remarkable, and worth the test of putting the etalon a few centimes more to the back.
by bart1805
Sun Nov 24, 2019 11:42 am
Forum: Solar Scope Modifications
Topic: "Magic" distance of Lunt LS50PT etalon from focal plane?
Replies: 15
Views: 553

Re: "Magic" distance of Lunt LS50PT etalon from focal plane?

marktownley wrote:
Sun Nov 24, 2019 11:07 am
I suppose we should define front and back too - my 'front' would be objective side, my back would be etalon side ;)
We agree. (-;
by bart1805
Sun Nov 24, 2019 10:53 am
Forum: Solar Scope Modifications
Topic: "Magic" distance of Lunt LS50PT etalon from focal plane?
Replies: 15
Views: 553

Re: "Magic" distance of Lunt LS50PT etalon from focal plane?

Ah great! I guess that's the diameter of the etalon x the focal ratio of the objective - makes sense. That 140mm is measured from the focal plane to which part of the etalon unit? To the back of the unit, so the back lens. I'd say the front lens Bart, but sat here reflecting on it all with my coffe...
by bart1805
Sat Nov 23, 2019 9:29 pm
Forum: Solar Scope Modifications
Topic: "Magic" distance of Lunt LS50PT etalon from focal plane?
Replies: 15
Views: 553

Re: "Magic" distance of Lunt LS50PT etalon from focal plane?

Roel80 wrote:
Sat Nov 23, 2019 12:02 pm
Ah great! I guess that's the diameter of the etalon x the focal ratio of the objective - makes sense.
That 140mm is measured from the focal plane to which part of the etalon unit?
To the back of the unit, so the back lens.
by bart1805
Tue Nov 12, 2019 8:54 pm
Forum: This is SolarChat !!
Topic: Mercury transit and proms
Replies: 16
Views: 371

Re: Mercury transit and proms

Congratulations, beautiful pictures and great processing! Thanks!
by bart1805
Sun Nov 10, 2019 8:43 pm
Forum: This is SolarChat !!
Topic: Sun in Ca II K - Bad seeing 20191110
Replies: 5
Views: 195

Re: Sun in Ca II K - Bad seeing 20191110

Hi Stu, the one without the Barlow, with the 1920 is by far the best. If the seeing tomorrow is as bad as it was today, that would be the one to go for in my opinion. Wish you all the luck (and a great seeing)! Bart.
by bart1805
Sun Nov 03, 2019 6:20 pm
Forum: This is SolarChat !!
Topic: How to locate the Dust Bunnies
Replies: 6
Views: 497

Re: How to locate the Dust Bunnies

Most of the time it is the camera. So check what you see if you aim just the camera to a light source.
Did you check the sensor or cleaned only the protective window?
by bart1805
Sat Nov 02, 2019 10:29 pm
Forum: This is SolarChat !!
Topic: Which etalon is better? Please, look, think and vote.
Replies: 12
Views: 1034

Re: Which etalon is better? Please, look, think and vote.

I agree with Mark. Both excellent.
by bart1805
Sat Nov 02, 2019 10:27 pm
Forum: This is SolarChat !!
Topic: Black 3.0
Replies: 5
Views: 493

Re: Black 3.0

Hi Bart, I’ll be very interested to hear your assessment of black 3. :) Stu. Hi Stu, It is for sure more black than the Berger Antireflexfarb. When you see them next to each other, the Berger paint is more super dark grey. And yes, I agree with what you say: at acute angles there is still some refl...
by bart1805
Wed Oct 30, 2019 3:52 pm
Forum: This is SolarChat !!
Topic: We met the goal!...barely...:)
Replies: 4
Views: 446

Re: We met the goal!...barely...:)

Cool, that is good news!!
by bart1805
Sat Oct 26, 2019 1:00 pm
Forum: Solar Scope Modifications
Topic: A 6" f/8 PST mod? Are we kidding ourselves?
Replies: 30
Views: 1835

Re: A 6" f/8 PST mod? Are we kidding ourselves?

(150/1500) * 200 = 20 mm. It is the same as
(150/1200) * 160.
by bart1805
Sat Oct 26, 2019 11:25 am
Forum: Solar Scope Modifications
Topic: A 6" f/8 PST mod? Are we kidding ourselves?
Replies: 30
Views: 1835

Re: A 6" f/8 PST mod? Are we kidding ourselves?

If it it satisfies me is not so important, if it works is the question. Yes, this is perfect.
now find the minus 160mm spot and place the GP there. Good luck!
by bart1805
Sat Oct 26, 2019 11:23 am
Forum: Solar Scope Modifications
Topic: 12" White light Newtonian
Replies: 7
Views: 531

Re: 12" White light Newtonian

marktownley wrote:
Sat Oct 26, 2019 10:58 am
bart1805 wrote:
Sat Oct 26, 2019 8:20 am
Don't forget to de-aluminise the secondary mirror!
Depends how much light you want coming through 😉
Yep, you are absolutely right!