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Transit of Mercury in the Spicule Layer. Phil took this great image with his Quantum 6 Scope, Solar Spectrum etalon and PGR Camera.

Welcome to Solar Chat! The best forum for Solar Astronomy
Moving forward from solar cycle 24 to 25

Search found 120 matches

by george9
Fri Nov 15, 2019 12:29 am
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: large spectroheliograph - India
Replies: 10
Views: 183

Re: large spectroheliograph - India

Thanks. So nice to see that, and neat that you found it. You can look up the daily sunspot numbers for that day: 41 was recorded.

George
by george9
Tue Nov 12, 2019 5:38 pm
Forum: This is SolarChat !!
Topic: Mercury-Solar Transit Mega Thread | Nov 11th 2019
Replies: 15
Views: 176

Re: Mercury-Solar Transit Mega Thread | Nov 11th 2019

Awesome images, and so nice to help out NPR. Congrats.

George
by george9
Thu Nov 07, 2019 8:50 pm
Forum: This is SolarChat !!
Topic: Anybody going to catch the Mercury Transit?
Replies: 22
Views: 399

Re: Anybody going to catch the Mercury Transit?

I too am hoping for clear skies. I may go small just because of the low chance and don't want to break a big scope down in the rain. Some of you probably saw this on CN, but here is fun thing to do on timing. See how much sooner Mercury hits the Sun (or later it leaves) due to seeing the chromospher...
by george9
Wed Nov 06, 2019 4:14 pm
Forum: Solar Scope Modifications
Topic: PST mod on a C14
Replies: 11
Views: 377

Re: PST mod on a C14

If you use an off-axis mask, you will likely need to tilt the etalon towards the incoming light if the normal tuning range is not wide enough to get to H-alpha with a tilt. E.g., the Quark Combo comes with a tilt adapter for off-axis SCTs.

George
by george9
Mon Nov 04, 2019 2:32 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: 14May2019 Spectroheliograms: A Sunspot Study
Replies: 6
Views: 307

Re: 14May2019 Spectroheliograms: A Sunspot Study

That is very awesome, Peter. I am trying to think how you could see some of this in real time, at least in theory. For line shift and width, only thing I can do now is tune a band back and forth and note the change in view. E.g., in H-alpha (I know this one is not H-alpha) with a pressure tuner, you...
by george9
Thu Oct 24, 2019 3:45 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Lunt monster
Replies: 14
Views: 1247

Re: Lunt monster

Thanks, Bob. I hope they set it up at NEAF. Imagine full disk views through an 12" H-alpha scope. With a 13mm Ethos, you would still be full disk at 160x. And you can binoview those. Or 70x in a 31mm Nagler. If the contrast is like my LS80 DSII with the circular polarizer--and I assume it is better-...
by george9
Thu Oct 17, 2019 8:43 pm
Forum: This is SolarChat !!
Topic: 11" SCT for imaging at 393nm.
Replies: 17
Views: 469

Re: 11" SCT for imaging at 393nm.

Awesome results!

George
by george9
Thu Oct 03, 2019 7:31 pm
Forum: Solar Scope Modifications
Topic: Solar mod using a double stack etalon?
Replies: 18
Views: 533

Re: Solar mod using a double stack etalon?

Thanks, Brian and thanks for the info. Awesome. I was considering trying mine at f/10, too. It seemed to me that a system designed for f/7 should work fine for f/10, as long as you place it so that the final focus (i.e., back focus without any equipment) is the same place as it would have been at f/...
by george9
Thu Oct 03, 2019 7:24 pm
Forum: Solar Scope Modifications
Topic: Easy PST Module with ERF (non-destructive, no cutting of OTA, & no-black-box rebuild)
Replies: 62
Views: 1690

Re: Easy PST Module with ERF (non-destructive, no cutting of OTA, & no-black-box rebuild)

For imaging I expect it is fine. The red-CCD should cover what the camera should be sensitive to. For visual, I am just not that well versed in near-, intermediate, and far-IR. The Lunts are very redundant for safety I know (so that, for example, forgetting the blocking filter doesn't blind you). Wh...
by george9
Wed Oct 02, 2019 1:45 am
Forum: Solar Scope Modifications
Topic: Solar mod using a double stack etalon?
Replies: 18
Views: 533

Re: Solar mod using a double stack etalon?

Also, the Lunt LS60 might be f/8.3, which would be even closer to f/10. But it was nice using the LS80's DSII so that I did not have to modify it in the process; I just tighten it in. George
by george9
Wed Oct 02, 2019 1:42 am
Forum: Solar Scope Modifications
Topic: Solar mod using a double stack etalon?
Replies: 18
Views: 533

Re: Solar mod using a double stack etalon?

James, I use a Lunt DSII etalon (made for LS80) with my Quark on a 155mm f/7 refractor. I picked it because I already owned it and because the f/7 matched. It works well with only a slight reduction in sweet spot size; pretty much unnoticeable visually. It goes: Baader 160mm DERF -> 155mm f/7 scope ...
by george9
Wed Oct 02, 2019 1:07 am
Forum: Solar Scope Modifications
Topic: Easy PST Module with ERF (non-destructive, no cutting of OTA, & no-black-box rebuild)
Replies: 62
Views: 1690

Re: Easy PST Module with ERF (non-destructive, no cutting of OTA, & no-black-box rebuild)

For the 10mm blocking filter, will you skip whatever the mirror is accomplishing? I am guessing it is redundant with your red CCD filter. E.g., in current Lunts, it passes IR out the system instead of reflecting it up into the eyepiece. Not sure about pre-Meade Coronado, but it is the same team. Not...
by george9
Wed Oct 02, 2019 12:40 am
Forum: This is SolarChat !!
Topic: August and September Sun - longest post ever
Replies: 22
Views: 433

Re: August and September Sun - longest post ever

Wonderful shots, and really wonderful green flash. Glad you caught an image, even if it doesn't do justice to the view. George
by george9
Wed Sep 25, 2019 1:09 pm
Forum: Solar Scope Modifications
Topic: PST modification - idiots guide
Replies: 28
Views: 876

Re: PST modification - idiots guide

Put another way, the helical focuser can help in two ways. 1. Because you are unlikely to find spacers of exactly the right length, the helical focuser lets you set the camera exactly 200mm back behind the etalon. Then use the SCT focuser to bring it into focus. How do you get exactly 200mm? If you ...
by george9
Wed Sep 25, 2019 2:50 am
Forum: Solar Scope Modifications
Topic: PST modification - idiots guide
Replies: 28
Views: 876

Re: PST modification - idiots guide

Just curious, with an ERF in front of the C11, why add another HA filter in the back? Assuming the ERF is going to cover UV and IR and most of the visible (simple red glass will not). Is the PST etalon particularly sensitive? By the time you get to the blocker, the etalon comb filter gets rid of mos...
by george9
Mon Sep 23, 2019 12:54 am
Forum: Solar Scope Modifications
Topic: Lunt CaK PST #1 follow up
Replies: 0
Views: 140

Lunt CaK PST #1 follow up

I am using a 92mm f/7 apo with Lunt B1200 CaK followed by a PST #1 filter and then an ASI290, mainly for real-time viewing. It looks pretty sharp even without limiting the aperture. I usually view the disc surface, and I have never noticed extra reflections despite not tilting. In my R2 imager, I th...
by george9
Thu Sep 19, 2019 10:26 pm
Forum: Solar Scope Modifications
Topic: Budget scope for visual
Replies: 18
Views: 581

Re: Budget scope for visual

That's good to hear. I really just don't have the experience. (Do mirrors reflect 5% in UV and IR, etc.)

George
by george9
Thu Sep 19, 2019 5:46 pm
Forum: Solar Scope Modifications
Topic: Budget scope for visual
Replies: 18
Views: 581

Re: Budget scope for visual

Sorry if I am misunderstanding, but I'm not sure I trust a random UV-IR filter to block all appropriate wavelengths bouncing off an uncoated mirror. I would want to actually know or measure the density 200nm to 5000nm. For visual, I would probably ignore light loss off the mirror and see that it dro...
by george9
Wed Sep 18, 2019 5:19 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: PST etalon repair, decontacted?
Replies: 14
Views: 392

Re: PST etalon repair, decontacted?

Then I think I might try just pressing them together and see what happens (if the spacers are still stuck to one side). If they come right apart, I don't think you are any worse off.

George
by george9
Wed Sep 18, 2019 4:44 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: PST etalon repair, decontacted?
Replies: 14
Views: 392

Re: PST etalon repair, decontacted?

I successfully recontacted my Coronado ASP-60 etalon. The hard part was sawing into the etalon chamber without disturbing the etalon or producing any debris whatsoever. Once I got in and saw that the spacers appeared to still be stuck to one side, I literally just pressed the two together. No attemp...
by george9
Thu Sep 12, 2019 8:35 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Lunt monster
Replies: 14
Views: 1247

Re: Lunt monster

The first lens is a 304mm f/7 doublet that looks clear but blocks IR. The second section also has a clear-looking element. The last section has a mirror-like element at the entry. George
by george9
Mon Sep 09, 2019 7:08 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Blocking filters and wintertime
Replies: 17
Views: 499

Re: Blocking filters and wintertime

My Lunt LS80’s B1800 blocking filter begins to show effects at 45F, is noticeably worse at 35F, is not very good at 25F. A 3” dew heater solved the problem. I have not measured whether it is a CWL shift or other induced aberration. The effect is loss of contrast and dimming. I have a new B1800 so I ...
by george9
Tue Aug 27, 2019 12:20 pm
Forum: Solar Astronomy Shop and Swap
Topic: Baader TZ4 Telecentric
Replies: 8
Views: 454

Re: Baader TZ4 Telecentric

It is a telecentric amplifier, so it turns a scope of f/7 to f/28 or say f/10 to f/40. Usually placed before a solid etalon, like a Solar Spectrum or DayStar Quantum or Quark Combo. Maybe a PST etalon with no lenses, but I understand that air-spaced etalons are extra sensitive to focal ratio and f/2...
by george9
Tue Aug 27, 2019 8:36 am
Forum: Solar Astronomy Shop and Swap
Topic: Baader TZ4 Telecentric
Replies: 8
Views: 454

Re: Baader TZ4 Telecentric

(I'll just point out that at this price, it is crazy not to purchase one for a solar experimenter who does not already own one. Mine is working well. George)
by george9
Wed Aug 21, 2019 10:43 pm
Forum: Solar Scope Modifications
Topic: Blocking Filter In a Collimated Beam?
Replies: 10
Views: 527

Re: Blocking Filter In a Collimated Beam?

I put my Lunt 2A prominence filter (from an old Prom 15T blocking filter) in series with my Quark and with my Lunt LS80 SS. It gets darker for sure. It seems a little higher contrast, but hard to tell because darker can fool you and look like more contrast. In fact, I A-B tested the 2A versus an ND ...