Search found 130 matches

by george9
Thu Feb 13, 2020 10:43 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Available external DS etalons??
Replies: 29
Views: 2807

Re: Available external DS etalons??

The pre-Meade Coronado were very nice but they varied just like today’s filters so be nice to try before buying. I have or had two 60s (astro buddy has them now). One was better than the other. They worked very well together. But my LS80 DSII actually has higher contrast and better sweet spot perfor...
by george9
Tue Feb 11, 2020 5:34 am
Forum: This is SolarChat !!
Topic: Some tests with double stack etalons (mica & FS) and the C8 EdgeHD
Replies: 20
Views: 485

Re: Some tests with double stack etalons (mica & FS) and the C8 EdgeHD

Christian, yes my original blocking filter (for an ASP60) was also 2A (Prom15T), not because it needed 2A but I think because they simply repurposed their old prom filter. Nevertheless, if after tuning you still see a double limb, I would just try the 2A blocking filter and see if it eliminates it. ...
by george9
Wed Feb 05, 2020 12:31 pm
Forum: This is SolarChat !!
Topic: Some tests with double stack etalons (mica & FS) and the C8 EdgeHD
Replies: 20
Views: 485

Re: Some tests with double stack etalons (mica & FS) and the C8 EdgeHD

I agree that with those two filters double stacked and centered, you should eliminate the double limb. If not, then something else is going on. Like leakage on a side spike through the blocking filter. If the space between spikes (FSR?) on one filter is narrower than the blocking filter is made for...
by george9
Mon Feb 03, 2020 4:56 am
Forum: Solar Scope Modifications
Topic: Newtonian vs SCT thermal handling with full aperture D-ERF
Replies: 25
Views: 695

Re: Newtonian vs SCT thermal handling with full aperture D-ERF

Marty, sorry it hasn't worked out (at least yet) but thanks for posting as we learn how to use larger scopes. A Barlow high enough up the light cone might address it by increasing the focal ratio, but then might as well use the SCT. And you would have to make sure it works at 393nm for that work. A ...
by george9
Mon Feb 03, 2020 4:18 am
Forum: This is SolarChat !!
Topic: Some tests with double stack etalons (mica & FS) and the C8 EdgeHD
Replies: 20
Views: 485

Re: Some tests with double stack etalons (mica & FS) and the C8 EdgeHD

Those are awesome images, Christian! The annotation says 0.4 arcsec seeing. If you commonly get that kind of daytime seeing, I wonder what a C14 would show. I agree that with those two filters double stacked and centered, you should eliminate the double limb. If not, then something else is going on....
by george9
Sat Feb 01, 2020 3:29 pm
Forum: Solar Scope Modifications
Topic: Newtonian vs SCT thermal handling with full aperture D-ERF
Replies: 25
Views: 695

Re: Newtonian vs SCT thermal handling with full aperture D-ERF

Regarding the secondary mirror : - On the SC, the f-ratio of the primary is F/1.5, so I would say the secondary of the SC gets a more focused beam. Still, the problem is with the Newtonian, not the SC. So, this is not an explanation. Christian, even thought the SCT primary f-ratio is shorter, would...
by george9
Thu Jan 30, 2020 4:41 am
Forum: Solar Scope Modifications
Topic: Newtonian vs SCT thermal handling with full aperture D-ERF
Replies: 25
Views: 695

Re: Newtonian vs SCT thermal handling with full aperture D-ERF

Like the others, I suspect the hand test is due to the f-ratio. The two secondaries about about the same size, so the power being delivered to them is not too different--8" disc of sunlight compressed to a 2-3" disc--but I am sure the Newtownian is a little smaller. The Baader red CCD will drop some...
by george9
Wed Jan 15, 2020 12:17 am
Forum: This is SolarChat !!
Topic: Visual Solar Observing
Replies: 17
Views: 513

Re: Visual Solar Observing

I do visual only, except real-time monitoring at wavelengths I cannot see, like CaK. Image processing is too much like my day job, so I avoid that. I do love tweaking the equipment because that is more mechanical.

Amen to binoviewers.

George
by george9
Tue Dec 24, 2019 10:37 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Lunt PT O rings
Replies: 2
Views: 211

Re: Lunt PT O rings

When I changed mine, Lunt recommended 34mm ring on the inside and 32mm ring on the outside. That way it was easy to thread on (with the smaller 32 going in first), but the second ring, the 34, being a little bigger and likely to hold air more tightly. It has been working out, but I am thinking of sw...
by george9
Thu Nov 28, 2019 5:15 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Lunt 80 internal double stack questions
Replies: 4
Views: 367

Re: Lunt 80 internal double stack questions

Hi, Carson. I also own the LS80 DSII. The double stack unit will show you details that will be missed single stack during the solar minimum. Subtle active regions, small, dim filaments, small fila-proms, fibrils on the surface, etc. Spicules and prominences will be a little dimmer though. Great advi...
by george9
Fri Nov 15, 2019 12:29 am
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: large spectroheliograph - India
Replies: 10
Views: 488

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: 16
Views: 511

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: 1045

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: 1067

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: 807

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: 1906

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: 3117

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: 983

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: 2958

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: 983

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: 983

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: 2958

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: 880

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: 38
Views: 2138

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: 38
Views: 2138

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...