Search found 3970 matches

by Merlin66
Sun May 13, 2012 5:53 am
Forum: Solar Scope Modifications
Topic: Removing BF5 filter and placing on camera?
Replies: 4
Views: 902

Re: Removing BF5 filter and placing on camera?

Peter,
Anything's possible. It may help the FOV but I don't think it will affect the hot spot...
Where ever you place it make sure it's sitting square.
The bandwidth of the BF is already designed for the etalon finesse so there's no additional benefit in double stacking....
by Merlin66
Sat May 12, 2012 2:34 pm
Forum: This is SolarChat !!
Topic: William Optics Megrez 80SD or other for CaK and WL?
Replies: 15
Views: 1509

Re: William Optics Megrez 80SD or other for CaK and WL?

Gabor,
If you can, think about the HEQ5pro version...it's 100% better than the standard EQ5....
by Merlin66
Sat May 12, 2012 2:33 pm
Forum: This is SolarChat !!
Topic: Ha and WL - 2012-05-12
Replies: 20
Views: 1419

Re: Ha and WL - 2012-05-12

It would be really great if we could ALL agree to use the same orientation...
Bass has North to the top:
http://bass2000.obspm.fr/ephem.php

Any chance we can agree and present all our images with the same orientation????
by Merlin66
Sat May 12, 2012 2:27 pm
Forum: This is SolarChat !!
Topic: William Optics Megrez 80SD or other for CaK and WL?
Replies: 15
Views: 1509

Re: William Optics Megrez 80SD or other for CaK and WL?

Gabor, I have an original TV Genesis, serial #0007 - it's a great scope...BUT For solar I've been using an SW ED80pro (2" TS focuser)-DS SM60 and a Vixen M80aF - 88mmPST mod/ WL with wedge (again with a TS 2" focuser) - I also use the SW accu-motor for focusing. They work very well on the ...
by Merlin66
Sat May 12, 2012 1:24 pm
Forum: This is SolarChat !!
Topic: William Optics Megrez 80SD or other for CaK and WL?
Replies: 15
Views: 1509

Re: William Optics Megrez 80SD or other for CaK and WL?

Hmmm
I use many different refractors for spectroscopy and have to image the spectrum all the way from 380nm out into the NIR. Other than the refocusing issues I've never had a significant problem....
by Merlin66
Sat May 12, 2012 1:12 pm
Forum: This is SolarChat !!
Topic: William Optics Megrez 80SD or other for CaK and WL?
Replies: 15
Views: 1509

Re: William Optics Megrez 80SD or other for CaK and WL?

Gabor, Don't get misled about achromats and chromatic focus/ field curvature.. This really only becomes an issue when you try to do full spectrum imaging ie blue to red in the same image - like DSO stuff. When you use it for solar you're working basically in monochromatic light. ie Ha, CaK or narrow...
by Merlin66
Sat May 12, 2012 1:02 pm
Forum: This is SolarChat !!
Topic: First Light DMK51
Replies: 20
Views: 1276

Re: First Light DMK51

Great results from what looks a very promising camera!
Geee all you need to add to the video is a series in WL -Continuum filter and then you have the full view...pretty neat.
Well done!
by Merlin66
Sat May 12, 2012 8:55 am
Forum: This is SolarChat !!
Topic: Double-Stack Question
Replies: 4
Views: 461

Re: Double-Stack Question

I'm not aware of any real need to get double stack etalons "factory tuned".
I and many others successfully use external double stacks with no issues.
Yes,
finding the best tuning position can be a bit of fun....but no real problem.
I'm sure others will also comment.
by Merlin66
Sat May 12, 2012 6:28 am
Forum: This is SolarChat !!
Topic: Problem with blocking filter
Replies: 5
Views: 834

Re: Problem with blocking filter

It seems strange that both in the Coronado and the Lunt offerings that this "mini-erf" element can fail so quickly... I would have thought the previous 10 years experience and current coating technology would have resolved this issue. (I had major problems convincing a local UK supplier th...
by Merlin66
Sat May 12, 2012 6:20 am
Forum: This is SolarChat !!
Topic: WL WEDGE - LUNT or BAADER? or SCOPIUM?
Replies: 10
Views: 1115

Re: WL WEDGE - LUNT or BAADER? or SCOPIUM?

Hmmm
It looks like a 1.25" size unit....
Can't figure out where the "heat dump" is..
Never heard of it or seen it before...
by Merlin66
Fri May 11, 2012 3:25 pm
Forum: This is SolarChat !!
Topic: WL WEDGE - LUNT or BAADER? or SCOPIUM?
Replies: 10
Views: 1115

Re: WL WEDGE - LUNT or BAADER? or SCOPIUM?

I have and occasionally use an ED80 (as well as the Vixen 80/910) for white light ( when the clouds permit) - the DIY wedge based on a Surplus Shed flint prism gave excellent views! Even an ol' cynic like me was impressed!! I was recently lucky enough to pick up a Baader "cool" wedge, and ...
by Merlin66
Fri May 11, 2012 3:13 pm
Forum: This is SolarChat !!
Topic: 2012-05-08: AR11476 and ARs11471 and 11472 in closeup (up-dated)
Replies: 21
Views: 1556

Re: 2012-05-08: AR11476 and ARs11471 and 11472 in closeup (up-dated)

Amazing detail!
THIS is what it's all about!!!
A good Ha filter system with a narrow bandwith (<0.4A)- just makes things happen!!!
Well done!
by Merlin66
Fri May 11, 2012 6:46 am
Forum: Solar Astronomy Shop and Swap
Topic: Compact Littrow Spectrohelioscope - Any interest in an "IKEA" Kit???
Replies: 38
Views: 5227

Re: Compact Littrow Spectrohelioscope - Any interest in an "IKEA" Kit???

Peter,
Yes, there are still some challenges!
There are a few software solutions around, I don't think that will be the problem and the more people who get involved in spectrohelioscopes the more we'll drive the boundaries....
(If you catch up with Maurice - pass on my regards!)
by Merlin66
Thu May 10, 2012 3:55 pm
Forum: Solar Astronomy Shop and Swap
Topic: Compact Littrow Spectrohelioscope - Any interest in an "IKEA" Kit???
Replies: 38
Views: 5227

Re: Compact Littrow Spectrohelioscope - Any interest in an "IKEA" Kit???

Colin,
Is there any real reason you would consider a mechanical spectrohelioscope, when the "electronic" version seems much easier to make and just as capable???
by Merlin66
Thu May 10, 2012 6:13 am
Forum: Solar Astronomy Shop and Swap
Topic: Compact Littrow Spectrohelioscope - Any interest in an "IKEA" Kit???
Replies: 38
Views: 5227

Re: Compact Littrow Spectrohelioscope - Any interest in an "IKEA" Kit???

Colin/ mark, I'll do some sketches to show the layout, but at this stage think in terms of a 1.5Kg box, 80mm x 120mm x 350mm. I already have access to the polished stainless steel slit blades. The collimator would be a 600mm focal length, folded and a micrometer head adjuster for the 50mm grating......
by Merlin66
Wed May 09, 2012 6:21 pm
Forum: Solar Scope Modifications
Topic: Large Aperture Solar Telescope Using Double Stacked Coronado Etalons.
Replies: 42
Views: 6768

Re: Large Aperture Solar Telescope Using Double Stacked Coronado Etalons.

For any collimated secondary systems, the collimating lens will be "aperture stopped" to the scope f ratio. ie f10 in gives f10 out, even if the secondary lens is say f8. The distance between the lenses is determined by the focal lengths , not the focal ratios.
by Merlin66
Wed May 09, 2012 6:17 pm
Forum: Solar Scope Modifications
Topic: Large Aperture Solar Telescope Using Double Stacked Coronado Etalons.
Replies: 42
Views: 6768

Re: Large Aperture Solar Telescope Using Double Stacked Coronado Etalons.

Only because the original PST arrangement was designed for an f10 beam. This gives the 200/10 etalon dimensions....
by Merlin66
Wed May 09, 2012 3:57 pm
Forum: This is SolarChat !!
Topic: AR11476 - The Monster Grows!
Replies: 21
Views: 1359

Re: AR11476 - The Monster Grows!

Who said observing the Sun was boring.......
by Merlin66
Wed May 09, 2012 1:38 pm
Forum: Solar Astronomy Shop and Swap
Topic: Compact Littrow Spectrohelioscope - Any interest in an "IKEA" Kit???
Replies: 38
Views: 5227

Re: Compact Littrow Spectrohelioscope - Any interest in an "IKEA" Kit???

Stephen,
This site is 100% solar!
What about "Radio and Spectroscopy" ??
by Merlin66
Wed May 09, 2012 1:25 pm
Forum: Solar Astronomy Shop and Swap
Topic: Compact Littrow Spectrohelioscope - Any interest in an "IKEA" Kit???
Replies: 38
Views: 5227

Re: Compact Littrow Spectrohelioscope - Any interest in an "IKEA" Kit???

Stephen, Thanks for the offer... I'd be happy just putting any "technical" stuff under the Solar telescope section.. (We should rename it to something like" Solar instruments" - there needs to be an area for general equipment - telescopes - standard filters - cameras not just for...
by Merlin66
Wed May 09, 2012 1:02 pm
Forum: Solar Astronomy Shop and Swap
Topic: Compact Littrow Spectrohelioscope - Any interest in an "IKEA" Kit???
Replies: 38
Views: 5227

Re: Compact Littrow Spectrohelioscope - Any interest in an "IKEA" Kit???

Sorry mate, they are only available to members as an "IKEA" Kit.
(The idea is - as you assemble it you gain a better understanding of how it works)
by Merlin66
Wed May 09, 2012 12:51 pm
Forum: Solar Astronomy Shop and Swap
Topic: Compact Littrow Spectrohelioscope - Any interest in an "IKEA" Kit???
Replies: 38
Views: 5227

Re: Compact Littrow Spectrohelioscope - Any interest in an "IKEA" Kit???

Stephen, You're not alone! I have about 400 members on my yahoo group "astronomical_spectroscopy" most of whom have had the same concern. The commercial units are very good (Baader Dados, Shelyak LISA/LhiresIII and the SBIG DDS7/SGS)but very pricy. About three years ago I started building ...
by Merlin66
Wed May 09, 2012 11:53 am
Forum: Solar Astronomy Shop and Swap
Topic: Compact Littrow Spectrohelioscope - Any interest in an "IKEA" Kit???
Replies: 38
Views: 5227

Re: Compact Littrow Spectrohelioscope - Any interest in an "IKEA" Kit???

I'll cost it up over the next few days, but based on the Spectra-L200 Kit, I'd say around $750. It's possible to use it visually as a very high resolution solar spectroscope - the FOV would probably be 120A wide. Use the Liege Solar spectrum website to get an idea of the coverage and resolution. As ...
by Merlin66
Wed May 09, 2012 8:26 am
Forum: Solar Scope Modifications
Topic: Maximum diameter or optical resolution possible with a PST modded telescope?
Replies: 4
Views: 641

Re: Maximum diameter or optical resolution possible with a PST modded telescope?

I'm not sure I understand the second part of your question... I think there is some limit to amount of resolution you can get, thus a camera beyond X? pixels is pointless.. The resolution you obtain will be a result of the seeing conditions, the optical resolution of the objective you use and effect...
by Merlin66
Wed May 09, 2012 7:10 am
Forum: This is SolarChat !!
Topic: White Light filtering comparisons in poor seeing
Replies: 6
Views: 499

Re: White Light filtering comparisons in poor seeing

Under poorer seeing conditions, I think you're correct.
I do notice in the bottom of the sunspot - umbra to penumbra region that the clarity seems better with the Continuum filter. Like wise the granulation...
by Merlin66
Wed May 09, 2012 7:05 am
Forum: Solar Astronomy Shop and Swap
Topic: Compact Littrow Spectrohelioscope - Any interest in an "IKEA" Kit???
Replies: 38
Views: 5227

Compact Littrow Spectrohelioscope - Any interest in an "IKEA" Kit???

I'm currently in the middle of a batch build of twenty Spectra-L200 spectroscopes. Seeing all the components lying around and thinking about all the recent discussion on expensive filters and bandwiths, made me investitage the possiblity of making a spectrohelioscope Kit. This would have everything ...
by Merlin66
Wed May 09, 2012 5:57 am
Forum: Solar Scope Modifications
Topic: Large Aperture Solar Telescope Using Double Stacked Coronado Etalons.
Replies: 42
Views: 6768

Re: Large Aperture Solar Telescope Using Double Stacked Coronado Etalons.

The end result would be based on the scope f ratio...if this is f10.9 then that's the beam which goes through to the collimating scope.
The collimator should give a parallel collimated output. the extreme edges of the suns disk will then give the f/105
by Merlin66
Tue May 08, 2012 6:58 pm
Forum: This is SolarChat !!
Topic: "Astrophysics of the Sun" - Harold Zirin -First read through
Replies: 24
Views: 3377

Re: "Astrophysics of the Sun" - Harold Zirin -First read through

I recently bought my copy through Abe books.
Check out the usual suspects - Alibris/ Amazon.
Well worth finding a copy!!
by Merlin66
Tue May 08, 2012 6:49 pm
Forum: This is SolarChat !!
Topic: Any tricks to getting a flat full solar disk image or 100% sweet spot?
Replies: 14
Views: 1223

Re: Any tricks to getting a flat full solar disk image or 100% sweet spot?

I use a SM60 double stack on an ED80, both at prime and with a x2.5 powermate...
How can I help?
by Merlin66
Tue May 08, 2012 2:30 pm
Forum: This is SolarChat !!
Topic: Solar Filters for imaging??
Replies: 2
Views: 230

Solar Filters for imaging??

The attached pdf file gives some detail on the various solar features which can be imaged and some recommendations for filters. Note that the quantum efficiency curve (QE)of your camera will strongly influence the outcome. Any additions/ corrections/ amendments welcome. If we all agree it has some m...
by Merlin66
Tue May 08, 2012 9:16 am
Forum: This is SolarChat !!
Topic: "Astrophysics of the Sun" - Harold Zirin -First read through
Replies: 24
Views: 3377

Re: "Astrophysics of the Sun" - Harold Zirin -First read through

Brian, I understand your reasoning... Let me quote: "Because the mean free path of a photon inside the Sun is a few centimetres, the photons produced in the core must follow an incredibly long random walk of about 10^21 steps before they reach the photosphere. Even though they travelled at the ...
by Merlin66
Tue May 08, 2012 8:54 am
Forum: This is SolarChat !!
Topic: "Astrophysics of the Sun" - Harold Zirin -First read through
Replies: 24
Views: 3377

Re: "Astrophysics of the Sun" - Harold Zirin -First read through

Part II I've just found out that Harold Zirin died in Jan of this year. It would have been great to meet him.... p100 The photons we record are over 10,000 years old p118 The average lifetime of a granule is 18 mins p157 Spicules (around active areas)are more visible in the Ha red wing (Ha+0.7/1.0) ...
by Merlin66
Tue May 08, 2012 5:31 am
Forum: Solar Scope Modifications
Topic: Maximum diameter or optical resolution possible with a PST modded telescope?
Replies: 4
Views: 641

Re: Maximum diameter or optical resolution possible with a PST modded telescope?

The size of the suns disk is roughly 1/100 the focal length. In a PST mod the etalon must be placed -200mm inside prime focus and the recommended focal ratio is f10. This means the size of the solar disk at the etalon will be (200/10 +fl/100) The etalon is just 20mm diameter, so longer focal lengths...
by Merlin66
Mon May 07, 2012 3:59 pm
Forum: This is SolarChat !!
Topic: 20,000!!!!
Replies: 7
Views: 516

Re: 20,000!!!!

Stephen,
As I said before, you've given us a home!
This is only the beginning.......
by Merlin66
Mon May 07, 2012 1:48 pm
Forum: This is SolarChat !!
Topic: First post - AR1476 and '71
Replies: 22
Views: 1783

Re: First post - AR1476 and '71

Yeah....
It seems to shine everywhere other than Belgium!!
by Merlin66
Mon May 07, 2012 1:36 pm
Forum: This is SolarChat !!
Topic: Vertical lines on CaK images
Replies: 10
Views: 914

Re: Vertical lines on CaK images

Hmm
Which camera are you using?
Frame rate and exposures?
by Merlin66
Mon May 07, 2012 9:46 am
Forum: This is SolarChat !!
Topic: AR1476 Closeup - 6th May
Replies: 16
Views: 1045

Re: AR1476 Closeup - 6th May

Very nice!!
- have you posted any photos for your PST mod?? Couldn't see any...I'd be interested in the final set-up.
by Merlin66
Sun May 06, 2012 6:44 am
Forum: This is SolarChat !!
Topic: From photosphere to chromosphere and back (anim)
Replies: 14
Views: 754

Re: From photosphere to chromosphere and back (anim)

One method I've seen used, to get almost instantaneous WL and Ha images, is to detune the etalon away from Ha enough to give a WL image....
A great results!
Love to see more of this!
by Merlin66
Sat May 05, 2012 10:53 am
Forum: This is SolarChat !!
Topic: 20120429 C8 White Light Sun with ASI130MM
Replies: 9
Views: 857

Re: 20120429 C8 White Light Sun with ASI130MM

Wah!
Welcome on board!
If you're thinking of a PST mod, drop me an email and I'll send you a copy of the PST Mod write-up...all you need to know.
by Merlin66
Sat May 05, 2012 10:15 am
Forum: Solar Scope Modifications
Topic: Orion ED80 conversion
Replies: 4
Views: 930

Re: Orion ED80 conversion

Yes, the SM40 (or the SM60) is a good match for the ED80.
Well done!
by Merlin66
Fri May 04, 2012 1:16 pm
Forum: This is SolarChat !!
Topic: Lunt Vs Baader Herschel Wedges
Replies: 9
Views: 1408

Re: Lunt Vs Baader Herschel Wedges

And the Baader has the "sexy" case!
I found the internal filter adaptor is also a T thread - I can fit a T thread to C thread adaptor (for the DMK) directly to the wedge body - neat!
by Merlin66
Fri May 04, 2012 10:29 am
Forum: This is SolarChat !!
Topic: Experiments with Multi Radius Iterative Unsharp Masking
Replies: 46
Views: 3058

Re: Experiments with Multi Radius Iterative Unsharp Masking

I'll review and edit the contents of this thread and upload to the library.
by Merlin66
Fri May 04, 2012 1:08 am
Forum: This is SolarChat !!
Topic: Camera Feature Spreadsheet
Replies: 7
Views: 301

Re: Camera Feature Spreadsheet

Brian,
I haven't downloaded your spreadsheet yet, but this listing may also be of assistance...
http://www.licha.de/astro_article_ccd_s ... p?iOrder=2
(Resolution is usually based on a sampling of 2 pixels for mono and up to 4 for colour chips. Plate scale is sec/pixel etc)
by Merlin66
Fri May 04, 2012 1:00 am
Forum: Solar Scope Modifications
Topic: Large Aperture Solar Telescope Using Double Stacked Coronado Etalons.
Replies: 42
Views: 6768

Re: Large Aperture Solar Telescope Using Double Stacked Coronado Etalons.

Bob,
I'm sure your concept will work.
I had a 90mm version using a SM40 etc.....
Look forward to seeing your progress...
by Merlin66
Thu May 03, 2012 1:44 pm
Forum: This is SolarChat !!
Topic: Mt Wilson Seeing scale
Replies: 3
Views: 203

Mt Wilson Seeing scale

http://obs.astro.ucla.edu/150_draw.html

I thought this may be of interest to the members.
The Mt Wilson Seeing scale is at the bottom of the page.
Library???
by Merlin66
Thu May 03, 2012 9:36 am
Forum: This is SolarChat !!
Topic: Bill Edelen's new profile pics! You choose!
Replies: 10
Views: 328

Re: Bill Edelen's new profile pics! You choose!

#3 does it for me!!
by Merlin66
Thu May 03, 2012 6:24 am
Forum: This is SolarChat !!
Topic: Whats the difference?
Replies: 1
Views: 149

Re: Whats the difference?

Brian,
Good question.
Reading the Baader notes it seems the quality of the glass substrate(and flatness?) was improved..as was the type of coatings applied.
They both seem to have very similar bandwidths around Ha....
by Merlin66
Wed May 02, 2012 3:51 pm
Forum: Solar Scope Modifications
Topic: Large Aperture solar telescope using a modded Lunt etalon?
Replies: 171
Views: 21974

Re: Large Aperture solar telescope using a modded Lunt etalon?

The lens is very close to 20mm.
But even in the PST there is vignetting!
At 200mm inside foucus the beam width is 20mm, add the size of the sun at 1/100 the focal length and the answer is 24mm.....
by Merlin66
Wed May 02, 2012 2:34 pm
Forum: This is SolarChat !!
Topic: "Astrophysics of the Sun" - Harold Zirin -First read through
Replies: 24
Views: 3377

Re: "Astrophysics of the Sun" - Harold Zirin -First read through

Good point Alexandra...
Maybe instead of worrying about far IR we should be looking for X-ray filters? ;-)