SolarChat!

mark,
Yes. Just put the filters in front of the spectroscope and pointed to the Sun.
The intensity values are on the same scale ie the etalon gave a reading of 194000 (1sec)whereas the BF only gave about 44000 in 20sec. (both from a base of approx 40000)

The attached image shows a 1sec exposure through the SM60 etalon. The "comb" extends across the whole spectrum, but should be blocked around 600nm by the ERF. The trace extends from about 580nm to 700nm. The bandpass is 0.8A and spacing 10A. You can see where the solar Ha line sits on the ...

Vanter, I'll find the images of the etalon "comb" and the results with the BF15 and upload later today. I had to use the Spectra-L200 spectroscope to get the high resolution. The MG80 only has a 300 l/mm grating so its designed for lo res spectra. The etalon "comb" I'm sure exten...

Hmmm
When I put the spectroscope on a Ha scope with a good blocking filter/ etalon I don't pick up anything other than the narrowband 0.8A at Ha........

http://www.astrobuysell.com/uk/propview.php?view=52900

There may be some interest in this scope!

Hmmm
Certainly sounds interesting - a 25mm combined Ha/ blocking filter for $200 odd ....
Telescope Service have a couple of filter tilters but I don't think they would be accurate enough for this job....

Are we talking about Solar Ha imaging i.e. with an etalon filter? If so, then the only way of improving things is the double stack. If we're talking white light and additional contrast filters, the best performers seem to be the green filters - continuum or OIII. Andrea, I'd be very interested to he...

I have the Std DMK21 which has worked well for me for the last few years - yes, I think it would be a good upgrade, but my $$$ are going towards a CaK filter set-up. Anyway I have the DMK41 firewire which is good.
Re the QE curves...we generally make the assumption that the peak will be around 60%.

APM - Herschel wedges - http://www.apm-telescopes.net/en/Observe-the-Sun/Optical-Accessories/Herschelwedges.html Baader Herschel wedge / Solar film - www.baader-planetarium.de/ Coronado Ha Scopes - www.meade.com/product_pages/coronado/coronado.php Daystar - www.daystarfilters.com/ Lunt Europe - www....

Have you checked out the solar tutorial on the Registax site?
There's also a section in the library....

Brian, Drop me an email and I'll send you a copy of the "PST Mods" write-up.... The BF should be as close to the CCD as possible. The PST etalon assembly has a built in barlow at the front hence the magic -200mm and then a re-imaging lens at the rear which gives the f10 beam. There's anoth...

Stephen,
I think you've given us solar guys and gals somewhere to call "Home"
Appreciated!

I have the DMK21 usb and a DMK41-firewire.
Steady, capable cameras - I can even use the larger chipped DMK41 for the spectroscope.

In your experience, what's a suitable load for the Vixen Porta Mount II??
I'm looking at getting a s/h one for the 88mm modded PST

Looking very good!
I'm sure there are many more excellent images still to come.
Well done.

Roel,
excellent solution! Definately looks like a fully finished professional instrument.
Well done!!

OK.
I haven't found an PST etalon yet that would not unscrew using two industrial strength BOA wrenches.....

The original "ol' gold" PST etalon were relatively easy to remove; the first couple of batches from the Mexican assembly plant were overloaded with loctite and are VERY difficult to separate..the latest PST's don't seem to be as bad....

Well done! Looking good.... The Stage 2 mod results even with a BF5 are always better than Stage 1!!!! (The next thing you need for aesthetics to to make a tube adaptor between the SCT focuser and the end of the OTA - a lever clamped on the PST adjusting ring and a slot in the tube would give that &...

Geee
I like the CaK image!
One of these days I'm going to get an image like that!

Very well done!
Looks like you have a great teaching set up there...
When you want to install a spectrohelioscope/ spectroscope in the beam after the Meade refractor...let me know, I can help.

It's true what they say...
Every hour, everyday is different in solar observing...nothing boring here!
Well done, your efforts are appreciated by all.

Another vote for the larger etalon....

It's got to be a PST etalon with a tuning lever added to allow tuning from the outside of the OTA. Probably mounted onto the front SCT threads of the focuser....
Is that correct, Roel?
(I had a similar arrangement on a El Cheapo 90mm mod....)

OK, let me re-phrase...
If you elect to remove the inside etalon ERF....would replacing the exterior etalon ERF with a Baader D-ERF make a significant improvement....
( The reason I ask is the added significant cost of the Baader....)

Mark,
Do you think the performance improvement from the original ERF to the Baader D-ERF makes such a difference?

I've been in transit for the last couple of days with limited web access. I'll catch up with the Library additions early next week.
Thank's for the continued imput.

Removing BOTH ERF filters for the etalons in a double stack will certaintly improve the light and energy throughput; but, before all the energy reaches the eyepiece/ camera most of it still has to be removed... If the "secondary" ERF is internal then the absorbed/ reflected energy (dependi...

Very impressive!
You do a great job.

(Well worth spending a few minutes looking carefully at Jim's images to compare the views at 0.8A and 0.5A - you can see the differences in the surface detail and the filaments....)

Great start.
Shows the potential is there...a bit more practise and you'll be even more impressed.

Kev, Peter and many others use a 100mm aperture with the PST mod.
I'm currently using a 90/880 Meade "First scope" as a donor for a 88mm mod. Works very well.
Remember you can always add a suitable external etalon (SM60 etc) to get a double stack, narrowband, with your PST mod.

That new sunspot looks really interesting...good catch!

Alexandra,
I've added the book.

IMHO for the PST assembly the "sweet spot" of f10 aperture seems to be around 100mm.
(I have a comprehensive write-up available on PST Mods - just need an email address to send a copy)

"Guide to the Sun" by Kenneth H.J. Phillips, Cambridge, 1995 http://books.google.co.uk/books?id=idwBChjVP0gC&printsec=frontcover&dq=guide+to+the+Sun&hl=en&sa=X&ei=BWFGT8T5B-2V0QWu9qWVDg&ved=0CDIQ6AEwAA#v=onepage&q=guide%20to%20the%20Sun&f=false "The Sun...

Chris, Great idea...but unfortunately no.. The issue is the f10 beam requirement (unless you're going to get involved with some special optics - which can be done - at a cost) and the size of the solar disk at the etalon when positioned at the magic 200mm inside prime focus. Your 10" (250mm) sc...

If you have any book (or eBook) recommendation for the library listing let me know.
I'll check through my collection for starters....

That's pretty good for a PST etalon!!
Impressive.

I see there's a neat sunspot and AR just creeping into view on the north east.....

Thanks for the suggestions....links added to the Library.

(Based on users and developers comments on other threads) Basic intro: Alexandra:....try and start with a simple picture, say one of your nice WL ones with a spot in the middle. Start ASK2 up Click open, and open your file Click the dot to say 'surface' Now go over to the picture frame and point you...

http://www.avistack.de/
http://www.astronomie.be/registax/
http://www.autostakkert.com/

Can't see the images without logging in in Dutch...
The Schott is a type of glass ie RG610

I think you've come a long way from those "humble beginnings"
If we had "The Image of the Month" compo - I'd definately vote for yours!
Anyone who can achieve those results from a PST has my admiration!

I'd lay a pound to a penny is one of the old Schott glass ERF, Still works well, but doesn't have the same IR cut-off (and bandwidth) as the current D-ERF versions.

The original C-ERF from Baader were different...maybe you have one of those. Does it have a highly reflective front surface or just looks a dark red?

from what I understand (I think Mark has more info...)
The Baader CaK has a bandwidth of 80A
The PST CaK and the Lunt have bandwidths of 2.2A and 2.4A respectively.
If this is correct, then I'd have to say that the narrower bandwidth would give better resolution in the Cak region.

Neat piece of gear!
What do you think the maximum load carry capacity would be?

Mark,
By default there's a lot of detail over in the "Solar Scope Modifications" section, but yes, we don't have a "show and tell" area.....yet!

I'll use this thread to keep everyone uptodate with additions and changes to the "virtual Library" material.
I've just added links to the SOHO and GONG sites.

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