Search found 3231 matches

by Merlin66
Wed Feb 13, 2019 6:07 am
Forum: This is SolarChat !!
Topic: Software Section On The Forum
Replies: 14
Views: 142

Re: Software Section On The Forum

Mark,
I like the concept...
What criteria do we apply? Discussions on the actual software? or examples (could be an issue?) using the software?
Do we have a suggested list of software which should/ could be included?
(There are some tutorials already in the Library)
by Merlin66
Wed Feb 13, 2019 4:56 am
Forum: This is SolarChat !!
Topic: The effect of a circular polarizer in a double stack
Replies: 17
Views: 481

Re: The effect of a circular polarizer in a double stack

https://www.edmundoptics.com/resources/ ... aveplates/
George,
Fig 9 shows what I think you are saying....
This infers either way should work.......
by Merlin66
Sat Feb 09, 2019 10:41 pm
Forum: This is SolarChat !!
Topic: Old Coronado BF30
Replies: 27
Views: 1223

Re: Old Coronado BF30

All's well that ends well.
by Merlin66
Sat Feb 09, 2019 3:23 am
Forum: This is SolarChat !!
Topic: The effect of a circular polarizer in a double stack
Replies: 17
Views: 481

Re: The effect of a circular polarizer in a double stack

Here we go..
The video tutorial from Edmund Optics shows the set-up and answers the question.
The section starts a 2:30
https://www.youtube.com/watch?v=NkfLOUr2Z3g
by Merlin66
Tue Feb 05, 2019 5:44 am
Forum: This is SolarChat !!
Topic: The effect of a circular polarizer in a double stack
Replies: 17
Views: 481

Re: The effect of a circular polarizer in a double stack

Trying to come to grips with this "issue" I note that some Variable ND filters using in astronomy (ie "Orion Variable Polarizer") are actually two linear polarizers rotating against each other...... OK, I think the "key" is that the reflections from the etalon surfaces change the direction (left and...
by Merlin66
Mon Feb 04, 2019 11:14 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Available external DS etalons??
Replies: 25
Views: 669

Re: Available external DS etalons??

Mark,
Yeah, I normally do crop...this was just a test shot while tuning the DS.
by Merlin66
Mon Feb 04, 2019 12:16 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Available external DS etalons??
Replies: 25
Views: 669

Re: Available external DS etalons??

As I mentioned, tuning the SM60/ PST DS is ongoing....
This shows, under poor seeing the current status.
Sun_110846_l4_ap3912_conv.jpg
Sun_110846_l4_ap3912_conv.jpg (112.75 KiB) Viewed 223 times
by Merlin66
Mon Feb 04, 2019 12:01 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Available external DS etalons??
Replies: 25
Views: 669

Re: Available external DS etalons??

marty,
If you find a good pre-Meade external SM60 (not the SM60ii) let me know...I've been chasing one for a couple of years!
by Merlin66
Sun Feb 03, 2019 11:13 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Available external DS etalons??
Replies: 25
Views: 669

Re: Available external DS etalons??

Marty, Yes, the original PST f10 etalon arrangement. With the external etalon - it's sitting in a collimated beam - the light from the Sun. Behind it the objective of the scope then focuses the light at the f ratio of the scope ie f7.5 for an ED80. If the front etalon is a 60mm aperture this restric...
by Merlin66
Sun Feb 03, 2019 11:12 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Available external DS etalons??
Replies: 25
Views: 669

Re: Available external DS etalons??

Thinking about it....you could mount the bare PST etalon IN FRONT of the SM60 as a DS, BUT this would limit the effective aperture to 20mm.
No really an interesting option.....
by Merlin66
Sun Feb 03, 2019 10:31 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Available external DS etalons??
Replies: 25
Views: 669

Re: Available external DS etalons??

Marty, If you need any more info.....just ask. The key I think is to get the optimum positioning (and rotation alignment) of the PST etalon assembly - the -200mm Majic number. For completeness I also had for a few years 2007> a double stacked SM60 arrangement on the same ED80 - I thought it was grea...
by Merlin66
Sun Feb 03, 2019 9:55 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Available external DS etalons??
Replies: 25
Views: 669

Re: Available external DS etalons??

Originally I set up the PST mod behind the SM60 back in 2010.... PST SM60 double stack.jpg Later I had a similar set up but using the TS102 Which was interchangeable with the Baader wedge. TS102_PST 006.JPG TS102_Baader 003.JPG This arrangement was then transferred to the ED80 using a further adapto...
by Merlin66
Sun Feb 03, 2019 9:19 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Available external DS etalons??
Replies: 25
Views: 669

Re: Available external DS etalons??

Marty, What you are describing is exactly what I use..... The SM60 is fitted to an ED80 which has the focuser removed to allow the "PST Stage 2" mod to be fitted as a DS. Then finally a BF15. I'm still trialling the radial positioning of the PST etalon v's the SM60 to give the best "transmission ski...
by Merlin66
Mon Jan 28, 2019 5:22 am
Forum: This is SolarChat !!
Topic: The effect of a circular polarizer in a double stack
Replies: 17
Views: 481

Re: The effect of a circular polarizer in a double stack

Valery,
It sounds like the female side - the side which would normally face "outwards" in a conventional arrangement (think about screwed into an eyepiece)
by Merlin66
Sun Jan 27, 2019 1:05 am
Forum: Solar Scope Modifications
Topic: Adapter for doublestacking PST etalons
Replies: 15
Views: 550

Re: Adapter for doublestacking PST etalons

The ATiK 314L is 400gms.
by Merlin66
Sun Jan 27, 2019 12:50 am
Forum: Solar Scope Modifications
Topic: Adapter for doublestacking PST etalons
Replies: 15
Views: 550

Re: Adapter for doublestacking PST etalons

Bart,
The T rotator was holding the ATiK 314 camera on the rear of the spectrograph...no issues.
I'm using a short Lunt Crayford focuser on the SM60/ED80/PST mod DS - I find it very useful, when changing cameras and or barlows etc.
by Merlin66
Sun Jan 27, 2019 12:18 am
Forum: Solar Scope Modifications
Topic: Adapter for doublestacking PST etalons
Replies: 15
Views: 550

Re: Adapter for doublestacking PST etalons

Bart,
We have used these T2 rotators for some years on the spectroscopes - work well...
You can also get a T thread to 1.25" filter thread adaptor ......
by Merlin66
Fri Jan 25, 2019 6:23 am
Forum: Solar Scope Modifications
Topic: Collimator for Omega Bobs Filters
Replies: 7
Views: 245

Re: Collimator for Omega Bobs Filters

Notwithstanding all the grief being posted around Omega filters, I’m happy with the CaK series filters I got and use in the CaK filter stack.
Checking the transmission curves with the spectroscope verified the quoted curves.
by Merlin66
Wed Jan 23, 2019 11:29 am
Forum: Solar Scope Modifications
Topic: Adapter for doublestacking PST etalons
Replies: 15
Views: 550

Re: Adapter for doublestacking PST etalons

Yeah, that sounds about right!
by Merlin66
Wed Jan 23, 2019 2:52 am
Forum: Solar Scope Modifications
Topic: Adapter for doublestacking PST etalons
Replies: 15
Views: 550

Re: Adapter for doublestacking PST etalons

Bart,
I have a set of the Neumann filter drawers. Could use a standard 1.25” CPL filter.
Just needs a couple of T thread to M50 Adaptors?
by Merlin66
Tue Jan 22, 2019 11:10 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: What camera?
Replies: 23
Views: 872

Re: What camera?

Mark,
The ZWO T2 tilter has a built-in light foam seal which stops any light leakage through the tilt gap. No need for gaffa tape etc.
by Merlin66
Tue Jan 22, 2019 12:52 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: What camera?
Replies: 23
Views: 872

Re: What camera?

Alexandra,
With the tilter...when it's installed just takes a minute or so to set it - no NR!
Never have to adjust it again, just leave it in place on the camera.
by Merlin66
Mon Jan 21, 2019 9:13 pm
Forum: Solar Scope Modifications
Topic: PST Etalon Adjustment
Replies: 21
Views: 751

Re: PST Etalon Adjustment

Snug firm and tight....
(I'll enclose a couple of the O rings in your "package" ;) )
by Merlin66
Mon Jan 21, 2019 8:13 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: What camera?
Replies: 23
Views: 872

Re: What camera?

Alexandra,
I use the ASI 174mm on my PST mod, SM60/ED80 and the Spectroheliograph. The camera is always used with a T2 tilter as 99% of the time there are NR generated.
by Merlin66
Mon Jan 21, 2019 8:04 pm
Forum: Solar Scope Modifications
Topic: PST Etalon Adjustment
Replies: 21
Views: 751

Re: PST Etalon Adjustment

Bart,
If the knurled rubber tuning ring feels "loose", then there's a good chance that the O rings have flattened over time and the replacement would help make it feel firmer.