Search found 3611 matches

by Merlin66
Mon Dec 26, 2011 10:43 pm
Forum: This is SolarChat !!
Topic: low cost spectrograph
Replies: 18
Views: 1062

Re: low cost spectrograph

Hmmmm
You learn something new everyday....
I'll have a look at that when I get back from Oz.
by Merlin66
Mon Dec 26, 2011 10:05 pm
Forum: This is SolarChat !!
Topic: low cost spectrograph
Replies: 18
Views: 1062

Re: low cost spectrograph

Mark,
I'm not sure you can remove the ERF element from the SM40 front etalon.....
by Merlin66
Fri Dec 23, 2011 8:27 pm
Forum: This is SolarChat !!
Topic: low cost spectrograph
Replies: 18
Views: 1062

Re: low cost spectrograph

The next step up is to use a transmission grating like the Rainbow Optics or Star Analyser - these are capable of giving a resolution of around 30A - which is ideal for brighter stars, nova and comets....
by Merlin66
Thu Dec 22, 2011 11:48 pm
Forum: This is SolarChat !!
Topic: Greyscale Sun MKII
Replies: 13
Views: 715

Re: Greyscale Sun MKII

I find it very difficult to get good flats on anything other than high magnification images...any workable ideas for gradient removal on full disk images?
Kev on SGL, has had some success with Pixinsight "Dynamic Background Extraction" -"PST Removing the hot spot" - July 2011
by Merlin66
Thu Dec 22, 2011 10:48 pm
Forum: This is SolarChat !!
Topic: Rogerio Marcon's Solar time-lapse H-alpha movies
Replies: 14
Views: 1036

Re: Rogerio Marcon's Solar time-lapse H-alpha movies

You can use a DMK (I use the DMK41) to produce an AVI video straight from the camera.
by Merlin66
Thu Dec 22, 2011 10:45 pm
Forum: This is SolarChat !!
Topic: low cost spectrograph
Replies: 18
Views: 1062

Re: low cost spectrograph

A cheap way of demonstrating diffraction and obtaining a spectrum.
Great introduction, but you need to consider a slit/ grating as a minimum to obtain measurable spectra.
by Merlin66
Sun Dec 18, 2011 10:11 am
Forum: Solar Scope Modifications
Topic: Question about the PST etalon tuning ring
Replies: 1
Views: 572

Re: Question about the PST etalon tuning ring

I've moved the index screw as you say on a few etalons, but so far I've never been tempted to "go all the way".....
A replacement etalon is around $500 if it doesn't work ;-)
by Merlin66
Sun Dec 18, 2011 9:12 am
Forum: Solar Scope Modifications
Topic: PST Blocking Filter
Replies: 18
Views: 1504

Re: PST Blocking Filter

I haven't had the opportunity to do spectroscopic testing of the Lunt etalons or Blocking filters.... From what you are describing the Lunt BF has a different transmission from the Coronado... The centre of the band width of the BF must align with Ha and the FWHM must be consistant with the finesse ...
by Merlin66
Sat Dec 17, 2011 10:26 pm
Forum: Solar Scope Modifications
Topic: How to properly align your crazy mods?
Replies: 10
Views: 911

Re: How to properly align your crazy mods?

Glad it helped!
by Merlin66
Fri Dec 16, 2011 4:38 pm
Forum: This is SolarChat !!
Topic: ERF behind front lens?
Replies: 15
Views: 740

Re: ERF behind front lens?

Hmmm
I did try the combo of the HMC 77mm red and a 2" Baader UV-IR as a pseudo EFR - whether it was tube currents or poor lens...don't know.
Do a star test on the combo...see how it performs.
by Merlin66
Fri Dec 16, 2011 3:26 pm
Forum: This is SolarChat !!
Topic: ERF behind front lens?
Replies: 15
Views: 740

Re: ERF behind front lens?

I'd think the 6mm thick Arriflex would be a nice piece of glass!! All my failures have been with "standard" +/- 3mm camera filters (Hoya etc). I did get a couple of thick (8mm?) 4.5" diameter red filters from Surplus Shed a few years ago (Ex-Aerial cameras) and only one of them was usable.... If any...
by Merlin66
Thu Dec 15, 2011 3:51 pm
Forum: This is SolarChat !!
Topic: Coronado Solarmax40 H-a Filter.../ LUNT B600-1200 BF
Replies: 6
Views: 706

Re: Coronado Solarmax40 H-a Filter.../ LUNT B600-1200 BF

There's a couple of guys who have successfully used the Lunt BF1200 on the PST mod.
It would appear they are 'compatible"
(I'd love to be able to double check this with the spectroscope - but no one has offered a Lunt BF for testing ;-) )
by Merlin66
Thu Dec 15, 2011 2:15 pm
Forum: Solar Scope Modifications
Topic: Double stacked SM60 on ED80
Replies: 41
Views: 2337

Re: Double stacked SM60 on ED80

Tuning two etalons for optimum bandwidth is a "black art" I have some details available.... (One etalon needs to be set just to the blue side of Ha, and the other just to the red side..the resulting narrow bandwidth is then centred on Ha.) Once the front etalon is "set" I need to make 100% sure it d...
by Merlin66
Thu Dec 15, 2011 12:01 pm
Forum: This is SolarChat !!
Topic: Coronado Solarmax40 H-a Filter.../ LUNT B600-1200 BF
Replies: 6
Views: 706

Re: Coronado Solarmax40 H-a Filter.../ LUNT B600-1200 BF

To mount the SM40 etc on the scope you'll also need the T max tilt adjuster...I'm not sure that is always included with the SM40 DS/PST option....
by Merlin66
Thu Dec 15, 2011 9:46 am
Forum: Solar Scope Modifications
Topic: Double stacked SM60 on ED80
Replies: 41
Views: 2337

Double stacked SM60 on ED80

Thought you might like to see one of my workhorses...
I use a DMK41 (firewire) for imaging...
The Patented "Vegemite Universal Tilt Controller" makes things very easy for tuning for Doppler shift...

by Merlin66
Thu Dec 15, 2011 9:39 am
Forum: This is SolarChat !!
Topic: problem uploading images?
Replies: 3
Views: 621

Re: problem uploading images?

OK
I've changed over to the old Dell running XP, and guess what...
I've managed to upload my Avatar for the first time, so, I assume other images will also upload.
Seems the Acer/ Win7 may have been at least part o the problem?
by Merlin66
Thu Dec 15, 2011 8:43 am
Forum: This is SolarChat !!
Topic: ERF behind front lens?
Replies: 15
Views: 740

Re: ERF behind front lens?

Also regularly check out Surplus Shed.. they sometimes have interesting stuff...
by Merlin66
Thu Dec 15, 2011 8:17 am
Forum: This is SolarChat !!
Topic: ERF behind front lens?
Replies: 15
Views: 740

Re: ERF behind front lens?

With conventional filters they absorb the wavelengths they don't pass and re-radiate the energy absorbed as heat. The interference type (D-ERF) reflect back the non-pass wavelengths...this, depending on where the ERF is positioned behind the objective can re-focus 99.99% of the incoming energy onto ...
by Merlin66
Wed Dec 14, 2011 4:11 pm
Forum: This is SolarChat !!
Topic: ERF behind front lens?
Replies: 15
Views: 740

Re: ERF behind front lens?

It's tha basis of the LADD/LADS design.
We recommended that the ERF be larger than 50% the aperture and slightly tilted to minimise ghosting.
There have been some users who say the heat build-up does cause some deterioration of the image.....
by Merlin66
Wed Dec 14, 2011 10:35 am
Forum: Solar Scope Modifications
Topic: How to properly align your crazy mods?
Replies: 10
Views: 911

Re: How to properly align your crazy mods?

The front aperture etalon assemblies like the SM40/ SM60, have a red filter built in as an ERF element.
The pure etalons are normally clear glass....
by Merlin66
Wed Dec 14, 2011 10:16 am
Forum: Solar Scope Modifications
Topic: Fast f/5 and telecentric for a f/10 PST mod?
Replies: 16
Views: 1668

Re: Fast f/5 and telecentric for a f/10 PST mod?

based on the mods done to date, there seems to be about a 3-5mm tolerance band before you get collimation problems with the etalon.
by Merlin66
Wed Dec 14, 2011 10:13 am
Forum: Solar Scope Modifications
Topic: How to properly align your crazy mods?
Replies: 10
Views: 911

Re: How to properly align your crazy mods?

Yes,
All etalons work on the same principle. The finesse of the etalon defines the actual pass bandwidth v's gaps between....
by Merlin66
Wed Dec 14, 2011 7:35 am
Forum: This is SolarChat !!
Topic: problem uploading images?
Replies: 3
Views: 621

problem uploading images?

I use the Attachments section below... Click "Add file" select the image from my HD.... The options presented are then "Remove file" or "Insert" If I do nothing and just press "Submit" - nothing seems to happen???? If I press "Insert" all I seem to get is a text line in the message where the image s...
by Merlin66
Wed Dec 14, 2011 7:21 am
Forum: This is SolarChat !!
Topic: How it works
Replies: 2
Views: 553

Re: How it works

The etalon produces a series of very narrow bandwidth images (about 0.7A wide) spaced every 10A across the whole spectrum, from blue to far red. Like an optical "comb" One of these images coincides with the wavelength of H alpha. The job of the blocking filter is to "block" all the other bandwidths ...