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Lou took this great image of a prom with his Lunt152 double stacked with a Quark

Welcome to Solar Chat! The best forum for Solar Astronomy
Moving forward from solar cycle 24 to 25

Search found 130 matches

by mdwmark
Wed Sep 07, 2016 5:50 pm
Forum: This is SolarChat !!
Topic: Daystar d line sodium quark
Replies: 17
Views: 2581

Re: Daystar d line sodium quark

So what's the difference at looking at white light near Na and white light? They are going to show you the same image.
And .5Ang is not that narrow for Na. The next problem will be keeping it on band.
Mark W
by mdwmark
Mon Jul 11, 2016 6:55 am
Forum: This is SolarChat !!
Topic: Comparing 0.3A and 0.6 A bandpass in Ha
Replies: 27
Views: 1882

Re: Comparing 0.3A and 0.6 A bandpass in Ha

Hi Christian, I liked your images. But they where all in the red wing. They are good examples of what .3-.5Ang red looks like. When you see the tips of the surface detail with the higher contrast. Then you know you are past the center line. It will look softer when you are in the center of the line....
by mdwmark
Wed Jun 08, 2016 8:05 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Quark Dial Test. On band?
Replies: 6
Views: 1545

Re: Quark Dial Test. On band?

Ok,
1 is closes on band, 2,3,4 are moving into the red wing. 4 is about .5 Ang in the red.
Mark W.
by mdwmark
Sat Jun 04, 2016 12:22 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Baader D-ERF Question
Replies: 15
Views: 3643

Re: Baader D-ERF Question

Camera filters are usually not 1/4 wave on transmission. They don't need to be. If you use them at the objective end, the image will be soft. If they are used at the image end(before the image). Then they should work. But it allows extra heat in the scope when they are inside the tube.
Mark W.
by mdwmark
Tue May 31, 2016 3:58 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: TecnoSky152 H-alpha scope - worth the price?
Replies: 28
Views: 4927

Re: TecnoSky152 H-alpha scope - worth the price?

My concern with this scope is the internal ERF. The idea of the ERF was to keep the heat out of the scope. If there where fans moving the air through the scope then out. Then the internal ERF is fine. But with an enclosed scope you have problems with temperature gradients. This is just saying the im...
by mdwmark
Mon May 09, 2016 3:31 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: My NO WORKY Edwin Hirsch Daystar .8 H ALPHA filer
Replies: 5
Views: 1451

Re: My NO WORKY Edwin Hirsch Daystar .8 H ALPHA filer

Thats odd, I replied to this post but I don't see it. Well the control circuit used in the old Daystar controllers goes back to Carson(that is who Del worked for before he started DayStar). The control chip are really hard to fine now days. The circuit has its disadvantages,they only work correctly ...
by mdwmark
Tue May 03, 2016 5:54 am
Forum: This is SolarChat !!
Topic: Really interesting wave length 8542,1A in IR range.
Replies: 12
Views: 1041

Re: Really interesting wave length 8542,1A in IR range.

Hi Valery, I have made etalons at that wavelength. The best where around .8Ang. And they where a pain. The problem with mica is the thickness. The thicker you need to be, the harder it is to be parallel. I took an etalon that was coated for 8554. The coating design allowed pecks down is the blue-gre...
by mdwmark
Mon May 02, 2016 8:06 am
Forum: This is SolarChat !!
Topic: Fibrils Flower on the Sun. 280mm aperture. NEW IMAGE added!
Replies: 23
Views: 1288

Re: Fibrils Flower on the Sun. 280mm aperture. NEW IMAGE add

Valery,
I was looking at the second image , I see that was not yours.
But yours still soften outside the center.
Any idea why?
Mark W.
by mdwmark
Mon May 02, 2016 7:58 am
Forum: This is SolarChat !!
Topic: Fibrils Flower on the Sun. 280mm aperture. NEW IMAGE added!
Replies: 23
Views: 1288

Re: Fibrils Flower on the Sun. 280mm aperture. NEW IMAGE add

HI Valery,
Question: why is the center of the image sharp, but everything else is so soft and out of focus.
I would think the whole image should look the same as the center.
Mark W.
by mdwmark
Thu Apr 07, 2016 6:10 am
Forum: Solar Scope Modifications
Topic: ETX90 for CaK Work
Replies: 7
Views: 1548

Re: ETX90 for CaK Work

Hi Mark,
I don't think that scope is corrected that far down in the blue. If the AR is a standard TIO2,SIO2 4 layer then it will be absorbing a lot below 400nm.
I have seen them used at Ha but not at K-line. That my be why it didn't look good when you tested it.
Mark W.
by mdwmark
Sun Mar 20, 2016 5:37 am
Forum: This is SolarChat !!
Topic: 135mm D-ERF to C14
Replies: 5
Views: 982

Re: 135mm D-ERF to C14

Michael,
You might contact Baader Planetarium.
They should have it.
Mark W.
by mdwmark
Wed Nov 25, 2015 6:20 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Dream come true!
Replies: 113
Views: 22608

Re: Dream come true!

Hi Bob,
Andy will fix you up. Its his system, he is the best person to deal with the problem.
Mark W.
by mdwmark
Tue Nov 03, 2015 7:01 am
Forum: This is SolarChat !!
Topic: Ca-K options:
Replies: 8
Views: 770

Re: Ca-K options:

Hi Michael,
You mean telecompressor not telecentric right. The bandpass for these K-line filters are broad enough that you don't really need to uses a telecentric.
by mdwmark
Thu Jul 02, 2015 7:57 am
Forum: Solar Scope Modifications
Topic: Internal DERF ina Schmidt Cassegrain
Replies: 4
Views: 1075

Re: Internal DERF ina Schmidt Cassegrain

If you where going to try this. You are going to need a really good ERF 1/10wave or better on transmission. You would be going through the ERF twice. I would tilt it so the reflection would not go straight back to the main mirror. You might want to cut a fan or two to pull the hot air out of the tub...
by mdwmark
Sun Jun 07, 2015 2:02 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Polarizer for visual/Quark
Replies: 15
Views: 2298

Re: Polarizer for visual/Quark

For Valery's questions, 1) a linear polarizer would clean up a leak from the other axis. You would rotate it till you where lined up with the primary axis your using. I would think this maybe a low level problem. 2) how can a etalon have a longer base then expected. This is a coating problem. With a...
by mdwmark
Thu Jun 04, 2015 7:57 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Polarizer for visual/Quark
Replies: 15
Views: 2298

Re: Polarizer for visual/Quark

The polariser does nothing with the HW of the filter. The polaroid inside the filter is a circular polaroid. It has two functions. 1) the circular side blocks the internal reflections you will get from the blocker and the etalon mirrors. 2) the linear side blocks the axes that your not using from th...
by mdwmark
Fri May 29, 2015 12:54 am
Forum: Solar Scope Modifications
Topic: newton PST mod
Replies: 8
Views: 1589

Re: newton PST mod

If you put the bandpass type ERF in front of the secondary. Then just tilt it so that it reflects the beam down in the corner some place.
OR
If you use a 45% cold mirror the IR goes on through . Then block the rest of the reflected light with a piece of RG630. Then the filter.
Just an idea
Mark W.
by mdwmark
Fri May 08, 2015 9:30 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: New quark f/15
Replies: 10
Views: 2820

Re: New quark f/15

Doesn't the Q3.5 have a 2X barlow built into the eyepiece holder. So you can flip it in and out?
I used the Q3.5 with an SO-1 on the camera port. I also stopped it down to 60mm with an ERF. I worked find.
Mark W.
by mdwmark
Sun May 03, 2015 11:57 pm
Forum: Solar Scope Modifications
Topic: Barlow F30?
Replies: 17
Views: 3298

Re: Barlow F30?

I'll find the specs for this telecentric and post them.
If you ever seen any of Pat Stoker's images they where shot with this telecentric design on his Sky 90 stopped to 85mm.
Mark W.
by mdwmark
Sat May 02, 2015 9:34 pm
Forum: Solar Scope Modifications
Topic: Barlow F30?
Replies: 17
Views: 3298

Re: Barlow F30?

I got it from the diagram where all the rays are going through the etalon from the objective lens. That is what I thought you where going for. I have tried using short negative focal length lens but it works out better if you use longer ones. I attached and diagram for an Sky 90 to push it out to F/...
by mdwmark
Fri May 01, 2015 7:51 am
Forum: Solar Scope Modifications
Topic: Blocking filter mirror.
Replies: 6
Views: 1470

Re: Blocking filter mirror.

The front element shows it as a polished RG630 window. But RG630 has the same profile as the "filter glass" window in the back. The front would need to have a short pass coated on it to get that profile. And it would probably turn back on at 800-1200nm. The "filter glass" would be red so that when y...
by mdwmark
Thu Apr 30, 2015 8:36 pm
Forum: Solar Scope Modifications
Topic: Blocking filter mirror.
Replies: 6
Views: 1470

Re: Blocking filter mirror.

Like my grand daughter's books, what is wrong with this picture.
Mark W.
by mdwmark
Thu Apr 30, 2015 8:30 pm
Forum: Solar Scope Modifications
Topic: Barlow F30?
Replies: 17
Views: 3298

Re: Barlow F30?

I see you can do an ray trace for the telecentric. There is no way you can make an 5X telecentric with an -40mm singlet and keep the aberrations under control. I can see you want to use the small etalon for a full disk. But,please show what the aberrations look like ( spot size ,OPD,MTF)from your ex...
by mdwmark
Wed Apr 29, 2015 11:31 pm
Forum: Solar Scope Modifications
Topic: Barlow F30?
Replies: 17
Views: 3298

Re: Barlow F30?

There is nothing magical about F/30. An air spaced etalon will not improve by just making it F/30. I would keep it the same.
Mark W.
by mdwmark
Mon Mar 09, 2015 1:26 am
Forum: Solar Scope Modifications
Topic: Improving contrast on a Daystar... double stack?
Replies: 28
Views: 3850

Re: Improving contrast on a Daystar... double stack?

OK, Geoffrey the Quantum uses a heater to keep the bandpass on band. The most common problem is that it is not on band. Do not go by the wavelength number on the oven. These really mean nothing unless your telescope system was calibrated with that filter. I would start at a lower wavelength to make ...