Search found 107 matches

by mdwmark
Sun Jul 15, 2018 5:57 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: NEW direction in the solar narrowband imaging.
Replies: 53
Views: 1359

Re: NEW direction in the solar narrowband imaging.

The graph is for a simple 1/4 wave design. The high end etalons for solar will use a broad band mirror. So they are usually from K-line to Ha or Ha to the Ca lines in the IR.
The broad band mirrors will have more layers which means a higher cost.
Mark W.
by mdwmark
Sat Jul 14, 2018 1:08 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: NEW direction in the solar narrowband imaging.
Replies: 53
Views: 1359

Re: NEW direction in the solar narrowband imaging.

That is what I though it would look like. I guested 24Ang peak separation.
Attached is a coating design for Ha. The narrower peaks will be where the transmission is the highest. As the transmission drops the HW will broaden and the bottom of the curve will not be near zero.
etalon mirror Ha.gif
etalon mirror Ha.gif (9.62 KiB) Viewed 92 times
by mdwmark
Mon Jul 02, 2018 11:43 pm
Forum: Solar Scope Modifications
Topic: Baader Telecentric - Lower flux in blue/CaK?
Replies: 4
Views: 728

Re: Baader Telecentric - Lower flux in blue/CaK?

It may be something with the AR's. Must broadband AR's are designed from 400 to 700nm. If they where using TIO2 as the high index then you will be getting absorption from it(this is the most common design). It also maybe where the AR designed was centered. If they are a MGF2 AR centered at Ha then y...
by mdwmark
Thu May 31, 2018 9:01 pm
Forum: Solar Scope Modifications
Topic: WILL IT BURN? - ..Filter Killer..
Replies: 35
Views: 1034

Re: WILL IT BURN? - ..Filter Killer..

OK, I though the original concern was Daystar's statement that Quark didn't need an ERF. If they want to change blockers. That there concern. The filter is still safe to the eye even when a front blocker fails. I have been making Ha filters for 30+ years and have never hear of anyone having problems...
by mdwmark
Tue May 29, 2018 3:37 am
Forum: Solar Scope Modifications
Topic: WILL IT BURN? - ..Filter Killer..
Replies: 35
Views: 1034

Re: WILL IT BURN? - ..Filter Killer..

BUT , when you move in and out to focus, you will run into that problem of high heat.

Mark W.
by mdwmark
Mon May 28, 2018 11:45 pm
Forum: Solar Scope Modifications
Topic: WILL IT BURN? - ..Filter Killer..
Replies: 35
Views: 1034

Re: WILL IT BURN? - ..Filter Killer..

I was thinking, The front of the telecentric is not at prime focus. So it will be hot but not as bad as prime focus. If your using an F/5 then I don't think it would make much difference. I'm not sure the distance for the Quark but I would guest about 45mm in front of prime focus would be a good pla...
by mdwmark
Mon May 28, 2018 9:37 pm
Forum: Solar Scope Modifications
Topic: WILL IT BURN? - ..Filter Killer..
Replies: 35
Views: 1034

Re: WILL IT BURN? - ..Filter Killer..

Yep, I know. Over the years repairing filters, I have come across many that where damage using to fast of scopes. Like your burning ants analogy. 100mm F/15 with no ERF will melt a .54" spot in the delrin of the front plate and take out the blocker over time. The point of the front mounted ERF was t...
by mdwmark
Fri May 25, 2018 11:02 pm
Forum: This is SolarChat !!
Topic: Messing With a Sodium Quark - 22nd May
Replies: 21
Views: 649

Re: Messing With a Sodium Quark - 22nd May

Hi Mark, Working with Na, you will find there is a very small window where you have a increase of contrast. They advertiser it to be 0.5Ang. If you can keep it in the center of the line at .5Ang Hw(F/40). This is the maximum Hw were the cells will still be highlighted. The Hw really need to be in th...
by mdwmark
Sun May 20, 2018 2:55 am
Forum: This is SolarChat !!
Topic: Replacing the Rusted BF30 Filter
Replies: 54
Views: 1890

Re: Replacing the Rusted BF30 Filter

You got me worried here. When you start replacing part without knowing the design. If you look at the blocker filter. It will be between .6nm-1nm HW. I'm petty sure its a standard coating. Well put it at 656.3nm +/-.3nm. Just the bandpass will turn back on at about 700nm on the red side and 480m on ...
by mdwmark
Sat May 12, 2018 5:10 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: The ultimate solar imagers filter?? The ultimate visual?
Replies: 2
Views: 379

Re: The ultimate solar imagers filter?? The ultimate visual?

Hi group, Being in this group I try to explain and I don't try to get free advertising or talk down about other systems. The SO-1, 0.3A (name change to RG18 but the same price) are all Research level uniformity. They all have three cavity hard coated blockers, (so the blockers are very unlikely to e...
by mdwmark
Tue May 08, 2018 7:49 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Baader Triband SCT
Replies: 19
Views: 1040

Re: Baader Triband SCT

Hi Group, I've seen Schott's ERF. But not a 220mm one, it might have been 160mm. They take an thin RG630 and laminate it to a coated bandpass. The one at the show was about 4mm thick. I asked how it would keep the 1/4 wave they clam, if it was in the heat. The problem I have with this idea is that I...
by mdwmark
Mon May 07, 2018 8:15 pm
Forum: Solar Scope Modifications
Topic: A high quality telecentric 3X made by itself
Replies: 15
Views: 1253

Re: A high quality telecentric 3X made by itself

Hi Group, For the FS78, I have the Zmax design and the one I did with OSLO edu. The Sky 90 was done with Zmax and used Thor lens. Images shot with the sky 90 telecentric where still quite good. Even thou it looks like your pushing the limit on the spot diagram. Mark W. S-1 sky 90.pdf S-1 fs78(SO-1.5...
by mdwmark
Sat May 05, 2018 4:05 am
Forum: Solar Scope Modifications
Topic: A high quality telecentric 3X made by itself
Replies: 15
Views: 1253

Re: A high quality telecentric 3X made by itself

OK, I'll dig them out. Your F/99 really would not be that much better then an F/45. The image size would be large. If you where going for a collimated system. Then you will fine that the over all performance of the system will work it best when it is not at "infinity " but at about F/60. Then your b...
by mdwmark
Fri May 04, 2018 7:11 am
Forum: Solar Scope Modifications
Topic: A high quality telecentric 3X made by itself
Replies: 15
Views: 1253

Re: A high quality telecentric 3X made by itself

Hi, When it come to designing telecentrics with stock lens, sometimes you need to be creative. Also the higher the power the harder it will be. For an FS78 I used two -lens to make an bi concave lens. The front side was an -200mm then a -50mm back to back with an positive meniscus lens to get to a g...
by mdwmark
Thu Nov 09, 2017 9:11 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: H-alpha Zeiss APQ 130
Replies: 26
Views: 2244

Re: H-alpha Zeiss APQ 130

OK , I forgot to say. The AP telecentric was designed for his old 6" F/12. It was an 2X telecentric. So the idea was to stop the 6" scope to 4" to get to F/36 where it work well. It will work on a 100mm scope, but it won't really be a telecentric. All solar filters will move off band from the extra ...
by mdwmark
Thu Nov 09, 2017 8:30 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: H-alpha Zeiss APQ 130
Replies: 26
Views: 2244

Re: H-alpha Zeiss APQ 130

HI Christopher, Well, the T-Scanner was ship in 3/1990. The temperature for on band, would depend where we would had sent it. If it was going where Del thought it would be be cold then, it would probably be 6564-5A at 25C. In Southern California then it would had been 6563A at 25C. But most where +1...
by mdwmark
Mon Aug 28, 2017 7:14 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Solar Spectrum filters available from stock!
Replies: 15
Views: 1376

Re: Solar Spectrum filters available from stock!

Hi group,
All of the SO-1's will be uniform. They where designed for imaging . When it comes to 19mm etalons if they are not inform I toss them.
Mark W.
by mdwmark
Tue Aug 15, 2017 4:47 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Solar Spectrum filters available from stock!
Replies: 15
Views: 1376

Re: Solar Spectrum filters available from stock!

Hi Group, I make a point not to advertize when I am on the site. But I will explain my filters systems and how I check the etalon for uniformity. Questions about uniformity and how I judged the filters. I scan the etalons across the silt of a .5 meter spectrograph. I have a camera on the spectrograp...
by mdwmark
Sun Jul 02, 2017 5:35 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Different Ca-K options, differences?
Replies: 50
Views: 4059

Re: Different Ca-K options, differences?

One more cent,
With refactors, if you stop them down .This will help with correcting for K-line.
Even 50mm at a F/20 or so, does quite well with K-line. And with these HW's you can get away with using a barlow.
Mark W.
by mdwmark
Sun Jul 02, 2017 4:06 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Different Ca-K options, differences?
Replies: 50
Views: 4059

Re: Different Ca-K options, differences?

Wow, a lot about K-line. This wavelength really doesn't sell to many filters. Only the younger people can really see anything normally. I like K-line, in the days of film it worked fine. With the cameras today and processing you can make the image look like it was shot with a narrower filter. 1) ref...
by mdwmark
Wed Jun 28, 2017 9:21 pm
Forum: This is SolarChat !!
Topic: HA 22.06.2017
Replies: 19
Views: 968

Re: HA 22.06.2017

Nice images, The movie is in the red wing moving farther red as it goes The next one is still a little red, don't go by the wavelength on the meter. Just move it down and see if it gets better. When you are in the red wing, the peaks will have a higher contrast. When you are in the center of Ha. It ...
by mdwmark
Fri Mar 31, 2017 11:53 pm
Forum: This is SolarChat !!
Topic: Heat damage to rear etalon spot???
Replies: 5
Views: 367

Re: Heat damage to rear etalon spot???

Damaging an rear etalon. If you are taking about a mica etalon. More likely it would be the blockers or polaroids. I have seen filters where the blockers where gone and the polaroids where bleach clear. but the etalon was still OK. As a rule, with just a red ERF or no ERF a 4" F/15(.54" spot) will t...
by mdwmark
Mon Jan 23, 2017 6:57 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Quark > Optical Design > Detail available?
Replies: 9
Views: 1577

Re: Quark > Optical Design > Detail available?

Yes ,these would be custom lens. But you can make an telecentric with stock lens. What objective did you plan to use, and what kind of back focus( distance from the back lens to focus) where you looking for? If also depends on the CA of the etalon you plan to use. I may already have something design...
by mdwmark
Fri Dec 09, 2016 8:39 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Bad bad bad BF30
Replies: 11
Views: 1728

Re: Bad bad bad BF30

The realty for standard warranty's for bandpass filters from the manufacture (Andover,Barr, Omega) for standard bandpass filters is one year. The longer warranty is the risk of the company that is making the complete filter. Hard coated is 5 years. The term hard coated is a broader term now days. Th...
by mdwmark
Wed Dec 07, 2016 2:50 am
Forum: This is SolarChat !!
Topic: Baader 4x Telecentric Setup
Replies: 14
Views: 1212

Re: Baader 4x Telecentric Setup

I look at your set up image and, most refactors the prime focus is 4 to 5" behind the focuser, when the focuser is racked in. I usually back it out about 3/8". From there it usually takes about 50-60mm spacer tube. Then the telecentric. The TZ4 is design for a 2" diagonal, so that eats up most of th...