Just blocking filters.

Frankenscope? Let's see it!***be advised that NOTHING in this forum has been safety tested and you are reading and using these posts at your own peril. blah, blah, blah... dont mess around with your eyesight when it comes to solar astronomy. Use appropriate filtration at all times...
Post Reply
User avatar
Valery
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 3050
Joined: Sun Nov 18, 2012 3:13 pm

Re: Just blocking filters.

Post by Valery » Tue May 24, 2016 12:13 am

Ghost-Fire wrote:Has anyone experimented imaging with just your blocking filter and erf?

I have a small thought that TWO blocking filters and no etalon create a "prominence" system?

The back end filter of the blocking element is essentially a narrowband filter. I think 8 angstroms in lunt/coronado blockers. In affect, two blocking filters with the right orientation and brightness in tandem with a baader planetarium D-erf should be able to display edge detail with performance similar to a 5angstrom promscope.


I only have one blocker, so I cannot experiment. However this seems (in theory) like a great way to expand prominence viewing capability by utilizing wider bandpass.

Can you, please, explain what is the sense of your constant attempts to create something a bit cheaper device, but much worser than a standard solar scope or standard train for a narrow band scope??? I really can't understand such an approach.

For example, two blockers. They cost more than a LS50THa or more than a good Quark etc etc. So, such a scope will cost more than a much narrower instrument which can be used without any hassles.

Valery.
"Solar H alpha activity is the most dynamic and compelling thing you can see in a telescope, so spend accordingly." (c) Bob Yoesle.

Largest full size 185 - 356mm Dielectric Energy Rejection Filters (D-ERF) by ARIES Instruments.

User avatar
solarchat
Site Admin
Site Admin
Posts: 3952
Joined: Sat Feb 01, 2014 3:10 pm
Location: Atlanta, GA USA
Contact:

Re: Just blocking filters.

Post by solarchat » Tue May 24, 2016 2:28 am

I have extensively used about 20 different blocking filters from Lunt and Coronado. Since the same people designed and manufacutred most of them and they both use the same source for their glass I would think that my results are pretty typical.

They are ALL different. The larger the glass, i.e. BF30 or B3400 the more likely that it will not have a constant brightness over the field of view. To be honest I don’t believe there is a solar scope made where anyone would ever need more than a B1800 Lunt of BF15 from Coronado since they are all around F5-F7 scopes. Im sure their are some mods out there that might need a larger blocking filter but not any dedicated scopes that I know of from manufacturers.

I personally use B1800s on all of my solar scopes and that is also overkill in my opinion. The 15-18 mm glass from Meier seems to be pretty consistent in quality.
Stephen W. Ramsden
Atlanta, GA USA
Founder/Director Charlie Bates Solar Astronomy Project
http://www.solarastronomy.org

User avatar
solarchat
Site Admin
Site Admin
Posts: 3952
Joined: Sat Feb 01, 2014 3:10 pm
Location: Atlanta, GA USA
Contact:

Re: Just blocking filters.

Post by solarchat » Tue May 24, 2016 2:30 am

and the reason that no one makes an H-Alpha solar scope from just blocking filtersis because of the heat involved. The CaK modules are basically just a series of blocking filters.
Stephen W. Ramsden
Atlanta, GA USA
Founder/Director Charlie Bates Solar Astronomy Project
http://www.solarastronomy.org

User avatar
Valery
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 3050
Joined: Sun Nov 18, 2012 3:13 pm

Re: Just blocking filters.

Post by Valery » Tue May 24, 2016 3:17 am

Hi Stephen,
solarchat wrote:
The 15-18 mm glass from Meier seems to be pretty consistent in quality.
Does above means, that Meier makes complete blocking filters, not just a substitute to a "blue glass" in
Lunt blockers?

Thanks,

Valery.
"Solar H alpha activity is the most dynamic and compelling thing you can see in a telescope, so spend accordingly." (c) Bob Yoesle.

Largest full size 185 - 356mm Dielectric Energy Rejection Filters (D-ERF) by ARIES Instruments.

User avatar
solarchat
Site Admin
Site Admin
Posts: 3952
Joined: Sat Feb 01, 2014 3:10 pm
Location: Atlanta, GA USA
Contact:

Re: Just blocking filters.

Post by solarchat » Tue May 24, 2016 11:03 am

No, Meier makes all the glass used in the blocking filters. The manufacturers machine their own holders (BFs).
Stephen W. Ramsden
Atlanta, GA USA
Founder/Director Charlie Bates Solar Astronomy Project
http://www.solarastronomy.org

antonello
Ohhhhhh My!
Ohhhhhh My!
Posts: 67
Joined: Tue Mar 24, 2015 12:34 pm

Re: Just blocking filters.

Post by antonello » Tue May 24, 2016 12:18 pm

Ghost-Fire wrote:Has anyone experimented imaging with just your blocking filter and erf?
Why you thought it was done by many people, for example:

http://www.considine.net/dgroski/halpha/

However, the quality of an ERF-ETALON-BF system is superior ...

Post Reply

Who is online

Users browsing this forum: No registered users and 2 guests