Baader D-ERF with Lunt etalon and trimming filter?

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Jdgoguen
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Baader D-ERF with Lunt etalon and trimming filter?

Post by Jdgoguen »

Hello All. My first post to this forum. I have just purchased a used Lunt LS50FHA etalon, without the blocking filter. Rather than buying the blocking filter, I'm considering getting a Baader D-ERF to mount in front of the etalon and a trimming filter to mount near the eyepiece. The D-ERF would be large enough to cover the full aperture of the scope. Although this would be a bit more expensive than buying the blocking filter, it would leave open the option of converting the etalon (with the addition of field lenses, etc) to internal use giving me full aperture resolution. The D-ERF may also be use full on its own. I have a milling machine and lathe, so making the adapters to fit the etalon to the objective and the large filter in front of the etalon for initial use is not a problem.

Is there any reason to expect this arrangement would be inferior to just getting the stock blocking filter?

Thanks in advance for your comments,

Jon


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marktownley
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Re: Baader D-ERF with Lunt etalon and trimming filter?

Post by marktownley »

what trimming filter do you plan to use?


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Jdgoguen
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Re: Baader D-ERF with Lunt etalon and trimming filter?

Post by Jdgoguen »

656.3nm center 0.7nm FWHM 25mm dia.

Jon


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Valery
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Re: Baader D-ERF with Lunt etalon and trimming filter?

Post by Valery »

Jdgoguen wrote:656.3nm center 0.7nm FWHM 25mm dia.

Jon
What is the brand of this filter? And the price?


Thanks,


Valery


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Jdgoguen
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Re: Baader D-ERF with Lunt etalon and trimming filter?

Post by Jdgoguen »

A few are available from bjomejag on Ebay, item #151278728955 for $135. He sells overstock and cosmetic seconds from Omega, a large filter manufacturer, and provides a measured transmission spectrum with each. I have purchased filters from him for use in very sophisticated microscopes and that have been fine, but of course the specs were not as demanding. Seems worth a try.

Jon


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Re: Baader D-ERF with Lunt etalon and trimming filter?

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