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Unmounted Filters?

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#1 Scanning4Comets

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Posted 09 February 2013 - 03:12 PM

Does anybody know if you can get O-III Filters in the 2 inch size unmounted?

I have a couple of extra 2" filter cells and I wanted to know if I could buy one unmounted so I can put it in one of the cells I have.

If not, I plan on picking up a 2" Orion or 2" Thousand Oaks O-III filter.

Cheers,

#2 Scanning4Comets

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Posted 09 February 2013 - 04:02 PM

Also,

I am curious about the Orion O-III filter and it's performance. What are your thoughts on this filter? I am looking for answers from people who have actually used this filter.

Cheers,

#3 Scanning4Comets

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Posted 10 February 2013 - 02:01 AM

Nobody knows ??? :question:

#4 faackanders2

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Posted 10 February 2013 - 11:16 AM

OIII filter is good for reflection nebulas, and especially planetary nebulas. However, I prefer Orion Ultrablock since it blocks out less starlight (see more stars).

#5 Scanning4Comets

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Posted 10 February 2013 - 02:09 PM

OIII filter is good for reflection nebulas, and especially planetary nebulas. However, I prefer Orion Ultrablock since it blocks out less starlight (see more stars).


Actually, that is incorrect. O-III filters are a "line" filter and focus on doubly ionized oxygen and are not really meant for "reflection" nebulae. The Ultrablock filter is more suited to reflection nebulae. Also, O-III filters are based close to, or around 11nm-12nm, with some a bit broader, (Orion O-III), and some a bit narrower), Celestron / Baader O-III), and I have already owned the Celestron / Baader O-III which I find way too dark.

I already know this but was wondering what the bandpass of the Orion O-III was and also the Thousand Oaks O-III, and also if you can order any of the two I just mentioned, (Orion O-III / Thousand Oaks O-III), unmounted.

As far as these filters "blocking out starlight", they are meant to enhance nebulae, and are not for looking at stars, so the blocking out starlight thing is of no concern to me.

Cheers,

#6 faackanders2

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Posted 10 February 2013 - 10:15 PM

OIII filter is good for reflection nebulas, and especially planetary nebulas. However, I prefer Orion Ultrablock since it blocks out less starlight (see more stars).


Correction OIII is good for emission and planetary nebulae.
Ultrablock and skyglow block out less stars and less light.
Emmision nebulae actually would requiew skyglow or unfilterd from dark sky.

When I had to screw filters on individually I used Ultrablock most for nebulas (emmission and planetary). Now that I have all 3 mounted on my astrocrumb filter slide I often compare all 3 filters plus unfiltered on all types on nebulae, but usually prefer ultrablock.

P.S. Skyglow works well if the nebula contains open star clusters, or open star cluster contains planetary nebula, or there is a nebula and non nebula object in same view. Plus Jupiter and its bands also are more noticable in skyglow.

#7 Scanning4Comets

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Posted 10 February 2013 - 10:20 PM

This STILL doesn't answer the questions I asked...

Does anybody know if you can get O-III Filters in the 2 inch size unmounted?

I have a couple of extra 2" filter cells and I wanted to know if I could buy one unmounted so I can put it in one of the cells I have.

If not, I plan on picking up a 2" Orion or 2" Thousand Oaks O-III filter.


Also,

I am curious about the Orion O-III filter and it's performance. What are your thoughts on this filter? I am looking for answers from people who have actually used this filter.


Thanks anyways...If anybody knows, please post.

#8 kevint1

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Posted 11 February 2013 - 01:35 PM

Omega might be able to supply them.

www.omegafilters.com

#9 Scanning4Comets

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Posted 11 February 2013 - 03:57 PM

Thanks Kevin!

Cheers,

#10 Scanning4Comets

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Posted 12 February 2013 - 01:48 PM

I made a post here yesterday, but it seems to have been removed. What I wanted to know was bandpass specs on filters.

I know a couple of the specs, but not all. Anybody know what the bandpass specs are on the ones with the question marks beside them ?

Celestron / Baader O-III: 8.5nm
Lumicon O-III: 11-12nm ?
Thousand Oaks Optical O-III: ?
Orion O-III: 15nm ?
Astronomik O-III: ?
DGM Optics O-III: ?

Cheers,






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