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OIII Filter Shootout

Started by Rod Kaufman, 10/30/2011 05:26PM
Posted 10/30/2011 05:26PM Opening Post
First of all, do any of my filters meet the following Floyd Blue specs: Class ONE Bortle skies under filter-induced eclipse conditions during Gary Cooper's high noon?
Nope! Now that we got that out of the way, here we go:
Under conditions of moderate light pollution in a suburban setting (milky way visible overhead), I set up my 16" f4.5 dob with paracorr/filter slide in place and put three 0111 filters through their paces. The contestants: 1. Celestron 0111 which reportedly is a re-badged Baader 0111. 2. Orion 0111 (I found it would actually thread quite nicely into the bottom of my paracorr and my 30mm ES eyepiece, as well as a few others!)3. Generic 0111 filter(likely GSO or equivalent).
The familiar targets: Veil, crescent, M57.
Before we get to the outcome, let me add a comment to my previous review of the broadband filters: I found that my astrotech broadband filter allowed me to view NGC 891, the needle galaxy in Andromeda, whereas my Orion broadband would not detect it, and I could barely see it at all without the filter in place. Score another one for the AT broadband filter! I found the AT filter was quite useful in detecting more galaxies: NGC 7814, 7332, 7339 and 7331 in the constellation of Pegasus. NGC 1023 in Perseus was also easily pulled in out of the skyglow.
I see one dealer has run out of the AT broadband while another still has stock on hand. I can't wait to try this filter out under dark sky conditions.
Now to the 0111 filter comparo.
The Orion filter is the least aggressive of the 0111 filters in the group. It dims the overall star background the least. However, it enhanced the view of the veil and the crescent the least as well. In other words, you get a brighter overall eyepiece field but the contrast and the image of the nebulosity of the latter targets were not as good as the other filters. HOWEVER, the view of M57 was the best in the Orion filter and the individual specs of the tested filter was consistent with that of a premium filter. I suspect the view of the crescent and the veil would improve significantly with the Orion filter under dark sky conditions. If you do most of your observing under light polluted conditions and you have sufficient aperture, get the most aggressive 0111 filter: the Celestron(high likelihood it's a baader). It really brings out the detail in the cresecent and the veil under moderate light pollution, but less so on the ring nebula where the Orion excelled. Both the Celestron and Orion models were 2" filters while the generic 0111 filter was a 1.25". The latter was fairly descent on the aforementioned objects and I would characterize it as being in between the Orion and the Celestron 0111 filters in aggressiveness in killing the stars and enhancing the nebulosity.
So, those are my results for three 0111 filters(really four if you count the Celestron as representing a baader as well)>
Your mileage may vary...
Posted 11/09/2011 04:10PM | Edited 11/09/2011 05:36PM #1
Rod,
What do you think of the TO OIII for a R200SS, AT6RC, & 152 mm f8?
FYO FWIW I'm in a Yellow Zone outside DC

Thanx T-Man. 8)