Just to add, Astronomik have just further explained that for the past two years all OIII filters are of the 12mm design.Astronomik curves can be found here:
http://www.astronomi...uhc-filter.html
http://www.astronomi...er-visuell.html
read post #109 above for more current info on the O-III
I guess current UHC bandwidth is ~24nm and the O-III ~12nm.

Spectroscopic Analysis & Comparison of Nebula Filters
#101
Posted 12 September 2016 - 05:30 AM
#102
Posted 13 September 2016 - 08:04 AM
Thanks everyone for all the useful information. I can't add anything scientific to the debate, but when the Astronomik uhc and o-iii arrive I'm happy to do my best to convey impressions from the eyepiece.
CS to you all.
#103
Posted 23 September 2016 - 02:11 AM
A very interesting thread on a Russian astro forum re this topic, with lots of spectroscopic data. Those who do not speak/read Russian can use Google translate (but even that might not be needed if just browsing for spectra). Bear in mind, though, that the text sometimes indicates whether the filter analysed is an old one or a new one.
http://www.astronomy...ic,68257.0.html
#104
Posted 23 September 2016 - 09:08 AM
A very interesting thread on a Russian astro forum re this topic, with lots of spectroscopic data. Those who do not speak/read Russian can use Google translate (but even that might not be needed if just browsing for spectra). Bear in mind, though, that the text sometimes indicates whether the filter analysed is an old one or a new one.
Awesome thread.
#105
Posted 23 September 2016 - 09:38 AM
A very interesting thread on a Russian astro forum re this topic, with lots of spectroscopic data. Those who do not speak/read Russian can use Google translate (but even that might not be needed if just browsing for spectra). Bear in mind, though, that the text sometimes indicates whether the filter analysed is an old one or a new one.
Awesome thread.
I was sure you would be interested.
Edited by BGazing, 23 September 2016 - 09:39 AM.
#106
Posted 05 October 2016 - 01:31 AM
Astronomik OIII (12nm) arrived yesterday. No detailed specs, but the back sticker says Tmax 96,3%...