[monoxide]

well i got home yesterday and found a nice little parcel containing a Baader UHC-S, Baader O-III and celestron 2x omni barlow.

of course it clouded over lastnight so i didnt get a great chance to check them out, i caught a long enough break in the clouds to get a comparison on m42 so i put in my 25mm with the UHC-S and took a peek, and there was a tiny bit more nebulosity than i could remember seeing before.

I started thinking oh crap this isnt a whole lot better until i realised how light it was outside. i took the filter off and it was bad enough that pretty much all i could see were the stars making up orion with a tiny hint of nebulosity.
at this stage i was very impressed. i only have a 6" dob so going by what everyone was saying about the O-III filters (the baader being as far as i know the most narrow band of them) i didnt think the views would be very good at all, but there was m42 against a really dark background.

after slewing around to as much as i could in the course of 5 mins, if not for the hint of colour produced by the UHC-S i probably would have forgotten it was in there. the O-III was a bit more dramatic dimming things down noticably but the view was very pleasing on nebulae and i definately wouldnt be advising anyone with a 6" arpeture agaisnt using an O-III.

final rundown on m42.

UHC-S: gave a really natural view, still resolving all of the stars in the core whilst enhancing the nebula, id be confident to say that i saw more with this filter on a light enough night that i could read the side of the filters than i have on a darker night without it, you could definately leave this filter in whilst hopping around.


O-III: this was the real contrast enhancer, the nebula appeared a lot brighter than the UHC mabee because of the pitch black backdrop but i lost some of the stars at the core, it was a very pleasing view, you probably wouldnt leave this in while hopping around.

in all, the UHC-S would be great even for smaller arpetures than 6"
smaller than 6" though id probably shy away from the O-III even though the nebulae stands out like a sore thumb you will lose the dimmer stars.

so thats my take on these filters,
thanks.
Tj