I am hopefully getting a proper 1.25" IR/UV filter next week! So this is probably the last image I will ever take of Carina without a filter.
So I spent tonight getting the best Carina/Keyhole Nebula I could without the filter so I can do a good comparison test after getting the filter.
I also believe this is one of the best Carinas I have ever captured with the trusty but humble Modified Toucam. I pushed it harder than I ever have before, and with the bright moon too!
ED80, Focal Reducer, Modded Toucan 840k Pro II, 25 x 240 second images captured in 'Desire', guided with Standard Toucam in Guidedog with a 100mm short tube Achro, stacked in Registax 3, processed in PhotoShop CS.
Processing involved: Slight noise removal with PS Actions, Brightness up +4, Contrast up + 2, Blackeyes removed in 'Loreal', Gaussian Blur 0.2 pixels. Final image enlarged by 20%.
I hope it reproduces in here as good as it looks on my monitor before reducing quality for posting.
EDIT: I forgot to mention - Temp 1 degree, Seeing 7/10, Transparency 8/10, thin hazy cloud, very windy, lots of moonshine.
Last edited by ballaratdragons; 27-06-2007 at 01:44 AM.
lookin good Ken! Be great to see the comparision image with the uv/ir filter. That will fix the star bloat.
Well guided and processed too!!
way to go Ken!!!!
The Autoguiding really helps.
Will be nice to finally get rid of the star bloat with IR filtering and keep the nebula bright with UV filtering.
The little Toucam IR filter just couldn't do it quite right as it still lets the UV through which fades the Nebula or Galaxy. Gives better stars but at a loss to DSO light.
Thanks for the comments re the processing. It's often tempting to go toooo far and ruin the data.
I have been informed by Bert that I don't need both IR & UV filtering for my skies. The UV really only helps when things like light pollution are a problem, which I don't have. It turns out that Nebulas and Galaxies are faint when I used the Toucam one because of the quality of the Toucam one. It isn't Astro quality glass and has no coatings. After all, it is only designed for gawking at other people on the internet.
Hmmmm, just done some reading about IR/UV filtering.
The UV part of Filters can actually make 'Reflection Nebula' and some galaxies completely dissappear!!!!
Practically everything I read says I only need IR filtering with a CCD, not UV filtering.
Bert certainly knows what he is talking about, that's for sure.
Killing Reflection Nebs & some Galaxies kind of defeats the purpose of DSO photography doesn't it.
Thank goodness! I had an IR filter on my "to buy" list, but then wondered if I'd have to find the extra dollars for an IR/UV after your first post, Ken. Can relax now - only have to stretch to the IR filter. Thanks.
Hi Ken, I've been using the IR/UV filter from Astronomiks for a couple of months now but I haven't encountered the disappearance effect yet.
The filter itself is very good and there is a real improvement over the standard Meade IR filter in my opinion.
I am also in the process of changing over the RGB filters as well.
