View Full Version here: : New 7 Nm Hydrogen Alpha images
tornado33
30-07-2005, 09:46 AM
Hi all
Here are some of my first pics with a Baader 7 Namometre Hydrogen Alpha filter, on my 50mm F1.8 lens
Eta carina region
http://www.users.on.net/~josiah/baader/h%20aplha%20eta%20carina%20335sec%2 0iso1600s.jpg
335 sec image ISO 1600
Faint nebulosity around Eta carina visible.
Milky way area
http://www.users.on.net/~josiah/baader/h%20alpha%20milky%20waysmall.jpg
Note intense hydrogen emission of the Lagoon nebula complex, as well as omega and eagle nebs.
1445 sec ISO 1600
both shot with lens wide open F1.8
Focus through viewfinder impossible, nothing at all is visible! Had to use trial and error method of taking short exposures, checking focus, adjusting focus and repeating.
I deleted the green and blue channels, then turned the red into greyscale.
Scott
[1ponders]
30-07-2005, 09:37 PM
Interesting images Scott.Where do you get the time and clear skies to take all these :) How do you deal with the amount of noise generated by the 300D during your really long shots? Single dark subtraction or meaned dark subtraction?
h0ughy
30-07-2005, 10:18 PM
Scott,
you have done some excellent :innocent: work there, all you need now is to sandwich that with some normal nebula shots and you will have another winner :thumbsup: :thumbsup:
tornado33
31-07-2005, 12:53 AM
Hi all
We have had some great weather of late, so Im making hay while the sun shines, or rather the stars shine hehehehe. My mount is permenently set up in the back yard, polar alinged so I just need to plug in the power, bring out the scope and drive corrector and Im ready to go, and in Winter can get several hours imaging in without a really late night.
I did a single dark subtraction. Extracting the Raw imahes through Photoshop is less loisy than the supplied Canon software. Utilizing just the red channel seemed to get ring of some of the noise too for the H alpha shot.
Scott
seeker372011
31-07-2005, 01:40 AM
Scott:
look forward to some more interesting shots with that new filter
On another related subject, with your long dexposures, do you have any trouble with amp glow? I find really big problems as soon as I go beyond say 6 or 7 minutes with the Canon.
Narayan
tornado33
31-07-2005, 11:03 AM
Hi Seeker
Yes I was having trouble with it. Dark subtraction helps but it often leaves a greenish colour instead, and I have to reduce the opacity of the dark frame in Photoshop anyway otherwise I get coloured spots all over any nebulosity in my images from the dark frame.
A much better thing is Gradient exterminator http://www.rc-astro.com/resources/GradientXTerminator/index.html
It magically gets rid of most of the amp glow in one go, as well as any vignetting. Its the next best thing to a proper flatfield. I use it all the time and often dont bother dark subtracting unless its a very long exposure (more than 15 mins for ISO 1600)
Scott
Raymond
31-07-2005, 09:41 PM
Dear Scott,
I cannot see any new 7nm Ha filter from Baader's website. Can you show me the link for such new filter.
I currently have a Baader 45nm Ha and a Baader 8nm OIII. I shall be interested to upgrade to 7nm for Ha narrowband imaging.
Raymond
tornado33
01-08-2005, 07:18 AM
Hi Raymond
Its actually not yet released, they are kindly letting me test one beforehand, they found out about my Baader UHCS filter images and kindly sent me the H Aplha filter :)
Scott
interesting shots scott :)
Raymond
01-08-2005, 10:58 PM
Dear Scott,
I now have Baader's 45nm Ha and 8nm OIII filters. While the OIII is narrow band, the present 45nm Ha is not narrowband.
Will Baader release other narrowband filter such as SII ?
Raymond
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