Monday, 29 June 2009

Hydrogen Balmer α

Apologies for not blogging for so long. I blame the summer twilight, and my new project. Since I got a reasonable picture of M83 (not the best of pictures - see below) I realised I could produce my own Messier mosaic. Unfortunatetly, this will take me the best part of a year, because I started in May. However, I am nearly there with the images - I have well over 90 of the 110 now and it's looking good. So I thought I would see what pictures I have that I am more pleased with. One of those I took last year with a single hand-guided exposure of about 6 minutes through a 400mm f/6.3 lens onto Kodak Elite Chrome 200 film. This was scanned directly from the slide film by Mike B, a much, much better quality scan than the crude messy job I paid the commercial photo processors to do. The field encompasses the star Sadr in Cygnus, M29, plenty of nebulosity and clearly shows the Crescent nebula - you can use it as a chart how to look for it. So here I've attached a higher quality *.bmp file for your perusal. As you can see from my previous images the Canon EOS's filtered sensor isn't a match for even ISO 200 film at the wavelength of Hydrogen Balmer α emission, 656 nm. Seriously want a modified one, but serious lack of £££!