Aurora Pics

Just got my photos back. half of them didn't come out for some reason
Anyway, of the ones that I got back, I scanned two of them, uploaded them in the files section and linked to them below.

www.irishastronomy.org/user_resources/fi...8-29Oct2003MOC-1.jpg

www.irishastronomy.org/user_resources/fi...3-29Oct2003MOC-2.jpg

They aren't as good as others posted here, but I'm reasonably happy with them as they were my first attempt at film astrophotography.
What struck me is that the colour, in particular the green, is more pronounced than it appeared visually. Is this due to the sensitivity of the film over the eye? Do diffrent speeds/brands of film vary? The film I used was Fujicolour Superia 200 (just happened to be in the camera at the time). What film would one recommend?

Regards,

Michael

I'm reasonably happy with them as they were my first attempt at film astrophotography.
What struck me is that the colour, in particular the green, is more pronounced than it appeared visually. Is this due to the sensitivity of the film over the eye? Do diffrent speeds/brands of film vary? The film I used was Fujicolour Superia 200 (just happened to be in the camera at the time). What film would one recommend?

Regards,

Michael

Hi Michael,
they are quite impressive indeed. I like the way Ursa Major comes through the green colouring! Well done for a first attempt!
The reason why the green is more pronounced on the film was due to your exposure time. Camera film is akin to a sponge to water... the longer you leave the sponge under a dripping tap, the more it will soak up. Camera film does this. So, the longer you leave the shutter open on your camera, the more 'saturated' your photograph will be when developed. It is recommended, for easy going, quick exposure times (for example, if you are in or near a town center) ISO 800 (or ISO 1600 max) should be used. For longer exposures at night, ISO 400 is perfect. For something like what you have taken, you could almost have left the shutter open for half the time on 400, than you did on 200, getting the same brightness of your aurora, and not getting as long star trails.
I'm only doing astrophotography myself for 3 years, and of course there have been lots of hits and misses. It helps though to have a notepad when photographing, so I can make a record of the specs of each photo taken, and then learn which measures are the best in future.
There are one or two more experienced photographers in the gourp who will (PLEASE!!) expand (or correct) what I have written here :!:

Seanie.

Thnaks for the kind words and advice Seanie. Much appreciated. After getting those results, I'm starting to get more interested in taking astrophotos with film. I have a piggyback rail and counterweights for my scope so I must try a bit of deep sky work. For the moment I might try just using the scope as a mount/tracking device and try large scale photos of a couple of constellations. As I get more comfortable with it I might then try some more advanced stuff.
BTW, what exactly is "afocal"? Is this where you remove the camera lens and use the telescope as a lens with a t-adapter and t-mount to connect the two, or is it where you use the eyepiece. And if afocal is one method, what do you call the other method?
(Must get myself a decent book on the stuff.)

Regards,

Michael

BTW, what exactly is "afocal"? Is this where you remove the camera lens and use the telescope as a lens with a t-adapter and t-mount to connect the two, or is it where you use the eyepiece. And if afocal is one method, what do you call the other method?

yep, thats afocal. using the eyepiece is called `eyepiece projection` afaik.

btw, is there a difference between `afocal` and `prime focus` or do they both mean the same?

Cheers,
~Al

Michael,
Con Buckley and I went up to Lough Derg on Wednesday, we used the same exposures you used and all of his did come out, did you check your negitives to see it the developer missed them ??, some auto developers are not sensitive to faint objects.

The vast majority of mine did not come out. Only about 20% of them I reckon. A bit fustrating to sat the least! Anyway around it?? When we handed the film into Spectraphoto, we specifically requested that all photos be returned, even if they appeared to be no good. However, when picking them up, we were told that alot of the negatives were blank, which the shop assistant proceeded to show us. Very strange!

Michael