Eta Carina

[Radar]

This shot is a 30 minute exposure using Kodak Elite Chrome 200 from a very very light polluted area. Morley Western Australia. I used a light pollution filter and autoguided through an ST4.

Takahashi Epsilon and Losmandy G11.

207

[AstroTasmania]

Hi Radar, nice shot, but it is time for you to go digital. 30 minutes! You could reduce your exposure time - and remove that serious vignetting if it was a digital image. What is causing your cut-off in each corner?

30 minutes of clear skies, where did you find that?

Clear skies...

[Radar]

The vignetting is this image is worse than normal because I took this photo from a very light polluted area. Usually the vignetting is not so pronounced, but the pollution (even with a filter) takes it toll.

[AstroTasmania]

Hi Radar

Your vignetting is not caused by light pollution, you have either not full coverage of the film plane by the optics, or there is a mechanical restriction, such as a drawtube which is too small. The effect becomes more obvious with a longer exposure. Have you got any images of your setup, focuser, camera adaptor etc.

On my Tak Epsilon 180ED, they supply (at extra cost) a wide T-adaptor, the standard ones used do cut off the corners, like you have in your images.

Just something you might like to check.

Clear skies...

[Radar]

Interesting. Thanks for that Shev. I'll investigate it. I'm pretty sure I have the wide t adapater though. I'll post some pics of my setup soon.

[Craig]

it is time for you to go digital. 30 minutes! You could reduce your exposure time


Clear skies...

While I'm very limited in astro knowledge compared to most people on this site, I can't help but add my two bobs worth and say that long live film. It has hidden depths, and as a very poor amteur photographer I still like it better. You can also always scan the negative onto a computer and get the best of both worlds. Sorry but I am a traditionalist at heart.

[rogerg]

Considering the circumstances that's a nice shot and definitely has good circular stars Ray.

I think I'd opt for tuning down the brightness a little - it's quite bright and so you wouldn't lose much but would make the noise etc less obvious I'd think?

I know what you mean about vinyetting in city skies. Obviously it's not caused by light pollution but light pollution sure makes it more obvious in my experience.