Barnard's Loop

[rmuhlack (Richard)]

I am in the process of selling my house for an interstate move from country NSW to Adelaide, so most of our stuff is packed away, including my scopes! I was getting "imaging withdrawal", so I decided to make the most of a few free nights to do some widefield imaging.

This is a widefield view of the constellation Orion, showing Barnard's Loop as well as the more familiar Orion, Horsehead and Flame nebulae. M78 and part of the Witchhead Nebula can also be seen in this image, which was taken using a Canon 1000D and a low-cost Nikon E-series 50mm camera lens at f5, mounted on a HEQ5. Capture details are:

147 x 2min dithered subs @ ISO1600
Processed in Pixinsight v1.8

To avoid diffraction spikes and reduce chromatic abberation, a DIY aperture mask (a piece of cardboard cut to size) was used to stop down the lens to f5. The DSLR has been modified to replace the original UV/IR filter with an Astrodon luminance filter. Ambient temps of 12-18C.

I can see some peculiar star shapes in the corners when viewing the full-res version (see here)- could be an issue with the lens or the canon-nikon adapter, or perhaps it's sensor tilt. I will need to investigate further.

Comments and feedback welcomed

[Regulus (Trevor)]

A satisfying result. Nice colour and symmetry in the composition.
I have decided to use the older lenses with adapters as well. There are a lot for sale at good prices and some of those lenses were outstanding, so I am happy to see this photo for that reason as well.
From memory the E-series was made as a budget lense made to go with a budget Nikon SLR, although I cannot remember the models (FG/F20 I think). The had the standard AI mount from memory, but had a lot of optical plastic rather than glass, so it is possible the problem u mention is in the lens it's self.
Trevor

[Rigel003 (Graeme)]

All the great sights in one shot. the full res is great. Nicely processed too. Whereabouts in Adelaide will you be?

[rmuhlack (Richard)]

Originally Posted by Regulus

A satisfying result. Nice colour and symmetry in the composition.
I have decided to use the older lenses with adapters as well. There are a lot for sale at good prices and some of those lenses were outstanding, so I am happy to see this photo for that reason as well.
From memory the E-series was made as a budget lense made to go with a budget Nikon SLR, although I cannot remember the models (FG/F20 I think). The had the standard AI mount from memory, but had a lot of optical plastic rather than glass, so it is possible the problem u mention is in the lens it's self.
Trevor

Thanks Trevor. I have several Nikkor lenses that I use (with EOS adapters) for astro work. I particularly like the Nikkor 135mm f3.5 (see example here) and the Nikkor 200mm f4 (example here). Both relatively inexpensive lenses that produce some nice results.

Originally Posted by Rigel003

All the great sights in one shot. the full res is great. Nicely processed too. Whereabouts in Adelaide will you be?

Thanks Graeme. You don't think it looks too 'washed out'? I'm wondering if I should increase the contrast a bit more...?

I am originally from Adelaide (and my family still live there) so I know the city quite well. My wife and I are looking at moving to a Hills location such as Mt Barker or Strathalbyn. Strath is probably the front runner as it has darker skies and a relax 'country town' community vibe.

[Stefan Buda]

Hi Richard,

I think the problem is astigmatism caused by the aperture mask being at the wrong place. A complex objective such as a camera lens must have the aperture diaphragm somewhere between the various lens elements, in order to work properly.
Other than that I like the image.

Cheers,

Stefan

[rmuhlack (Richard)]

Originally Posted by Stefan Buda

Hi Richard,

I think the problem is astigmatism caused by the aperture mask being at the wrong place. A complex objective such as a camera lens must have the aperture diaphragm somewhere between the various lens elements, in order to work properly.
Other than that I like the image.

Cheers,

Stefan

Thanks Stefan, that sounds quite plausible. Will check it out

[multiweb (Marc)]

Nice colors Richard. That's a lot of subs. Doesn't the mask reduce the light gathering too much?

[RickS (Rick)]

That's a good result, Richard.

[gregbradley]

What a great widefield image. Very beautiful.

Greg.

[strongmanmike (Michael)]

Nice, in the middle of moving house, result Richard

Was there a bigger file to view somewhere?

Mike

[rmuhlack (Richard)]

Thanks for the nice comments everyone. Mike - you can clicky here for the hi-res