Swan and Eagle with Nebula Filter

[avandonk]

Since there was a partial Moon thought I would try a deep widefield with a nebula filter. The stepper focuser works very well had to change focus after each exposure as the temperature dropped. Thats why the detail is so good.

Large image 1.6MB
http://members.optusnet.com.au/~avandonk2/SW&EAG.jpg

Details.
Canon 5DH with Canon 300mmm F2.8L @ F2.8, Hutech Nebula Filter, 7x10min at ISO200, processed with ImagesPlus (flats) and Registar (stacking).

Bert.

[Striker]

Everything looks to red bias Bert....I mean everything even the stars.

[Dennis]

Hi Bert

The full size image is well worth a look. You can easily make out the detail of the Eagle Nebula structure made famous by the Hubble telescope - quite remarkable for such a wide field. On the full size image, some of the stars look almost square - is this due to jpg compression, or pixel size versus focal length of the lens?

Cheers

Dennis

[tornado33]

Hi Bert
Great image there. heres my effort with your lens, though not as deep only 3x5 mins with UHC-S filter. I dont know if its because I set up your lens at least 1/2 hour before imaging and temperature has stabilized, but focus doesnt seem to change between exposures. It may change slightly if I point to another part of the sky, or after an hour or so has elapsed. With the UHCS filter when trying to balance the sky background sometimes, as Striker points out there can be a reddish cast, as if the UHCS filter really amplifies the red , which I guess it does anyway.
Scott

[avandonk]

Yes it is hard to get anything but Nebulae looking right with a Hutech Neb Filter.
If you look at the picture below they are transmission spectra in glorious colour of various filters.I put this together some time ago using a grating and the 20D.
From the top
Denko 'H Alpha'
Hutech Nebular filter
Nebular Filter brand unknown from R Davis eons ago
Hutech LPR Filter
Mercury (Hg) Lamp ie (streetlight)
High Pressure Sodium Lamp (streetlight)
Tungsten Globe

As you can see there is no yellow passed by the Hutech NF. If you push the yellow in colour balance a nasty green cast appears as well as 'yellow'.

Bert

[tornado33]

Thanks for the spectragrams Bert, most informative.
Scott

[EzyStyles]

great shot bert. abit red i have to admit but still plenty of details.