here's my first real attempt at the Horsehead Nebula. It was gusty and guiding was blown around a bit by the wind, I had to stop imaging in the
end as the wind got too strong.
Anyhow, hope you enjoy the image.
Paul Mayo
The Horsehead Nebula. IC 434, Barnard 33 & NGC 2023.
One of the most popularly known celestial objects to amateur astronomers is the Horsehead Nebula. Situated in the constellation of Orion, the Horsehead Nebula is a dark nebula laying about 1500 light-years distance from us. The familiar horse-head shape (centre image) is formed from a dark non-luminous nebula (Barnard 33) that silhouettes itself against the reddish-pink glow of the emission nebula IC 434.
The IC 434 emission nebula glows as stellar radiation received from the nearby star Sigma Orionis (not pictured) excites the gas cloud into producing photons (light). To the lower left of the Horsehead nebula is the tiny yellowish nebula surrounding the variable star V615 Orionis. At lower left of this image is the larger bright bluish reflection nebula NGC 2023 which is strongly reflecting light from the star that lays at the centre of this bright nebula.
Telescope: 304mm f/5 reflector telescope, hand guided.
Camera: Canon EOS 300D Digital Rebel (not modified).
Exposures:
5 x 6 minute exposures @ ISO400 +
2 x 10 minute exposures @ ISO200
Total Exposure time approx. 50 minutes.
Sky Conditions: Gusty winds. Seeing: 7/10 Wind: 6/10 Moisture: 0/10
Ambient Temperature: 21°C
Notes: Many guiding errors due to wind gusts, had to call it quits.
That is an outstanding effort for hand guiding! Lovely rich colours and detail. Do you actually mean no motor drives and you are sitting there tweaking manual slow motion controls? Or, is the mount driven in RA and you are making manual adjustments? Either way, a great job.
That is an outstanding effort for hand guiding! Lovely rich colours and detail. Do you actually mean no motor drives and you are sitting there tweaking manual slow motion controls? Or, is the mount driven in RA and you are making manual adjustments? Either way, a great job.
Great write up too, very informative.
Cheers
Dennis
Hi Dennis,
thanks for your kind comments, glad you liked it.
Regarding "hand guiding": To explain myself better - I use a guidescope to visually monitor the tracking of the main 'scope which has a 50Hz variable frequency drive on the RA axis and a tangent adjuster arm for the DEC axis.
My hand controller has fast, slow and bias speed controls for the RA drive so I constantly need to watch through the guidescope to make "manual" corrections.
so how do you adjust for something going out of whack so to speak and not have it show up on the image. do you cover your tube with a black cloth whilst adjusting?
so how do you adjust for something going out of whack so to speak and not have it show up on the image. do you cover your tube with a black cloth whilst adjusting?
signed
noobie
Hi davidpretorius,
Potentially it could take a chapter or two to answer that question in full.
However to keep it short - the guidescope has an illuminated bulls-eye reticle with concentric circles. You must keep a guide-star in the bullseye while the imaging is in progress. The guide-star will wander back 'n forth as well as up and down (to a lesser degree). The hand controller I have has a fast 'n slow button so that I can speed up or slown down the telescope tracking to keep the guide-star in the bulls-eye.
Basically that's it.
Of course there are many other factors to consider: like the guidescope should have a focal length of about 2.5x to 3.0x that of the photographic telescope - so the guide-scope "sees" errors that can be corrected before the photoscope records the error.
so using a canon 350d at prime focus (fl = 50mm???) that is 25x in my scope, i would need to have a 2nd scope with the old toucam in prime focus (6mm) that gives me at least 75x or greater.
it is slowly sinking in!
i am still in the mode that my 10" dob has to always have the biggest magnification and anything else attached must automatically be smaller.
so on really small planetary nebs, you really need a decent sized guide scope???
Regarding seeing the horsehead visually, I've seen it in a 20" obsession with a h-beta filter, and to me it was barely worth the effort. Very faint..
I doubt very much you'd see it in a 16" scope.
Mike, I have seen this with a C11 with a 2" H-beta filter and a 31mm nagler at Illford. yes you had to avert your vision but once you spotted it you were drawn to it. it was faint but you could still make out the shape. For me is was a awesome experience and I thanked the western sydney astro club member for the experience, unfortunatelly I don't remember his name, but I do have his picture. I tried to see it with my 12" but you really need that filter to see it at all. Paul's image is a great shot.
so using a canon 350d at prime focus (fl = 50mm???) that is 25x in my scope, i would need to have a 2nd scope with the old toucam in prime focus (6mm) that gives me at least 75x or greater.
it is slowly sinking in!
i am still in the mode that my 10" dob has to always have the biggest magnification and anything else attached must automatically be smaller.
so on really small planetary nebs, you really need a decent sized guide scope???
Hi Davidpretorius,
It's more to do with focal lengths rather than magnification. As an example: suppose the photo-telescope is 1000mm focal length, then the guide-scope should be around 2500+mm focal length (usually done with a barlow lens and small focal length guiding eyepiece in the guide-scope).
Does that make sense ? (I'm only on my first coffee for the day!)
Mike, I have seen this with a C11 with a 2" H-beta filter and a 31mm nagler at Illford. yes you had to avert your vision but once you spotted it you were drawn to it. it was faint but you could still make out the shape. For me is was a awesome experience and I thanked the western sydney astro club member for the experience, unfortunatelly I don't remember his name, but I do have his picture. I tried to see it with my 12" but you really need that filter to see it at all. Paul's image is a great shot.
Geeday h0ughy,
Sounds like this might be something we can do at the forthcoming IIS Camp.
"Spot the horsehead"...
Thanks for compliment regarding the image, but I can't say that I am totally happy with the image and so it remains on my "hit list". The winds stopped me imaging and the seeing wasn't that great. So when the weather is good again I intend on much more PhotonCollecting for this object.
Sounds like this might be something we can do at the forthcoming IIS Camp.
"Spot the horsehead"...
Thanks for compliment regarding the image, but I can't say that I am totally happy with the image and so it remains on my "hit list". The winds stopped me imaging and the seeing wasn't that great. So when the weather is good again I intend on much more PhotonCollecting for this object.
Regards
Paul
Paul,
I am quite willing to take the 12" up to lostock, but will have to get some members to set it up fo me. I cannot lift it by myself anymore. I have a wedge or use in alt az with the field derotator I have. we would need to use your filter of course!! then we could have a go at it with Scotts plastic fantastic canon with the filter on the 80mm widefield on the EQ6, I have an ST4 so we can take lots of shots and know it will be tracked accurately. that saves pulling down your scope! and I know Scott is not moving his mount
For insulation for your shed, did you see the post by 5ash on the insulation material. it is thin and not obtrusive and would line the shed quite well. I think I will be using it when I build my astro shed
Gotta admit its one of the best shots taken with an unmodified DSLR, shows even unmod. ones can take images of the real faint stuff.
Paul and I take astroimages exactly the same way, we even have the same make and model of mount. The only difference is Paul uses a guidescope I use an off axis guider, and we both shoot from suburban locations.
Scott
I am quite willing to take the 12" up to lostock, but will have to get some members to set it up fo me. I cannot lift it by myself anymore. I have a wedge or use in alt az with the field derotator I have. we would need to use your filter of course!! then we could have a go at it with Scotts plastic fantastic canon with the filter on the 80mm widefield on the EQ6, I have an ST4 so we can take lots of shots and know it will be tracked accurately. that saves pulling down your scope! and I know Scott is not moving his mount
For insulation for your shed, did you see the post by 5ash on the insulation material. it is thin and not obtrusive and would line the shed quite well. I think I will be using it when I build my astro shed
Hi H0ughy,
Up to you whether you want to take your 'scope. I don't really plan on doing any astro-photography there.
I was considering bringing my 'scope along, it's a 12" f/5 and it only takes me to lift it. Best of all it only takes 20 seconds to dismount my 'scope onto its dobsonian mount while leaving the equatorial mount in the observatory, then off I go in my MoonMobile (as Scott would call it - my car has a "Moon Roof").
Filter? err uhm I don't really use filters.
Regarding insulation - I've been thinking about that, but it simply isnt a big enough issue or even an issue at all to do anything about. And no insulation certainly has advantages when it comes to temperature equilibriums.
Probably the only downpoint at the moment is during winter I have to clean my optics 1 or 2 times as a little due can build up on the mirrors overnight in the cold and wet months. But again the optics are overcoated and very easily removed and cleaned, so you see it's not something on my high priority list.
By the same token, if I were leaving cameras and computers in the observatory then I'm sure insulation would jump up high on the priority list.
I recently made a solar powered cooler system for the observatory from an old plastic trumpet and a 3-inch fan running of solar power which exchanges air from the outside during daylight.
I'm going to buy another solar panel to recharge a 12V battery which will inturn be used for powering a thermostat controlled air heater during moist winter months, some red-light lighting, a map reader, and stuff like that. Just enough to raise the interior air temp by <1°C during nights when the observatory is un-attended/or attended for that matter.
But like I say none of this is a high priority.
Finally another little thing that helps is the fact that my observatory has a white roof. This was a really good move (to order the shed with a white roof) since as you can imagine it reflects heat and light away really well.
Anyhow let us know whether you'll be taking the lx200.
Clear Skies
PS. Can you really only see 22 stars from your place ?
