This image was done with my 12" GSO newtonian and my old Canon 300D DSLR modified with a clear class window over the sensor. No "Advanced" Telescope supplies and no "Advanced" User here, just me.... :-)
This image is taking a look near the centre of the Eta Carina nebula and shows many interesting objects. The image is only a 75-minute long exposure set to a low ISO-200 and auto processed with ImagesPlus and then a little brightening in Photoshop. The image is only a centre crop of the entire image. But we are seeing what the camera saw at prime-focus of the el-cheapo 12" scope from GSO.
I see many interesting objects in this image some of which I have arrowed in the accompanying pic. From arrows left to right;
a . they look like dark Bok/Thackeray globules. Also notice how red the nebula appears on this side of the image compared to the colour of the nebula on the other side of the image. It appears to me the bluish cast of nebula might be from those hot bright white-blue stars reflecting some of their light off the nebula (so they reflect blue light). Perhaps that's why the nebula looks a little pinkish ? In the old film days this area only appeared as red.
b. I've noticed this many times before in past images. This star appears to be shining a "beam of light" in a Northly and Southly direction. Can you guys/gals see what I am talking about ? I've never found any mention of it anywhere.
c. see how there appears to be a "arc of nebula" just North-East, must be due to radiation winds from that nearby star (at lower left of it) ?
d. Wow this nebula edge looks like the East coast of Australia, it's the same type of finger-like nebula activity seen in the centre of the Eagle Nebula.
finally look at how black the centre of the Eta Carina nebula appears at top-right of the image. hmmm. kewl.
I'm pretty happy with this look at the centre of Eta Carina Nebula sorry if the colours are not right (but who cares? what the picture reveals to me is far more important than whether it is the "right" shade of colour). Anyhow, interstellar redening, our atmosphere, and our eye's response to spectral colours change the original colours to the perceived colours that land here on Earth.
Very good image Paul. I used registar to make an image coinciding exactly with yours from a Spitzer IR image that shows the dark dust clouds. Can you see the correlation. This should give you a better idea of what is going on. All the dust columns point to Eta Carina.
I also used registar to make an image of the full Spitzer image against one of my Carina images done with the 100ED.
Every time I see one of your images it makes me think about building a 12" Newt astrograph.
Paul.
Great shot, rich detail and color not overexposed and focus is perfect.
The G-11 seems to be handling the load quiet well if you can pull this off.
The Losmandy saddle plate is replaced with my own 12mm thick aluminium plate which uses all of the six mounting holes in top of the G-11 equatorial head instead of only the 2 mounting holes used by the Losmandy saddle plate. My aluminium saddle-plate then seats two hand made hardwood timber "tube seats" lined with strips cut from a mouse mat which seat the optical tube assembly (you can see the timber seats in the pic, and if you look close you can see the mouse pad liner).
My mounting plate is (IMHO) far more secure than being held on with the Losmandy dovetail plate and a single thumb wheel to lock it in position - considering I am carrying such a large payload this was my design to ensure no movement and also to move the entire payload closer to the equatorial mount head, which decreases the potentional load on the mount.For smaller OTAs the existing Losmandy saddle and dovetail plates work just fine.
The OTA is held in position with a set of $15 luggage rack straps which are tension adjustable, infact enough to crush the OTA!!! ( I should know as I have already put a slight indentation in the tube from over tensioning), but they certainly do a very very very good job of holding the OTA in position without any movement whatsoever. To tell the truth I was skeptical when I first thought of using these (but using tube rings would have pushed the OTA further away from the centre of the mount - increasing the load ).
Getting to the point...
The guidescope is mounted and pointed with Bonney Lake Astro Works 5.5" guidescope rings and a modified 10" Schmidt-Cassegrain dovetail rail that I fitted to my own docking plate. My 6mm thick aluminium "docking plate" optionally bolts to the top of my hand made saddle plate. The docking plate slips under the OTA and out the other side where there is a counterweight to balance the guidescope. I can also drop off the guidescope and bolt on SLR
cameras or big telephoto lenses! so the docking plate works a treat. What you can-not see in these pics. is the other side of the docking plate and the counterweight on it.
Paul.
Great shot, rich detail and color not overexposed and focus is perfect.
The G-11 seems to be handling the load quiet well if you can pull this off.
Regards
Fahim
I know there is a lot of payload on this mount, it's a simple observation to make, but before putting it together I did my sums and calculated the total payload would be less than the rated capacity of the mount (well.... just).
The entire payload including guidescope, Canon 300D, SBIG 402 CCD guider and everything else you see in the pic. weighs in at just under 29kg. Losmandy rate the mount to carry 30kg, so I am just under. But to help stability and balance I also had Southern Cross Piers make the custom pier you see in the pic. It is a very solid and stable pier, and as some of you may already know the observatory floor is no ordinary concrete slab.
So at the end of the day I have the scope really well balanced and very sturdy, and under these circumstances it all seems to handle it okay... but I would recommend lesser payloads on the mount.
Very good image Paul. I used registar to make an image coinciding exactly with yours from a Spitzer IR image that shows the dark dust clouds. Can you see the correlation. This should give you a better idea of what is going on. All the dust columns point to Eta Carina.
I also used registar to make an image of the full Spitzer image against one of my Carina images done with the 100ED.
Every time I see one of your images it makes me think about building a 12" Newt astrograph.
Bert
Hi Bert,
that is excellent, how you have compiled the spitzer image for the same region as my own image. Yes I see how they correlate. The "beams of light" coming from that star ( I previously talked about ) look like they may correlate with those light green colours on left of the spitzer image? What does green represent from the spitzer?
12" astrograph eh? yep it worked for me. The way I looked at it was that the 12" didn't cost very much and if the project didn't work out then I would have a 12" dob too look through and revert to plan B which was to use a smaller and lighter 10" GSO OTA. The only other thing you need to make it all work is a Baader MultiPurpose Coma Corrector which has made my entire imaging field all but completely flat.
regards
Paul
Last edited by PhotonCollector; 20-01-2008 at 05:06 PM.
Reason: missed a word
As Jase pointed out, the system is is more likely close to $10K
(mount $5.3k, ST402 $2K, Modified 300D $2k?, GSO $0.9k, other bits say $.7k...wassat? about $10,000 big ones)
That said, the ensemble is clearly working well and I take my hat off to Paul
for making it hum
Quote:
Originally Posted by h0ughy
Peter the OTA i think is being referred to not the whole lot. Nice explainations and pointing things out Paul.
As Jase pointed out, the system is is more likely close to $10K
(mount $5.3k, ST402 $2K, Modified 300D $2k?, GSO $0.9k, other bits say $.7k...wassat? about $10,000 big ones)
That said, the ensemble is clearly working well and I take my hat off to Paul
for making it hum