Tarantula from the heart of Melbourne

[RayOfLight]

Hi guys,

Here is a fresh new luminance image mosaic (2-panels) of Tarantula Nebula straight from the Melbourne CBD. Although this is not the first imaging session from the balcony, this image represents a fresh set of luminance data, after a more thorough drift alignment process and conscientious focusing. Autoguiding seems pretty good this time round, and the seeing was a tad better than previous sessions. Despite the almost full moon around, I was quite surprised that the luminance captures are still manageable, probably because the moon seldom (in fact never?) traverses pas zenith point unlike in equatorial countries. The following is a 2-panel mosaic of Tarantula. I am still thinking if I should proceed with colour data as colour tends to be quite weak and granulated when taken from light polluted locations, but it could be worth a try if there are more clear sky periods. Last night was fine, except for the occasional interruption of passing clouds where some of the subs had to be prematurely halted. Each panel is a combination of about 8 sub-exposures each 5 minutes in duration. I have yet to go cooler than 0 degrees, but it would be worth a try on cooler nights, which should get the noise lowered by almost half if the difference is 6 degrees lower (but with the camera working harder!).

Image Capture Details:
Instrument: Vixen FL80S
Camera: SBIG ST2KXM
Exposures: 8x5 minutes per panel
Location: Melbourne CBD

http://www.celestialportraits.com/te...070mosaic3.jpg

[jase (Jason)]

Not a bad effort Remus, certainly given the environmental conditions of downtown. To overcome light pollution, you may find it beneficial to go deeper than 5 min subs, but this will depend vastly on the sky glow limit. If you plan to shoot from the burbs often, take up narrowband. You'll tear you hair out dealing with gradient of broadband RGB. Still, if you're keen, it can be done. Personally, I think the data could have been sharper, looks a little soft in my opinion. Perhaps focus was slightly off or post processing steps need some refinement. Good job on the mosaic however. The composition adds an interesting perspective on this commonly imaged region and the stitching appears seamless. Thanks for sharing and look forward to seeing more...perhaps the complimented RGB data to the scene.

[iceman (Mike)]

Hey Remus, lovely work. How are you enjoying your time in AU?

Shame we missed you at IISAC this year.

All the best.

[sjastro]

Nice image Remus.

Regards

Steven

[atalas]

Nice Remus.

[RayOfLight]

Appreciate your thoughts on this new image, Jason, Louis (how are u!), Mike, and Steven!

Still trying to get the hang of the system, in particularly making sure the guiding is doing good. I would definitely agree the focusing is quite off, but with the stock focuser, it is an eye-balling affair. Made an enquiry to Starlight instruments on a suitable feathertouch for the FL80S but there was no mating adapter available for the refractor. Relying on the R&P action of focusing currently. Am planning on h-alpha soon. Have made another run at this object again earlier tonight, paid a little more attention on focusing (with the help of strings). The Bah. mask method seems ideal, but I am trying to make do with what I have now. I miss my taks back home (felt jiffy having to bring one through a plane flight!), everything seems easy with them. But it's a positive challenge with this current system!

http://www.celestialportraits.com/te...70L_121108.jpg