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Posts Made By: Ivan Ong

October 29, 2005 03:56 PM Forum: Digital SLR AstroPhotography

M52 and The Bubble Nebula

Posted By Ivan Ong

Hi All, here is a widefield shot of M52 and the nearby NGC 7635 (bubble nebula) taken last night off the Blue Ridge Parkway, NC. Blistering cold, great for a DSLR camera! Low noise.
Canon 20D, unmodified, A-P traveler with reducer. 7x6min, ISO 1600.

Thanks for looking!
Ivan

October 29, 2005 04:47 PM Forum: Digital SLR AstroPhotography

California Nebula

Posted By Ivan Ong

Like a great big slab of celestial country ham, this nebula is huge!!!
7x6min, ISO 1600, Canon 20D, AP Traveler with reducer. Tak EM200, STV.

Ivan

October 30, 2005 12:32 AM Forum: Digital SLR AstroPhotography

Horse Head and Flame

Posted By Ivan Ong

Hope I'm not boring you guys. Here's one more from last night, the Horse Head with the Flame Nebula. 7x6min, ISO1600, Canon 20D, A-P Traveler with reducer.

Thanks for looking!
Ivan

October 31, 2005 01:58 PM Forum: CCD Imaging and Processing/Solar System

Halloween Mars

Posted By Ivan Ong

Here is Mars early this morning at 00:15. Unusally nice steady skies, but I have the disadvantage of shooting over the roof of my house, which is not good. Yes, working on wife to cut down the trees.
C9.25"+3x barlow.
Ivan

November 3, 2005 03:51 PM Forum: Equipment Talk

Help on balancing an Eq Mount for astrophotography

Posted By Ivan Ong

Hi, I need some opinion/help here.

I am doing astrophotography with either a 4" and 5" refractor, with an SBIG STV mounted directly above the imaging OTA. I am using a Tak EM-200.

When I add a finderscope I mount it where the pre-drilled finderscope holes are, which is to one side of the OTA tube, not directly above (can't do it anyway as the STV will be in the way).

My question is balancing the whole setup with the finderscope attached on (I like it on to help me locate some dim objects to photograph). I balance the system on both axes with the OTA horizontal. But when I move the balanced system to point at an object somewhere else in the sky, I frequently find that the balance is no longer valid due to the non-symmetric weight attachement of the finderscope. I find that the STV and tracking are working harder, and are definitely more prone to inaccuracies. In fact, the degree of "dis-balance" is highly dependent on the orientation of the OTA given the attachement of the finderscope to one side.

So, question is, do the experts remove all non-symmetric attachements (i.e. finderscope) when doing imaging, or do they re-adjust the balance of the OTA at each orientation prior to imaging (much better, but more of a pain)? Or do they get a monster hairy mount that doesn't even care about these trifling balance issues?

Thanks,
Ivan



November 3, 2005 04:36 PM Forum: Digital SLR AstroPhotography

IC405 Flaming Star Nebula

Posted By Ivan Ong

Auriga is full of interesting things! Here is IC 405 at 7x6min ISO 1600 Canon 20D. I was surprised to see the bluish/violet region show up so distinctly.

Thanks for looking,
Ivan

November 6, 2005 05:29 AM Forum: CCD Imaging and Processing/Deep Sky

3 Auriga sisters

Posted By Ivan Ong

Here are M36, M37 and M38 in Auriga. While M37 is probably the most spectacular, I like M38 because you can see the "Have a nice day" smilely face to its right, with the smaller cluster NGC1907 on one of its cheeks. With my widefield refractors, it is quite remarkable to just pan around this region.

Photo details: A-P 105mm at f/4.4, Canon 20D, processing in photoshop and MaxIm DL.

Thanks for looking! Ivan

November 8, 2005 04:45 PM Forum: Digital SLR AstroPhotography

NGC281 Pac Man nebula

Posted By Ivan Ong

Interesting little object, needed lots of exposure 9x6min with a Canon 20D at F4.4/105mm, guided with an SBIG STV so I can snooze. Image scale is kind of tiny, I'll like to try again with a longer focal length soon.

Thanks for looking!
Ivan

November 27, 2005 03:11 AM Forum: Digital SLR AstroPhotography

M33

Posted By Ivan Ong

Hi All, this galaxy is tricky and to me it shows the limiations of DSLR's over cooled CCD's. This cries for more exposure time! I used an IDAS LPS filter for this shot. While contrast is significantly deepened, the filter bleaches off the reds, so we don't see the delicate red nebulosity that wreaths the galactic arms. Maybe this filter will be a great combo with the Canon 20Da, which emphasizes the reds so much. I go through periods wondering if it is worth keeping my LPS filer, but the gain in contrasts does offset the red color loss.

Here is 8x7min with a Canon 20D at f4.5 with a 105mm refractor. The image is a magnified portion, imager scale is very small with my setup.

Ivan

November 27, 2005 05:27 PM Forum: Digital SLR AstroPhotography

IC1848 wide field

Posted By Ivan Ong

I almost pulled my hair out for this shot. I was doing 7min exposures, but twice two pickup trucks drove by with headlights blazing, then four successive frames had airplane trials in it! Finally, I was able to get 6 7min frames. This is a vast nebular complex north of Persus just next to the more famous Heart/Valentine nebula (IC 1805). I think this is more interesting than IC 1805 as it has red nebular structures that look like Gumby and some penertrating dark nebulas. Anyway, a busy part of the sky!

6x7min, Canon 20D, IDAS LPS filter, f4.5, 105mm scope.

Thanks for looking!
Ivan