AIC 2012 day two has been excellent. After a fine breakfast, we started with the Hubble Award lecture from honoree Adam Block. He demonstrated some of the techniques that make him such a renowned imager and the excellent teaching style that makes his out reach and tutorials so effective. Alistair Symon followed with a good presentation on making wide field mosaics using Photoshop and Registar.

After the break, Travis Rector spoke on Presentation Quality Image Processing. He had some very good lines in his talk including “Astrophotos are like your children, you love them because they are yours not because they are pretty.” Working for the observatories, he is careful not to use any aggressive processing on the image, and he still gets emails with people seeing hidden aliens in image processing artifacts.

He hit the key points in the ongoing discussion of “what does it really look like?”. Or as he said, it doesn’t look like the picture because:

• surface brightness is constant, if you are closer to the object you still couldn’t see it
• People can’t see color in faint light
• Our eyes have poor sensitivity to red light
• Processing compresses the dynamic range does not match direct perception
• Filters and wavelength go beyond visual

So asking what it looks like is a meaningless question. Travis tries to translate what a telescope can see into what we can appreciate. That is his art and he does it very well. Everything he does in processing is done with curves and levels, and he follows some simple rules:

• Know your object – do research and plan what data to capture
• Take educated risks – try what others haven’t
• Crop and rotate to show what you want the viewer to see
• Use color well
• Surface brightness is your friend as an amateur – big scope, you get more small dim objects, smaller scope higher f ratio better on larger objects

Check out the paper Image processing techniques for the creation of presentation quality astronomical images. Available at Arvix.org/abs/Astro-ph/0412138/. (I’ll fix the URLs later)

After lunch we had an excellent talk from UC’s Geoff Marcy on the Hunt for Exoplanets. Then Astronomy magazine’s David Eicher spoke on the Future of Amateur Astrophotography.

The Spotlight presentations were very good. Tom Field presented Simple Spectroscopy. There is a range of options from $200 to $2,000+ for doing spectra, and it is real science. A very enthusiastic presentation. He told a great story about how a strange emission line was seen in a spectra of the sun taken during an eclipse. It did not match any known element. So the unknown element was named Helium for the sun, Helios. Years later, the spectra was seen from a gas coming from decaying uranium. That gas was helium, now really found.

Jerry Bonnell presented on Planetary Nebula on behalf of Don Goldman. Excellent theoretical background was provided. Apparently the hourglass shape of the nebulae comes from the fast moving later stellar pushed above and below the rotation axis by slower stellar winds that primarily go on the rotation axis. All of this is occurring as the star goes through its giant phase at the end of its life.

Sal , a young astrophotographer from Florida, presented on Astrophotography Under Light Polluted Skies. He presented an excellent set of Photoshop centric approaches for producing good images. This included Jay Gabany’s layered contrast stretching approach that, once I get Sal’s presentation I might actually understand how it is done. Sal recommends RGB at 1×1 and same duration as Luminance, combining the RGB with Luminance for a master luminance frame. This FITS my experience when imaging in the city. His paint bucket on background smoothing seems like adding data to me, so I’d avoid that.

Excellent times with the vendors. Altogether a good day!

AIC 2012 has begun! Day one has been filled with some excellent sessions. The exhibitor hall is open and there will be a two-hour opening later this evening.

My first session today was Ron Wodaski’s introduction to PixInsight. He covered many of the basics (that’s a lot) and gave some glimpses of the advanced features in the platform. Even an experience PixInsight user like me found it a useful and informative presentation. I am looking forward to seeing the full deck with all the details Ron promised.

I then attended Tim Puckett’s presentation on supernovae searching. He has built some amazing telescopes and quite a robust process and team for finding supernovae. When it is clear, his team will image 2,000 galaxies to find potential supernova. I learned that fit order 3 or 4 is required in PinPoint for astrometric reporting, and how to access the reference magnitude function in Maxim DL.

After lunch, there was a great presentation by Steve Brady, co-developer of the great focusing program, FocusMax. FocusMax uses the idea that there is linear relationship of the half flux diameter or HFD to focus that can be used to quickly and accurately focus a telescope using a CCD. HFD is the circle that evenly splits the flux or total ADU of a star regardless of focus. It is expressed in pixels. Max flux for a system is best calculated by plotting max pixel and max flux vs. time and picking a max flux value below where the curve flattens out. Focus convergence was clearly shown to be the best way to get to focus, even though it takes longer than the default of 5 exposures.

There was a very interesting discussion on precision vs. accuracy in FocusMax, and the key point is the size of the critical focus zone. More reading will be needed on that later. Focus is driven by the Vcurve, which is a hyperbola. Fit of measurements in creating a Vcurve are fit to the hyperbola, not to a linear fit of each side of the v. One should pick the point just above where the Vcurve moves away from the line as the near focus HFD, with the start HFD being about five units higher. Get at least 12 Vcurves for best results.

A major new release is coming sometime in the relatively near future. For now, the beta version is quite stable and is the one to use.

Finally, there was a great presentation from Ken Crawford on using masks in Photoshop CS5. I think I understand alpha channels now — they are containers for masks. He will have a video tutorial for all AIC attendees.

I took this image of NGC 7814, a spiral galaxy in Pegasus, last November but only am getting around to posting it now. I am afraid that the color is a little weak in the blue, but I’m not up to going back to the drawing board on this one. Click on the image for a full sized version and more information in the gallery.

Back on June 5th (in the Pacific time zone) was a singular event:  The Transit of Venus.  Venus passed directly between the Earth and the Sun, passing across the face of the Sun as seen from the Earth.  This happens rarely.  While the last transit was eight years ago, the next is 105 years from now.  Clearly unique in my lifetime.

The last Transit was not visible from Southern California.  This one was, starting at about 3pm and continuing until sunset.  I had prepped my C-8 on my old CGE mount (both worked flawlessly) with a Mylar solar filter.  I made a filter for my wife’s 200mm Nikon zoom.  We had Sun goggles.  I’d arranged my schedule to take the afternoon off, arriving just in time to open the observatory and point the scope.

The Transit started right on time.  There were a few sunspots on the face of the Sun, adding some visual interest.  One friend came by to see it.  It was a nice, low-key event, somewhat visually interesting.  What really made it fun was knowing that we won’t be seeing it again.

I took two images through the C-8.  The first was taken early in the transit, pointing my digital camera through the eyepiece. Some visual interest with the sunspots.

Venus transiting the Sun, taken with eyepiece projection through a C-8 at about 3:30pm PDT 5-Jun-12.

The second was taken with my trusty ToUCamPro directly through the scope with a f6.3 focal reducer. Not all that pretty, but an accurate image.

Venus transiting the Sun, taken at about 5pm PDT 5-Jun-12 with a ToUCamPro on a C-8 @ f6.3

Jerry Kamienski took a beautiful video of the Transit out at Lake Riverside.

Transit of Venus by Jerry K

Finally posting here, two versions of the first real image taken with the new CDK 12.5 telescope. The full set-up: CDK 12.5 on an AP-1200 mount, ST-10XME camera, Pyxis 3″ rotator. Data captured with Maxim DL and CCDCommander, reduced and aligned in CCDStack, extensive processing in PixInsight with a final touch up in Photoshop. It is 3 hours, 25 Minutes LRGB with 100 minutes luminance and 35 minutes each of red, green and blue. All subexposures were 5 minutes and the color was binned 2×2.

This is the first version.

Here is the second version. A bit more aggressive on the processing on this one.

Click on the images to go to the gallery and vote on your favorite!