Clearly Amazing Moon

Last night I took the best picture of the Moon I have ever been able to capture, using a 10.1 megapixel DSLR with a 300/480mm lens, a sturdy tripod, and a focusing method using "nearby" Jupiter which guaranteed maximum sharpness. (Maximum for me, that is -- of course if I had a camera-equipped telescope I could fill the photo frame with the moon, and I would have a better picture. But I digress.)

Here is a zoomed-in portion of the result:



Then, I took 24 more pictures just like it. So, all 25 photos were identical, except for different details getting smudged by the atmosphere and camera sensor noise. Combining them all together with RegiStax resulted in this photo, zoomed in to the same lunar region as in the image above:



To see the full impact of the improvement, you might want to look at a side-by-side comparison of the whole Moon, before and after stacking:



This calls for a paradigm shift. I had formerly known that image stacking was used by both amateur and professional astronomers, but didn't fully appreciate how it might benefit my casual efforts at sky-shooting. Now its impact to my work is "clearer." A lot clearer.

Stacking the Odds; Hushing the Noise

Air molecules are big -- much, much larger than the light photons struggling to get through the Earth's atmosphere from space to my camera's sensor. So, when I photograph something in the nighttime sky, there is a significant probability that some details will get smudged by the plethora of air molecules in the way.

Another problem is in the camera's sensor itself. Many sky objects are dim, so it is necessary to increase the ISO setting -- analogous to the old "film speed." Higher light sensitivity allows dimmer objects to be imaged. Except for the pesky noise. Higher ISO values result in random image artifacts -- visual "noise" that detracts from the image.

Mike to the rescue! He found a freeware software tool that significantly helps with both of these problems: RegiStax, which implements a concept called image stacking. The idea is simple: take many pictures of the same object. Details that are smudged by air movement in one frame will likely be sharper in another frame. Also, random image noise can be subtracted because the "real" image is not random.

As a test, I cranked up my camera's ISO to 1,600 -- a level that is guaranteed to cause significant image noise. Then, I shot 23 pictures of Jupiter through an almost-dark dusky sky. The result was about what I expected: grainy photos of an inconsistent image of Jupiter and its moons. Here is the best of the 23:



After running the 23 shots through RegiStax, the image had a stunning improvement of clarity and quality:



Another tool in the arsenal for this casual astrophotographer! (Thanks, Mike!)

HDR Takes a Walk Around Vernonia Lake

Sunday after church, Kathy and I visited Vernonia, a small Oregon town whose main tourist attraction is the adjacent lake. It takes about 10 minutes to circumnavigate the lake on the nicely-paved walking path -- 30 minutes if you take time to photograph what you see along the way.

Assuming, that is, photography is capable of capturing and conveying what you see. For one of the scenes we encountered, the phrase comes to mind: "The picture doesn't do it justice." At least, that was true for ordinary photography. But a three-shot HDR photo saved the day. Here is a normal shot of an old mill building, followed by the High Dynamic Range version. (The latter matches much more closely what I saw with my own eyes as I gazed up at the edifice.)





From the mill location looking back across the lake, another shot demanded HDR to "do it justice." The first picture was exposed to show the detail in the picnic table, which unfortunately results in a completely washed-out sky. (Exposing for the sky makes the picnic table nearly disappear into a shadow.) HDR photography to the rescue:





If you would like to see seven more shots (with captions) from Vernonia Lake, click here.

Youthful Crescent Moon

Sunday night is when we take our trash and yard debris bins to the curb for pick-up the following morning. On the way back to the house from that rather mundane errand, I beheld a very young crescent moon setting in the west. After dashing inside to get my camera and a tripod, this is what I captured:



If you look closely, you can see cratering at the terminator. But IMHO, the best part of this shot is how the crescent is nestled in the distant trees.

Note that autofocus would probably have chosen to make the trees sharp, at the expense of the more distant moon. In order to make sure I was focusing on celestial objects rather than the Oregon deciduous trees, I enlisted the help of Jupiter. It was in the southeast, and became a handy beacon for me to manually focus on "infinity" using diffraction spikes.

"Goodnight, young little Moon! Sleep well!"