Friday, January 11, 2019

Far and Near...

As my time at "Ketelsen East" winds down, I still keep my eyes open for photo opportunities even in the midst of Winter. And while I tell people I can't really do astronomy with the skies so bright from the light pollution of Chicago, I still look up. After all, a month ago I did manage to shoot a comet next to the Pleiades in the back yard! Unfortunately, the bane of astronomers in the Midwest are mosquitos in the Summer and in Winter, temperatures can get frigid! Even so, one of the prettiest views in winter are the prominent constellations seem through the naked trees. Shown at right here is Orion visible through the bare oak trees just a few steps from my front door. This is a single 13 second exposure with the kit zoom lens set to 28mm and F/4.  Any longer of an exposure and the sky was way overexposed...

That very night, while it was under freezing, it wasn't really frigid. But I did note on the weather forecast that evening that there was likely going to be morning fog. Well, for some reason I didn't sleep well that night, so got up at the crack of 8am and stepped out to find a very impressive display of frost on the downed oak leaves in the yard. So dutifully I got out my newish "super macro" lens, the Canon MP-E 65mm with the ring flash mounted in the front for some hand-held focus-stack images.

Now I often mention "focus-stacking". The depth of field of macro lenses are quite narrow, so to extend the part of the field that is in focus, several-to-many frames are taken with slightly different focus settings, or lens positions, and Photoshop or other software can combine only the parts of the frame that is in sharp focus. For example, at left is a 7-frame focus stack, and at right is a single frame from the sequence that shows how narrow the depth of focus actually is! See how only the upper part of the frame at right is sharp. Photoshop does a great job at combining all the sharp parts of the frame as seen at left.

Some of the frost photos were quite astounding! There was about a 3-meter square patch in the center of the yard that showed needle structure. I DO NOT know how they form - I guess I need to look around on crystal formation! In some of the frames the "needles" appear tubular or hollow, and in some they have a general hexagonal hollow form. Those are visible at left.

And at right one of the stunning images of spikes emanating from a single point, and quite large - over a centimeter in diameter!

I first stopped at a moss patch that never gets much Summer sun. While not as impressive as the larger spikes I found a few minutes later, they are interesting in their own way.

All of these are combinations of 7 to 11 frames to extend the range of focus, and are all "focused" manually by hand-holding them. It was my first time attempting this and as you can see, came out ok! Some I used some combination of flash and the rising sunlight.

Of course, as soon as the rising sun cleared the horizon, since the temps were barely under freezing, all the crystals melted quickly, and the show was over!

I present the rest without comment, other
than I will certainly keep an eye out for such events in the future!

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