Friday, August 4, 2017

The Hitchhiker!

July was a bit weird at "Ketelsen East"!  The past few years I've spend time almost daily searching for and finding some of the weirdest bugs I've ever seen! At left is a composite showing some of my favorites the last couple years - all taken within a few yards of the house! But this year, whether the cool spring or wet weather, there has been NOTHING to be seen! Searching the same areas I've taken images of the insects at left have revealed almost nothing!

The other day after my bike ride, I drove into town to pick up a morning NY Times and gas up the car. I immediately noticed a hitchhiker atop the car - a Katydid! Now I've seen these before in the woods, but found them pretty shy and tending to avoid me when I get the camera out. Even when using my cell phone to take the image at right at the gas station, he was constantly moving away from me. After the snapshot, I ignored him and drove home - about what, 5 miles away.

So I was surprised upon arrival that he was still there! He must have found somehow to hold on tight to withstand the 50mph speeds I got up to. Perhaps from that very buffeting, he was pretty docile and I had time to go get my good camera (Canon 6D), macro lens and about 30mm of extension tubes. Still atop the car, I couldn't use my tripod, but used the top surface to brace on and shoot him. The result is at left - the dramatic lighting is due to his being under a cross-brace of the car rack, so was in it's shade, most of the light coming in from behind him.

Note that this photo, as well as all of the photos above, are "focus-stacked". Several-to-many images were combined, all focused at slightly different zones to extend the depth of focus of the image. It is almost necessary at this magnification, and in this case in the left image, 24 frames were combined in Photoshop to keep much of him in focus. The image at right shows one of the individual frames, shot at F/8 - a moderate aperture to let in light yet minimize diffraction effects. Note that only his right shoulder and left leg are in focus, most of the rest of him a little out of focus. You might have to click to load a larger image to see the differences.

Focus stacking is a powerful tool! Think of the work that Photoshop has to do to align all the images (these were handheld, braced against the roof of the car, but there was motion of the camera between frames while I made slight focus adjustments). Note also that the magnification changes slightly as the focus is changed, so the scale has to change too when they are combined. Then they take only the sharpest part of each frame and reassemble the image. It does pretty well too - check out this full-resolution crop of the focus-stack, showing detail in its compound eye!

I was able to take one set of images for stacking, went to get out of the strong sunlight to examine them closely, then repeat for this set of images. After spending 10 minutes to download them and stack them, I went back out, but he was gone by then. But it was fun to get this fellow w/just basic tools of camera, macro lens and Photoshop - not even a tripod...  He may well be my only "get" of the Summer!

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