Wednesday, April 2, 2014

A Spring Long Sprung!

It has been a warm, dry Winter!  While it didn't break 80F until the end of January, there were 22 days that month over 70F, and lots more days in the 80s in February and March.  And dry!  We've only had .6" of rain this year, that back the first 2 days of March, so it has been dry, even for the desert.  As a result, we had a pretty dreadful wildflower season, and we're coming up fast on the cactus flower season, which will bloom even if we've had no rain, though not as plentiful or long-lasting as if we'd had more substantial moisture.  And I'm always looking to show off more examples of the focus stacking technique in macro shots, so was about time to get out looking...  I've got a number of posts on focus stacking, check out some of those results too!

These first shots were actually taken a month ago in March after the little rain we got.  The plant is Desert Globemallow, a native plant to the local desert that while considered a weed in most yards, I let it grow in our pea-gravel front yard...  I give the plants a squirt of water when I think of it, otherwise just leave it along and it gives a bit of color even with it as dry as it has been.  It was also a month ago that I went chasing after it with the macro lens and tripod, and even though it was a windy day, got a couple decent shots.

While the flower looks pretty big in the shots here, they are moderately small, about 1.5cm, 3/4" in diameter.  With the meager wildflower season we had, what few flowers there were around were heavily trafficked with pollinators.  With Arizona now populated by "killer bees" that moved up from South America, you have to assume bees and colonies are of the Africanized versions and you need to be careful not to upset groups of them.  This one in particular was small, and totally zoned-out on the pollen in this flower.  I took a couple multi-shot sets (several frames-per-second while cranking focus slightly) for focus stacking.  Since the 2 shots are clearly different, he was clearly paying no attention to me.  while I didn't quite get the full range of focus for every detail, sharpness is pretty good.  I think the wind was more of an issue rather than pollinator motion!

Now in April we're approaching cactus flower
season, and my neighbor Susan's prickly pear are covered with buds about to pop.  I had a few minutes before heading in for an afternoon shift at work, so again got out the macro and tripod for some focus stacking.  Wind was substantial, but affected the prickly pear less than wildflowers, so didn't have any issues.  With focus stacking, you don't need to stop way down to increase the depth of field, in fact, doing that increases diffraction which decreases overall resolution.  Keeping it at a moderate f-stop, in this case, F/8, taking several shots at different focal positions to get everything in focus, then combining them in Photoshop gives some excellent results!  At left is shown one of the subframes, and you can see the 2nd bud from the right is in focus, but the others are less sharp.  Loading all 6 frames and following the workflow (I follow the YouTube tutorial by Tony Northrup), only the sharpest part of each frame is combined into the final image, shown at right.  I didn't go too extreme and get the background parts of the cactus in focus, but all the buds along the pad shown here are shown in sharpest focus.

While the full-frame of the camera is shown in the above examples, the focus stacking technique seems to work right down to the finest resolution.  At left here, you can look pretty closely and I don't see any artifacts or defocus, which is very close to the resolution limit of the camera from the focus-stacked shot above.

I continue to be amazed with the technique, and once learned, comes second nature - easy to both take the exposures as well as run them through the software.  I can't wait to continue to apply what I've learned to my macro imaging!

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