Macro/micro photography

Andy Resnick

The "butterflies" thread has inspired me to get my act together and take some proper images. I spent a couple hours (!) last night trying to take a picture of a flower, but at the magnifications I am working at, I need the optomechanical equipment in my lab to keep everything stable. To see why, here's the flower:



It looks ok, but that's my limit. Here's a 100% crop of the same flower, using the 16mm Luminar:



I got lucky with this shot- notice the miniscule depth of focus.

So today, I set up everything on some rail and took images of a 1/32" ball bearing sitting on some foam. I illuminated it with a LumenPro metal halide source coupled into a liquid light guide- no diffuser. The light is so bright the glint off the bearing was enough to blind me. Here it is with the 63mm, stopped down most of the way:



And here it is wide open, followed by a 100% crop-




The detail is quite good, and there is little chromatic aberration- dig the bokeh!

Now stepping up the the 25mm: again, full frame and a 100% crop





Again, the image is quite sharp, but the depth of focus is so small that the detail appears out of focus.

Now the 16mm:





This is where things get interesting- the depth of focus is negligible, and what you are seeing in the crop is not blur, but speckle. The magnification and sharpness of this lens is sufficient to resolve speckle from an extended, broadband source.

Just for fun, I stuck on a 16x epiplan objective and took an image of one of the plastic foam flecks. The full-frame image is rather dull, but the 100% crop shows an interesting optical effect: diffraction off the sharp edge and interference:



The colors are real, not chromatic aberration. I suspect they are interference fringes caused by a varying thickness of the 'flake'. The diffraction off the edge is pretty cool, too (IMO)- I count 7 periods.

Something I find interesting in this sequence, is that there is a definite change around 10X magnification- the images change from being recognizable (but magnified), to unfamiliar and confusing. Hopefully there's enough time left in the summer to explore this a little more....

Andre

To solve that issue, maybe notice this post in the photomanipulation thread:

Andy Resnick

I've heard of those programs, but haven't tried them.

I use a deconvolution program (an ImageJ plugin), and from what I can tell, the concept is the same. I should compare it to, say, Combine ZP..

Thanks!

turbo

Here's a Panasonic pocket-cam pic of a Japanese beetle. See the raised white dot on the carapace? This beetle is a goner. That's the egg of a parasitic fly, and in a couple of days the wonderful little maggot will burrow into the beetle and start eating it alive. The beetle will drop to the ground and dig in to try to get away from the attack, giving the maggot a nice safe place to eat and mature.

Andy Resnick

Heh... I guess that makes you a photo*journalist*. Prime directive and all that...

turbo

Well, at least I don't deal in "bug porn" like Pooh does.

Andre

Would that bug you?

turbo

Andre

Talking about bugs, I was cleaning out my bug folder and came across some nice ones that I had not shared before.

Hovering bumble bee visits fuchsia.



more to follow

Andre

Hornet, busy with 'harvesting' wood for her nest




Aphids on a rosebud

Andre

All animals eat. Damselflies eat other flies.