Jun 28, 2018
I've been creating this podcast for 30 years now. Or is it 30 minutes. 30 parsecs? Kessel run? I dunno how that got in here, but there's a 30 involved somehow. If you'll strap on your blaster and strap into the ventral cannon, I'll see if we can make it in more or less 12 (sources disagree)(also, save your groans till the end).
Twin Suns of Different Mothers?
Countless people contributed to our understanding of optics and light and human sight, and they did so along a non-linear path. In this episode I share a bit about Claudius Ptolemy, though really only so I can introduce a "second Ptolemy," the Arab polymath Ibn al-Haytham, also known as Al-Hazen. He lived at the turn of the millennium — the turn of the previous millennium, that is — and furthered man's understanding of how light and lenses work. His is also the first clear description of the camera obscura.
Abu Ali al-Hasan Ibn al-Hasan ibn al-Haytham, also known as Al-Hazen. Artwork by Adolph Boÿ, engraving by Jeremias Falck.
His contemporary in China, Shen Kuo — also a student and investigator of a wide variety of fields — made a similar description just a few years later, doubtfully aware of Al-Hazen. It was Al-Hazen's study of human vision, though, that led to what was considered the best description of that human sense, and it took another six centuries for the German astronomer and, well, studier of many other fields, Johannes Kepler to make further, significant progress.
Each of these people, Al-Hazen, Kuo, and Kepler, are worthy of at least a little recognition and study. Hopefully this episode provides the former, and you can continue with the latter at Wikipedia.org:
Quoth the Falcon
I also let the men speak for themselves, on remarkably similar tangents, I'll note.
"The duty of the man who investigates the writings of scientists, if learning the truth is his goal, is to make himself an enemy of all that he reads, and ... attack it from every side. He should also suspect himself as he performs his critical examination of it, so that he may avoid falling into either prejudice or leniency." — Al-Hazen
"Most people can only judge of things by the experiences of ordinary life, but phenomena outside the scope of this are really quite numerous. How insecure it is to investigate natural principles using only the light of common knowledge, and subjective ideas." — Shen Kuo
"I much prefer the sharpest criticism of a single intelligent man to the thoughtless approval of the masses." — Johannes Kepler
Macro. Or Macro Not. There is no Why.
Macro photography has always fascinated me, as it lets me see details that aren't readily accessible to the human eye. Not microscopic details, far beyond native sight, but small enough that seeing those details is more of an, "oh, that's what that looks like!" kind of experience. If you want to take such close-up images, it might help to understand some of the terminology, and to ignore some of it.
I mostly spend time in this episode explaining about reproduction ratio and how that figures into the definition of macro photography, but if you'd like to skip the time you'd spend listening/napping through the segment, let's see if this very short description helps: if you can take a photo of a 35 millimeter photographic slide, those small photos with the white cardboard border that go into a slide projector and have their image enlarged on the wall/white sheet hanging on the wall/rickety projection screen pulled out of the closet where it's been for a decade — if you can take a photo of just the film portion of that slide with another 35 millimeter camera and totally fill the camera's screen with that piece of film, that's a one-to-one reproduction ratio.
An object in reality, that little piece of film, was captured filling the frame on a recording medium (another piece of film) of the same size. One-to-one.
What are called full-frame-sensor cameras have a digital sensor the same size as that 35 millimeter film camera's image area.
Many/most cameras have sensors that are smaller. If your camera has what is called a cropped-frame-sensor, that sensor is two-thirds the size of 35 millimeter film, give or take. So an object of that size, a bit larger than your everyday postage stamp, filling your viewfinder would constitute a one-to-one reproduction ratio.
The importance of the one-to-one reproduction ratio is that some people consider it to be the minimum ratio to qualify as true "macro" photography. "If you can't at least enlarge to life size (another way of saying "one-to-one") on your sensor, you can't join my club. Didn't you see the sign?" I'm not so picky.
If you can photograph a standard business card (3.5 inches by 2 inches in America, 85 mm by 55 mm in Europe) with your full-frame camera, that's half-life-size and you'll still see things in that image you may not have noticed just looking with your optic orbs.
The concept of one-to-one holds for any size sensor, by the way. Got a point-and-shoot? If it can fill the image with an object that is a half-inch wide, like 13 millimeters, that might be one-to-one. Smartphone? One-to-one means filling your frame, in focus, with something half the size of your pinkie finger fingernail. It's tiny.
None of this is as important as those cranky, "gotta be one-to-one," people might have you believe. If you want to take close-up photos, there are plenty of ways to do so — what you call it is not something you should worry about.
That's No Zoom
Speaking of macro photography (were we?), one of the difficulties I have with my smartphone is the fixed focal length of the lens. Unlike a bigger screen or a can opener, that something you can add to most phones. So I tried one.
Actually, I tried three, because that's what you get with the UmAid F-516 3-in-1 Photo Lens kit. It's three lenses, two clamps for attaching them to your phone, plus lens caps and a drawstring bag to haul it all around.
Here's what it looks like and some photos I took with it. Take a gander and, after the photos, I'll cook its goose. (Whaaaa?)
The kit and caboodle (and drawstring bag) of the UmAid F-516 3-in-1 Photo Lens kit.
Here's my very dusty grill's thermometer shot with my iPhone 6s Plus, no extra lens.
Add the macro lens from the F-516 kit and you have to move the phone much, much closer to (sorta) focus on the subject. It appears I'm a millimeter too close, since you can see a ring of better-focused texture around most of the "500." If I had the camera positioned so the digits were in focus, which I would have preferred, then that ring of better-focused texture would be out of focus, as you see outside the ring.
Here's almost the entire lid of the grill, captured by attaching the wide-angle lens on top of the macro lens, which is how they do it. A more expansive view, to be sure, but also suffering from color fringing and very poor focus around the edges of the composition.
A bit of my backyard out here in rustic, rural, Arizona. Sorry about the mess.
Fire up the wide-angle lens and the view expands but doesn't seem to have focused much except in the center — just the details I want you to focus on, the water cubes for watering the fruit trees (those short, green shrubs)(note: that is sarcasm). You'll note the obvious geometric distortion, curving the saguaro and other peripheral objects.
Clip on the fish eye lens and the geometric distortion is actually about the same, with just a wider view of the area. Still with the center focused and the not-center not-focused.
If you've wondered what a saguaro cactus spine might look like, this is it, shot with the macro lens. Note the very shallow depth of focus, which is adjustable in cameras with adjustable apertures, but smartphones don't have adjustable apertures and, to allow them to gather light in low-light situations, have rather capacious apertures and, thus, shallow depth of focus.
Here's about 10 millimeters of business card, top to bottom, showing how the lens can get in there and show you what you might not otherwise see, like how a color print is made of matrices of ink dots.
In conclusion, your honor, the optical performance of the lenses is not impressive. Lots of distortion, color fringing, and a definite propensity to allowing only a narrow circular center of good focus. The up side? You can get the kit for twenty bucks at B&H Photo Video. If you're just looking for some fun wide angles and macro, this kit might be just the thing without dropping a lot of money on the endeavor. It's well made, in terms of materials if not optically, and it will clamp onto most smartphones with the need for special fittings or cases.
I'll Tell You the Odds
I don't recall how I came to connect with my guest in this episode, Ken Ross, but something definitely went my way. It was an honor to sit down with him, and also the source of much jealousy on my part — this guy's got it going on! Photographer, world traveler, raconteur — certainly not a nerf herder. Listen in and see if you can count the number of things he has done, places he's been, people he's met, and adventures he's had — then you try not to be jealous.
Ken Ross. Photo by Karen Shell.
Also Ken Ross (he's the one in the middle) in Papua New Guinea. Photo by unknown.
I Have a Good Feeling About This
Thank you for listening and, if you're here, for reading. I know one of the reasons I produce this podcast is as an outlet for my creative urges. You know another reason? Feedback. That's right, reading or hearing from listeners (and readers) is a great pleasure. Imagine you're relaxing in your holding cell and someone, anyone, even someone who's kinda short for a Stormtrooper, pops in — you're happy to see them, right? That's how I feel when someone pops in — happy.
So, if you want to make me happy, pop on in by commenting, below or at iTunes, and if you go to iTunes, you can also give the show a rating and help other people find out about it.
Finally, of course, may the f/stop be with you. (Now you may groan.)