Two Weird Tricks for Presbyopia

I used to have perfect vision: In my 20s I passed the rigorous Air Force optometry screening for pilot candidates. Now in my late 40s I have developed the inevitable presbyopia that comes with age: The lenses of my eyes have lost so much flexibility that I can’t focus on things as close as I used to. I can no longer read fine print that used to be easily legible. In dimly lit restaurants I struggle to read menus. Both of these can be solved with reading glasses, but I don’t routinely carry those. So I often rely on two tricks to compensate.

The first trick is to increase light. I can read almost anything in direct sunlight.. In a restaurant I pull out my phone and shine its illuminator on the menu. Why does adding light sharpen text that is otherwise blurry or out of focus? There are some interesting optics at work.

The following image contrasts two photos of the same human eye. The photo on the left was taken in a dimly lit room, which has encouraged the pupil to open to let in more light. The photo on the right was taken with daylight coming through a window: The extra light causes the pupil to close.

Photos of the same eye in dim (left) and bright (right) light.

The wider the aperture (which in an eye is the pupil), the greater the focal range of a lens. In sunlight our pupils are as small as they can get, which gives us the maximum focal range. With presbyopia, my lenses can’t accommodate (i.e., change shape to shift focus) as close as they used to, but they can still go far enough that the added focal range from a small pupil brings close objects into focus. The same physics applies to camera lenses, as I demonstrate in the following image:

Illustration: First row: A camera pointed at a pill bottle inside its lens’s minimum focal distance. Second row: The lens aperture shown open to f/2.8, and the photo produced with the aperture wide open (f/1.7). Third row: The lens aperture stopped closed to f/22 and the photo of the same scene

I put a pill bottle closer than the minimum focal distance of this camera lens. A photo taken with the lens aperture wide open (f/1.7) shows that the lens can’t bring the text into focus. Keeping the lens at the same distance and focus setting, but stopping the aperture down almost as small as it gets (f/22) increases the focal range and brings the text into focus. (The photo of the lens in the second row actually shows the diaphragm at f/2.8 because at f/1.7 it can’t be seen.)

Bright light causes our pupil to contract naturally. The second trick is to create an artificially small aperture. You can do this by putting a pinhole lens close to your eye. I do this by closing my fingers and looking through the tiny opening left between two of them at the joint:

David Bookstaber creating pinhole lens for one eye to bring closer objects into focus.

The aperture trick can only compensate so much: With too little light the subject may be in focus but the contrast might be too low to read it. In the camera example: The exposure with the wide aperture was made in 1/640 of a second, but it took 1/4 second to get an adequate exposure at the minimum aperture (holding all other settings constant).


I have a related post on my substack: Why I Dislike Dark Mode.

On the new default font: Aptos

Given my surname, Bookstaber (German for speller), I could be more of a typeface geek. At least I am paying enough attention to appreciate the appearance of a new default font in Microsoft Office: Aptos has replaced Calibri.

I never felt completely comfortable with Calibri, though I can’t articulate why. I can point to one particular failure, which it shares with many other fonts: Upper-case I (“eye”) and lower-case l (“ell”) are virtually indistinguishable. There’s no reason for a workhorse typeface to perpetrate such an ambiguity. (Aptos, like others, avoids this by giving the l a little tail, as shown in the image below.)

Other ambiguities that appear in many typefaces:

  • Lower a that looks too much like lower o. See, for example, Century Gothic below.
  • Insufficiently distinct upper O and number 0.
  • Upper Q that is insufficiently distinct from upper O. This has become particularly annoying where TV manufacturers have begun using the term “QLED” to describe their displays, sowing confusion with the distinctly superior and more expensive “OLED” (organic LED) technology.
Typeface Ambiguities

How to Cook Chicken

I don’t like raw chicken. I associate its smell with salmonella, and when I see it I want to don a hazmat suit and break out a bottle of clorox. I long ago gave up cooking chicken myself: I err on the side of overcooking, and overcooked chicken is tough and dry. But I do like properly cooked chicken. It so happens that my mother is a phenomenal and experienced cook. So I asked her how she makes chicken so delicious every time. Here is her answer:

First, equipment: An accurate instant-read thermometer is essential. Expect to pay at least $40 for one by such companies as ThermoWorks or ThermoPro.

Now, for boneless, skinless chicken breasts:

  1. Pound.  Place the thawed breasts in a zip lock bag and pound the thickest portion (using a heavy bottle, rolling pin, or the bottom of a glass) so the breast has a more uniform thickness throughout. You want it to be about ¾” thick.  This helps it cook more evenly. 
  2. Cut.  Cut each breast into about a 6-8 oz portion. 
  3. Brine. Place the breasts back Into the same zip lock bag. Add about 2 cups cold water and 2 Tablespoons salt. You want the water to cover the chicken.  If you need another cup of water and tablespoon of salt, add it.  Close the bag, pressing out some of the air.  Massage slightly to try to dissolve some of the salt.  Place in a container like a pie plate or shallow bowl in case the bag leaks.  Refrigerate for 30 minutes.  (Note: If you want to prepare the chicken ahead of time, you can let it soak in a weaker brine for hours.  About 1 teaspoon salt to 2 cups cold water.)
  4. Cook.  The most important thing is to cook it until it is 155-160 degrees F. To check the temperature, insert the probe into the thickest part of the breast. 
  5. Rest.  After it reaches 155-160 remove it from the heat to a plate, tent it with foil, and let it rest for 5-10 minutes before you cut into it.  Covering it lightly with foil and letting it rest off heat brings it up to 165 degrees, the safe temp for chicken.  Letting it rest allows the juices to recede away from the surface and back into the muscle tissue.  

Reheating Chicken

Even if chicken was great when first cooked, microwaving it inevitably ruins it for me. Apparently this is a problem called “warmed over flavor” that is so well known that foodies refer to it as WOF. Minimizing the meat’s exposure to oxygen can prevent this. Also reheating sous vide, or even in a conventional oven, seems to reduce WOF compared to microwaving. But supposedly nothing short of prompt vacuum sealing can totally eliminate WOF for those who are sensitive to it.

Autumn Equinox

I happened to be in Salt Lake City during the equinox, where I learned that Utah has outlawed a lot of things. One random example: Happy Hour. Probably Utah also prohibits human sacrifices during equinox celebrations – I didn’t even bother to ask.

So aside from weird rules what else is there in Salt Lake City? Mountains. As my many readers know, I love to photograph interesting celestial events. So I went for a hike to get this equinox sunset:

Salt Lake City autumn equinox, 7500′ ASL

These foothills can be deceptive. I parked at one between the Big and Little Cottonwood Canyons and began to climb straight towards a peak. The first few hundred feet was fine gravel, so I had to kind of scamper from weed to weed to avoid sinking and sliding back. Then I reached sturdier ground which supports thickets of shrub-like oak trees. Those obstruct the view of what’s above, so I couldn’t be certain whether I had a good path ahead. I did eventually run into a trail bearing human footprints (though I saw no one else the entire hike). The trail wound back and forth between rocks and trees, and it was still very strenuous: When I got back I checked a topographic map and found that the straight-line route I followed from 5500 to 7500 feet averaged a 45 degree slope!

Breakfast

Here is my new favorite breakfast: A chocolate protein smoothie with banana, peanut butter, almond milk, and cold-brew coffee concentrate.

For more than two decades previous my breakfast was half a box of Post’s Great Grains Raisins Dates Pecans. Every few weeks drug stores would put that cereal on sale and I would buy every box on the shelf. (Before COVID sale prices would be $2.50/box. 5+ years ago $2/box. $1.50/box before that, and 20 years ago the (Air Force) base commissary would often sell them for $1/box!) Keeping a stock of more than 60 boxes was not uncommon. Here’s a typical view of my pantry:

My custom is to steep cereal in milk for a few minutes until it gets a little soft. I used to use skim cow’s milk, but some years ago I developed a lactose sensitivity and switched to almond or oat milk.

There was an interlude about 20 years ago after I bought a batch of this cereal that was infested with moths. That took away my appetite for it for a few years, during which I switched primarily to General Mills’ Basic 4 cereal.

In college and earlier my appetite was enormous: In dining halls I would fill my tray with 4-6 bowls of cereal (granted, dining hall bowls aren’t very big), leading people to jokingly suggest that I switch to Total cereal. Total is just boring cereal that General Mills mixes with extra multivitamins. For many years they ran commercials like this showing how many bowls of competing cereals it would take to accumulate those extra vitamins:

Perseid Meteors

Perseid Meteors, composite image by David Bookstaber
Perseid meteors. That’s Jupiter near the middle of the frame.

I set up my old Sony A77II with an intervalometer for an hour and managed to capture these Perseid meteors. I was using my widest lens, 16mm, shooting ISO 1600 with 10 second exposures. It took some real work to post-process and compose this image: I had to find the frames with meteors and stack and align them in Photoshop. The result is nothing great for several reasons, including that (a) meteor shower photos should use a wider lens, and (b) should include a horizon or some ground feature for perspective.

It’s easier to get better results using a smartphone, not only because a typical smartphone has a very wide lens, but also because software can take care of identifying frames that contain meteors and aligning them. After the fact I checked the app store and found at least one cheap app that does this with a built-in “Meteor Mode.”

Why Chester County Cops Dislike Me

When I lived in Berwyn, Pennsylvania, a neighbor was murdered in her home. I had installed a video surveillance system around my house when I first bought it 6 years prior. (My house was isolated from the street and backed up to a county trail that I thought could be a source of trouble, but to that point nothing bad had happened.) When detectives came knocking I suggested that my video might have picked something up that would help them with the crime. But when we went to the corner of the basement where I had the recorder, we discovered that it had no power because it was plugged into a GFCI outlet that had tripped. The last recordings showed a thunderstorm a few weeks prior.

This misfortune really piqued the police. They came back with search warrants, not only for my surveillance system, but also for all of my computers! (Evidently, at least in Chester County, Pennsylvania, judges will sign any warrant put in front of them.) They took all my electronics to their “computer forensics lab” and told me I would get them back when they got around to imaging them. They didn’t care that my job and income depended on my computers. They seemed determined to punish me for … I guess buying a house next door to someone who would later be murdered, and failing to monitor my private video recorder?

It takes a few hours to make a forensic copy of a hard drive, but the police didn’t return my computers for over a week. Months went by and they didn’t return my surveillance recorder (which stores everything on a standard hard drive that is easily cloned). I repeatedly asked the detectives and the assistant district attorney (ADA) who had joined the murder investigation (still unsolved) to return it, and they did not. I suggested that if they wouldn’t clone it they could just keep the hard drive and return the recorder to me, since I could install a new drive to get it back in operation. They continued to ignore me. So more than a year later I petitioned the court that had warranted its seizure to order them to return it to me. The ADA really didn’t like that!

I mention all of this because it provides another explanation for why some Chester County law enforcement officers subsequently took a special interest in harassing me. To be continued…

Bullies and Mismatched Senders

As described in Malcom Gladwell’s book Taking to Strangers, a strong body of research has revealed that many people have mannerisms that are incorrectly interpreted by others. The academic literature refers to such people as “mismatched senders,” because their non-verbal communication does not match what they intend to communicate. Or rather, to place the blame where it belongs: Many people erroneously think that they can deduce things from non-verbal communication, and mismatched senders are the victims of that error.

I am a mismatched sender. I have often been told this by people who become acquainted with me. Apparently my bearing superficially suggests an arrogance that really isn’t there. I am prone to smile or laugh when I am nervous or confused. Et cetera. Unless you have read Gladwell’s book, you might be surprised at the problems this can create.

I have also been a target of bullies my whole life. Physical bullying mostly stopped when I became dangerous: At age 12 I gave two bullies black eyes and that was the end of that. There was no payoff to psychological bullying because I didn’t have many friends and didn’t seem to care.

But I’m still an attractive target to people who are looking for somebody to take down a notch. Where do bullies go when they grow up? I believe a disproportionate number go into law enforcement, where they are equipped and paid to bully, and where their victims are at a systemic disadvantage to defend themselves. Police abuse has finally gotten enough attention that this should not be a controversial hypothesis. And this hypothesis might explain some of the abuse I have personally suffered at the hands of law enforcement. (More on that to come in future posts….)