Mashed Potatoes, Lima Beans, and Pears: Textures and Autism

I’ve never liked lima beans.  They taste just awful and have an odd texture.  Pears would actually be halfway decent if it weren’t for their texture, which in my mind is similar to that of lima beans.  Yuck!

My son, on the other hand, absolutely hates mashed potatoes.  In the beginning, he would only form of potatoes he would eat was french fries.  All other forms of potatoes were only grudgingly eaten because he didn’t like them (and we would only put a spoonful or so on his plate, and he had to eat them).  We can now get him to eat Au Gratin potatoes and Julienne style potatoes, which he has learned to like, but he still won’t eat more than a bite or two of mashed potatoes.  I tend not to push the mashed potatoes as much now because there are lots of other foods that he does like.

Haircuts are another dislike of his.  Something about the cut hair getting on his skin really irritates him.  Fortunately his mom usually gives him the haircut.  When he was younger, he would have a meltdown and would cry and say through his tears how itchy the hair was.  We’ve gotten around this by wrapping a towel snugly around his neck to keep the hair from going down his shirt, but invariably when removing the towel a few hairs would go down his shirt and he would start complaining again (though not a full meltdown) about how itchy he felt.

Our solution to the itchy problem? Immediately after the haircut, send him to the shower.  The water rinses the hair off of him, and he is no longer itchy.


My Return to Shooting Film

When I was a child and well into my adulthood, still photography was all done on film.  I quit shooting film cold turkey in 2001 when we got our first digital camera.  I liked the immediacy of seeing the picture as soon as I took it, and knew immediately whether or not it turned out okay.  You don’t get that with film.

As a child, and later a college student, I shot slide film and projected it.  First, because by projecting slides, you can see your images in whatever size you want, and second because even though the slide film was more expensive than film for prints, it was cheaper to process, which was important to me because as a boy (and later a college student), keeping costs down meant I could actually afford to have this as a hobby.

Fast forward to early 2011.  I had been shooting digital only for ten years.  Had never gotten the slide projector out in all that time.  I’d just purchased a scanner with the intent of digitizing all the pictures I’d shot years before, and was going through the slides in a drawer looking for the ones I’d taken on a trip to Yellowstone.

I need to back up for a sec.  My son is a big Penguins of Madagascar fan.  In one of the episodes, the penguins are having a slide show to prepare for a mission.  This was my son’s only exposure to slides up to this point.  I needed to tell you that so you will understand his reaction.  Returning to early 2011 now…

My son walks into my bedroom where I am looking for the slides of Yellowstone, and his eyes got as big as dinner plates.  He said “Whoa, Dad, what are these?”  I explained what they were and he said “Can we look at some?”  I promised that if the projector I had stored in the garage still worked, that we would look at some that night after it got dark.

The projector hadn’t been used in 12 years and guess what – it still worked!  My nephew was over that night and we had a slide show.  My nephew said they looked better than digital, and it got me thinking that I needed to have slides to project.  After doing some research, I discovered that the least expensive way to get slides was to simply shoot slide film rather than shoot digital and then put the files through a film recorder.  And that’s how I returned to shooting slide film and projecting the results, just like when I was a boy.

Strange Number Sequence in Photography

In my last photography post, I shared three sets of numbers: Film (sensor) speed, Shutter Speed, and Aperture (f-stop).  The sensor speeds and shutter speeds made sense; each one was roughly double or half the preceding number.  The aperture series of numbers, however, was rather odd.  If you’d like to know why that set of numbers is so odd-looking compared to the other two sets of numbers, read on, this post is for you!

The numbers in the aperture series represent the ratio of the focal length of the lens to the diameter of the aperture.  That’s why it’s called an f/number, and why in my last article you saw me refer to an aperture as f/11 instead of f11.  By using a ratio, photographers avoid having to memorize a different sequence of numbers for each focal length lens they own.  Imagine what would you have to do for a zoom lens!  Thus f/8 on a 100mm lens lets in the same amount of light as f/8 on a 28mm lens which lets in the same amount of light as f/8 on a 500mm lens.

But why aren’t the numbers doubling or halving as you step through the sequence?  Because the amount of light that passes through a given aperture is dependent on the area, not the diameter of the opening.  In High School Geometry class, we learn that the area of a circle is equal to pi times the square of the radius.  So for a 100 mm lens, f/2 would have a diameter of 50mm.  The area of this aperture on this lens is 3.14 x 25 x 25 is about 2000 square mm.  The next number in the sequence, f/2.8, would have a diameter of approximately 35.714 mm.  3.14 x 17.85 x 17.85 is about 1000 square mm.

Instead of memorizing the whole sequence, there’s really only two numbers you have to remember: 1.4 and 2.  Double 1.4 and 2 and you get the following two sequences:

  • 1.4, 2.8, 5.6, 11, 22
  • 2, 4, 8, 16, 32

Merge the two series together in ascending order and you get the whole series:
1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, 32.

Why I don’t take “I can’t” for an answer

There’s a young man named Matt Stutzman.  He is the current record holder for longest accurate archery shot.  You may think this is no big deal, but it is.  You see, Matt was born with no arms.

The previous record was set by an able-bodied person.  I showed this video to my son, and told him that “I can’t” isn’t okay.  If he cannot do something the regular way, we will figure out a way that he can do it.

Case in point: He’s always struggled with reading.  One day his mom showed him a note that she had left for him a few days before.  He acted like he couldn’t read it, but when we pushed him, he read it.  When we asked him how he knew what it said, he told his mom, “Oh, those were easy words.”

Another case in point: He had some math homework he was supposed to do.  He told me “My teacher lets me use a calculator.”  I said “Oh, really?  Well go ahead and get started.” I didn’t bother to get him the calculator.  After he’d finished his assignment, I checked his work and he’d only missed 3 problems, which I had him correct – without the aid of a calculator.

Just because your child with autism cannot do something the regular way doesn’t mean it cannot be done.  As parents we need to find alternative ways of doing things where they are needed.

Math and Photography

Here are some numbers for you:

  • Sensitivity: ISO 50, 100, 200, 400, 800, 1600, …
  • f/stop (size of lens opening): 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, …
  • Shutter speeds (exposure times): 1, 2, 4, 8, 15, 30, 60, 125, 250, 500, 1000, …

The first set of numbers is a range of sensor sensitivity (or film speeds, if you prefer). Each succeeding number is double the previous number, which means that half the light is needed for each step right that you go on the scale. The second set of numbers is the sequence of f/stops commonly found on camera lenses. Each succeeding number lets in half the light per unit time of the previous number. Thus f/4 lets in ½ the light of f/2.8, and ¼ the light of f/2. The third set of numbers is the set of numbers used to indicate shutter speed on most cameras. Each succeeding number exposes your sensor, whether it’s CCD, CMOS, or film, for half the time of the previous number. That third sequence should probably be written 1s, ½, ¼, 1/8, 1/15, 1/30, 1/60, 1/125, and so on, but most camera manufacturers dispense with the “1/” since it’s implied.

What does this have to do with photography? Actually, a lot. For a given light level (let’s say it’s a sunny spring or summer day), in the sun, there is an amount of light that is needed to produce a correctly exposed image. The amount of light that is needed is inversely proportional to your sensor’s sensitivity. That is, the amount of light needed goes down as your sensor’s sensitivity goes up.

There are several combinations of shutter speed and f/stop that will let in the same amount of light. For our scenario of a sunny day, with your subject (let’s say it’s your dog) in full sun, and a sensor sensitivity of ISO 200, the correct exposure would be 1/250 second at f/16. But you could also get a correct exposure at 1/125 second at f/22, or 1/500 second at f/11. Why would you want to vary your settings? Because maybe your dog is running across the yard, so you want a higher shutter speed to freeze his motion (or a lower shutter speed to show motion with blur). As you go to the right on the f/stop scale above, for each position in the sequence you go right, you must go left one position in the shutter speed sequence to get an equivalent exposure. Likewise, if you go right one position in the shutter speed sequence, you must go left one position in the f/stop sequence to get an equivalent exposure. It’s all about the math. In most cases, your camera’s built-in meter will figure this out for you automatically, but it can also be useful to take control of some of the parameters yourself!


The Photographer Dad


Welcome to The Photographer Dad. Allow me to introduce myself. I’m a Dad who happens to enjoy photography. This blog will be about raising kids and photography. My daughter, M, is a typical teenage girl. My son, D, has autism. Both like taking pictures, so that will help me tie being a Dad in with photography.

Why did I pick “” instead of “” for a URL?  Well, partly because was already taken.  But also because I have German ancestry.  And in German, “photo” is spelled “foto.”  See, it all makes sense now!