Year: 2018

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A 35mm Lens on a APS-C Camera

When I bought my camera, it came with a 28-80mm lens. In use, it behaved like a 42-122mm because the camera didn’t use 35mm film in it: it had a smaller APS-C digital sensor. This article briefly describes what is happening, and how to read the names and number on some Nikon lenses.

The lens I got with the camera was a “Nikon AF NIKKOR 28-80mm 1:3.3-5.6 G”. It’s described in detail at Ken Rockwell, and that’s where I found out it behaves like a 42-122mm lens on my camera. The name is a mouthful, so I’ll detail the parts here:

  • Nikon – the brand
  • AF – “autofocus” and “F” mount. The F type mount is the most common for Nikon.
  • Nikkor is Nikon’s lens brand.
  • 28-80mm means the lens will have a focal length ranging from 28mm to 80mm. This means it goes from a “wide” angle of view at 28mm to a zoomed-in angle or view at 80mm.
  • 1:3.3-5.6 means that the maximum aperture is 3.3 at the 28mm position, and 5.6 at the 80mm position.
  • G – means “no aperture ring”.

One thing missing from the name is “DX”, which indicates that it’s part of the “DX” line of lenses, for digital SLRs with the “DX” sensor, which is a smaller “APS-C” sensor.

Sensor Sizes: 35mm or APS-C

The Single Lens Reflex (SLR) camera emerged in the late 1950s, and became the standard professional camera for journalists through the 1960s to the early 2000s, when digital took over.

These cameras used 35mm film. The dimensions of a frame are 36mm x 24mm.

In the 1990s, a new format, Advanced Photo System, was introduced. This was a smaller roll of film, and enabled a smaller camera. The film supported different cropping formats, and one was APS-C, which covered an area of approximately 25mm x 16mm.

APS-C was adopted by the major camera makers as the new standard size sensor for prosumer digital SLRs.

Since then, the market for DSLRs has been divided into “full frame” or “APS-C“. Full frame means the sensor is the same size as 35mm film. More recently, a new format, “four thirds”, which is even smaller, has further split up the market.

Due to the increased splits in the market, the lens buyer must exercise increased vigilance to make sure that they’re not only picking the right mount, but the right product line for their sensor.

The Effect of a Smaller Sensor Size with a 35mm Lens

The picture above shows two “cameras”, the one on the left with a full frame sensor and the one on the right with a smaller sensor, like the APS-C.

If you use the same lens on both cameras, the smaller sensor will capture only the middle part of the image.

It’s as if the lens now has a narrower angle of view.

Because the convention is to describe the angle of view in terms of focal length, the focal length changes; the effect is to increase the focal length.

So the 28-80mm lens for a 35mm sensor acts like a 42-122mm lens for an APS-C sensor.


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Scissor Switch Keyboard vs Mechanical

A scissor switch keyboard refers to a mechanism under the keycap that helps to balance out the forces on the top of the key, and allows for a flatter keyboard.

A mechanical keyboard refers to the way the switch actuates, but doesn’t specify the exact mechanism. It’s called “mechanical” to distinguish it from the more common membrane keyboard.

How Keys Feel

There is one keyboard that gets classified as mechanical, but is actually a membrane keyboard: the legendary IBM “clicky” keyboards, often called the “M”. The mechanism is called a buckling spring, and it’s a mechanism that emulates the IBM Selectric typwriter’s keys, but a bit lighter. The key buckles, and the a small plastic lever presses the membrane switch.

A scissor switch keyboard is also a membrane keyboard. The main difference between a regular membrane keyboard and the scissor switch keyboard is the shape of the membrane, and the hardness of the membrane switch. Generally, scissor switch keyboards have stiffer domes, and the keycap sits right on top of the dome.

With regular membrane keyboards, the dome is higher, requires less pressure, and travels down farther before actuating. That said, different keyboards feel different. Compaq, Dell, HP, Lenovo, Logitech, Apple, and Microsoft all have their fans. They feel different.

For mechanical switch keyboards, there are a variety of different options. Some switches actuate near the top of the keystroke, and some actuate lower down. Some bottom out to a hard surface, and others hit a soft bottom, and some people add rubber o-rings to create a soft bottom. Some switches click, and others are silent. Some switches require more force than others.

Flexibility

You can replace keycaps on many keyboards, but the different brands are generally not interchangeable.

Keycaps on mechanical keyboards are more uniform, and they all match the Cherry keytop, so you can replace the keycaps.

Mechanical keyboards can be repaired. If a switch fails, you can desolder it, and install a new switch. Switches are $1.50 to around $3, so it’s an inexpensive fix if you know  how to disassemble the keyboard and solder in a new switch.  If  you don’t… it’s a bit more expensive.

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Japan, Islands of the Rising Sun, by Jane Werner Watson – A Deceptive History for Children

I found this library book at the thrift store, and bought it because it was 昭和レトロ Showa Retro USA. Published in 1968, this childrens book, written for elementary school readers, explained the daily life of people in Japan, described some of the traditional culture, described modernization, and covered some parts of history.

The history presented in this book, however, was deceptive.

Remember, this was 1968, during the Cold War, and Japan had been integrated into the US sphere of influence, and had (and has) military bases to threaten China.

The first thing that stood out for me was the story about the rebuilding of Tokyo after WW2, which was necessary after the massive US firebombing campaign which destroyed Tokyo. This incident wasn’t mentioned, directly, though the rebuilding was.

What did they have to say about the use of atomic bombs on Hiroshima and Nagasaki? Fortunately, the book provided an index, so I could quickly find all the references to the two cities, and see if the facts about the bombings were also minimized.

Interesting. There’s no entry for Hiroshima or Nagasaki.  There is an entry for Nagasaki under “Cities”, and refers to page 77. The page is part of a section about trade history and how Japan was closed off to foreign trade.

So, the bombings of Hiroshima and Nagasaki are not mentioned. These were the first, and only, uses of the atomic bomb, a significant event in world history, but it was completely omitted from this history of Japan, and also of the United States, in this book.

What about this book’s treatment of World War II? It turns out that there is a section that includes WW2. Given that it was the primary military conflict that defined the relationship between the two countries, and led to the US takeover of Japan, and the inclusion of Japan in the US sphere of influence, there must be something.

There’s approximately one page that covers the Empire of Japan, Japanese imperialism and colonization, World War II, Occupied Japan, and the reconstruction of Japan. It’s the period, not the facts that are described: of all those terms, only “World War II” is used.

US imperialist and trade interests in the South Pacific, as well as China’s participation in the war, are completely left out — but that’s still left out of history, so what can you expect.

Compare the fact that three pages were used to describe the period from 1542 to 1615, which might be called a period of Portugese attempts at religious imperialism, while Japanese imperialism and US imperialism and World War II merited only a single page.

Though this was a childrens book, and you cannot get into too much complexity with them, what amounts to the complete omission of World War II makes me wonder what’s going on here. There are different ways to critique this work, but I haven’t put in the mental energy to do so. You’re on your own.

This deceptive distortion of history is available for sale on Ebay or directly from me.

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Depression and Postwar California Pottery

Thrifting and seeking in the Los Angeles area hasn’t been that great for glassware and ceramics, at least the well known kinds that show up online. Chicago, all of Ohio, and some areas of the East Coast seem to turn up great examples of cut glass, blown glass, ceramics, and lamps.

That’s largely due to the fact that the Los Angeles area didn’t get huge until the 1930s, and didn’t have many local potteries and glassworks. Then, in the postwar era, with imports restricted, the Los Angeles area, and some other areas, flourished, and there were hundreds of potteries.

Consequently, I find a lot of California pottery from the postwar era, and a little bit from the Depression era. So far, I’ve found Bauer, Metlox, Coors, Gladding McBean (Franciscan and Catalina), Maddux, and Weil.

I haven’t kept track of tile, but there’s a lot out there. You can find some of the well known items like Batchelder at some antique stores.

The heyday of California potteries ended in the 1960s, when relaxed import restrictions were lifted, and imports from Japan increased. US companies couldn’t compete with the less expensive imports.  I also find a lot of china from this period, often branded with companies from the Los Angeles area, but manufactured in Japan. This is the stuff I grew up with, and am most familiar with.

Memories? Not Really

So, going backward in time to the 1940s and 1950s, is new to me. I have had some plates from that era, but not that many. We did use some, but, again, not that many. My mother was buying her stuff from the 1970s and onward, so, it was mostly imports like Mikasa.

Most of my current research about California pottery is studying the Kovels book about Depression Glass and American Dinnerware.

Being On the Lookout

I’m not starting to try and spot a few kilns that are local to me. First is Vernon Pottery, which would be maybe a mile or two from where I live.

Second is Pacific Pottery, which operated in Los Nietos, now a part of Whittier, and also had a plant in Lincoln Heights on Ave 26, which three blocks from a Goodwill, and the St. Vincents I frequent.  (The old plant was at the corner they call Ave 26 tacos.)

Both are prewar kilns, so their stuff isn’t plentiful today. I suspect the people who owned it all died, and their plates were in the thrift shops by the 1990s. I bet they are in antique shops.

Lead Risks?

I don’t buy much of the pottery, because it’s chipped. That harms the resale value. There’s plenty I’d like to buy, even with chips, but I wouldn’t be able to use them, because the glazes may contain lead or other harmful metals.

See Also

Colorware at the Maximalist – an excellent history.

http://articles.chicagotribune.com/2014-06-13/marketplace/sns-201406051730–tms–smartclctnda-a20140613-20140613_1_china-plates-pattern

https://putnamandspeedwell.com/category/ohio-river-pottery/

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Sanyo DRW1000 DVD Recorder with VCR – setting up to digitize home video, and revisiting formats

I picked one of these up because it was at the thrift shop, and I have some videotapes I wanted to convert to a digital format.  DVD recording seemed a lot easier, and cheaper, than using a video digitizer on the computer.

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