Stars and stripes

A technical post today—after all, this is a technical learning blog.

When you see a picture with details like this (from my Mac’s background picture)…
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…then you know that a small aperture was used for this photo.

The only way to get the sharp star shape you see here, you see, is to use a small lens opening. Meaning a small aperture (“aperture” means “opening”). Meaning a high “f-number”. In this case, I used an aperture of f/22. The reflection is from my flash, which was aimed straight at the car.

I have other clues. Other detail in the picture includes:
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That is at least proof that the lens was not wide open. If it had been, the polygon at the top would have been not a polygon, but a circle.

Other notable facts: the lines (there’s your stripes) all converge where the sun is. And finally, the lens is probably an expensive one: the polygon has seven sides. Most have five or six sides. The more sides, the more the lens approaches the ideal, a circle. That ideal gives you great bokeh.

Bokeh

THE TERM BOKEH, by the way, when used correctly, is used to describe the quality of the fuzzy background. “I want bokeh” is not a correct term: when people say this, they usually just mean “I want a blurry background”.

Correct usage: A lens that has great, beautiful bokeh is a lens whose blurry background is wonderfully smooth and evenly creamy. A cheap lens, on the other hand, has bokeh (especially “fully open” bokeh) that is more like clotted cream: much less smooth, more uneven. I can tell a cheap lens from an expensive one immediately, and I bet you can, too, when you see them side by side.

And that concludes today’s lesson. For more, attend one of my many upcoming workshops: scroll down to read more.

 

Doggone it

I have dogs on my mind, it seems.

Why? Because I did an outdoors portrait session of two dogs today. A little challenging, because it was cold (-9ºC), and it was bright, and the dogs would not sit still.

I started with flash held by an assistant (in casu, the dogs’ owner) and the standard outdoors settings. That gave me:

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But TTL is not easy here, because of the dark subject offset against the reflective snow, and “manual” means “keep the distance of the flash from the subject constant”, which is near impossible. So on to additional ways to shoot:

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Additional advantage: fast shutter speeds are now possible. When you use flash, 1/250 or 1/200 sec is all you can do. Without flash, this limitation is removed. Note that I use back button focus, and this means I need to keep pressing the button as I point at the subject. Having first, of course, selected AI Servo (Nikon calls this AF-C).

After this, I did some with simple on-camera flash, which can be perfectly OK if, as in this case, you mix with lots of ambient light:

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And finally, I did some standard bounced indoors shots:

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The lesson here is threefold, namely that you must know a multitude of techniques; that you must be prepared, willing and able to switch between them; and that you must be able to do so quickly.

This, incidentally, is what I teach in my workshops; including the January 28 one in Toronto, for which there is still space. See http://learning.photography for details and to book. If you know the starting points, the magic formulas that match the situation at hand, you can easily and quickly vary from them: your starting point will already be close enough to get acceptable results. Also, you will feel more confident.

After the shoot, I sat in traffic for a few hours, then downloaded and finished the images in a few more hours, and finally I uploaded a preview web site for the client to look at.

If you have every considered hiring a photographer, you now know why this costs some money. Knowledge, experience, expensive equipment, spares, and time all combine.  “My nephew has a camera too, so he can shoot this to save money” simply does not work except in the simplest cases. And as today showed once again, the world rarely consists of simple cases.

And yes, I do pet pictures too.

Quick! Flash!

Speedlighter.ca. Speedlighter. Speedlighter!

So yeah, let me talk about speed for a moment. Speed as in “fast exposure speed, in order to freeze movement”. Fast exposure speed = short exposure time. 1/2 second is a long exposure time, i.e. a slow exposure. 1/1000 second, on the other hand, is a short exposure time, i.e. a fast exposure.

So how so you get a fast exposure time? One of two ways, it turns out. Either one of:

  • A short shutter time, or
  • A short light flash.

You see, what matters is the duration during which the light reaches the sensor. Whether that is short because the shutter only opens for a short time or because the light itself only flashes for a short time makes no difference at all. It is the same thing. A short exposure.

So let’s say I’m taking a fresh picture of a rapidly spinning spinning top. And let’s say further that I want to freeze the motion, to see the spinning top detail. Since I’m using a flash, I cannot use a fast flash shutter speed; The fastest I can go with my 5D camera is 1/200 of a second. So I’m going to have to achieve a fast exposure by using a short flash of light.

Fortunately, that is exactly what a flash fires. At full power it fires a flash of about 1000th of a second, or 1/4000 second at 1/4 power. Nice. Assuming that ambient light plays no role, your effective shutter speed is now nice and fast: 1/4000 second.

But not fast enough:

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(1/200 sec, 400 ISO, f/32, 1/4 power flash)

OK, it’s still blurry, because it is spinning rather fast, so even 1/4000 second cannot freeze that motion. Now what?

The solution is in the sentence above: “At full power it fires a flash of about 1000th of a second, or 1/4000 second at 1/4 power”.

Because how does a flash set its power? Simply by shortening the time that it is on. Full power means 1/1000 second on a typical flash (small or large). Any longer and it overheats and burns out. So:

  • Half power means 1/2000 second, half the time.
  • Quarter power means a quarter of the original time, so 1/4000 second.

Oh wait. So “lower power flash” means “shorter duration flash”?

Yes! So if I set the flash to 1/128 power, I get an effective exposure time of 1/128,000 second. That’s like a really, really fast shutter:

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(1/200 sec, 400 ISO, f/5.6, 1/128 power flash)

Now, as you see, with an effective exposure time of about 1/128,000 second, the top’s motion is completely frozen. So while my shutter speed is unchanged, it does not matter. The light is only on for 1/128,000 second. So that is my effective shutter speed.

The lesson? To freeze motion, use low power flash. The lower the better.

 

The Clouds

The Clouds is, in fact, a play by Aristophanes. He who also wrote “Lysistrata”. And who said, famously, that “under every stone there lurks a politician”. If you want to understand ancient Athens and its parallels to today, read Aristophanes’ plays (and their explanations to a modern audience).

But if you want to store your images away from home, there’s the cloud. Singular.

Alas: while The Clouds is ancient history, the cloud is not quite ready. It offers great advantages, of course. Backups that actually get done. Off-site storage. Storage that is accessible from everywhere. One place for your files. Unlimited storage.

But the drawback in today’s world is simple: speed. An image can easily be 15-20 MB, and a shoot can contains hundreds of such images. Until we all have fast fibre right into the house, and all the routers are fast, it is just not practical. The infrastructure does not quite support it. Yet. Try moving a year’s shoots to another provider (you cannot be locked in)—you will see it will take days or weeks or even longer. So the cloud is not there yet for us.

It will be, of course—this is one area where Moore’s Law still holds. As long as human law does not protect the Telco’s and we have a reasonably open, competitive market, speeds to the home will increase

Until that time: store all your images on a hard disk. And back them up onto another disk. And then back them up onto another disk, which you keep off-site, in someone else’s home or studio. Only then can you relax. Each image must be in at least two places, preferably in at least three, one of which should be offsite. Don’t lose your images – every hard disk fails. Not IF, but WHEN.

And if you fail to heed my advice, like the Athenians failed to listen to Aristophanes’ anti-war message, then so be it—just don’t say I did not warn you.

What’s in a name?

What IS in a name? Rather a lot, as it happens.

Take the company formerly known as Artisan State. They do great albums and other print-related items. I cannot recommend them highly enough.

Except, that is, for their current name. It is now “Zno“, which every world citizen except an American pronounces as the monosyllabic Russian-sounding “zno”, Vaguely sounding like “snow”.

But the company thinks it should be pronounced as “Zeeno”. Because while the entire world calls the letter Z “zed”, since it is derived from the Greek zeta, Americans, and only Americans, call it “zee”.

And so, apparently, should we.

Except some of us—meaning me—feel rather strongly about language, and while I’ll gladly let Americans pronounce Z as “zee”, or “zoo”, or “za”, or “zeeblebrox”, or anything else they like, I just cannot get myself to do it. Z is zed, not zee.

But of course there is a bigger thing behind this. Namely American exceptionalism and ignorance of the world, and even, if you like, cultural imperialism. Much as I love my American friends, I think they should perhaps educate themselves just a little bit, and realise that the entire world is not America. And something as crucially important as a brand name… why on earth would you choose something that either puzzles or antagonizes the rest of the world? Unless, of course, you only want to sell in America.

So we have problems. Until I live in the USA, I do not want to start pronouncing Z as “zee”, even by stealth, and I do not want to buy from a company that is at the very least either ignorant or culturally insensitive at its senior levels. When I have pointed this out to the company’s support email, all I got was a “we think of it differently”, or some such non sequitur.

So just like I would find it difficult to respect a president who is a racist and a mysogenist (and I am not pointing at Mr Trump here: I suspect he is a lot more intelligent than we think), I also find it difficult to buy from a company that is either ignorant or is trying to push American culture down my throat.

So yes, there is a lot in a name. A name is culture and language, and people care about culture and language.

Am I making a big deal of this? Nah. No big deal. I can buy albums, even good albums, elsewhere. I can recommend other print companies to my students. No skin off my nose.

But I do wonder why a company chooses not to care about antagonizing a great proportion of their market. Are they ignorant, or do they want to push American culture down the world’s throat? I’d say both are equally likely.