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)…
…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:
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.


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.


Faster… faster!

As regular readers will have read yesterday, I just bought a 50mm f/1.2 L lens.

As some here have mentioned, this lens is not known for being the very sharpest at wide open apertures. It is also not known for being one of the cheapest: you can buy an f/1.8 lens for $120, so why spend $1,800 on a f/1.2 lens? Especially a prime lens-  meaning not a convenient “10-500mm” zoom lens?


  • It is yet another bit faster (meaning, lets in more light) than the f/1.4. A third of a stop more. And as you saw in my post of two days ago, that is important: every little bit helps.
  • And it allows me to blur the background even more.
  • And it gives me beautiful bokeh when used wide open.

Here’s an f/1.2 snap:

Food held out

Food held out

…and another one, showing nice blurry background:

Laptop at The Royal

Laptop at The Royal

Of course even at smaller apertures, like f/2.8, you can get a nice blurred background:

Hold out your glass...

Hold out your glass...

But wide open you get this wonderful soft bokeh (the nature of the blur):

Glass with bokeh

Glass with bokeh

And that is why I am happy to invest in this type of lens.

Plus unlike a camera, a lens keeps its value. A lens’s value depends on the intrinsic value of the optical glass, so it is great.

So when people ask me “should I spend money on a lens or on a new camera”, well – you know they are both great and useful and fun. So either decision is good. But lenses are more important to your photos, and they keep their value, so do not ever feel bad about purchasing a great lens.