Pentax digital spotmeter... a question.

Why does it command such high prices?

There's one about to go for £300 or more, and this is pretty typical, from what I've seen recently.

Why is it so desirable?

Highly desirable because it is unique, other spot meters- and there aren't many of them - aren't as narrow or as accurate. They are used a lot by TV land movie ighting directors as well as photographers. Spot metering along with knowledge and skill will give far better results than matrix reflected metering. www.spotmetering.com

Personally, I prefer incident metering and hardly ever use my (Minolta) spot meter.

Maybe it's just that my knowledge and skill aren't up to scratch, but spot metering doesn't seem to be what it used to be with film.

More often than not, I find now that the thing I want to spot meter is a lot darker than the background, so the sky (as it usually is) ends up getting horribly burned out, which ruins the shot.

So what practical use is it with digital these days, where it's more important to expose for the highlights, and then pull detail out of the shadows?

Hi Chris,

There is more, a lot more to this, than appears at first glance. In film terms you have to know and understand the gamma and D Log E curve of the film (forgive me if you know this but I'm sure lots of people who might read this might be unfamiliar with the terms) This is a graph which plots density (of the exposed film) against the logarithm of exposure resulting in a curve a bit like this _/ (with another horizontal line going l to r at the top). The angle of the diagonal portion describes 'gamma' - in effect the contrast ratio of the film/developer combination and the idea is to place the exposure somehere on that line before highlights on the right and shadows on the left encroach onto the more horizontal parts of the
line. (crushed shadows and burnt out highlights)

You meter highlights, mid tones and shadows.

Digital media is even less forgiving given the restricted dynamic range.

For 90% of general stills work we can use the built in meter with confidence but, again knowledge and skill play their part.

I have never seen anyone on a film location or studio use general reflected light readings (the cameras dont have meters) by hand, there is just too much at stake professionally and financially to get it wrong.

Ken

Actually, what it means is that you take readings of the highlights, shadows and midrange, and, from there you can see how many EV points there are between the brightest and darkest area of the scene, so you can figure out the best compromise to get the maximum of details in your picture. You can also more easily bias your exposure toward the shadow or highlight end of the spectrum, taking into account what is more important for you. Hople you can figure out if it is worth the investment for you!

Yes, this makes a lot of sense, thanks to you and Gartmore for taking the trouble. It's not going to be high on my pre-lottery win priority list, but I understand the principle much better now.

If you really want a stick to beat yourself with, you can always use the camera's spot function to the same effect

Actually, the spotmeter on the K10D is 2.5 degrees vs. 1 degree for a "real" spotmeter, plus I'm not sure the center circle of the focusing screen is really where the "spot" is perfectly located on the K1k0D, so the precision might not be the same.

But with what lens????
It can be 1 degree with the right lens - a 148mm lens according to the website
Matt

MattMatic has a valid point concerning the focal lenght, but there is still no guarantee the spotmeter of the K10D is perfectly centered, then the longer the focal lenght, the bigger the mistake. But it is rather easy to check the centering with a narrow led in front of a black background. I checked mine, and it is slightly below the center of the viewfinder screen (not by much, but...).