Wonderful Weston

Wonderful Weston

You might be thinking this will be about someone called Edward, or Cole, or Brett, and will involve nudes and peppers.

No. Not today. This is a very British Weston, my first light meter, and still my favourite, a Weston Master V, complete with leather case and grey cord lanyard, and the incomparable Invercone.

It isn’t just a device for measuring light, though within its sensitivity parameters the Weston does that better than anything else I’ve met. It’s a delightful piece of engineering, an object to caress and treasure, and a lesson in photographic exposure.



There are three big pluses to the Weston, apart from the standard of manufacture: first, it uses a selenium cell, so that its colour sensitivity is not a mismatch for eyes and film, as CdS meters were at the time. As the selenium cell generates current when light strikes it, no battery is required. And the Invercone.

While Sangamo Weston still existed, Invercone was a trademark: it’s still incorrect to call the centimetre hemisphere that most modern meters have by that name, but there’s no risk of legal action. The Invercone is bigger, more complex, and more accurate, because its shape collects light hitting it from a greater range of angles, as real, three-dimensional subjects do.

And the essence of it is that when you fit the Invercone, you use the meter by placing it in front of the subject, with the cone facing towards the camera position. It measures the light falling on the subject, instead of the light it reflects. So it will give the same reading held in front of a white sheet or black velvet – which may, at first, sound odd.



Think, though. You want the sheet to come out light in the picture, and the velvet dark. If you simply take a reading from each, both will come out grey, which is obviously wrong. An incident light reading will give correct exposure…

The Weston can also take reflected light readings, without the Invercone, and the grey baffle that sits over the cell for bright daylight folds back to give greater sensitivity for less bright conditions. It runs out of sensitivity in dim indoor lighting – but then, when it was made, so did conventional film, even with a very fast lens.

I’ve bought other meters since, because a Weston doesn’t read flash exposures, and because I sometimes want to shoot in light that demands a tripod – but it still has a special place in my heart and in my gadget bag.