Sekonic Light Meter Calabration

Gary752

For those of you who own a Sekonic light meter that think the calibration is off and want to check it, here is a tip I learned from a workshop with Tony Corbell on Creative Live.

1. Set ISO & SS to 200 (anything as long as they are the same value)
2. Take meter reading in direct sunlight with dome pointed towards the sun

You should get an F-stop reading of F16. If you do, your calibration is OK. If not, do the following to correct:

1. Hold in both ISO1 & ISO2 buttons until is says ADJ and then turn wheel to the amount it is off.
2. Take another reading to verify you get a reading of F16. If not repeat the process.

Tony Corbell claims this will work with any Sekonic light meter that has the dual ISO buttons. Hope this helps someone.

GaryB

pathfinder

Interesting post, Gary. It certainly makes sense to use a consistent light source for calibration. and the sun near noon is pretty consistent worldwide, barring clouds or overcast, usually easy to find, and inexpensive too.

I have a Sekonic L-358 that I have had for years and I've just always "assumed" the calibration was built in, but I haven't ever specifically checked it against Sunny 16. https://en.wikipedia.org/wiki/Sunny_16_rule

Since the Sunny 16 rule of exposure says 1/ISO for a shutter speed at f16 in broad daylight ( between 10 am say, and 4pm or thereabouts ) that sounds like what they are using to calibrate the the Light meter in your post.

A light meter that is a incident light meter should read very close to the Sunny 16 rule.

I compare Sunny 16 to my camera's light meter fairly often, and find very good agreement if the camera's REFLECTED light meter is used correctly eg: with a 16% grey card or equivalent. Note that Incident and Reflected Light meters should agree if the reflected meter is used with a neutral 16% grey target. Reflected meters will vary a lot with white or black subjects, hence then need for +1-2 stops of exposure in snow scenes over the reflected readings. Indeed, if my camera's reflected light meter does not agree with Sunny 16 with sunlit shots ( even even shots in the shade or cloudy bright ) I tend to favor the Sunny 16 version over my camera's reflected light meter.

There is even a Sunny 16 Exposure Calculator in the Apple App store, so there still are lots of us using Sunny 16 from time to time.

Thanks for your post about how to calibrate Sekonic light meters. I will check mine when I see the sun again in a few days, after Winter Storm Goliath finishes with us.

pmbpro

Wow. Thank you or the information Gary. Much appreciated. Just like pathfinder, I too, have a Sekonic L-358. I will test this calibration procedure out the next time I get a nice sunny day.