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Neil Gordon
29-Dec-2007, 10:41
I had recently purchased a used Sekonic L-398M meter and had noticed a label, attached to the rear of the sensor, warning the user of a "powerful magnetic field." Does anyone know if any of my gear, i.e. digital camera, might be affected? I've sent sent an inquiry to Sekonic but after several weeks I still haven't had a reply. Thanks, Neil

Mark Woods
29-Dec-2007, 11:05
Hello Neil,

I'm not sure if the magnetic field is something to be avoided, or being created, by the meter. I know that I've been on sets with large lights and BIG cables with a lot of amperage. As you know, when they are coiled (even in a figure 8) they create a magnetic field. I've had my electronic meters go totally off calibration. I spoke to George at Quality Light Metric about this, and he said, get out of the field, take the battery out, count to 10, put it back in and it should be fine. That's what I've done and never had a permanent problem.

Hope this helps.

MW

Neil Gordon
29-Dec-2007, 11:31
Mark, Thanks for your quick response. To be totally clear the label states: "This meter has a powerful magnetic field." To test the theory I placed a pocket knife to the meter's backside and it stuck like glue! I guess I could try placing heavier objects next to the meter to see what sort of weight it's capable of pulling but I don't have the technical know how to interprolate the information into units of gauss?

Matt Blaze
29-Dec-2007, 11:31
I can't imagine what kind of strong magnetic field could be emitted from a light meter. Perhaps they are talking about the electroluminescent backlight (which uses a high voltage driver)? But even that shouldn't be a STRONG magnetic field.

Neither my L558 nor my L358 have such a label, but I just measured them both with a Gauss meter. They give no appreciable reading with the backlight off, and a small reading (still smaller than my cellphone) with the backlight on. Maybe the 398 has some other feature?

BBW
29-Dec-2007, 16:04
I had recently purchased a used Sekonic L-398M meter and had noticed a label, attached to the rear of the sensor, warning the user of a "powerful magnetic field." Does anyone know if any of my gear, i.e. digital camera, might be affected? I've sent sent an inquiry to Sekonic but after several weeks I still haven't had a reply. Thanks, Neil

The meter movement has the magnets but the only time I would worry about the magnetic effects of this meter would be with data erasure on floppy disks (am I dating myself now with this comment :) ) lying right next to it for a long period of time. Cheers!

Ben Chase
29-Dec-2007, 16:46
The meter movement has the magnets but the only time I would worry about the magnetic effects of this meter would be with data erasure on floppy disks (am I dating myself now with this comment :) ) lying right next to it for a long period of time. Cheers!

Don't feel too bad - I still remember playing with a Commodore VIC-20 and using cassette tapes to load programs (and I'm only 28) when I was a kid.

Why in the world would a light meter have a strong magnetic field, meaning, for what purpose?

Mark Woods
29-Dec-2007, 17:13
I just checked my old Spectra meter that is similar in many ways to the Sekonic. It didn't work as a refrigerator magnet. ;-) I don't have a clue why the Sekonic would have such a strong magnetic field.

MW

Matt Blaze
29-Dec-2007, 17:59
I just realized the 398 is a battery-free analog meter, not a electronic meter, which makes my previous reply rather nonsensical. Sorry about that!

In any case, the movement of such meters does use a rather strong permanent magnet, but it should not emit a strong enough field to do any damage to electronics. I wouldn't wipe my credit cards across it, though.

ericantonio
5-Jan-2008, 20:52
I opened up one of these before. The bottom end of the needle is between 2 half round magnets.

ericantonio
5-Jan-2008, 20:53
I opened up one of these before. The bottom end of the needle is between 2 half round magnets.
Wait a second, I may be mistaken. I'm confused with my Gossen Pilot 2. I know i opened them both up and I remember seeing a magnet.