Just reporting a problem I've noticed with my M6TTL's ISO dial. The dial can be seemingly set at the ISO you want, but the meter can still be off by a 1/3 stop if you don't make certain that the spring loaded dial has seated properly.

I first noticed this when my SF20 would be off, showing 250, or 125, when the dial was at 200 or 100 respectively. A little nudge and the correct ISO would be displayed.

This behaviour is consistent, in retrospect, with my getting back boxes of slides that seemed curiously dark or underexposed very slightly.

Unfortunately, without the SF20, it is well nigh impossible to be sure if the meter has been set correctly.

Is it just my camera, or have others noticed this too?

-- Mani Sitaraman (bindumani@pacific.net.sg), May 29, 2001

Answers

Are you using the camera's internal meter? With the M6's "partial" meter, I find it's almost impossible to get perfect meter readings every time anyhow. One-third of a stop? For me, that's easily within operational error. Remember, the M6's shutter is typically off by up to a third of a stop anyway, so why bother trying to meter precisely? Lastly, it takes time and skill to meter a scene perfectly anyhow, and is rarely done properly. I guess my point is that unless you have a hand-held spot or incident meter and lots of patience, it's going to be off a little bit anyway.

About the ISO dial: although I do not have a flash for my M6, I have noticed the same behavior where the dial is aligned but not "set." Nudging the dial in one direction or the other elicits a small click and the dial is firmly in place, hopefully where you want it. Despite what I said in the paragraph above, I still obsess over it. At least I'm inconsistent. :)

-- Colin (colin@longitude.com), May 29, 2001.

You do have to make sure that the dial has "clicked" into place but I have never had any troubles with it. It is also a good idea to occasionally move the dial through its full travel several times to "wipe" the contacts clean. Mild corrosion can build up if the dial is left in one position most of the time. Perhaps this might be the source of your problem?

Cheers,

-- John Collier (jbcollier@powersurfr.com), May 29, 2001.

John, good point. I'll check. Just another quirk to learn to compensate for in our dearly beloved precision machines, I guess ;-)

IMHO, a consistent bias of 1/3 of a stop is quite noticeable when shooting chromes. Bright days look a bit dim, cloudy days look positively dark etc.

-- Mani Sitaraman (bindumani@pacific.net.sg), May 29, 2001.