Hi Klose,
Did you manage to find out more?
I just checked and read something:
Spot
Spot metering is useful for metering very precisely a single subject or area within a scene. The metering is weighted at the center of the frame covering 3.8% of the viewfinder area.
With AF points limited to 11 or 9 (custom function 13 is 1 or 3) the metered spot will follow the AF point.
The custom function settings stated are:
Number of AF points / Spot metering
Set the number of selectable AF points and if spot metering follows the active AF point or is locked at the center of the viewfinder
• 0 - 45 / Center AF point
• 1 - 11 / Active AF point
• 2 - 11 / Center AF point
• 3 - 9 / Active AF point
So, from that, I figure that if all your settings are set to default, aka, '0' on CFn 13, you should be getting a correct reading if you're metering using only the central AF point, and if the portion of the subject you metered on is closet to 18% grey. If the subject if off 18%, and your meter is not compensated, it will drag everything back to 18%, causing over or under exposure. Personally I found that selecting that '18% grey' equivalent portion on a subject was one of the trickiest part even when I was using an old fashioned 1 deg spot meter.
Could I check, were you facing the problem while shooting Leanna? Why I ask is because the 1D MKII 'spot' metering
may not be a true spot in the sense that it's not a 1 deg area that gets metered, but speced at being "3.8% of the viewfinder area". How many degrees that works out to, I don't know, but I doubt if any in-cam 'spot' metering could ever be as tight or precise as a seperate, hand-held spot meter.
It could be that
the 'spot' area that got metered included fringing in on by the brighter, more contrasty parts beside or behind the subject, thereby causing underexposure. This I found to be another common cause or errors when I was using an OM4ti with the in-built spot metering function as opposed to using my Minolta spot meter -
readings often got affected by a brighter or darker area just beside or outside the area I thought I was metering.
IF that makes sense, then a bit of careful testing with a constant apeture lens and an 18% grey card will reveal if the problem was caused by:
1) a 'corrupted' exposure reading (because the metered area was a little too wide) and
2) metering off an area that was not 18% grey and compensated for.
Also, if you're really up to it, you could also include taking incident readings as I've found them to be the most accurate reference, or compare your 1D MKII 'spot' readings against a 1 deg hand-held spot meter using an 18% grey card.
Hmm...does that sound right? Man oh manz, I hope I'm not sounding like a total dope in front of the experts here since my experience on a 1D MKII was limited to less than a day's usage!
