Metering query

benjie · #1 September 20th, 2011, 10:16 AM

I've got a query re metering, regarding all 3 of my G-series cameras. I have my camera set to multiple metering and spot focusing. When I focus on something I half-press the shutter, which I've always thought fixes both focus and exposure, and then recompose. But often, although the image looks ok in the EVF, after I've taken it, it is, say, over-exposed. Or it may look over-exposed before taking it, but the final result is acceptable.

I assumed that when looking through the EVF, WYSIWYG.

Any explanations or advice gratefully received!

meyerweb · #2 September 20th, 2011, 11:33 AM

One kind of annoying thing I've noticed with my GH2 (and I think my wife's G2), is that even though you lock the exposure, when you move the camera the EVF view of the exposure doesn't lock. IOW, as you move the camera around the EVF will maintain a steady brightness, so you can't use how the image looks in the EVF to judge exposure. Turn on the histogram and use it, instead.

The other thing, and excuse me if you already know this, but the camera meter assumes that what you're metering from is of "average" reflectivity. If you spot meter off of something that is appreciably lighter or darker than "average", the image will be under or overexposed.

At the risk of belaboring the obvious: If you spot meter off of a white shirt, the camera doesn't know it's white. It assumes it's 18% gray (an 'average' subject), which is a moderately light gray. So the metering system tells the camera to make that shirt gray, which will make everything else darker, too. Conversely, if you spot meter off of something that's dark brown, the camera again will lighten the exposure to make it 18% gray, which will make the entire image overexposed.

benjie · #3 September 20th, 2011, 11:59 AM

Thanks for the comment. I know about the 18% lark; my question was about the first point you raise, ie the fact that the EVF image doesn't lock. Is this the same with non-Panasonic EVIL cameras? I find it a little annoying: is there any way round it via the settings?

~tc~ · #4 September 20th, 2011, 12:44 PM

There are approximately 4,326,187 threads on Panny WYSIWYG.

Suffice it to say the standard EVF display is always gained up and does not show the result of the metering. You can press the "trash/DOF" button and it will show it as focused/metered (unfortunately, you have to do it every shot - no way to lock it). You can then press the "diplay" button to mimick the effect of the shutter speed. Only THEN is the display truly WYSIWYG.

The other problem you may be having is using the matrix metering. It is going to average the entire field of view, so if you have a few very bright spots, the subject may be underexposed and if there is a lot of dark area, it will likely be overexposed. Obviously, the solution is to use spot metering (or face detection if your subject is human)