Reference photos

If you wanted to make a library of photos as a reference for a particular group of objects over a period of time, would you meter each object or use a grey card for exposure? Let's say for example you wanted to document house bricks (no I don't, it's only an example!) I could use a colour card for accurate colour rendition and use the same lighting for each shot but would you use different exposures by metering the bricks or work off the GC? Bear in mind that the objects may range from quite light to dark.

Any thoughts?

If you want to be strictly accurate you could do a custom white balance and incident light metering for every shot. That would require a separate meter.

Otherwise, if the light was consistent then you would need to meter correctly, reducing exposure for dark subjects and increasing exposure for light ones.

In a studio setting the same manual exposure could be used for every shot as the light will be repeatable.

White balance and exposure from an Expodisc

Or use a QPCard 201

QPCard 201 (the one I have) is Jpg only, but does set the colours correctly.

The newer card also handles RAW.

Thanks guys. I have a QP Card for the colour but how would that help with exposure? I also have a Tiffen card somewhere as well.

I just leave it on auto and then further adjust colour balance in Post Pro to taste. Much easier

Take the exposure off a grey card. You could use a filter
such as the Expodisc but it would mean pointing the camera
towards the light source.

A handheld incident light meter reading would also work.

If it's that important why not exposure bracket at least
3 shots.