I guess this is a general lighting question moreso than an eye macro photo, but I ran into the problem while shooting eye macro so here goes:
I preface by saying I know almost nothing about lighting and I've been learning as I go.
In the shot below, I ran into a couple of problems with my catch light.
The first is that I set my flash too powerful for the distance (sb200 on a lens ring mount), thus over exposing the reflection while at the same time metering correctly for everything other than the catch light. I know how to fix this, but I didn't notice while I had the shoot set up so I didn't correct it in a later exposure.
The second thing is that when I managed to hold steady enough (this was a self portrait that had me looking through the lens to see the upside-down viewfinder HUD and align my eye correctly, and then making a mirror-up exposure with a remote), the color version of this shot shows the surface of my eye as uneven. Is the surface slightly cratered, and does it mess with a properly focused catch light, or is this another manifestation of the over exposure problem?
Tips welcome, I value your opinions here in my winter-bound apartment. ;)