Binnur, Geoff, John, Jack, Izzie, Manfred, Richard and Mike, thanks for all your time, thoughts and comments.
I've read them all thoroughly. I'll try and respond by subject rather than to individual comments.
Exposure/Brightness/Histogram
I dramatically reduced the brightness of my monitor after my first post.
However, that excuse "papers over the crack" of the problem Mike identified. I understand the histrogram, but I'm not checking it. I was checking my exposure with the image on LCD on the back of the camera, which, given the comparatively dark position the camera was in, made me see the exposure as brighter than it was.
Where I self-identify in post that the exposure is wrong, it is almost always under-exposed. It's taken this thread (intervention?
) for me to realise this.
As to whether the exposure was artistically correct vs technically correct, I think I should be tending towards the technically correct for now (if those two are indeed different in this case).
Just to clarify on Manfred's flash power comment. No equipment deficiency was holding back the exposure. Yes, Manfred, flash was manual and set too low. I had at least 4 stops of flash power available to me (plus flash could've been positioned closer). Plus a few stops of ISO.
What Did I Want the Image to Convey?
I think sub-consciously I had an idea at the time, but if you'd asked me, you probably wouldn't have got a good answer.
Here it is: Warmth and closeness. My son adores his Grandpa. I didn't want the image to look cold and brightness to me would convey this. Trying to minimise bright whites was a conscious goal at the time. I knew I didn't want the light wall to camera left. I tried re-positioning the flash, but I didn't try getting it closer, which may have helped.
I thought too much contrast within the image might go against this goal, also. However, I didn't really try it to be honest.
I'll break into another post...