Hi westr70 !
Thank you for your report.
I assume your 5D III was the tool for that portrait session.
Additionally, could you tell us what lenses you used most during that shoot, among the three you mentionned ?
In similar situations, I find it safe to shoot quite a bit "wider than necessary" (eg. 35 or 85 rather than 135 mm, in your case).
This gives more options later on, to crop in PP and adjust to whatever's required by the model / client / situation.
OK you'll be losing some definition BUT ….
… we, as photographers, are often much more concerned by ultimate sharpness, detail etc. than our models are !
Even more true, considering :
- less than perfect skin, spots, wrinkles etc. that we'll have to somehow soften and restrain in PP
- the final purpose of the shot, in this case a low def. web site illustration
Bottom line, it's more a question of overall allure and expressiveness than technical perfection, for real world portraits (as opposed to overprocessed, unreal and so boring magazine pictures, for instance).
A friend of mine who runs a photo boutique somewhere in France, displays a wonderful large print headshot of a pretty model.
Actually, this is heavily recropped from a standing portrait of the lady, shot with a 12 Mpix Nikon D700.
Only a few Megapixels left over, for an unanimously acclaimed result : such a natural, lovely expression to fall in love with !