Nikonian72 wrote:
Via computer Post Processing, an under-exposed raw file will still produce an acceptable JPG, but with noticeable digital noise.
On the other hand, an under-exposed camera-generated JPG may be too dark to correct in PP to a useable image.
Third-party speedlights (like Yongnuo) may not register in Canon or Nikon Exif info.
Thank you for your quick reply Douglass. By the way, my original jumper is still hunting on the cover of the compost heap. I am so pleased because I thought I had frightened him off.