Not on the flash topic, but I got the chance to use a friends 100-400 f/4 canon lens to shoot my daughters gymnastics meet last weekend. Never figured I would put my hands on a big white lens. It took some awesome shots, not qute fast enough, but took great pics. I have the 55-250 IS lens, and it takes great pics also. I would like to get a 70-200 f/2.8 if she stays with the gymnastics and soccer, but the glass is high, so I may have to settle for Sigma or Tamron.