[mac888]

請問師兄, TTL 及 TTL II 兩者有什麼分別? 我剛買了430EX II 但發覺同舊的420EX 沒什麼大分別.

[canonfever01]

Check this out and you will know.
http://www.the-digital-picture.com/Reviews/Canon-580EX-II-Speedlite-Flash-Review.aspx

[Obi-Wan]

check this out
http://photonotes.org/articles/eos-flash/

[Obi-Wan]

that is only one difference between 430EX & 420EX, the focal length information of the lens is input to the flash by 1.6X if using an APC-C camera, so the 430ex can zoom to that range, e.g. a 50mm lens will zoom to the 80mm range for 430EX, but only zoom to 50mm range for 420EX, so 420EX waste more power & longer recycle time.

BUT FOR ME SINCE I ALWAYS USE BOUNCE FLASH, there is no difference between 420ex & 430ex on my 20D & 50D