It looks small to be consider as a flash. It has a GN of 20, a little bit better than the pop-up GN. It basically does what a pop-up suppose to do, not quite, and it has two extra features: it has a up-bounce function and tele-wide flash selection.
Yup, it's a WL commander for A900 only.
Nothing to talk about the back side of this flash. It has no buttons at the back side. To turn the flash on, simply turn the flash mount. Can't do it when it's not mounted on a camera, not to say cannot do, it's difficult to do lar.
How small is this flash ?
I can keep it in my pocket for sure. LOL.
So, is it a good flash? Well, if you don't own an A900, why you need another "pop-up" flash for yourself ? It can't do WL, it can't be the WL commander when mount on non-A900 camera, it don't even has a manual flash control. Somehow I do find the pop-up flash for A700 is much better than this HVL F20AM ! At least the pop-up can do ALL (but the bounce and tele part) with even a manual flash setting for A700's pop-up flash !
I was hopping this F20 would be a better WL commander with ratio control etc like what a F58 do in WL part for ALL models of Sony DSLR but look like Sony wish to keep the customer room of upgrading. You want to play WL ratio ? Upgrade to A700 or A900 with F58. :D
Just a small conclution about this pocket size flash:
1) Small and light.
2) GN 20.
3) No manual control. A700's pop-up even has 1/16 - 1/1 flash level control.
4) Only be a WL commander for A900.
5) Even you need it as a WL commander, it can't do WL ratio.
So, if you don't have an A900, don't waste your money on this.
If you have an A900, and wish to use this as your WL commander, I think I have a solution that way cheaper than this RM 599.00 (RRP) "pocket flash". (Well, it's ain't pocket wizard for sure.) LOL
No, I didn't test this flash, b'cause I don't want to. LOL
Yay to another piece of Sony useless stuff that only target to small group of user. Yay !