Today I finally got around to making a solution.
Cost: About $5.
1 roll of film (yes, a roll of film)
A piece of thin cardboard (find at maybe a craft store, works better than thick stuff)
A couple pieces of tape
Ruler / measuring device.
|Flash filter, side view, with bottom to the left.|
Step 1: Measure out a piece of the cardboard, 2 inches high and 3.5 inches wide. On the wide side of the cardboard, bend two flaps about 3/4 of an inch inward.
Step 2: Take a piece of film from the roll (and cringe as you overexpose it), and tape it tightly from one arm to another (see photo above). It's actually preferable ff you bend the arms inward slightly from the tension, as this causes the filter to sit a big snugly on the onboard flash.
Step 3: Probably completely optional, but I also taped a small piece of film over the top of the filter to catch any stray beams that might pour out (probably unneeded though). See below photo:
|Flash filter, with top part of film on right side.|
|Flash filter mounted atop A77.|
The important question - How does it work? Awesomely! the film essentially filters everything but the IR light coming from the onboard flash when used as a commander, which is just fine for us - our remote flash is looking for IR anyway. Also, our camera's internal filter is going to filter any IR coming into the lens, so it's going to make zero contribution to the exposure. Hell yeah! The only downside - now your A77 looks like it has a Hannibal Lector mask on or something.
For me, at least, the functionality trumps the looks. It allowed me to snag a couple of photos for my wife's cooking blog by freeing up my second hand to help steady the camera or move props, etc.
|Final photo used. HVL-43AM flash to camera right, shooting into 42" umbrella. Piece of white foam core board to left acting as reflector. A77 with Minolta 28-105, editing in NX2 and Lightroom 4.|