I thought it would be helpful to the Polaroid shooters out there to see a comparison of the flashes available. All images were shot with a Sonar SX-70, all on the Impossible Project's PX70 Color Protection film (the old edition) with the wheel set 1 click dark. This is the setting I've found works best with the light meter in my camera. There was white butcher paper behind and under the object, a creepy Jack in the Box toy from my childhood because there just aren't enough shots of creepy Jack in the Boxes on film. There were no lights turned on in the room, but there was a little window light and they were shot around 2 in the afternoon.
I recently picked up an ITT Magic Flash off of eBay, along with another Sonar SX-70 for $75.00. It was a steal. The Magic Flash runs off of 4 AA batteries. The camera clips into the base once it is unfolded and you pop the flash head in just like you would a flash bar. The cord does not disconnect from the base, so be careful. It's obviously the largest and bulkiest of the options. I'd say the flash is about 3 flash bulbs big when compared to the flash bar. The unit charges quickly and recycles fast. I was using Energizer Lithium batteries.
The Mint Flash, which is sold by the Impossible Project runs off of 2 AAA batteries. This is my second Mint Flash. The first one I purchased was not syncing properly with the shutter of my camera. It would fire as the shot was ejecting from the camera. I wrote the Impossible Project and without question, they sent me a new Mint Flash and I sent them the malfunctioning one back. The second Mint Flash fires perfectly. I have noticed that it eats up batteries and it takes longer to fire up and recycle. It is about the same size as a flash bar.
The old reliable GE Flash Bar. This is my trusted flash, but as you know, they won't be around forever. Every now and then, you get a dead bulb that won't fire and they are hot as all heck after you shoot them.
ITT Magic Flash
The ITT flash was a little blown out at this setting. I'm still getting to know how this flash reacts with my camera. I think another click dark would have given it just enough contrast.
The Mint Flash was slightly underexposed. I would have left the wheel at neutral to get the proper exposure, but this was a test at the same levels. You will notice that the Mint Flash is much cooler than the ITT Magic Flash and the GE Flash Bar. I'd say that the colors are more true to what I was seeing.
GE Flash Bar
The GE flash bar is dead on in my opinion. Again, the colors are a bit warmer in this shot.
Honestly, you can go with any of these flashes. Personally, I'm leaning towards the ITT Magic Flash. I have plenty of rechargeable AA batteries and once I get the levels down, I think it will be just as good as the flash bar. I just don't like the recycle time of the Mint Flash and that I have to bust out a new set of AAA batteries every time I want to use it. I also don't tend to have AAAs on hand. If you're looking to pack light, the Mint and flash bar are space savers.
Note: the pack of film I was using was a bit older and all the shots from the pack have that dark patch on the right hand side.