Comments about Vivitar Vivitar DF183 Digital TTL Shoe Mount Power Zoom /Swivel /Bounce Auto-Focus Flash for Olympus Evolt Digital Cameras, Guide Number 45m (147'):

The listed specs are completely incorrect. This flash is less than half as powerful, and it has no zoom or swivel or variable power. Correct specs for this model are:

Guide Number: 22m at 35mm
Zoom Range: 35mm only (no zoom)
Bounce Capability: Vertical bounce angle: 0°, 45°, 60°, 75°, 90°
Power Selection: none
Special Features: Focus beam to assist in low light conditions, auto shutter speed setting
Recycle time: 0.3-10 sec
Power source: 2 x "AA" (alkaline batteries)
Number of flashes: 100 times (times with fresh batteries)
Dimensions: 65 x 54 x 98mm
Weight: 127g (w/o batteries)

The pluses here are it's simple, small, cheap, and when on the hot shoe works with your camera to do autofocus assist and TTL metering to get the proper exposure.

The negatives are it doesn't have many features, and some will consider it underpowered. At ISO 100, the practical range for good exposure would only be within about 15-18 feet (figure a GN of 22 meters, divided by 5.5 meters = f4.0). But, you can up the ISO to 400 and get pretty good range (say 30 feet). This still produces maybe twice as much light as a typical on camera flash on an entry level DSLR.

Comments about Vivitar Vivitar DF183 Digital TTL Shoe Mount Power Zoom /Swivel /Bounce Auto-Focus Flash for Olympus Evolt Digital Cameras, Guide Number 45m (147'):

On a PEN E-P1, this shoots underexposed. At 15 ft. this shoots about 3 EF low At 10 ft. it is closer to 2 EF low. At 2 ft. is is correct. Obviously this makes it hard to get good results without manual EF adjustments. In fact it really isn't any better than my old Vivitar 2000 that I've tested with this camera in Manual mode. Unfortunately the old Vivitar is not TTL so it would eventually damage my PEN. This new flash is at least safe for the camera. But my 1974 Pentax flash used with a Spotmatic IIa was more automatic that this is.

Comments about Vivitar Vivitar DF183 Digital TTL Shoe Mount Power Zoom /Swivel /Bounce Auto-Focus Flash for Olympus Evolt Digital Cameras, Guide Number 45m (147'):

The flash works with the camera very well. I bought it as a smaller flash for candid shots. It feels very lightweight and flimsy compared with my other flashes. The description says it takes 4 batteries; one reason I bought it. It only takes 2. A nice flash for little money.