Sunday, March 07, 2010

Do Not Buy!! Chinese RF-155 / F-155 O-Ring Flash Adapter

Bought one of these gadgets at a store in Plaza Low Yat for 180 MYR ($54). There is a store in Singapore which sells these for much less, S$ 60 ($43). This is also sold in the rest of the world under the Phottix brand.

Now you may think this gadget looks very similar to the $300 Ray Flash, or the $200 Orbis Ring Flash adapter. Well, it does.. but it is far, far, far less efficient. I guess the factor-of-four price difference does count for something.. although honestly I don't see the value in a $300 ring flash adapter when you can buy a Sigma EM-140 DG ring flash for $380.

In my informal testing, you lose about six stops!!! of flash power. From 1/32 power at f/4.0 on my Pentax AF-360FGZ, I had to go to full power, and my target was still under-exposed. Of course the target was about 2 - 3 meters away, so if using this gadget for macro, then you'll have plenty of flash power.

But six stops of flash power loss is crippling. Overall, had I known how much light loss this thing has, I wouldn't have bought it, $50 price notwithstanding. I think there are LED ring lights out there that produce more light.

This guy reports only a two-stop power loss.

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