More pictures on my web site: macro flash
Compatible with 58mm filter size. I am use it with a Canon 100mm 2.8 macro USM 1:1. The light is strong, enough to be use camera from hand. Generated light is much superior to the macro rings with regular leds.

Technical desciptions:
Total current drain ~ 2.2Ah at 7.4V, (LI-IO battery or indoor use 7V DC adapter with min. 2A)
lightweight: macro ring 102gr
The circuit is designed to have two phases of light, full or half (only half of the LEDs light up)
Ideal for super macro.

Step 1: LED and HeatSink Specs

LED (1Watt):
Emitted Color : White
DC Forward Voltage (VF): 3.6 ~ 4.0 Vdc
DC Forward Current (IF): 300 ~ 400 mA
Viewing Angle: 140 Degree
Intensity Luminous (Iv): 90 ~ 95 LM
Chromaticity:5500-6500K
10pcs 6$ +1.10$ shipping

Copper Heat Sink
100% brand new and high quality.
Great for high performance or over clocked systems.
Dissipates RAM heat improving its performance.
Reduce the temperature of the memory by up to 35%.
Dimension: 12 x 11 x 4 mm.
8pcs 1.49$ +shipping 2.99$

Step 2: Files+result Photos

SCH and PCB you can download http://www.apcc.tk/downloads/category/2-macro-flash

I recommend to build this ring for macro photography lovers.

Home page: APCC DIY