Canon EOS 5D Mark II Instruction Manual - Page 18

DS50 and DS125 Substrobe Compatibility - Older DS50 Substrobes with Serial Number below 63,850 can NOT be updated to operate correctly with the latest TTL conversion circuitry. Older DS50 Substrobes with Serial Number between 63,850 and 69,999 require upgrade of electronics to operate. Cost of update depends on strobe circuitry. Strobe must be returned to Ikelite for evaluation to provide an estimate of upgrade cost. - Older DS125 Substrobes with Serial Number below 2,500 can NOT be updated to operate correctly with the latest TTL conversion circuitry. Older DS125 SubStrobes with Serial Number between 2,500 and 4,999 require upgrade of electronics to operate. Cost of update depends on strobe circuitry. Strobe must be returned to Ikelite for evaluation to provide an estimate of upgrade cost. Red LEDs (Compensation) Manual Mode - Yellow LED TTL Mode - Yellow LED Mode & Compensation Buttons Using Non-Ikelite or Ikelite Non-DS Substrobes (Substrobe 50, 100A, 200, 400) with this Housing The Conversion Circuitry is automatically disabled when used with a Non-Ikelite or Non-DS Substrobe. These Substrobes can be used in their manual mode utilizing any power settings provided on the Substrobe. 18