Trick to gain more UV exposure with Canon 199A flashes

[dabateman]

The old Canon 199A flashes actually have 4 different power settings. The right most switch changes from Automatic to full power slave manual. But I doubt many of us have Canon FD cameras.

The A setting has 3 sub settings, and the dial hints that they are 2 stops apart. Red is first click, with lowest light emmission, followed by green and then yellow. My full slave manual M mode looks white to me on my flashes.

The flash manual says that when using Alkaline batteries the recycling time is 10 seconds, and when using NiCd batteries it should be 6 seconds.

 

I have seen mixed recycling times depending on the flash unit (I now have 3 fully working flashes and 2 others). I can get either 6 seconds or about 10 seconds using Alkaline batteries in full M (white mode). Using Energizer Lithium ion batteries I get 6 seconds for all my flash units in M mode.

 

But that is in Full manual mode. If instead you switch to an Automatic mode, the recycling time is much faster. The red setting is instant on my flashes, but also has the lowest UV power when I tested with 370bp15 filter. The yellow setting almost outputs as much UV as the full M mode. Not as good but close. However, the recycling time is only 2 seconds on all three of my flashes using this setting.

So if you are using multiple flash bursts, you actually get more UV output when the recycling time is 2 seconds than 6 seconds and the base UV is similar.