"Contrast control" setting on AF360FGZ and wireless flash setup

I am reading Nigel's flash guide and the world of flash is beginning to get less opaque. But I am confused by the Pentax flashguns (AF 360/540) "contrast control" setting, and the "flash output adjustment (ratio) setting.

My understanding from Nigel's guide: If I mount one AF360/540 on camera as Master and use another 360/540 as slave, I can use the "flash output adjustment" (ratio) setting to have one flash produce 1/3 of the total calculated exposure and the other produce 2/3.

The manuals for The K1 and the AF360 refer to the "contrast control" sync setting on the flashgun saying that if two flashguns are used , you can set one of them to "contrast control" sync, and the output will be a ratio of 1:2 with the gun with the setting on producing twice as much power as the other.

These two scenarios both produce the same result, or am I missing something? If I use the "flash output adjustment" setting do I need to set the "contrast control" sync switch on one flashgun? And if not, what exactly is it's function?

Hi Peter, good questions ! Firstly, do you have the 2nd edition of the Guide? If not there's a link for it in my signature below here. This has an expanded and improved wireless section with more info on the ratios.

Pentax have made things rather confusing in their manuals, I think it's fair to say. Contrast Control Sync mode is for extension cord working. For wireless working then ignore that mode. For clarity I have coined a new term, 'wireless lighting ratios' for the setting that appears on the flashes to set ratios (1/3, 2/3 etc).

The automatic 1:2 ratio described in the manual relates to using the built-in flash, so the built-in flash will contribute half of the light that the slave flash/s do. With accessory flashes then the ratios are set directly on the flash controls, and yes, the Master (on camera) one will follow it's set ratio. Flash compensations' set on the flash also will have an additional impact if the contrast needs to be increased further beyond what the ratios are providing.

There's always some trial and error, and indeed many photographers' using two or more flashes to create a lighting balance may be inclined to switch to manual mode for even finer control.

Hi Nigel, thanks for the response. Yes I am reading the 2nd edition.

Thanks for clarifying that. Despite being a photographer for many years I have never really got to grips with sophisticated flash use. This is going to be my mission this year! I am now using a K1 which has no built-in flash and a AF360 so I will need to get another 360/540.

I do have an older AF330 also , but I understand this is not P-TTL capable.

Stand by for more questions.

That's a great mission, I'm sure you've got a very interesting time ahead!

I would definitely recommend another AF-360/540FGZ (either the 1st or 2nd versions), as this will unlock lots of potential. I often use wireless ratios with one flash on-camera in 'master' mode set to 1/3rd, and the slave set to 2/3rds. With the slave on an umbrella providing the main light from the side and the master flash providing fill (usually bounced from a corner opposite to the umbrella) this set-up gives quick and accurate flash exposures even if the subject moves a bit.

The global flash exposure (the total amount of lighting) can be controlled with your camera flash compensation control, still available on your K1.