645N / Pentax 67
Daylight Balanced Fill-Flash
It never ceases to amaze me when companies sell professional-oriented products and then fail to provide their customers with the basic information needed for them to be utilized properly. An example of this is when trying to do daylight balanced fill-flash with either a Pentax 67II or Pentax 645NII camera.
I use Pentax's top-of-the-line flash unit, the AF500FTZ. (The information below may apply not only to this unit but to a great many other Pentax and other brand flash units, such as Metz, that work with the camera's TTL metering capability).
This flash is capable of performing daylight fill-flash. But, unlike units from Canon and Nikon, for example, this flash does not have any means on the flash head to set a fill ratio.
As anyone doing fill-flash knows, it's important to set the flash to about -1.5 stops as compared to the ambient light level. Otherwise the flash effect is too strong and the subject looses modeling.
Not including the ability to do balanced fill-flash in their top-of-the-line flash is a serious oversight on Pentax's part. Particularly so since I'll bet dollars to doughnuts that the flash unit itself is actually made by either Canon or one of its OEMs.
Making It Work
Now, with that off my chest, here's how to do balanced daylight fill-flash with this and similar units.
Set the camera to Manual mode and set the shutter speed and aperture by either using the built-in meter or a separate hand-held. Make sure that the shutter speed is a 1/60th sec or slower on the 645 camera or 1/30sec or slower on the 67 camera.
Turn on the flash unit and now set the Exposure Compensation dial on the camera to -1.5, or whatever compensation you prefer. That's all there is to it. The flash unit will read this compensation and will cut back on the flash. The camera is in manual mode and therefore isn't effected by the compensation setting.
OK Pentax. How about putting this in your instruction manuals?