I went on a big excursion recently where I used off-camera flash and full manual setting control. The nice thing about Pentax cameras is that you can have a few conveniences in manual that make setting changes faster and more accurate.
Here is a video describing the technique I was planning on using:
For example, changing the green button functionality from “P Line” to “Av Shift” allows you to get a quick exposure reading that changes the aperture, but not the shutter speed. This is important when you are limited to the flash sync speed of your camera, because you don’t want the green button to select a shutter speed that will be too fast for the flash to function with.
“P Line” (aka. Program Line) bases your sampled exposure on a number of simple options. There is one for maximum sharpness (MTF), one for maximum background blur, one for action, one for landscape, and so on.
The flash sync speed is the fastest shutter speed that still allows for your camera’s sensor to be completely visible without the shutter covering a portion of it. This is necessary because a flash normally needs to illuminate the entire sensor at once. In my case, the flash sync speed is 1/180th of a second. 1/180th outdoors can be an issue depending on your aperture, so using the standard green button functionality would often result in the camera selecting a shutter speed too fast for my wireless flash setup to handle.
High speed sync is an option, but in my case I can’t do that wirelessly with the Cactus V5 triggers that I have. I often use HSS when I have my Sigma 530DG Super flash directly connected to the camera.
Another technique you can use when in manual mode is related to the AE-L button. Once you select a proper exposure, you can press the AE-L button to lock the exposure in and link the shutter speed and aperture values together. This allows you to adjust either the aperture or shutter speed and have the camera change the other setting automatically to keep the same exposure.
I went on the excursion was it was successful. I ended not using the automated helper methods much because I seemed to feel pretty confident with controlling the shutter speed, aperture, and ISO by hand. The situation wasn’t fast paced enough to really require it, but I do plan on using that technique more in the future.