Greetings,
As a former K20D and now K3II user I have learned the ins and outs of shooting manual and am quite good but by no means a master/pro etc. As a new father I find many great opportunities to use my camera, and most of the time it is in manual.
Indoors to supplement the lack of decent lighting I'll bounce a flash off a wall attached to the hot shoe, again most of the time using manual program line on the K3II. Today I used the program mode and something confused me I wanted to ask this great group about...
One shot - 1/80 F2.8 ISO 800
Other shot - 1/100 F6.3 ISO 800
Both shot in program line mode with the flash on P-TTL Digital, auto zoom. Flash is a Pentax AF-540FGZ from around 8 years ago or so.
So my question is: does the flash perform its own calculations and fire at the power it is required based on the lighting and camera settings for each shot (when in a more auto mode like Program Line)? Because with a faster shutter and smaller aperture on the second shot the exposure is super close (slightly different scene).
ie: First shot, sensor/camera saw more light from the slower shutter and faster aperture so the flash didn't shoot as bright, but on the second it saw a faster shutter, more narrow aperture and (the flash) increased its output on its own?
I think I was expecting the camera to adjust the aperture if I moved the shutter speed, and the shutter speed if I adjusted the aperture. However it wasn't the case I adjusted both and the ISO remained static.
Thanks in advance all. Appreciate any thoughts or guidance.
Shane