Flash bug

This is, as far as I can tell, a bug that affects all Pentax dSLRs. (I've informed Pentax, but no firmware updates have appeared, and no comments from them... so this is a "heads up")

When the ambient lighting requires a shutter speed higher than 1/180s and the flash is turned on the camera will be limited to 1/180s, no warning is given, and the shot will be overexposed.
(Does not occur when using the "HS" flash mode of the AF360/540)

The Pentax metering system will normally flash at you to indicate that the shot will be under or over exposed. Unfortunately when the flash is powered (pop-up or external) this warning doesn't happen!

To demonstrate:
* Turn off the flash
* Choose Av mode on the camera
* Pick a wide open aperture (e.g. f/1.4 is a good one)
* Choose a high ISO rating (like ISO1600)
* Make sure that the shutter speed is higher than 1/180s (e.g. 1/500) - you may need to use daylight or a constant light source.
* Now turn on the flash
* The shutter speed will be fixed at 1/180s with no warning
The shot will be overexposed!

Obviously the shutter speed cannot increase above 1/180s, but a warning in the viewfinder would have been extremely helpful!!!

Workaround: use the "HS" mode of the AF360/540 when in bright conditions.
Workaround: check that the ambient light with selected aperture & ISO does not go above 1/180 by temporarily turning off the flash (either power off the AF360/540 or push down the pop-up)

I've been caught out a couple of times...

Matt

Thanks for that Matt, I have been looking at the strobist website and getting ready to step up the use of my battery strobes.
This is a real pain if your shooting around that point where the HS sync turns on and of.
Hopefully Pentax will be working on a fix ASAP, do you think another email will help?

Peter - there is no problem when the flash is on HS. The flash will automatically switch between HS and non with no problems at all.
The problem occurs when you don't have HS selected on the flash
Hope that clarifies it!
Matt