Flash synch speed

This might be a silly question but I'm sure my K-r used to go to the sync shutter speed of 1/180th when I used the onboard flash or my 360-FGZ on the hotshoe. Now, in AV mode the shutter speed seems to vary but the results are exposed correctly. Is this right?

Yes, it is right. The camera will try to expose for ambient light (while still keeping a shutter speed that's hand holdable)and will use the flash to properly illuminate the foreground.

There's also a choice of how the camera does the metering

In the flash menu (on the body) you can choose between normal & slow sync flash. The normal one will tend to underexpose the ambient and aim for higher shutter speeds, while slow sync will aim to get the ambient - with a much slower shutter speed.

Additionally, if you switch the AF360-FGZ to "HS" mode you can flash sync at any shutter speed (But be aware the flash distance is halved)

HTH!
Matt

Thanks guys, very helpful. I've not been a big flash user and had forgotten some of it and was a bit lazy. Having checked the manual as well (rtfm:wink I think it will go to 1/180th with manual and non DA lenses.

From my observations:

In Av mode, the camera sets a shutter speed (in my experience) for flash that is partially based on the focal length used. In a dark scene, the K100D in combination with DA55-300 uses roughly 1/FL (1/60 @ 55mm, 1/125 @ 100mm, 1/180s @ 150mm). In a brighter scene the same combo uses 1/180s regardless of focal length, possibly attempting 'fill-in flash'.

K5 with FA31Ltd or DFA100WR is more conservative and uses 1 / (2 * FL) in a dark scene; not tested in a bright scene.

I have the K7, but I think the principles apply here also - its true that in Av with flash (even with 'slow sync' active) the camera still makes some 'intelligent' choices when setting shutter speed. This is related to controlling camera shake, so this will be factored in as well as the lighting levels.

This works automatically for DA lenses. Bear in mind also that in most flash situations the shutter speed will not affect the flash exposure; this is controlled by aperture and/or iso settings. So in fact, if you're looking to get firm control over the balance between a flash lit subject and the ambiant lighing of the background, then really 'M' mode is the best choice.

In full manual you take control of the ambiant lighting precisely - you will see an ev scale of plus & minus stops displayed (how many stops depends on the camera), and a pointer indicating the set ev level. So you could use Av quickly to take a meter reading and get you ballpark starting settings, then switch to manual. You could then (for example) set a shorter shutter speed (by a stop or 2) to lower the background a bit thereby allowing your flash-lit subject to stand out. And you can control the flash level from the flash settings page by turning the rear dial to set (eg) -o.5 or -1.0 flash exposure.

And finally... when using manual as I have described, you don't have to bother setting the flash mode to slow sync - so that cuts down on that step!