K-5 Over-Exposure with flash

I only received my K-5 yesterday so it may be that my problem is due to unfamiliarity.

If I use the AF-360FGZ flash unit it seems to expose correctly using PTTL if the flash is pointing towards the subject but if I bounce the flash off the ceiling or have it at 45 degrees angle with a STO-FEN type diffuser then the photo is over-exposed by around two stops.

Just to check I put the flash back onto my GX20 (K20D) and using the same settings and lens the photos were perfectly exposed in any flash position.

I am quite concerned about this and would welcome any advice.

Thanks.

Yet another K-5 "feature".

LINK

I'm surprised that people are using such high ISO values with flash. With studio flash we would be using ISO100 or ISO200 and getting apertures from f8 to f16 depending on the setup.

If the ISO is too high there is no aperture small enough to expose correctly.

It is probably more to do with the fact that the camera just sets everything for ambient light in auto. So unless you go through the process of setting everything to manual, you end up with a camera that sets shutter speed and iso for low light shooting and then fires the flash as well. I have a Olympus EPL1 that resets ISO and shutter speed to sensible flash settings as soon as you raise the flash. Flip the flash down and it ramps ISO back up for ambient light. Canon and Nikon seem to do this as well, as soon as flash is enabled they drop the ISO. It is a bit of a problem with Pentax, I knew the Kx did this, did not realise the K5 did as well, oh dear.

I'd suggest not using auto ISO. I always set a fixed value so that all images will have the same noise structure. ISO can be adjusted manually very easily if needed.

Yes, I guessed that might be the answer I got, but it would just be nice for the system to be just a little more intelligent. It is not as if we have a vast choice in bodies at the moment and I do find the auto ISO handy at times in uncontrolled environments when I am also likely to want flash occasionally and don't have the time to geek about with settings.

You don't have to geek around much, simply set the ISO on 400 and most of the time that's just perfect for lighting a dark room.
Just take one test shot and see if your flash has to work hard or not.
If it's working hard use higher ISO's to give you some room so you can make 2 to 3 photos continuously.

I have taken some examples. It seems that the effect is at wider appertures.

Flash facing forward:



Flash Pointing up at 45 degrees



Flash Facing Forward



Flash Pointing up at 45 degrees



This problem does not occur if I do exactly the same thing on my GX20 (K20D)

what were the ISO settings?

ISO 200

I'm having similar results with my K5 and the Metz 48 AF1 gun. I'm having to work in manual mode (which is fine) except that with the Kx or K10 the process of P-TTL flash was totally seamless.

I've double checked that all settings are normal with no under/over exposure of the flash from either the gun's menu or the camera set up.

I haven't checked yet if the Metz is meant to work with the K5 however I'll be interested to see if any suggestions to help Daydreamjay might also help me.

Thanks

Having done some Googling it seems that this is a inherent problem with the K5 - I can't believe that Pentax haven't sorted it yet.

I have now run the Metz firmware upgrade and its made not one scrap of difference.

Has the K5 been released before it was ready?

I have no huge issue with working manually when using or bouncing flash however I do feel the "flagship" DSLR should be able to make a better job of automation than its is doing.

My results in green or P modes are far worse than shown above -I'd say 3 to 4 stops overexposure.

With my Metz 48 the flash isn't even picking up the zoom info from the lens. It works perfectly with the Kx and K10.

Are other Forum members not having any flash problems? Does anyone know if, as mentioned elsewhere, Pentax are working on a firmware fix?

For the benefit of members who are maybe still hovering about upgrading to the K5 please speak up if yours is working as it should.

I had a problem with P-TTL at a pro shoot, over-exposure on many shots, with both on and off-camera strobes. However the temporary solution, suggested by the Pro, is an on-camera soft-box .... which is working perfectly. Hopefully just a temporary workaround - but it's a solution nevertheless.

The camera works fine with pentax flash guns and studio flash as far as my usage so far seems to indicate - one problem is that Pentax and all manufacturers do not guarantee what will happen when you use other manufacturer's kit with their cameras. It may be that Metz need to do something to the flashgun.

Manual flash should be fine in any event.

The flash systems on the K-7 and K-5 do seem much better than the K10D and K20D.