K-X Bulb problem

Morning
I've been doing a few long exposures with the k-x since the arrival of the B&W 110. Most times everything works fine. However, I occasionally get a complete freeze up of the camera. I use a proper Pentax remote which I press once at the start and once to stop. When I stop the exposure it just makes a very small clicking noise (instead of the noise the shuter normally makes when it closes). The camera at that point basically seizes up and I have to take the batteries out to reset it.

I just wondered if anyone else had any issues or ideas as to what was causing it. Its the only problem I've had this far with the camera.

When you take a long exposure (say 5 minutes for example) when the shutter closes the camera will take a second exposure of the same duration (5 minutes again) with the shutter closed - this is to allow it to work out how much of the image is sensor generated noise and is called "Dark Frame Subtraction".

During the second exposure the camera will, indeed, be unresponsive to anything you do as it's busy.

So effectively a 30 second exposure takes 1 minute, a 10 minute exposure 20 minutes, a 1 hour exposure 2 hours, etc.

Some of the Pentax DSLRs allow you to switch off Dark Frame Subtraction but I don't know if the K-x is one of them - it'll be in the Custom Menu if it does.

By the way, the reason the noise is different is because the mirror remains up between the two shots - all you hear is the shutter closing (which is quite a bit quieter than the usual mirror slap).

Nope sorry - the dark frame subtraction is not an issue. This is entirely different. It only does it perhaps once out of every ten - sometimes more and sometimes less - long exposures. The shutter does not seem to close correctly or maybe hasn't opened correctly in the first placce, hence the different sound from the normal long exposure. The camera then completely freezes up - and will not come back no matter how long you leave it. I left it half an hour on one occasion for a one minute exposure. Its not a battery issue either as it happens with brand new ones.

Hi Mark, don't know if it is remotely related but have you updated to the latest firmware?

link

Cheers Jim

I'd updated it to the previous one and thought this latest was just for bigger cards. Having read your link I've noticed the catch all phrase "improve general stability". I'll give it a go and see how I get on.