Can't get a manual exposure

I'm trying to take a picture of my neighbor's yard light at night from my bedroom window. I thought manual (M on the mode dial) would let me shoot a frame even if its way underexposed. When I press the shutter I hear like half a thunk, but no image or even black frame appears in the LCD or memory card. When I try a tripod and 30 second exposure, I hear the same noise, but no image. ISOs 100-3200. 4.5.
Its like I've got something turned on that's protecting me from myself, only in this instance I want to experiment and learn, maybe post exposure manipulation. But, I need some exposure, some image even a grossly underexposed one to work from.
But, I can't get my k-7 to take a picture.
Can anybody offer a little guidance?
I had a similar experience on vacation when I tried to capture a timed exposure of a Gulf of Mexico night sky.

Bear in mind that the camera will probably take a dark frame after the actual shot, and that the camera may appear to be frozen up during that time. A dark frame is a shot with the same settings as the actual exposure but with the shutter closed. It's used as a reference to be able to subtract the noise from the "real" photo.

If there isn't enough light to focus the camera might not let the shutter fire depending on your settings. Try putting it on manual focus and make sure focus-catching is turned off.

K.

Depending on the available light, you should get something from settings similar to 800 iso, F4.5 and a 20 second exposure, use " Bulb " the " B " on the dial and just hold your finger on the trigger, as Jonathon suggests there is a reference shot taken after a long exposure aimed to eliminate noise, you can turn this feature off in the menu's if you wish.

Also switch to manual focus, the lens may not be obtaining focus confirmation and if the option is turned off in the menu's the shutter wont fire, focus on the light, re-compose and try again.

Chris

I agree on all the above, great advice there .

How much of the frame is taken up with the lamp? If it is very small, surrounded by lots of black space, then you are probably taking too long an exposure anyway, and will just end up with a blown-out white spot. Can you zoom in and fill a good bit of the frame with the lamp, and switch to spot meter mode .... This should give a good exposure for the light source (this would work fine in Av mode for example), and you shouldn't have a massively long exposure time. Once you've metered for the lamp, note the settings and then fix them in manual, then zoom back out for your whole image.

The behaviour you describe does sound normal for the K7 when shooting long exposures, like 10 secs plus. I think you are interrupting the image recording each time. Just leave it to complete the process (it can seem forever!). It's a necessary evil in order to control the noise generated from the long exposure and very little image data in such a dark picture.

I didn't think it was possible to switch off dark frame subtraction ... ? I thought the custom settings for NR related only to software image processing by the Prime II processor for JPEGs ...?

I had the same problem trying to photograph the aurora about two years ago and found that switching off slow shutter speed noise reduction solved the problem just as Jonathan-Mac suggests.

Thanks, guys, for all the good advise. Special kudus to womble for realizing some of us are so oblivious we ask the camera to auto focus in the dark, and then wonder why it doesn't work.

IRRC I think you can in the debug mode for the K-20D/K-7

before I realised this - I remember taking a 40 minute exposure with my K20D once and then having to wait frustratingly for another 40 minutes while it took the darkframe - ARRRRGGGGGGGGHHHHHHH!!!!

So you agree with me that it is not being switched off with the custom NR settings?