Help with Bulb function on canon 400D?

Question

im really new at this =)

my friend was teaching me something called light painting, which i needed to do in a dark room. So i had my camera set to M, Shutter -Bulb, F stop - 4.5, ISO1600. Yet the camera still would not take the photo, instead it kept adjusting the focus. The bulb function works in normal light, but i need it to work in the dark.

Ive read the manual back to front and it didnt help very much.

Any suggestions?

Answer 1

If your camera is struggling to focus, then why not take the auto focus off and then take the picture it should take it right away. Low light conditions can effect the auto focus feature.

Answer 2

The shutter should stay open while ever the shutter (or remote) is pressed, no matter what the light level is when in 'B' Mode.

Turn the ISO down you'll just get noise with that high a setting.

Turn Auto Focus off, it will just hunt looking for an edge to focus on before it allows the shutter to open.

Chris

Answer 3

Turn off AF and IS if your lens has it.  Use a tripod, use custom function 7 to lock up the mirror and use canons cable release with a lock.

If you are concerned about focus then use a torch to illuminate the subject, (if it is very dark shine the torch through the viewfinder and turn the lens until the edges of the projected light are in focus on your subject)

By using a smaller aperture like f8 to f16 you will get a greater depth of field so focus needn't be as critical.   If you try and use towards the wide angle of the lens as well everything will appear sharper. (if need be zoom wide and move the camera closer to get the composition you want)

To me, 1600 is a bit high, the camera is going to introduce a lot of noise at this setting, even more so when combined with a long exposure.  I would do some test exposures at f8 and keep the ISO as low as you can.

If you shoot in RAW mode you have more scope to play with the exposure at the editing stage, I find RAW can pull back even 2 stops of underexposure at lower ISOs.

Answer 4

Your problem is that the autofocus can not find anything to focus on in the dark. Set your lens to manual focus. Turn the lights on. Focus  on where your subject will be. Then turn the lights off and take your shot.