My camera's usually on a tripod for serious work, so I generally selct the appropriate focus point - centre point and recompose just doesn't work on a tripod.

When handholding it's a bit of both. Manual focus mainly for macro work.

Dan

Results are in!

Dan

The problem with interchangeable sensors, is that, assuming the new sensor is of a higher resolution, the camera then can't process the extra information (per photo) as quickly as it did before, so frame rates would either drop, or the buffer would fill up much more quickly, or both.

We can see that with the new 645D, which is essentially a K-7 with a comparatively massive sensor. The frame rate has dropped from 5fps to 1.1fps, 645D raw files apparently being up to 50Mb in size.

The original Kodak DSLRs had interchangeable (upgradeable) sensors, not sure how well they did. The problem is that new cameras generally come with other improvements, not just changes to the sensor.

Dan

My bag contains a DA16-45, a FA50mm 1.4, a Sigma 105mm macro and the DA*300mm, plus a (rarely used) Tamron 1.4x teleconverter. Wide angle to telephoto, with plenty of 'gaps' in the range, but it suits my work. And it's not too heavy.

Dan

My FA50mm 1.4 rattles slightly too. Also produces lovely images. Never worried about it myself.

Dan

The usual place to discuss this week's weekly competition. I'll look in until we have our first entry, after that, PM any questions you may have to me.

Dan

I find it quite unusual that he's yet to contribute to this thread...

Dan

Dave, do you use a grip with your K20D?

If so, you may be inadvertently touching the shutter button on the grip with the palm of your hand when you're holding the camera to look at the screen. It might only happen with the Sigma because it's a heavier lens that needs more support, and you're holding the camera slightly differently. Just a thought. See this thread for something (a bit) similar, and this one for something more similar.

Cayman, as you use a grip too, does this sound familiar? I know you've only experienced it with one lens, but could it be coincidence? Do you always get the malfunction, or has it happened once or twice with this lens only?

Dan

Title corrected for you.

Dan

If you're still using the K10D you haven't got live view anyway. The digital preview, in my opinion, is pointless - you might as well take a photo instead.

Dan