Not fast, true, but more than adequate to shoot weddings with.

The SMC Pentax-DA 16-45mm f4 is superb and not too expensive.

All the time probably. Personally, I just go with the flow...

As this is getting very confusing, can we continue all three topics in this one please. I'm trying to merge them but it ain't working so far, so I'll lock the other two...

The Mk II is marked as such and is supplied with the new K20D. It will make a difference with the 14.6 MP sensor and also with large prints.

With your K10D the original 18-55mm is a very good lens anyway.

I would urge everyone to read the Wikipedia article, which explains the whole thing rather well, plus gives the appropriate references.

But the fluorescent tube is never at 0 volts. It's in a plasma state that constantly emits electrons. The phosphors don't switch in and out, they glow constantly.

Therefore, the colour temperature, which is what we are talking about, will be constant.

I've just been looking at http://en.wikipedia.org/wiki/Fluorescent_tube

Modern tubes with electronic ballast are flicker-free, but notwithstanding that, the article reminds us of the way these tubes work.

The charged gas is in plasma state and releases photons in the UV part of the spectrum. These photons hit and excite the phosphors than line the glass tube. The phosphors fluoresce with visible light, just like a CRT monitor. The colour of the light depends upon the phosphors used, not the nature of the AC power.

There is no mention in the article of changing colour balance and I really don't see how there would be.

Hope that helps!

It's not something that I would shoot on AWB, although sometimes mixed lighting sources are handled very well by AWB.

I'm still not convinced - I have never ever seen anything else on this subject anywhere, so I really would like to know where the information is sourced from and what experimental evidence there is for this effect.

Any ideas where to look?