Yes, based on a number of articles I've found this appears to be so.

Ok, I fully charged the Pentax brand battery, with the Pentax charger, until the light went out.

The voltage from + to - was 8.34, and from + to T 8.33.

Immediately after 20 shots with the Bigma, also AF and OS=1, this had dropped to 8.27 and 8.26 respectively.

After 5 mins, this had risen to 8.30/8.29.

For comparison, a knock-off battery that's been in the camera for a few days, but still showing full charge, indicates 7.97/7.96.

I'm measuring the voltage using an ordinary digital multimeter which reads to +/- 0.01V, but of course there's no way of knowing how it's calibrated - I only have the one

It's not really evidence for an undercharged battery, though.

I've found several, but they seem to have just two contacts, not three.

Is that relevant? What's the third contact with the D-Li90 for anyway?

Now there's a thought. Haven't thought about that one since I returned the original K-5, which did have a different charger.

I'd be much obliged if you would, thank you.

- AF-S almost exclusively.
- Lenses most used are Pentax DA 17-70 and Sigma 50-500 OS.
- No PZ lenses
- Flash rarely

The lens OS in the Bigma would be a suspect, but I'd noticed the short battery life long before I got it.

Appreciate the ideas - keep 'em coming.

I really wish I could work out what I'm doing wrong.

I hardly ever use LiveView, video even less, I chimp a bit but not excessively, have the LCD brightness turned down, and most of the settings that control the display time for various things set to the default or less.

Yet, with a Pentax battery and a knock-off, I only get about 150 shots per charge.

I use an Eye-Fi card mostly, which presumably must use some power to ship the pictures up to the computer. But I'd noticed the shockingly short battery life long before I got it, and also with the first K-5 I had, which went back and was replaced for various reasons, also long before I'd got the Eye-Fi.

So over two K-5s, three batteries, a variety of different SD cards, the short battery life is consistent. So it's clearly something I'm doing that's different from other people.

Drives me nuts, and I have no idea what it could be.

Yes, I'd agree.

With the Bigma, I'm forming the distinct impression that the OS in the lens is quite a bit more effective than the SR in the body.

Thanks for that, I hadn't noticed that one.

Yes, I know about all of those, thanks.

The 18-55 isn't really long enough, and as you may remember, I was far from impressed with the edge qualities of the 18-135.

That's why I was hoping to get an idea of what the Sigmas were like. If the Pentax 18-250 was still available, I'd be recommending that for sure.

I have a friend who's considering migrating from Canon land to the K-5, and the question arises as to what lenses to get with it.

She'd probably get one general purpose zoom, and a few second hand primes initially.

Specifically, what are the Sigma 18-125 and 18-250 like in terms of sharpness and handling?

Ideally, if you could compare them with the Pentax 18-135 and Pentax 18-250, it would be very helpful indeed, since I have some experience with these.

This is for Business sellers.