Interesting thread, and it seems performance varies.
Personally, I have had no problem with my K-5 battery, 1200 shots can be easily accomplished. Which for me is a relief, as I only have 1 battery for the K-5.....

As for third party batteries, best to go for an established brand (Hahnel for example) so you do get a reliable performing one. In fact the Hahnel is the best performing one I have got for the K10D/K20D, although the official ones are still good.

Above all else, follow the instructions to make sure you get the best out of a battery.
This means, don't charge when there is still life in it. Go to the menus on the camera and discharge it first before recharging. Older batteries will lessen their charge over time (should be years though). If it is not holding charge, replace it.
If you have not used a battery for a long while, discharge it, and then charge it again, even if you are not likely to use it for a while. Again this will keep it in the best condition.
Pentax chargers are okay if you forget that you have put a battery on charge, they have an auto switch off mode which won't damage the battery (unlike the Jessops charger for AA and AAA batteries, which keeps going - best to use the uniross charger for these batteries, as it also has an auto shutdown)

It's amazing how many Laptop batteries that have had to be replaced at work due to not following discharge-recharge instructions.
Having said that, camera batteries should be better for this, as cameras are not used as much.

Hope this helps.

Lucky, Lucky, Lucky!
I have read a lot that the 100/120 M lenses are spot on tele portrait primes, with great sharpness. And for a mere 20 quid! I am SO jealous!

Enjoy your lens, you have found a bargain!

I have always been an advocate of 3rd party lenses supporting a brand, means a healthy brand. It may have not come across like that in the past - why would a camera make be interested in what a 3rd party make does?

Well it comes down to this, If a brand (like Pentax) is successful, then the Tamrons and Sigmas of this world will want to have a piece for the lens market, and hence will increase the range of lenses for that mount, with the hope of getting some of the market share.
The reverse is also true. If a mount is not worthy of a lens, due to it being too small a brand, or heaven forbid, a declining brand, then they won't engineer a lens accordingly.
Yes, directly Ricoh/Pentax might not be interested in what Tamron/Sigma do, but indirectly they are. It's a vicious business circle.
What Ricoh/Pentax had to do is show that they are in for the long term, and a viable alternative to the CaNikonY's of this world, by showing the third parties that they are to stay with an increasing number of premium fast lenses, especially at the long end. Then, we can get some of the superior third party lenses on the Pentax mount, and hence make the mount more accessable to all.

I'm sorry if this is a rant, but its the way that I see it. Plus I would love to get hold of the Siggy 180 macro, the Tamron 60 macro, the Siggy 120-300 and 300-800.....

Very true John, but I intended to create this as the ultimate collection.
There would be no-way I would carry it all at once.....

But like you say, specialist lenses for certain things. Such as Studio work (the portrait stuff), Nature (the nature stuff), Travel/city (the Limiteds), Events (the events stuff) and general out and about (probably a wide zoom, standard zoom, couple of fast primes and a macro)
But, still we can but dream, and that collection would certainly cover all my photography demands.

We may have had this before, but hey, it is getting near Christmas and there are some lenses that we would like in our stocking.
So, lets go one further and put down what the ultimate collection of Pentax lenses that you would like to own. Anyone who says "all of them" is not taking this seriously. I would like to know, which and why.

So I will start

DA 10-17mm Fisheye. - It's a fisheye and can be used creatively.
DA 12-24mm F4 - It would be my replacement for my Siggy 10-20mm. I'm a sucker for superwides and the Big skies it can create for Landscapes
DA 15mm F4 Limited - Great on travel being small, and perfect for cityscapes
DA* 16-50mm F2.8 - Best "standard zoom" weather sealed, fast etc.
DA 21mm F3.2 Limited - Second tiny prime - again perfect for city/travel use. Nice and wide.
K 28 F3.5 Shift - the only shift lens that Pentax made - Will be good for Architecture(not perfect, needs tilt too, but you can't have everything)
FA* 28-70mm F2.8 - the best "bridge zoom" that when it comes to either the 16-50 being too short at the longest end, or the 50-135 being too long at the shortest end - a replacement for my siggy 24-70mm F2.8.
FA 31mm F1.8 Limited - what can I say? closest you can get what the eye see's on a cropped sensor and fast, sharp and a legend!
FA 43mm F1.9 Limited - Considered better than the FA50 F1.4 when it comes to sharpness, not as fast though, and odd focal length when it comes to APS-C, but a must have - would be great for travel.
FA 50mm F1.4 - I love this lens, not contrasty and soft wide open, but F1.4 is addictive. Anyway PS is there to boost the shortcomings wide open.
DA* 55mm F1.4 - Slightly longer focal length than the nifty, which is more flattering in portraits. Weather sealed too, so great for outdoors.
FA 77mm F1.8 Limited - Possibly the perfect Portrait lens. Small, beautifully made, and in the real world my first Limited purchase. Being so small, would make a great short tele lens for travel.
FA* 85mm F1.4 - Why have this lens when I already have the 77? well, its that extra half stop, and another Portrait lens to excel itself. Enough said.
DA* 50-135mm - Stonking tele zoom that is perfect for event photography and studio work. I would never get rid of mine.
DA* 60-250mm - A good tele zoom for most nature work. (A sort of Canon 100-400mm L on full frame)
DA* 300mm F4 - fastish prime for nature
FA* 250-600mm - Perfect Nature zoom
DFA 100mm Macro WR - The ultimate Macro.

So there you go, my ultimate collection of Pentax lenses, but not likely to be fulfilled easily.

Too tough to call but either one of two DA (yes that is D rather than F, K, M etc) but probably the DA* 50-135mm F2.8 - a stunner of a lens and one lens I use most of the time. But it hurts me to not have the DA 35mm F2.4 or my FA 50 F1.4 with me too............

Now If I had any of the FA limiteds, then it may be a different matter......

Great shot David. You have chosen wisely.
In all honesty it is better than the 170-500mm I have, I tried one at focus and it is faster focusing and sharper.

Big thumbs up.

Don't bother. unless you want to protect it. But make sure you take it off before shooting. I have never been a fan of UV, its just more glass for the image to go through.

I know a couple of people who have the Canon L 70-200 mug, another with the 24-105L mug, and the Nikon 70-200 mug. They are great!

I am only hoping the same company produce a DA*50-135 mug as I would buy one like a shot........

Now I know I have asked about getting a replacement for this lens, but recently the monies reserved for a replacement went to to studio flash units that I needed more.
So, now I have a little time to consider a replacement for this lens.
Why? well today I took some shots for work with the aformentioned studio units etc, and everything seemed fine on the back of the camera. However upon putting them on the computer and zooming in the people at the edges are soft to say the least. I was shooting at F11 1/125sec at ISO 200 at the time, so High ISO has nothing to with it. At the centre? no problem at all. I think that partially the DA16-45 has reached its limit of resolution on the K-5, certainly at the edges.

So, two questions.

1. Has anyone else seeing issues with the 16-45 with softness at the edges, especially on the K-5
2. What you would you consider to be better for edge to edge sharpness on a wide-short tele zoom? Obviously the usual suspects will appear. The DA* 16-50, The Tamron 17-50 and the Sigma 17-50 EX.

Advices please