The k5 is still staggeringly capable in low light. One of the things it retains (in my recent tests) is colour saturation. The images soften at 6400, but are still very pleasant. I find that the lack of AA filter is a bonus with noise because you don't have to sharpen as much, so the noise isn't enhanced further. And the focusing in low light from the K5ii era onwards is just brilliant.
I believe that if Pentax go for 'full frame' they will be all over the noise issue and it could be a terrific piece of kit. Personally (as some of you will appreciate) I hope they don't bring one out now!
David, that image is stunning.
John, W90!! blimey, very nice.
Matt, you have a touch with noise that seems to elude most of us, so your image is like a spike in the graph and doesn't count!

Thank you folks
It's definitely making me slow down and prepare. That's got to be a good thing.
It does seem to render creamier images with longer transitions to highlights.
My trip down the valley involved two lenses, a tripod, my Metz and a light stand with reflector boom. That was a bit much but I didn't know what would be best.
In the end the tripod came out as the most useful addition. Flash was typically useful for insect chasing.
It's very much like all my Pentaxes in that it is very nice in the hand and easy to find everything. I still haven't looked at the manual

Thanks Andy
Here's a woodland image crunched down for the web. Click it tho', it's still quite big
Had a fleeting chance to grab something as the sun came out.
55mm 2.8
F9, 1/100th, 100iso
Image was heavily under-exposed and details pulled out in post. The raw file was more than happy to be treated this way.

Here's a link to a full res image of a cranefly, taken whilst on my knees in a marsh.
It's 20MB and may be resized by you browser, so click on it when it's finished coming down
Pentax FA 645 120mm f/4.0 MACRO
Hand-held
F11
1/100th
200iso
Flash into a reflector
Local USM: 30,1,0

I'm going to need some bellows... and a trailer.

Thanks guys.
Still keep waking up in cold sweat wondering if I an get the most out of this and realise it's potential.
So far the talk about it being a hand-holding camera, is a bit far-fetched. Sure, if you reduce the images to normal size they look fine, but that's a little pointless. I'm going to need a more versatile tripod cos it's going to spend a lot of time on it.
Here's an example processed for the web, sorry, gotta go out now, but I'll get more relevant examples up when I can. But this just looked bang-on right out of the camera. Quite harsh sunlight, controlled very well.
click the image


Just for practice for when I use it in churches, I tried it at a dance event, where 6400 iso was the norm. The images were fine, but it didn't really have any real advantage over the more versatile K5iis which is just awesome in that environment.
Size isn't an issue really. It's very comfortable and easy to hand-hold, but to get the blistering quality it's capable of, you really need to keep it still and put that big ol' mirror up, which is not practical.

I think the newer lenses are fractionally better. I have the old 120 macro already and that will cover a lot of ground on its own, but I stumped-up for the 55 'kit' lens as it is as highly regarded as the 120, but weatherproof etc. The 45mm may get used for group shots or something, but it's not really my length!
To be honest the Nikon glass was very tempting, but I couldn't face all that again and for only a slight change in sensor quality over the K5iis really. By all accounts the 645z is exceptional. We'll see

So am I !
I'm aware that the differences will only really show up in big prints and massive screens and that kit doesn't suddenly turn us into better photographers, but I think it's as much a change of working practice for me. I will consider everything just that much more, and the low-light stuff...

After a year and a half with the 645N, I have decided to stick with the lenses I have and get the 645z gulp:
My best payers are corporate and I'm frequently asked to design roll-up banners, so it's not too irrational, but I'm definitely going to have to step-up my business game and stop treating it as a bloody hobby all the time
I'll keep the K5 kit for all the normal stuff. It's still almost unbeatable everyday kit. But I've now got a spare if anyone wants one?
I looked carefully at the Nikon 810 and 3 or 4 lenses and a flash, but it was creeping up to MF price territory and it just didn't excite me one bit. The Pentax is familiar and I love the feel of the 'N'.
I am actually fairly certain it will be a game-changer for me personally. I plan lots of tiny macro work blown up to giant pieces of wall art and it's going to MAKE me get off my arse and spend more time on Dartmoor or down on the Lizard in my man-cave instead of waiting till 'tomorrow'.
So wish me luck and I promise to post plenty of examples

This is top value for such a cracking and versatile lens.

Anybody tried this combination?
The lens is so sharp, I can't help thinking it could cope with the heavy cropping involved?
I'm soooo tempted to go digital with my medium format, but this would be fun in the mean-time