I do landscapes and cityscapes in ambient low light (OK darkness). I have a K5 and like it a lot. It works well for my style. I have been following the rollout of the K3, along with the various reviews, with the obvious question of the K3 or K5IIs.
Over the last 7 years I have upgraded at every other model, passing over the K10 and K7. Also, I have only upgraded when there were significant capabilities that would provide specific benefits. So the K3 or K5IIs. In some respects I am thinking of neither - especially for the foreseeable future. My reasoning is as follows:
- ISO - I really prefer the lower ISO, and the K5/K5II/K5IIs has ISO 80. In shooting at night, and needing to go to higher ISO, I can go to 3200 and stack with multiple shots to capture moonlight or starlight, the random noise is averaged out, thus having the result of shooting at a much lower value. Even at higher ISOs, the K5 base is quieter than the K3 from what I have read. I am going to stop down anyway using a tripod.
- Resolution - It would certainly be nice, but so far I am very satisfied with the K5. A lot of the reviews call the K3 a landscaper's camera due to the resolution, and challenges Canon and Nikon - essentially being on nearly an equal footing with full frame. I pulled that from the review I watched yesterday. I went from the K100 to the K20 or 6MP to 14MP (133% increase). Then a couple of years later upgraded to the K5 which did not substantially increase the resolution but significantly reduced the noise. The K5 to K3 or 16MP to 24MP would be a 50% increase, with possibly a very slight increase in noise. After going from the K100 to the K20, I compared the shots on a very large screen TV and was amazed at how good the K100 was, when compared to the K20. I printed a 20" x 30" K5 image and was VERY satisfied with the result. I don't think I would print a 30" x 40" with the K5, although I have read that the K3 should support that size. So how large are you going to print?
- Dynamic Range - I think for landscapes, dynamic range is possibly slightly more important than resolution. Going back to the K100 to the K20, I am still amazed with the K100. I think that it has a lot to do with the CCD to CMOS comparison, but larger pixels does help here in gathering and recording the light. I think that stopping down, with good glass, taking advantage of hyper-focal distance all contribute. So rolling all of this together, I would still go with the K5IIs.
- AF - I usually shoot manual and have a lot of old manual lenses. When I do use an AF lens, its pretty nice to just let the camera do the work, I must admit. The better low light focusing in either the K5IIs or K3. The better white balancing would really help the K3. I saw a large difference in an early review.
- AA - I have read very few (as in no) complaints about the K5IIs and moire. The 8% increase in resolution over the K5/K5IIs was called good but not compelling in a number of reviews. Users seem to put a lot more stock in seeing better resolution in the K5IIs and in use they find it worth the upgrade. Right now, if I absolutely needed to get another body - it would probably be the K5IIs.
- Additional features - the K3 has a lot of additional features, focus tracking, higher frames per second, etc. that really do not matter that much for landscaping as in other types of photography.
Am I being just stupid and missing the boat. I don't know. Right now I am not feeling very compelled to do anything other than go out and take some more images. Perhaps, its just my lack of skill, technique or inability to see a great potential shot/image where others see tremendous opportunity.
So for me, I am going to continue with the K5. I have had it for 2 years now, and I can easily see using it for another 2. If I lost or damaged it, I would go to the K5IIs in a heartbeat. I do think that Pentax has hit a home run with the K5 family (K-01/K30/K50/K500/K5/K5II/K5IIs). I think the K3 is very worthwhile and appears to be an excellent body. I just do not feel the need - or perhaps I am just too cheap. For me its a hobby. If it were my bread and butter, putting a roof over my family's head, finding that extra bit of margin to make my images sell better - I might feel different - but then we would probably be talking a 654D.