[aurele]

SO what is it? Is the Kx better than the K10D and 20D strictly in terms of image quality?

Yes, the k-x is better. especially in Iso perf.

for jpeg, is suggest you to increase a bit the NR done by the K-x (if i remember well : menu/C2/14/strong.)

[audiobomber]

Yes, the k-x is better. especially in Iso perf.

for jpeg, is suggest you to increase a bit the NR done by the K-x (if i remember well : menu/C2/14/strong.)

The factory default for the K-x is Medium starting at ISO 800, This produces a plasticky look that I detest, Strong would be even uglier. I use the lowest setting for noise reduction, starting at ISO 1600. If I need more NR, I use Noiseware, which doesn't produce an overly smooth texture. I often wonder if the amazingly better ISO performance that people attribute to the K-x is mostly due to the excessive processing done by the camera. The factory default for the K20D is NR off. I tested my K-x and K20D with NR off. The K-x has more noise at ISO 3200 than the K20D has at ISO 1600, so I make the actual difference 2/3 of a stop.

As far as which has better IQ, it depends on what you mean by IQ and it depends on personal preference. The K-x wins at very high ISO. The K20D has better white balance in daylight, the K-x has better white balance in tungsten light. The K-x has wider dynamic range, which can be important if you push your files a lot in post-processing (I rarely do). The K20 has slightly more resolution. I prefer the look of K20D images because it produces deeper looking colours. When I try to bump up the saturation in the K-x, red and yellow start to bloom. The K20D exposes more accurately, which factors into IQ. For some, the increased dynamic range and higher sensitivity mean the K-x wins for IQ. I have different priorities and preferences, and I prefer the look of K20D files at any ISO below 3200. Coupled with the radically improved controls of the K20D, I use the K20D as my main camera.

The K10 has excellent IQ at base ISO, some say the best of these three, but falls behind in low light. I avoided the K10 because of so many reports of back and front focus. The K20D has AF adjust for each individual lens.

[Deniz]

So here I am going to the final-point. K20D or 40D. I've heard that K20D is so smart about one of the photographical genres that I'm interested in, which is shooting action in concerts. Also compering the ISO performance of K20D, 40D and the K-x, how are they different from eachother?

[metalmania]

So here I am going to the final-point. K20D or 40D. I've heard that K20D is so smart about one of the photographical genres that I'm interested in, which is shooting action in concerts. Also compering the ISO performance of K20D, 40D and the K-x, how are they different from eachother?

Coincidence? I have K20D, K-X and Canon 40D right now. I cannot discard any of them.

[RioRico]

So here I am going to the final-point. K20D or 40D. I've heard that K20D is so smart about one of the photographical genres that I'm interested in, which is shooting action in concerts. Also compering the ISO performance of K20D, 40D and the K-x, how are they different from eachother?

I can't comment on the 40D, except that it lacks in-body stabilization. Nikon depends on more costly in-lens stabilization. A Pentax (or Sony) camera can stabilize ANY lens that is mounted on it. When you consider a Nikon (or Canon) system, calculate how much you must pay for stabilized lenses.

My K20D is NOT what I would use for "shooting action in concerts" although it can do so. (I don't have real fast long lenses; my best primes are 135/2.5 and 200/3.5.) The Kx has MUCH better high-ISO performance, and the Kr is even better yet, from all I have read. Its performance, plus the in-body stabilization (SR, shake reduction) make the Kx and Kr ideal concert cameras.

[Deniz]

Coincidence? I have K20D, K-X and Canon 40D right now. I cannot discard any of them.

But you may help me about the issue The K-x is on-leave for me. Yet, compering it to the other two what can you say about the IQ and ISO performance? As fark as I've seen Canon 40D, and any other Canon basically, has that -somewhat- qualified 'Canon smoothness' while even RAW files that come out of a Pentax is fairly and kinda too sharp. Besides that, could you compare these two cameras, let's say shoot the same thing with the same settings with similar lenses (kitlenses may get handy if you have both). Some say the ISO performance of the 40D is just like the K-x and some say it's just like the K20D, could you enlight me about this? Thank you

I can't comment on the 40D, except that it lacks in-body stabilization. Nikon depends on more costly in-lens stabilization. A Pentax (or Sony) camera can stabilize ANY lens that is mounted on it. When you consider a Nikon (or Canon) system, calculate how much you must pay for stabilized lenses.

My K20D is NOT what I would use for "shooting action in concerts" although it can do so. (I don't have real fast long lenses; my best primes are 135/2.5 and 200/3.5.) The Kx has MUCH better high-ISO performance, and the Kr is even better yet, from all I have read. Its performance, plus the in-body stabilization (SR, shake reduction) make the Kx and Kr ideal concert cameras.

I haven't seen any significant advantage of SR in K-x, except for the tele-zoom shots around 250-300mm. And about the K-x's being an 'ideal concert camera', well: https://www.pentaxforums.com/forums/pentax-dslr-discussion/82293-kx-use-15.html#post1627773 I really can't so..

[audiobomber]

The Kx has MUCH better high-ISO performance, and the Kr is even better yet, from all I have read. Its performance, plus the in-body stabilization (SR, shake reduction) make the Kx and Kr ideal concert cameras.

If by MUCH better high ISO performance, you mean just under a stop, then I agree. The K-r is actually a very slight bit behind the K-x in high ISO performance. Please check the measurements at DXOMark for confirmation. What you're looking for is the Compare Sensors page, Measurements, SNR 18%. Six points on this graph represents one stop of ISO.
DxOMark - Compare cameras side by side

[metalmania]

I don't have the kit lens but using Tammy 17-50 and Sigma 24-60 on K20D and K-X, there is not much difference on IQ. Well I like K20D a little bit and I play manual lens on it too. The ISO performance is really good on K-X. Using 85/1.8 and 200/2.8 on 40D, IQ is great too but it feels different from K20D and K-X. 40D is OK for high ISO, similar to K20D but not good enough comparing to K-X.
You see I don't have a wide angle lens for 40D and the reason is obvious: 40D with 200/2.8 and 85/1.8 is great to cover the long range for sports and portraits. I will bring it to the concert if the security ppl is OK with that.

[audiobomber]

Some say the ISO performance of the 40D is just like the K-x and some say it's just like the K20D, could you enlight me about this? Thank you .

Check here: DxOMark - Compare cameras side by side
Compare Sensors -> Measurements -> SNR 18%.

DXOMark has them even up to ISO 1600. Above ISO 1600, the K-x pulls ahead by 2/3 stop. The other two are even. As I mentioned above, the K20D colour and contrast murders the 40D IME. The 40D is better for AF tracking and Canon has better long tele options, so if birds in flight is your main interest, go for that one. Of these three, for general photography it's the K20D for me.