[distudio]

BTW I don't use ISO 100, this makes sense to me.

It might make sense as a general theory but in the case of the K-x you would be best off referring to a poster with more technical credence than the one that you cited, see:

Re: Dynamic range of Kx vs. K10 vs. K7: Pentax SLR Talk Forum: Digital Photography Review

Re: K-x review: how did they test ISO 100?: Pentax SLR Talk Forum: Digital Photography Review

[er1kksen]

BTW I don't use ISO 100, this makes sense to me. Expanded ISOs over 6400 are also just a darker pics with K-x software positive exposure correction under the hood.

In your link: "ISO 200 is the lowest on K-x. This is the base ISO of the sensor in use. The sensor does not have lower ISO than 200.

To get to ISO 100, the camera uses a special trick. It is actually ISO 200, but exposed wrongly and then pulled so it works as ISO 100. "

^^^This is technically true, though it is not exposed "wrongly;" it's exposed exactly as intended for the artificial ISO 100.

"But staying with ISO 200 is strongly recommended, because this is base ISO and if you stays at base ISO without software tricks of any kind - you get the highest image quality with less noise."

This is an assumption based on previous models with artificial low ISOs. With the K-x this is not true; higher image quality can often be achieved with ISO 100 than ISO 200, even if you overexpose ISO 200 and pull it in post (similar to the way the camera produces ISO 100) due to the different signal response of the sensor when ISO 100 is used. Again, take a look at Falk Lumo's RAW analysis results.

[Karellen]

Yep, I saw the ISO analysis gives ISO "100" is ~127 for K-x sensor. However, you have to choose between DR compensation and ISO 127 over 200... Maybe I should really give it a try. I didn't test it in battle conditions yet. Thanks!

[audiobomber]

I have auto ISO set for 100-3200. I will go as high as ISO 6400 if I need to, but I don't let the camera make that decision.

[Internetpilot]

After owning an older fourthirds DSLR (Olympus E-500) and superzoom "bridge" camera (Panasonic FZ50) for a combination of the last five years (both of which are notoriously poor high ISO/low light shooters), I am very happy to not have to really "worry" about ISO on the K-X. I've posted this before and others here have said that I should worry about ISO, but coming from my previous cameras I don't have to worry about it anywhere near as much now!

So now I use Auto ISO with the range set from 200-3200. 3200 starts to approach the point where I can tell that it's a higher ISO shot, so sometimes I limit the top end to 1600. If I'm doing flash/studio type of work, I will set it manually for 200.

I don't use the ISO 100 option because I've instead enabled the DR feature. I'm a JPEG shooter and spend most of my time trying to figure out the best settings to get the best JPEG possible right out of the camera. If all the postprocessing I do is apply some USM and maybe a resize/crop, I'm a very happy photographer. Thankfully, even with other caveats, most of my cameras so far have had rather nice JPEG engines, so other than making several attempts at RAW (because "everyone else is doing it"), I've been able to stick with JPEG.

[GeneV]

Walking around in and out, it is set on auto, up to 1600.
Indoors, I set it manually to 1600 or 3200, outside at night, I set manually to 6400.

The auto range includes the ISO settings I find acceptable without paying attention to noise reduction.

[phzy2003]

i don't use auto iso too, i set the iso manully.

[ajuett]

I manually set my ISO, I have the expansion on (100-12800). Most of the time I have it set on 400 ISO. Also, Highlight control is on and Shadow comp on 1.

[EsBee]

I have mine on at 200 mostly unless I am out in the brightest of afternoons or shooting with flash, in which case I use ISO 100. Of course, I bump it up depending on what shutter speeds I want using the available light.

I have not used Auto ISO.

[pxpaulx]

But the point of this post is, that if you don't have to crop a high ISO shot from the K-x, it can really do an excellent job at 6400 and even above. I can't wait till we see the K-8.

That is my boat too. I still love my K20 a ton, and now that I have a GF1 too, well, 3 cameras is just too much. I would be swayed by the K7 but I wasn't enamored with the ergonomics (k20 fits me too well).

I am not hoping for a K20 replacement at this point, but whenever the K-8(?) arrives I will go back to one camera body (GF1 with the viewfinder +MF lenses works pretty well, making it a pseudo 2nd body anyway).

As far as my use with the K-x goes - daylight set at 200, lower/changing light conditions set to auto, 200-4000, for anything where beyond 4000 is needed I generally switch to SV (have it set starting at 5000 typically).

[dlacouture]

100-12800 auto iso...

Frankly, 12800 is so clean... Through LR3b2, it's easily better than a 400 iso negative (DR aside), and I've just scanned nearly 200 rolls on a dedicated film scanner.

And used with my FA50, 12800 iso is really reserved for ultra-low-light (as in "big-room-lit-by-a-60w-bulb-only")...

[jlaubza]

Please take note that if you activate Highlight control and shadow DR adjustment, you slow down the fps frame rate as the camera has more processing work to do.

[Ira]

And on the K-x, highlight correction has to be OFF to have 100.

[kiwi_jono]

Maybe my K-x ISO performance is not quite up to scratch but with Av mode (which mostly use) I normally use Auto 100 - 400. If I really have to for low light or fast action I will use up to ISO 2000 but noise is starting to get very obvious (especially in darker areas of image).

I know the base ISO is 200 but I have taken a number of series of photos outdoors and I can see a an improvement in IQ with 100 over 200. With 200, very slight noise that shows up in dark blue sky and sometimes other dark areas which is not seen with 100.
But again maybe my copy does not perform as well as others.

[bazzie]

I don't use the ISO 100 option because I've instead enabled the DR feature. I'm a JPEG shooter and spend most of my time trying to figure out the best settings to get the best JPEG possible right out of the camera. If all the postprocessing I do is apply some USM and maybe a resize/crop, I'm a very happy photographer. Thankfully, even with other caveats, most of my cameras so far have had rather nice JPEG engines, so other than making several attempts at RAW (because "everyone else is doing it"), I've been able to stick with JPEG.

I'm glad you said that. What is the point of having almost infinite JPEG presets, as we do with the K-x, when you then disregard them by fiddling with the RAW image?