[FHPhotographer]

A 6mp camera cannot resolve as much detail as a high quality lens, so testing lenses with a 6mp camera will show you colour rendition, contrast, bokeh and distortion, etc, but it won't show you any differences in resolution. You can't see differences between resolution in screen-sized web photos, but you will see a difference in comparing crops of a 6, 10 and 14.6mp camera, and you will see it in large prints.

I don't want to be a pill about this, and I know this is about lens comparison so I'll drop it after this, but you cannot state as fact that an APC-C 10mp sensor generates more resolution than an APS-C 6mp sensor, and then support that by using a circular argument where the deduction (that 10mp sensors have better resolution) contains the very proposition that the argument aims to prove, i.e., that 10mp sensors have better resolution. That's a fallacy of petitio quæsiti, or begging the question,
Brian

[audiobomber]

I don't want to be a pill about this, and I know this is about lens comparison so I'll drop it after this, but you cannot state as fact that an APC-C 10mp sensor generates more resolution than an APS-C 6mp sensor, and then support that by using a circular argument where the deduction (that 10mp sensors have better resolution) contains the very proposition that the argument aims to prove, i.e., that 10mp sensors have better resolution. That's a fallacy of petitio quæsiti, or begging the question,
Brian

This is not the time or place to discuss it. I did some testing that resolved it for me but not for others, so I will do a more rigorous follow up test, hopefully over the holidays.

I don't think anyone has mentioned flowers as a photo subject. They're even available here in the frozen north, as long as one is willing to pay for them. A bowl of fruit is pretty universal.

[Class A]

I'll keep this short. We should move this somewhere else, if someone feels it is worth continuing.

Lots of lenses reach optimal sharpness at F5.6. The FA 50mm reaches maxiimum center sharpness at F4.

The FA 50/1.4 is a very sharp lens. Most consumer lenses do not peak below f/8. Certainly most 70-210 lenses will be a lot less sharp than the FA 50/1.4.

So you would say a K10D, with the same sensor and higher pixel density, produces better images than a K100D at high ISO. That's a controversial statement, isn't it?

I wouldn't say that. There are a lot more differences (sensor, firmware) between these two cameras than just pixel density.

The linked article below is pretty dense reading

Nice article. Thanks!

the conclusion at the end is simple enough. More pixels produce higher noise at higher ISO and larger sensors with more pixels produce higher quality images at low ISO.

That's not the message of the article. The article directly supports what I've written:

Rather than having strong dependence on the pixel size, the noise performance instead depends quite strongly on sensor size

In other words, the biggest factor (primary effect) is sensor size.

While it is true that big pixels (currently, this is technology dependent) have an advantage in high ISO applications, this is a secondary effect not comparable in magnitude to the primary effect of sensor size.

Note that the article says

...for fixed sensor format, the light collection efficiency per unit area is essentially independent of pixel size...

and

Noise performance per unit area was seen to be only weakly dependent on pixel size.

plus

if anything, smaller pixels perform somewhat better in terms of S/N ratio (while offering more resolution).

which supports what I've written.

[audiobomber]

All the sensors we're discussing here are the same size.

I'm not continuing this discussion after this post. Let's take it up again in a couple of weeks when I post K20D vs K100DS resolution tests.

[Fl_Gulfer]

I can use my Ricoh 70-210 f3.9 on my K20d, K10D & my K1000 with a tripod and shoot the same subject at the same distance and we can see if they look that much different...

[audiobomber]

I can use my Ricoh 70-210 f3.9 on my K20d, K10D & my K1000 with a tripod and shoot the same subject at the same distance and we can see if they look that much different...

That would be great. I suggest you choose a subject with some fine print, in order to show resolution. A cereal box works well.

PS, I think it would be best to start a new thread for your test.