Since I have the NEX 5, I have put my A900 too much on the side... reason: portability ... and video. But ... I was thinking about if I should not bring my A900 in my Very low light rock band photography due to the fact that the NEX is now very good at high ISO.

The question was: For a same 14MP from the 24MP of the A900, is the NEX even better than the FF sensor. I know some people will say : ok but the answer is easy the file of the NEX is near than three time smaller than the size of the A900...

On the left NEX, on the Right A900 (reduced to 14MP). NO NR applied to both, JPEG straight from RAW in LR3.2.
Crop ISO3200:


Crop ISO6400:


Complete Large and crop image here if you want to do your own tests. I have also included upscale NEX 5 pictures to 24MP. http://www.pbase.com/nadeauf/nex5_vs_a900_highiso

So ... the answer to my question is that I should continue to use for the moment the A900 for my most of my serious shooting, even in very low light condition. Yes, there is a lot of lost of detail in the A900 sensor ... but my test results seams to shows that It is not loosing enough detail to switch camera body for ISO3200. I'm mostly using ISO4000 and 5000 usually in low light Bar environment where there is a kind of big difference compare to ISO6400 in noise. The 14MP of the NEX seams to shows less noise at ISO6400, but there is equivalent details. I might have took a ISO5000 and ISO4000 to compare ... next time

Regards,

Frank

but can you select iso4000 on the NEX, this is my 1 big wish for the A550, to be able to select ISO in between 1600-3200-6400

In fact, you can select ISO4000 on the Nex - dial in ISO3200 and AE -0.3EV. That would be exactly the same as ISO4000 if you shoot raw.
You even can control the JPEG output brightness/gamma somewhat - the 'standard' has normal/higher gamma and the 'landscape' has it much lower.

The high ISO capability of newer cameras is greatly overrated. The a700 v4 had the lowest noise of all Sony CMOS sensors before the new 16.2Mp arrived. Even the newer tweaked 12Mp one found in a500 (and in the K-x) shows an advantage over the a700 one only at WB of 2500K and below, and even then you may use the high ISO raw NR set to low with a700 and break even.

Surely it all applies only to the raw data processed with a good modern converter like Lr3.

This is interesting. So, does the landscape mode change the colors (such as enhancing the greens)? If so, I'm not sure I want to use it as a default setting. What do you think is optimal? I've been using standard, dialing back the EV sometimes. (Although, many times I like the bias towards overexposure, at least when my subject ends up in the darker areas.. If clouds are blown out, it's less of a concern.)

Vidgamer, the 'landscape' surely is greener than 'standard', but it's not so necessarily bad. If you do some indoor/tungsten/sodium light shooting, that green boost is a good thing. Just make sure to tone down the saturation and better use the aRGB. When we had no good support for the Nex raw, shooting JPEG 'landscape' in aRGB with contrast '-3' and saturation '-2' was a real option for me - this way I had enough latitude for PP with those JPEGs; and that PP could well be quite automatic most of the time.