[gregbradley]

I've been researching DSLRs for a while now and I see a lot of criticism of the megapixel trend in DSLR manufacturers where more megapixels is regarded as not necessarily a good thing.

I'm interested in a thread on this. My experience with astro CCD cameras would indicate more megapixels is usually a good thing (within reason but I see the KAI1600 chip is not that popular and that is essentially a 16mp STL11 sized chip). I also don't see a lot of people racing to get a new 29mp KAI29050 camera (29mp STL11 sized sensor).
Certainly matching pixel size to seeing and optics is a good thing.
I don't know that matching pixel size to terrestial type photography is as important. There is no seeing to get in the road and normally scenes are fairly well lit.

It seems it is usually an argument of low noise, high ISO performance verus resolution (where small pixel size gives "better resolution").
Some posters act as if you are an idiot if you want large numbers of megapixels.

Normal CCD theory has you wanting signal to rise above the noise floor. DSLR engineers seem to be more advanced than Astro CCD makers in reducing noise with firmware, filters and upgrading their chips with their built in circuitry.

That is another difference between astro and terrestial. Terrestial uses CMOS technology usually and astro uses CCD usually. Each has its advantages. CMOS has the advantage for DSLRs because the amplifiers and circuitry is on the sensor itself which takes up space leaving less room for the pixel to collect light but makes it all very compact and cheaper.

Given this extra degree of freedom of on-sensor circuitry, filters, firmware smoothing it seems DSLR engineers routinely improve noise performance of small pixels to the point where it seems you can have the best of both worlds within a certain range of performance ie; large number of pixels and low noise performance. There must be an optimum number of pixels for full frame sensor with ideal low noise and high ISO performance. What do you think that may be? It hard to say for sure as engineers keep improving the existing but they must hit a wall at some point.

How long before Nikon/Canon put out a medium format DSLR? It must be getting close to that being the next step up for them. The Nikon D800 is already being seen as an alternative now to medium format digital cameras.

Comments?

Greg.