j1clark@ucsd.edu
Veteran
There are advantages to oversampling even if you know your work will never be seen at higher than HD. My 31 megapixel Hasselblad images definitely DO look crisper downsampled to 1600 x 1200 pixels than the 12 megapixel Canon 5D shots or even than 21 megapixel Canon 5Dii shots. Oversampling is only a part of the reason but it definitely helps. Oversampling at the front end of data acquisition is always a good idea if you are trying to get your final product right up there to the resolution limits of the final distrubution format.
I think you are sort of mixing up a couple of things... Naturally a 'larger sensor delivers a larger image'... if this were not so, there would be no difference between a 35mm film film neg, and the 2 1/4 square (aka 70mm) negative...
The ARRI Alexa has a sensor size which is approximately the same size as current 35mm film (I'm presuming 'movie film'...) and so the imaging area is actually smaller than the typical 35mm still film imaging area.
In sensors... size counts...
But back to Hasselblad... one of the reasons why the Wife and I did not make the 'digital jump' with Hasselblad... was the price... at the time when it made sense to do so, spending $30K for the digital Hasselblad just made no sense at all. There may be a reason for someone whose business is to make billboard sized enlargements... but for many applications the 35mm digital is the best compromise for price/performance/desired result. (And we always did have the film film Hasselblad in the closet if an absolute need arose...).
