I'm curious. How does digital MF have better low light capability? From what I've read on Luminous Landscape and other sites many (most?) MF backs don't even do above 800ISO and if they do it's not very good, also I've read they have issues with long exposure heat build up? Have I missed something lately that they are getting good 4 and 5 digit ISOs on digital MF backs now?
Most MF digital backs use CCD-based sensors and most smaller format cameras these days tend to use CMOS sensors so there is a difference in technology. The SNR numbers I put down are based on calculations where equivalent technology is employed, the only difference being the size of the sensor.
I think most new MF backs are actually CMOS these days. I remember reading that somewhere...although I could be wrong. But for quite some time, yea, CCD. However, most still don't have the super-high ISOs that 35mm CMOS has been getting lately.
Also just as an aside, why so much comparison to Canons Cinema line? Did medium format film get used that much? Other than 70mm that is.
I didn't make any comparisons to Canon's cinema line, so I'm a bit confused. Was that question meant for someone else?
MF film (120 roll) used to be used constantly, and actually has experienced somewhat of a slight resurgence thanks to the whole Holga type movement/experimentation, and the fact that hobbyists like myself have discovered MF and a rather low price for the older (but still great) film gear.
Also, the comparison is partly due to the rather high price of MF Digital. Most especially for the digital backs, and the lenses since they tend to be much larger (e.g. bigger pieces of glass, which is more expensive) than the 35mm lenses. Especially some of the bigger formats, such as 6x9, where the lens had to project a significantly larger image circle.