Any "summary" is going to gloss over some details but here is a quick summary:
P45+
- max long exposure = 1 hour
- Kodak color rendering
- larger sensor (1.1 crop from 645 frame)
- slower frame-to-frame shooting (around 40 frames per minute)
P40+
- max long exposure = 1 minute
- Dalsa color rendering and tonal smoothness
- Bit more dynamic range
- zero latency mode allows for use on tech camera without wakeup
- smaller sensor (1.3 crop from 645 frame)
- faster frame-to-frame shooting (around frames per minute)
- allows setting of custom functions of DF body (if using DF)
- has built in virtual-horizon
- allows rating images in the back
- has sensor+ mode which allows higher ISO shooting at lower resolutions (up to ISO3200 at 10mp)
Both start at ISO50 and work fine with a tech camera (neither has any issue regarding microlenses). I really don't think the release date of the back should be a factor in the purchase - only how it performs.
The P45+ still demands a high price because it is the best back in the world when it comes to capturing long exposures. They've just recently ran out of their inventory of sensors to make new ones, so there will not be any more made. We have a few on our shelf and I don't expect them to last.
P45+
- max long exposure = 1 hour
- Kodak color rendering
- larger sensor (1.1 crop from 645 frame)
- slower frame-to-frame shooting (around 40 frames per minute)
P40+
- max long exposure = 1 minute Not as clean as the p45+ when both compared same long exposure speeds.
- Dalsa color rendering and tonal smoothness Really very minor differences here "Dalsa tonal smoothness" or Dalsa/kodak color.....
- Bit more dynamic range Phase one states that they both have 12f stops of dynamic range
- zero latency mode allows for use on tech camera without wakeup Chews through batteries like nuts in this mode.
- smaller sensor (1.3 crop from 645 frame) actually it's a 1.3 crop from the usable 645 film frame which is 56 x 42 mm. P40 is 44x33mm, barely medium format.
- faster frame-to-frame shooting (around frames per minute)
- allows setting of custom functions of DF body (if using DF) No big deal as the screen on the back is small and all these functions can be set on the camera anyway.
- has built in virtual-horizon small screen however makes it quite limiting
- allows rating images in the back Files can be rotated, not the sensor. It's better to rotate the camera because the screen is so small that a rotated file will display so damn small.
- has sensor+ mode which allows higher ISO shooting at lower resolutions (up to ISO3200 at 10mp) Might as well shoot with a 35mm DSLR... results at such ISO will be far better and bigger files, especially if you factor in MF low light focusing limitations.
IMO the larger sensor is a much better choice.
Emil already has a high res 24x36mm sensor. The look optical look of a crop sensor on MF lenses will not be as nice as the same lenses on an almost FF 645 sensor.
I really see no point for a 44x33 sensor as an additional camera for a high end 35mm DSLR user.
Just the optical resolution loss from cropping the lens. A lens resolves x line pairs per millimeter. Crop away those milimeters and you are throwing away part of the lens resolution, not to mention better bokeh etc due to slightly lower enlargement of the projected image.
MF marketing keeps on going on about ... big sensor advantage, but then they suggest that a 44x33 sensor is just fine
Another important thing to note is that the Phase One DF has only one viewfinder option that is designed for full frame.
Any crop sensor will need a mask for the viewfinder and the resulting image viewed in the viewfinder is going to be small and harder to focus on and view the subject. Hasselblad on the other hand has interchangable viewfinders. There are two Hasselblad H prisms. One for cropped sensors and one for larger sensors. Each optimized for the sensor size.