If I were buying today for low iso work and exposures up to 30 sec. I would get a IQ160 or a IQ180. They are superb backs with stunning image quality and are the best value today if you want a recent product that does not feel ancient. They are easy to work with. The IQ2xx backs are almost identical, they just add wifi and in the case of the new 50mp CMOS back, they add high iso and long exposure capability but with you will loose some detail compared to the 60/80mp backs and also usability with tech camera systems (the 60mp IQ160 and the IQ260 are probably the best backs ever made for tech camera use, overall). The Leaf Credo counterparts are also great alternatives.
Its best to get in contact with a dealer. They can provide a bunch of great info including raw files of different back/camera/lens combinations. I use DT in NYC (Lance/Doug). They drop by these forums from time to time. Ci also chimes in.
I would not wait for the next best thing. It could take months or years and even then it will most likely be very expensive. Prices have stabilized on used backs as of late so it is a good time to buy.
Actually as a tech user, and owner of a IQ260, I would tend to disagree that the 260/160 are the best solution.
The 160 may be a better back than the 260, as I don't really see any advantage to the 260 over the 160. I feel that the 260, can not come close to the result of a P45+ from 10 minutes out, even in the best conditions. Excessive noise and stuck pixels make the long exposure mode questionable. I have owned a P45+ and know at 50 for long exposures it can't be beaten still (in MF land). I had hoped that Phase One would continue to tweak the long exposure results from the 260 with new firmware, but I feel it's apparent any further tweaking is not going to happen the results are what they are.
The 160/260 still have issues with movements on wides, albeit not as much as the 280. But it's can be very hard to totally correct a blue sky on a 15mm shift with a 40mm Rodenstock on my 260 without a lot of work. No more work than it took to work on Guy's images (from getdpi) in his Credo 50 review. Plus there appears to be a total lack of micro lens ripple which can have a huge effect on the 260 movements, even with a retro focus Rodenstock. The huge advantage on the Credo is you can just take 3 shots, knowing that you can push the shadows as much as 2.75 stops and still have a great image that holds up at full resolution.
I have gone back to using sensor plus with my 260 at iso 400 and 200 as the results are just so much better in mixed light. I have to go vertical and stitch for a single image but it can still be printed quite large.
Tech cameras with Copol shutters are actually better suited for a CMOS back as you can push CMOS. Your copol shutter is very limited in available shutter speeds, no 1/3 or 1/2 settings. The CCD backs would benefit from these extra shutter settings, as many times just a bit more light can make the difference, where as the CMOS can easily handle the fixed shutter speeds of a copol shutter and allow for push.
I also don't see any loss of detail in the CMOS Credo or 250 files, going back to DT's testing, the 250 was superior in details as it has so much less color aliasing, along side of that amazing shadow recovery.
CCD loves light, it's just that simple, when I find conditions that work out, I get good results with the 260, and it can work OK even at iso 200 as long as you are only trying to push shutter speed faster in good light, but forget it in low light. The files are much more noisy and have much less color retention, and you won't get it back in post, it's gone. So a windy mixed lighting condition (where I tend to find myself) just is not a great solution for a 260/160 or really any CCD back as you just wont' get the shot. When you are talking to the dealer, ask for a 1 hour exposure raw file from a 260 or even a 30 minute file, and see what you think. Dealers can help here a lot as trying to rent a back is cost prohibitive for many due to insurance issues. I run a 2 person studio and I still could not get coverage from my policy to cover the rental of a 280 or 250, for 2 days.
After going through Guy's images (thanks again Guy), I have no doubt that the 250 or Credo 50 is a better solution for my shooting style and I would make the move right now if it was not a 1:3 crop, I would take it for a 1:1.
Paul
