Despite having the same sensor in both products, there are many additional features that the Phase One IQ160 offers that the Phase One P65+ does not. One of these features is potentially faster sustained capture rates, even when the same sensor is used, due to the larger buffer and faster writing architecture of the IQ160. We decided to test this. So, in one corner we have the Phase One P65+M on a Phase One DF Camera and Schneider 80mm f/2.8 LS Lens. In the other corner we have the Phase One IQ160C on a Contax 645 AF Camera and Zeiss 80mm f/2.0 AF Lens.

Shooting to a Sandisk 16GB Extreme Pro CF Card, we found the capture rate of the 2 systems virtually identical through the first 30 seconds at 24 shots for the P65+M, and 25 shots for the IQ160C, respectively. From 30 – 60 seconds, the IQ160 began pulling away as the smaller buffer of the P65+ was unable to continue to empty effectively enough to maintain the capture rate of the IQ160. At 53 seconds, the P65+M reached the extent of this ability and maintained a significantly slower capture rate from then on through 2 minutes. In contrast, the IQ160C kept up the same capture rate it produced in the first 30 seconds throughout the entire 2 minutes.

 

Phase One P65+ versus Phase One IQ160

 

We then tested both products shooting tethered to a computer. First, we shot to our Apple Mac Pro Tower, a 2.26 Ghz Quad Core machine with 10GB RAM. The capture drive was a 500GB, 7200 RPM Seagate Barracuda Internal Drive. Then we also shot to my MacBook Pro Laptop, running 2Ghz Intel Core i7, 8GB RAM, and a 240GB OWC Pro6 SSD Internal.

In this case, we found the performance between the 2 products very similar, as the Mac machines did a better job for the P65+ at pulling data out of the buffer than the Sandisk Extreme Pro CF Card. This evened out the playing field for the P65+ and the IQ160, as the UDMA 7 compatibility of the IQ160 did not factor in the outcome. Interestingly, the performance of both the P65+ and the IQ160 matched the Sandisk Extreme Pro UDMA 7 performance of the IQ160, when shooting to my MacBook Pro laptop. Our hunch is that the faster write speed of the internal OWC Pro 6 SSD was the responsible party for the increase in capture rate over the Mac Pro.

 


The bottom line? For faster sustained capture rates for very high resolution digital backs shooting untethered to CF cards, the IQ160 cannot be matched by the P65+. But if you can shoot tethered, we have found that shooting to a top of the line SSD can provide sustained UDMA 7 level performance, not just for the IQ160, but even for the P65+.

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