Phase One’s 645 AF With P 65+ Digital Back; The Megapixel Race Is Still On Page 2

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You need to use the optical viewfinder or top panel to display exposure data. Moreover, when reviewing images, you have to cycle through several steps in playback before seeing exposure or clipping data or the histogram—all unmarked functions, I might add. But these are minor shortcomings when we look at the big picture—and a big picture it is.

Granted, many exposures in our tests were made at the lossy compressed setting, but you wouldn’t know it was lossy compression when looking at the images. I also made a few exposures at the Sensor+ setting, which reduces capture to 25 percent of the original file size while speeding up processing and boosting light sensitivity fourfold, with practically no added noise. To top it off, the sensor is firmware upgradable, so it won’t quickly become obsolete. When you add true 16-bit color capture, the complete picture of this camera’s incredible capabilities begins to unfold.

(Left): The Phase One 28mm lens is distinctive for its size—almost as big as the zoom, but with a built-in petal-shaped lens hood. This wide angle proved to be a remarkable and useful lens. (Right): While I didn’t use the Phase One 75-150mm zoom extensively, I found that when it was needed it delivered without question. Zooming was smooth, as was manual focusing.

The Lenses
Now let’s turn to the lenses. The three lenses tested (80mm f/2.8—the kit lens, 28mm f/4.5, and 75-150mm f/4.5) performed admirably, producing sharp images with good contrast. Given the large sensor, there is no sensor factor to contend with, so focal lengths remain as marked (in contrast to the Mamiya DL28). Even though these lenses lack internal focusing, the front element remains fixed, which means focusing should not interfere with use of a circular polarizer.

Autofocusing was a bit noisy, however, and not altogether a speed demon (a function for which the camera itself bears considerable responsibility). Low-light shooting clearly mandated manual focusing—easy enough with each of these lenses. I noted mild lateral chromatic aberration and purple fringing in one shot (easily corrected). Vignetting was apparent when shooting wide-open, and especially pronounced with the 28mm lens—surprising for such an expensive piece of glass. Go down one stop and the situation is vastly improved. The 28mm lens is remarkable for its lack of distortion, although the other two lenses appeared well corrected for distortion as well—certainly within acceptable parameters.

Inspired by images taken by the museum’s photographers, I was determined to get a nice shot of the Rose Center at “magic hour” with this camera. This close to the building, I needed the 28mm lens, with the camera on a tripod. Auto WB worked perfectly to capture this rich tapestry of color during this 1.6-second exposure at f/4.5 (ISO 200). In contrast to earlier exposures (using lossy compression), this shot and the one of the turkey were captured at best quality (lossless). There was no visible difference in image quality.

Final Analysis
I don’t really know that there is a reason to go beyond 60.5 megapixels in resolution, but I’m sure they’ll find one and develop an even richer chip. I’d prefer to see the R&D go into developing this chip with even less noise at high ISO levels, faster performance, and still broader dynamic range. Phase One tells me that the CCD remains the way to go for larger format backs. If that’s the case, then let’s see the company take this chip to the next level in overall performance, or find a viable substitute.

As is, noise levels proved acceptable at tested ISO settings. In fact, they were remarkably well-controlled. The camera even performs dark frame subtraction during long exposures to further reduce digital noise, albeit involving longer processing times.

What I found less than satisfactory was White Balance (WB) performance. While WB performed well under some conditions, it performed with less reliability under others. When we expected to achieve a fairly neutral rendition using the Tungsten WB setting with tungsten lighting, we were disappointed to see images with a strong color cast.

Even with overcast conditions, there was enough light for a quasi-handheld exposure (leaning on the railing) at 1⁄80 sec, wide-open (ISO 50, f/4.5), with the 28mm lens. Color balance proved to be a problem (regardless of the WB settings used), possibly owing to the combination of sky conditions and tinted windows, so I had to make the correction in Capture One.

While I would have preferred full integration (one on/off switch, one battery, full camera-to-back communications), still none of that hindered a smooth workflow. The Phase One 645 AF/P 65+ is a magnificent beast. If you’ve handled a medium format SLR before, then you should have no trouble with this resolution colossus. I ran with it moments after taking it out of the case. And my only regret is having to send it back so soon.

Phase One 645 AF Basic Kit
The basic kit costs under $42,000—includes camera body, 80mm f/2.8 lens, lithium-ion pack with charger, Capture One DB software (Capture One PRO version optional), custom roller case, plus all the necessary cables/accessories.

I set the 75-150mm zoom to 90mm and aimed the tripod-mounted camera above the crowd, emphasizing the menacing T-rex in the foreground while also capturing the dinosaur on the far side of the room. Backlighting mandated fill with a manually popped Nikon SB-900 (note the highlights reflected in the sharply rendered teeth). (ISO 100, f/11, 0.8 seconds.)

Additional lenses tested: 75-150mm f/4.5 ($3900), 28mm f/4.5 ($4500).

Phase One’s Capture One 4 PRO: A Brief Overview
The Phase One P 65+ comes with Capture One DB, which in itself is a full-bodied raw conversion utility with a good degree of image editing added. Optionally, you can go one better by licensing the PRO version. That supports other raw formats, with added functionality. Even if you use Adobe’s ACR or Lightroom, you’ll find this handy. Either way, Capture One is the only way currently to work with Phase One native raw files.

The interface is markedly different from the Adobe products, but there shouldn’t be that much of a learning curve. One of the things you’ll find different immediately is that you don’t save or export files as you normally would. You process them. Aside from that, each parameter—color balance, exposure, lens attributes (such as chromatic aberration, purple fringing, distortion, and vignetting), cropping, and details (sharpening, NR, clarity, and moiré)—is presented on separate pages or palettes, although a quick-edit palette places most-used functions all together at your fingertips.
Capture One 4 PRO runs under Windows XP and Vista (32- and 64-bit), but only supports OS 10.5 Leopard on the Mac. It’s a robust application and one I plan to make good use of in the future.

Technical Specifications
Phase One 645 AF Camera Body

Format: 6x4.5cm (actual image size 56x41.5mm) with electronically controlled focal plane shutter
Metering: TTL multiple mode AE plus manual (five-segment evaluative center-weighted average with bright point elimination; spot metering)
Autofocus: AF single lens reflex (TTL phase-difference detection type, user-selectable focusing point)
Backs: Both digital back and film ready
Lenses: Supports Phase One, Mamiya, Hasselblad V-series lenses
Power Requirements: Six AA batteries (alkaline-magnesium or rechargeable Ni-MH)
Size (WxHxD): 6x5x7.2” (153x128x184mm)
Weight: 61 oz (1730 g)

Phase One P 65+ Digital Back
Sensor:
Full-frame CCD
Lens Factor: 1.0
Resolution: 60.5 megapixels (15 megapixels in Sensor+ mode)
Active Pixels: 8984x6732 pixels
CCD Size Effective: 53.9x40.4mm
Pixel Size: 6x6 micron (Sensor+: 12x12 micron)
Image Ratio: 4:3
Dynamic Range: 12.5 f/stops
Sensitivity: ISO 50, 100, 200, 400, 800 (Sensor+: 200, 400, 800, 1600, 3200)
Powered By: Rechargeable lithium-ion battery pack
Note: For additional specs, visit www.phaseone.com.

For more information, contact Phase One at: www.phaseone.com.

The cooperation and assistance of the American Museum of Natural History and its staff is in no way an endorsement, expressed or implied, of the products tested or used for this review. Opinions and views expressed do not necessarily reflect those of the museum.

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merdeka04's picture
If you want a clearer

If you want a clearer resolution of pictures then you have to own Phase One 645, enabling you to edit pictures the way you want it. - David Contarino