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The DCS Pro 14n: worth the wait? - Continued

Image Quality: It's in the Details

Let's begin with the DCS Pro 14n's strongest suit. Like the 1Ds, the 14n captures substantially more detail than any of the current crop of 6 MP-range digital SLRs. Its 13.5 million image pixels in a 35mm frame-size sensor are the primary reason for this. A secondary factor is Kodak's decision to forego the placement of an optical low-pass filter, called an Anti-Aliasing filter in Kodak vernacular, in front of the sensor.

14n_Portrait2_crop
DCS Pro 14n, 100% magnification crop

An Anti-Aliasing filter reduces the visibility of moire patterns and colour-speckled highlights, but it does so at the expense of high contrast edge detail. In English, photos shot through a low-pass filter look slightly blurry, but are usually fairly free of extraneous colour junk that wasn't part of the original scene. The 1Ds, as well as all other digital SLRs from Canon and Nikon, include a non-removable low-pass optical filter atop the sensor, so the 14n is going its own way in this regard.

Previously, Kodak has made an Anti-Aliasing filter at least an option for its DCS cameras, if not standard equipment. To keep costs down, Kodak sought to take advantage of the fact that the higher a sensor's resolution, the fewer instances of colour artifacting. By eliminating an Anti-Aliasing filter from the 14n parts manifest, as well as sidestepping the need to design a place to put it if it were optionally available, Kodak was able to trim hundreds of dollars off the manufacturing cost of the camera.

Observations

The 14n captures plenty of detail. In fact, if your sole criteria in selecting a camera is so that you can make enlargements that are dramatically more detailed than any other Nikon-bodied digital SLR, then stop reading, visit your dealer and purchase a 14n. Photos from this camera, however, are not more detailed than those coming from the EOS-1Ds, despite the latter camera's lower pixel count and optical low-pass filter. The primary reason for this seems to be noise processing. To keep colour artifacting at bay, and to make low-contrast areas smoother, Photo Desk's noise processing does munge some fine detail. This is true even at its lowest settings (noise reduction can't be switched off completely).

The effect we're describing is evident in this 100% magnification snippet of the same scene shot with the 14n and with the EOS-1Ds. Both files have been treated to some first-pass sharpening (a standard technique around here that involves applying Unsharp Mask filtering at a low radius), to compensate as much as possible for detail softened by either the 1Ds low pass filter or 14n image processing.

Look closely and you'll see both cameras allow you to dig deep into the detail of the scene. Look even closer and you'll notice that the trees in the foreground as well as the ornamentation in flat areas of some of the buildings has been smeared slightly in the 14n version. This smoothing is largely invisible in an 8 x 10 inch enlargement, but larger prints take on a somewhat odd, processed look in flat areas like this.

A similar effect is visible in the two 100% magnification, first-pass sharpened crops below.

14n_Lighthouse_crop.jpg
DCS Pro 14n, 100% magnification crop

EOS-1Ds_Lighthouse_crop.jpg
EOS-1Ds, 100% magnification crop

The 14n version has an abstract, almost painterly look to the slopes in the foreground. The 1Ds version, by comparison, looks more like a high-resolution photograph. 14n smoothing pops up in all manner of images, and is a distraction in large prints, even at a reasonable viewing distance. Over-aggressive smoothing has been a trait of Kodak noise processing through several revisions of Photo Desk, but it has been possible to turn it off previously. As of Photo Desk 3.0 noise reduction is always on, at least for 14n files, so this smoothing is unavoidable.

To get a better sense of the detail rendering capabilities of each camera, be sure to download some of the full-resolution files sprinkled throughout this report. What you'll see is a level of detail in 14n files that eclipses all digital SLR cameras. All, that is, except the EOS-1Ds.

  14n_Skyline_ISO80_thumb.jpg
DCS Pro 14n (Zoom | Full-Res)

  EOS-1Ds_Skyline_ISO100_thumb.jpg
EOS-1Ds (Zoom | Full-Res)

The 14n also captures some moire and other colour artifacts. Less, certainly, than the 6MP DCS 760 does when used without its removable Anti-Aliasing filter, thanks to the 14n's higher resolution, but more than the 1Ds. Depending on the type of photography you do this may or may not be troubling.

In general, 1Ds photos exhibit virtually no colour artifacting and only the occasional moire pattern. Its noise reduction processing, which can be partially enabled/disabled (for RAW file processing anyway) but is not configurable, does a good job of zapping colour artifacts that its low-pass filter didn't prevent, and does seem to dent, if not eliminate, the few moire patterns that sneak through too.

On the other hand, Photo Desk's Advanced with Moire Reduction noise processing mode does a surprisingly good job of cleaning up moire - we've seen particularly good results in areas of white - though at the cost of extended RAW conversion times. We've shot 14n photos, including the portrait below, that are beyond the limits of Photo Desk's moire and artifact reduction, so Kodak still has some work to do in this area.

The full-resolution versions of the photos below demonstrate the strengths and limits of each camera's colour artifact and moire handling. In the 14n soccer portrait the hair and jersey show moderate but unwelcome amounts of moire and artifacting, despite applying near-maximum noise reduction in Photo Desk. The EOS-1Ds photo, by comparison, is fairly free of both image defects.

On the flip side, Photo Desk does a great job of cleaning up almost all moire in the white jerseys of the team photo test frame, moire which is faintly visible in several jerseys in the 1Ds test frame processed through File Viewer Utility.

  14n_Portrait1_thumb.jpg
DCS Pro 14n (ZoomFull-Res)

  EOS-1Ds_Portrait1_thumb.jpg
EOS-1Ds (ZoomFull-Res)

  14n_Team_thumb.jpg
DCS Pro 14n (ZoomFull-Res)

  EOS-1Ds_Team_thumb.jpg
EOS-1Ds (ZoomFull-Res)

To keep moire and colour artifacting at bay with the 14n requires careful tweaking of the Noise Reduction function in Photo Desk; default settings won't cut it in many instances.

The 14n offers Kodak's standard overexposure recovery. Which is to say you'll be able to recover overexposed photos well beyond what you might think is possible, and well beyond what can be accomplished with most any other brand of digital SLR. All the resolution in the world isn't much good if critical highlight detail is blown out, and Photo Desk's ability to recover detail from near-blank white areas in an overexposed 14n photo is simply the best around. This 100% magnification crop from an overexposed ISO 80 frame provides a glimpse of how powerful this capability is.

Kodak's highlight recovery magic is a result of the how the data coming off the sensor is processed at a given ISO, and how that effects the image's dynamic range. In short, the 14n depends on a combination of both analog gain (applied as the image data is converted to 0s and 1s) and digital gain (roughly akin to a Curves adjustment in Photoshop) to bring the image up to the level of the ISO set on the camera.

This is true regardless of ISO. For instance, with the camera set to ISO 80, the analog-to-digital conversion circuitry in the CMOS sensor pumps out image data with about an ISO 64 rating, says Kodak's Steve Noble. Digital gain applied to the image data during processing in Photo Desk, or in the camera out to ERI-JPEG, makes up the 1/3 stop between ISO 64 and ISO 80. Combine this with the dynamic range of the sensor and you're left with sufficient highlight headroom to rebound from fairly significant overexposure error.

Unlike previous Kodak digital SLRs, which depended on digital gain exclusively to achieve sensitivities higher than the base ISO, the 14n sensor utilizes analog gain at ISO 80, 160 and 400. Since analog gain and digital gain combine to give the camera's ISO range of 80-400 in 1/3 stop increments, the ISO settings at which digital gain is providing the biggest boost are the ones where overexposure recovery should be the most effective. In the case of the 14n, that's ISO 320 and ISO 125, or just shy of the upper two analog gain points.

Moving to three analog gain points should, in theory, mean a reduced ability to recover from overexposure at ISOs above the base ISO, relative to previous Kodak digital SLR models. In practice, a 14n file at any ISO can be tuned in Photo Desk to bring back gobs of detail.

The bottom line. The 14n captures impressive detail, and leads the way in overexposure recovery. But regardless of lens or scene, the 14n can't quite match the level of real, photographic detail, especially in low contrast areas of the scene, that Canon's high-resolution digital SLR produces. This doesn't seem to be a lens shortcoming - we've used focal lengths from 16mm through 600mm in testing - but a fault in 14n image processing.

How close you perceive 14n files to match those of the 1Ds, and whether or not you find the 14n's detail rendering acceptable, will depend in part on how distracting you find the smoothing effect of Photo Desk's noise reduction in particular, as well as other more minor image artifacts that seem to slip through the 14n's processing cracks. 14n detail rendering is very, very good, but it should be better.

Next Page: Image Quality: Noise
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