Kodak DCS Pro SLR/n Digital SLRKodak updates their Pro 14n with a new sensor, improved processing, and greatly reduced image noise.<<Video, Power, Software :(Previous) | (Next): Reference: Datasheet>> Page 12:Test Results & ConclusionReview First Posted: 02/12/2004 |
Test Results
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I haven't had time to subject the SLR/n to the full battery of my tests, nor to prepare the kind if detailed analysis that I'd like to give and that such an important camera deserves. Both will have to wait until I return from PMA, but hopefully will be up soon after. In the meantime, here's a thumbnail sketch of what I've found thus far:Resolution
Like the 14n before it, the SLR/n definitely wins the resolution derby, at least among handheld, "35mm format" SLRs. With a resolution that tops out at about 2100 lines/picture height both vertically and horizontally, it edges out Canon's EOS-1Ds for top honors in the resolution category. That said, the SLR/n does show more artifacts in the res target image as you get to very high spatial frequencies, although this doesn't seem to affect its images of natural objects too strongly. (As I noted in my Pro 14n review, some of the camera's exceptional sharpness derives from Kodak's decision to leave out the antialiasing (lowpass) filter, which had the (not unexpected) effect of producing artifacts such as jaggies and color aliasing in areas of very high detail)
Kodak does offer special anti-moire processing in its Photo Desk software, but I found it only partially successful at removing color "twinkles" around fine, high-contrast detail. I personally would much prefer to have an antialias filter and give up some of the cutting edge of sharpness, if it would mean losing the camera's tendency to produce color artifacts. Others may well choose differently though: I'm reminded of the response of many of my readers to the Sigma SD-9 SLR, which also lacked an antialias filter. I personally found that camera's jaggies and tendency toward luminance moire unacceptable, but many people don't seem to be bothered by it, instead exclaiming over the unusual sharpness of its images. I strongly suspect that the SLR/n will find a similar response among prospective owners.
Thanks to the improvements in noise coming off the sensor and through the analog electronics, the SLR/n seems to do much better with low-contrast detail than did the 14n. It still isn't hard though, to find areas in which its images look more like watercolor paintings than digital photos though. - Check the clumps of pine needles in my Far-Field test shot, for instance, or areas in Marti's hair as described on the preliminary picture-analysis page. The extent of the effect is much less than it was with the 14n, but there still remains a fair bit of room for improvement.
Color
Overall, I think the SLR/n deserves a rating of "excellent" for its color handling, as too my eye, it really nailed the subject color in just about every instance. (It got a bit too much purple in the always-difficult blue flowers of the Outdoor Portrait test, but everything else was pretty much spot-on.) I particularly like the range of "Looks" that Kodak provides, letting you choose more saturation for product images and the like, but less saturation (with particular attention to skin tones) in the Portrait mode. I felt too, that it did a particularly good job under incandescent lighting, a very tough light source for most digicams.
I processed all my images through Photo Desk to get the best JPEG quality, making some white balance adjustments in the process, so some of the excellent white balance performance is the result of manual tweaking, and as such could be said to not be representative of the camera itself. - But part of the story of the SLR/n is how easy it is to quickly crank through a large number of images, making small tweaks to exposure and color balance along the way. As practical tools for professional photographers, the SLR/n and the latest version of Photo Desk make a very effective combination. I'd ordinarily give negative marks for a camera that required some level of image-tweaking post-exposure, but the amount required by the SLR/n is pretty minimal, and the process to apply it is pretty fast and painless. For a professional camera like the SLR/n and 1Ds, color rendition is possibly less important than it is in consumer-level cameras, simply because pros are much more likely to employ some sort of a color-managed workflow. Both cameras seemed very well-behaved (that is, consistent) in their color handling, and both support color spaces with wide gamuts that are well suited to use in color-managed environments.
Exposure and Tonality
The SLR/n behaved very well in my testing, handling a wide range of exposure conditions with aplomb. Its exposure system responded similarly to those of other D-SLRs I've tested to my standardized subjects, actually doing somewhat better than average with the deliberately harsh lighting of the Outdoor Portrait test. It did a good job of holding onto highlight detail, and the Kodak DCR RAW file format and the associated ERI JPEG format have a surprising amount of "headroom" in them for pulling back highlight detail. (Much more so than most other RAW file formats I've encountered, which (truth be told) actually preserve precious little highlight information beyond that which is present in the JPEG files anyway.)
Tonality on the SLR/n generally seemed to be pretty good. Its native contrast level struck me as about right for general shooting, and its "Portrait Look" setting further reduces contrast to preserve more subtle tonal gradations. I'd like to see more options for control over the camera's basic tone curve, but the default camera behavior isn't too bad as a starting point, and the tools within the Photo Desk software should let you do pretty much anything you want with the RAW-format image files.
Image Noise
As with the 14n before it, image noise in the SLR/n is a little hard to discuss in objective, quantifiable terms, simply because so much of the camera's performance in this area is a function of how the images are post-processed in the Photo Desk software application. Furthermore, it's very much up to the photographer to choose how he/she wants to make the tradeoff between image noise and detail in areas of low subject contrast.
The issue has to do with how short-exposure noise reduction algorithms work in general, and how those employed by Kodak work in particular. The approach involved is to look at image contrast within a local area of the image, and make an assessment as to whether the inter-pixel variations are due to noise or to subject detail. The general idea is that variations below a certain magnitude, and involving areas smaller than a certain minimum size, are considered to be noise. If the camera thinks its seeing noise in an area where it believes there isn't any significant subject detail, it "flattens" the image, reducing the inter-pixel variations.
If the original scene at that point consisted of a flat patch of color or tone (a blank wall, MacBeth(tm) target swatch, etc.), this approach works very well: It reduces the image noise without any apparent side effects. On the other hand, of there's a lot going on in the subject at that point (res target patterns, lots of fine, contrasty subject detail), chances are the noise won't be noticeable anyway, so leaving the image alone lets the viewer see the subject detail without them being aware of the image noise overlaid on it.
The problem comes when you have significant subject detail with relatively low contrast between scene elements. In such situations, depending on where the thresholds are set for discriminating noise, the noise-reduction processing can turn into detail-reducing processing. This is what happened with the SLR/n in dealing with the detail in Marti's hair in the studio portrait shot and with the inner detail in the clumps of pine needles on the Far Field shot.
You can also see the SLR/n's noise processing "backing off" as it gets to an area of strong subject contrast, by looking around the edges of the color swatches on the MacBeth chart in the Davebox shots. There, you can see "fuzz" around the edges of the color swatches, which is the underlying sensor noise showing through. What happened is that the high-contrast edge with the black surround of the color swatch told the camera that there was strong subject detail in the area, so it needed to back off on the noise processing to preserve the subject information.
Properly setting the parameters for this sort of noise reduction processing is a ticklish and time-consuming business, as it's a matter of constant tradeoffs and experimentation. This is an area to which Kodak has devoted considerable effort since the introduction of the original 14n, and they happily seem to have had some success. The "Expert" noise reduction mode in the latest release of Kodak's Photo Desk software does a better job of suppressing noise while holding onto image detail than we've seen in the past. While the SLR/n's images are greatly improved over those of the 14n though, there's still room for improvement, as witness the examples of detail in hair and pine needles mentioned above.
Night/ High ISO Shots
I haven't yet run the SLR/n through my low light tests, but can say that there does indeed appear to be a fair bit of improvement over the 14n in this area. With the 14n, I felt that the ISO 400 option really wasn't usable, but the SLR/n's images looked much better at that point. Stay tuned, I'll update this section after I get back from PMA and have a chance to run a full range of low light tests on the SLR/n.
Shutter lag and cycle time/general responsiveness
Here again, I need to run more tests once I'm back from PMA, but the SLR/n appears to be a pretty responsive camera overall. Its buffer memory capacity is greatly expanded in RAW and JPEG modes, although RAW+JPEG burst capacity is still a paltry 5 frames. Still, while I like the RAW+JPEG mode myself, I have to admit that the speed and fluidity of the Photo Desk interface makes shooting entirely in RAW mode a very reasonable option. - And the 18-frame buffer capacity in RAW mode is excellent by any standard.
Battery Life
Battery life is one of the areas where the differences between the SLR/n and 14n are most obvious. The 14n approached legendary status in its voracious appetite for battery power, but the SLR/n in contrast does pretty well. I'd still strongly recommend having at least two batteries for the SLR/n if you're planning on serious shooting, more if you'll be away from a power outlet for an extended period. The nice thing about the SLR/n though, is that you can leave it sitting idle but powered-on, without incurring any significant battery drain.
Conclusion
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Note: Stay tuned, update coming:
As I've noted throughout this review, I was too crunched on time prior to the PMA show to run the SLR/n production model I received through my full battery of tests and measurements. I did want to get as much information out on the camera as possible though (particularly in the form of sample images), since it constitutes such a significant improvement over the 14n in so many areas. Stay tuned though, as I should have an update to this review completed within a week or two of my return (say, by early March), in which I'll give full details for all performance parameters.
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