|The Kodak DCS-620x
A Hands-on Review by Tom DeRousie, Modern Imaging
May 15, 2000
How do you improve on one of the most advanced, durable, high-quality professional tools like the Kodak DCS-620 digital camera? Kodak found a way!
The Kodak DCS-620
The Kodak DCS-620 was introduced just over one year ago as an answer to those working professionals that wanted the advanced technology that the Canon based DCS-520 offered, yet on a Nikon body. Previous Kodak Professional digital cameras were built on the Nikon 8008 or the N90 bodies, however, when the engineers sat down to design the DCS-620, they decided that it was time to incorporate the benchmark of film camera bodies, the Nikon F5. The Nikon F5 is built to be used, used, used, and even to some extent, abused. This made the Kodak DCS-620 a very viable choice for professional photographers that depend on their tools to do their jobs on a daily basis, under numerous, sometimes non-favorable, circumstances.
Kodaks software and firmware has continually evolved and improved over the years. Users of the DCS-620 enjoy such advanced features as
Introducing The Kodak DCS-620x
The Kodak DCS-620 offers ISO speeds ranging from 200 1600. This is where the DCS-620x departs from the DCS-620. Did they manage to tweak a "little more" out of the DCS-620? Hardly! The DCS-620x offers an amazing range from ISO 400 6400 (thats right, no misprint, ISO 6400!). For photographers working in low light and/or shooting fast moving subject matter, this new offering is a dream come true! Imagine those (not so uncommon) situations where you have your 300mm f/2.8 lens wide open to "get the shot" (even at ISO 1600). With the DCS-620x, you could get the same shot (using the same shutter speed) at f/5.6 (yielding more depth of field or allowing the use of smaller, less expensive lenses) or increase your shutter speed further guaranteeing the results you desire/need.
How do the images look at ISO 6400? As one might expect, the images are not "perfect" when shooting at the maximum ISO speed (otherwise, who would shoot at slower speeds?). The results are, however, quite impressive considering the lighting conditions (or lack of light) that they are obtained under. Kodak notes that the DCS-620x is "calibrated" from ISO 400 4000, but allows image capture up to ISO 6400. So what the heck does that mean? Photographers feedback indicated that some image quality loss would be acceptable in a trade-off to gain additional ISO speed. It is better to get a lower quality shot rather than no shot at all! Obviously, if the extreme ISO of 6400 is not necessary, better quality can be obtained at lower ISO speeds. Kodak therefore recommends normal usage in the ISO 400 4000 range.
When comparing images captured at other speeds, it is evident that there is clearly one (plus) full stop of speed gain with no apparent loss to image quality. Images shot at ISO 3200 on the DCS-620x look every bit as good as those captured at ISO 1600 on the DCS-620. This follows suit all the way down to ISO 400 (DCS-620x) vs. ISO 200 (DCS-620). Kodak has elected to drop off the lower ISO speed of 200 on the DCS-620x since the camera is designed for photographers that typically require higher ISO speeds and would likely not use an ISO speed that low.
I took the Kodak DCS-620x (pre-production model) around the Detroit area and "grabbed" several images. Most of these images were taken from a moving vehicle, using a handheld 80mm 200mm f/2.8 lens (aperture priority set to f8). The ISO was set to 1000. When I got back and acquired the images, I was floored by the quality of the results! Even under these "less than optimal" conditions/settings, the results were astonishing. Click here for image samples/details.
How Do They Do That?
The obvious question (especially for competitors) is "how is it possible to get that much speed without quality loss?" Essentially, this is accomplished by minimizing the amount of light loss at the CCD imager itself. Since all CCD imagers are color blind, they must have color filters in front of the CCD in order to determine the correct color of the scene/subject matter being photographed. The traditional CCD has an array of color filters (red, green, and blue) on the front that allows the chip to analyze the light passing through to a group of adjacent pixels. This group consists of a red pixel, a green pixel, and a blue pixel. The light (energy) levels of these pixels (along with adjacent pixel groups) is used to determine the correct color(s) for that group of pixels.
While the basic color analysis/processing concept has not changed in the Kodak DCS-620x, the color filters used has. Instead of using red, green and blue color filters, Kodak has incorporated the usage of cyan, magenta, and yellow color filters thereby reducing light absorption by the filters themselves. CMY filters pass through more light since they are single layer filters. RGB filters are "built" with CMY filter combinations. For instance a red filter is made with a layer of yellow and a layer of magenta. A green filter is made with a layer of yellow and a layer of cyan. A blue filter is made with a layer of magenta and a layer of cyan. As we all know, stacking color filters increases the amount of light loss. Therefore, using a single color filter for each of the three colors effectively increases the ISO speed of the CCD chip. Going from RGB to CMY color analysis is now possible since the recent advancements of the Kodak CCD chip(s). For a complete more in-depth technical discussion, click here.
Admittedly, I was a bit surprised that Kodak elected to introduce this enhanced technology on one of their "old" cameras. In the digicam world, resolution is the key comparison feature for most customers. Since consumer-level cameras are being introduced with 3+ megapixel chips, it would seem mandatory that Kodak introduce a higher resolution chip to "keep with the times". However, after considering all of the factors, this choice makes a lot of sense.
First, having used Kodaks 2 megapixel "blue" chips for over a year now, I can honestly say that the image quality yielded is simply awesome. I routinely print up to 12" x 18" dye sub and/or ink jet prints that leave nothing to be desired. I have printed 20" x 30" RA-4 prints that compare very favorably to 35mm film. Is this to say that there would be no difference in a 2 megapixel image when compared to a 3 megapixel image? Comparatively (side by side), yes, there would be some edge sharpness/detail definition differences. However, qualitatively (stand-alone assessment), you would not readily notice the difference (unlike jumping up to Kodaks 6 megapixel cameras). The key to this quality is not in resolution alone, but in color bit depth, pre-image processing optimizing, advanced software design, etc.
Second, there are some definite trade-offs for higher resolution. They include slower camera performance, reduced battery life, fewer images on storage media, slower image processing, etc. The "perfect" camera (is there such a thing?) is built with all factors balanced out for the intended application. Resolution alone is only one of the many factors to be considered.
The Nikon D1 vs. Kodak DCS-620x
Obviously, this comparison will be made time and time again. For the photographer that requires higher ISO speeds, the Kodak DCS-620x clearly fulfills this need hands-down over the D1. Also, more storage options are presented with the Kodak DCS-620x rather than the somewhat limited Type I or II CompactFlash only presented by the D1. Those DCS media options include:
Of course, the aforementioned software/firmware features/options set the Kodak DCS-620x apart from the Nikon D1. Direct cellular transmission of images while continuing to shoot is another clear-cut advantage of the Kodak DCS-620x (watch for my upcoming review of this new feature).
Forcing the photographer to work with "canned" image processing (JPEGs) instead of providing the photographer with a space-saving, lossless compression TIFF file (approximately 1/3 the size of a standard RGB TIFF) does not insure optimal image quality from shot to shot, condition to condition. Not providing the photographer with their "digital negatives" is like asking a photographer to optimize a bad print made from a negative rather than allowing the photographer to reprint the picture from the original negative (with appropriate processing compensations). Optimal results simply cannot be had, period! The Nikon D1 does offer NEF files that allow (with third party processing software) for some of the advanced options/processing that the Kodak software/files offer, but at the expense of storage space and camera performance. Nikons D1 NEF files are roughly three times the size of the equivalent Kodak TIFF files since the D1 does not offer any sort of compression (other than lossy JPEG compression).
I have used the Nikon D1 and compared image quality to the Kodak Professional DCS cameras. Although the Nikon D1 initially "feels" better in some respects, the ultimate test is really image quality under a variety of shooting conditions/circumstances. I am far more comfortable relying on and recommending the matured, advanced technology and image quality that Kodak offers at this time. Perhaps this would change if Nikon realized the importance of keeping the camera in shoot priority mode at all times (even when reviewing images on the storage card), providing the unprocessed "raw" files in a lossless compression form, allowing more storage media options, etc. Although Nikon will surely improve the D1s software/firmware over time, the D1 is not capable of offering all of these features do to its inherent design limitations.
As of May 15th, 2000, the list price of the Kodak DCS-620 is being reduced from $10,750 (street price of around $8,500) to a new list price of $8,995 (16.3% price reduction). The DCS-620 will continue to be offered for photographers that do not need the higher ISO speed of the DCS-620x.
The DCS-620x will be introduced on June 1, 2000 with a list price of $10,495 (slightly less than the DCS-620s old list price).