Kodak DCS Pro Back 645
Medium Format Retains its Edge
This review is part of a larger series
of ongoing articles and reviews of medium format digital backs.
If you have not already done so you might wish to begin by reading my Digital Back Survey
and then refer to the other reviews in this series that are linked at the bottom of that page.
Illustration Courtesy Kodak
The Kodak DCS Pro Back 645 started out for me with two strikes against it, but in the end scored a resounding home run. The first strike came from my review earlier in 2003 of the Kodak DCS 14n. I had been very disappointed with the 14n, both from an ergonomics / design perspective and also in terms of its image quality at anything other than ISO 80-100 in bright light. I found it to be a flawed design and said so in no uncertain terms in my web review as well as in Issue #7 of The Video Journal. This was the first Kodak Pro product that I had reviewed, and it didn't put them in a good light.
The second strike was due to comments I had heard from an industry pundit of my acquaintance. He wasn't terribly complimentary about the DCS Pro Back, citing all kinds of issues. But my approach to testing products is always to draw my own conclusions based on empirical evidence, though hearing these negative comments didn't lead to a feeling of confidence beforehand. Nevertheless, I proceeded to obtain one for testing, since it appeared on paper at least to offer a terrific mobile digital solution for medium format photographers.
My friends at Vistek, Canada's largest professional photographic and imaging dealer, were kind enough to lend me a Pro Back for testing for a week. I would have preferred a version that fit my own Contax 645 AF, but none was available, so they additionally loaned me a Mamiya 645 AFD and a couple of lenses. I'd like to express my thanks to Vistek for their generosity and support of this test.
Mamiya 645AFD with 16 Megapixel Kodak DCS Pro Back
80mm f/2.8 lens @ ISO 100
Out of The Box
The DCS Pro Back 645 comes in versions for three cameras; the Mamiya 645AF and AFD, the Contax 645, and the Hasselblad H1. Each is priced at U.S. $12,000 and is proprietary to that specific camera in terms of mechanical coupling, electronic interface and viewing screen overlays (provided). There is an earlier version called the Pro Back Plus that can be adapted to most older 6X6 medium format cameras as well as various 4X5" backs. It is priced at $15,000.
The back comes with nearly everything needed to be fully functional, including a rechargeable Lithium Ion battery (rated for 450 frames, but more likely to give less than 200) and a dual battery charger. Extra batteries come in pairs for $145. The back itself fits in a supplied padded case. The total weight without battery is 1.7 lbs (.77kg). An AC adaptor for studio use is also provided.
A CompactFlash card is the only additional item needed (in addition to your camera, of course) and the back takes both Type 1 and Type 2 cards including Microdrives. I had no trouble with Microdrives (which is what I mainly use), but the back wouldn't recognize a TwinMOS 1GB high-speed card. I have read elsewhere that these backs have some compatibility issues with certain cards so I would urge that you test cards yourself before purchase, or confirm with someone who already has that a card that you plan on buying will be compatible.
Using the DCS Pro Back is about as simple as it could can be. It attaches to the camera just as does a film back. The rear panel has a minimal number of control buttons, and a colour LCD screen. On the whole the screen menus and their control functions are logically laid out and easy to navigate. Figure 1 below, taken from the Kodak documentation, shows the control layout and interface ports.
Fig. 1 — Illustration Courtesy Kodak
Below in Figure 2 you see a representation of the LCD screen when an image is displayed, and the choices that can be made. All settings are "sticky", so that if, for example, like me you like to have a review screen with a superimposed histogram, that is what will appear whenever you press the OK (#4 above) button after a shot is taken. Note though that unlike with most DSLRs there is no way to have the review image appear automatically after a shot is taken. You have to push the button each time, or simply leave the LCD on while shooting. Since the LCD is a big consumer of battery power this isn't a good idea, except in the studio.
Fig. 2 — Illustration Courtesy Kodak
Note as well that there is no power button on the Pro Back. It is turned on and off via the camera's power switch, and if your camera goes into sleep or standby mode and wakes up with a touch of the shutter release then so too does the Pro Back. There are also auto-power-down settings and auto screen shut-off time settings available. (More on this below).
Build quality is exemplary. The back is made of slightly crinkle-finished black magnesium. It is both light weight and rugged. The CF card door is nicely designed and easy to access, and unlikely to open accidentally. The LCD screen is slightly recessed and the buttons and flat-joystick control for navigating the menus are well designed and simple to learn to use.
The fit and matching with both the Mamiya 645 AFD and the Contax 645 is excellent. The Kodak back looks and feels as if it's all-of-piece with the camera. You'd think it was a permanent part of the camera body once its attached. On both bodies there is more than adequate clearance for your face to get up close to the eyepiece of the camera, which is not the case with some backs because of their depth.
Cosmetic matching with the Hasselblad H1 will be somewhat less satisfactory since the Kodak back is black while the H1 is a mix of gray tones. This is a trivial matter, but should be noted by those that care about such things.
The Lithium Ion batteries attach and detach positively and simply with a single recessed catch. They live down underneath the back and are well out of the way and unobtrusive, and because they are Lithium Ion they weigh very little. There is a review screen which shows you at any time the number of frames on the card, the ISO setting, battery level and more. The supplied charger has two battery positions and can charge both batteries simultaneously, unlike Canon's dual battery charger for the 1D and 1Ds that can take two batteries but only charge one at a time. Well done Kodak.
I have some possible concerns about the fact that the left side of the back has a number of external power and connection ports, none of which are provided with covers or plugs. Whether this proves to be a problem in inclement weather remains to be seen, but a bit of black plastic tape, though unsightly, will provided needed protection in wet and dusty places.
I won't provide all of the detailed specs since these are available in depth on the Kodak DCS Pro web site. The basics though are that the back is a CCD device with 4080x4080 pixels and has a colour depth of 12 bits/color — 36-Bit RGB color. The files produced are 96MB when loaded into Photoshop in 16 bit mode. This produces a print that's 17" X 17" at 240 ppi. Because the files are so crisp it is trivial to ress them up slightly and to be able to produce stunning 24" X 24" inch prints. (If you ever needed an excuse to buy an Epson 7600 or 9600 printer, this is it!).
On the memory card each losslessly compressed file is approximately 20 Megabytes, so a 1 Gigabyte card will only hold about 50 images. Fortunately 1GB Microdrives are now under $200, so plan on buying a handful if you get one of these backs.
As mentioned above, the battery is rated at 450 frames, but appears to produce about 150 frames without problem. At $75 each (and likely cheaper from some sources) having an extra couple of batteries on hand is not a problem, and can provide more than a full day's shooting even for the busiest pro.
The warranty on the back is for one year, and there is a four year limited warranty on the imaging chip itself.
Depending on the camera used the back can record about a frame every second or two for up to 5 frames before the buffer memory is full and writing to the card slows things down. There is a Firewire port for connecting to a PC so that files can be transferred, or for the control of the camera back via the PC. There is also an NTSC and PAL video port for connection to a TV monitor.
A comprehensive suite of both Windows and Mac software is provided, and I'll have more on this subject a bit further on in this review.
Medium Format Advantage
Mamiya 645AFD with 16 Megapixel Kodak DCS Pro Back
150mm f/3.5 lens @ ISO 100
One of the most frequent cries of pain heard on Net discussion boards is from photographers that have spent a large sum purchasing a new DSLR only to find that within a relatively brief period of time something newer / bigger / faster / better has come along. For some, and unless they have a big inventory of lenses of one particular brand, this often means jumping from model to brand, while trying to stay abreast of the curve.
For most pros this isn't practical. One makes a commitment to a certain brand, and then baring some unforeseen and remarkable occurrence (such as happened to me when I had to abandon my Pentax 645 system because it was incapable of taking digital backs) most photographers stick with one brand for a long time.
The advent of medium format digital has changed that equation. The same body and lenses can be used with a wide variety of digital backs from numerous manufacturers, and depending on ones shooting needs (catalog work vs. fashion, for example), one can switch from a high-res multi-shot back to a more moderate resolution portable solution in seconds. And, when technology moves forward (as it is currently doing at breakneck speed) a back upgrade is all that's needed.
A Matter of Size
Products don't exist in a vacuum. Photographic equipment in general and digital imaging equipment in particular exist in a highly competitive marketplace. When the 11 Megapixel Canon 1Ds appeared in the Fall of 2002 it was quite an accomplishment, and changed a lot of photographer's perceptions of what 35mm format digital could do. In fact it challenged many 11 Megapixel medium format backs. Therefore I'm going to be using it as a point of comparison.
Kodak DCS Pro Back 645
Canon EOS 1Ds
The chip in the Kodak DCS Pro Back is 4080 X 4080 pixels and 36.9 X 36.9mm in coverage. This makes it like a square 35mm frame on the long side. It also means that it is smaller that the nominal 42 X 56 size of a 645 format frame. The magnification factor is therefore about 1.5X, just about the same as we find with so-called reduced frame 35mm digital SLRs.
This has two implications. The first is that the area of the frame is roughly 1,369 sq/mm while a 35mm frame is 864 sq/mm. Nearly 1.6 times the area, in other words. Does that mean that you can make prints that are that much bigger at the same resolution? No, because width-wise they are the same. If you crop a Kodak Pro Back frame so that it is the same format as a 35mm-sized 1Ds frame (or Kodak 14n for that matter), they will be the same resolution.
But, is that how one shoots? No, at least not me. I've been shooting with 6X6 square for about 35 years, and I love working with the freedom to compose the aspect ratio of a photograph based on what "it" wants, not what some manufacturer arbitrarily decided years ago, and that is what shooting square provides.
So, what is the real-world size advantage? I'd say it's about 30-35%, giving a greater freedom to crop, and the ability to make larger prints overall.
Then there's the issue of loosing really wide angle capability. That medium format 35mm lens (which is like a 21mm) becomes effectively just a 35mm, as it would on a 35mm format camera. What to do? Well, why not pop off the digital back and throw a film back on the camera? We can't be that film phobic that the odd roll of Provia 100F can't see the light of day, now can we?
Reduced Frame 645
An interesting sidelight of this math is that even though 645 format has a 1.5X size advantage over 35mm, and therefore lenses need to be thought of as covering a smaller angle of view because the frame is reduced with the current generation of 16 Megapixel backs by the same amount, 645 format lenses end up giving the same angle of coverage as do 35mm lenses. So, a 50mm lens, is a 50mm lens. But, this also means that wide angle coverage is wanting, and so since a 35mm lens is the widest generally available for 645 cameras, that's the widest that one can shoot without stitching frames in software.
There is one hidden advantage to shooting this reduced-frame 645, just as there is with shooting reduced frame 35mm digital, and that has to do with lenses and their inherent chromatic aberration. When the 1Ds first came out there were those that thought that the camera's chip suffered from chromatic aberration, especially when using wide angle lenses. This turned out not to be fully the case (though some CA from the use of microlenses on the chip does exist). We were indeed seeing chromatic aberration (CA), but it was mostly caused by the lenses themselves.
Why had we not seen this before? Simply because no camera could show it before in the same way. We never saw 100% magnifications in Photoshop with such clarity before because scans rarely were able to show it to us. We certainly never saw them with traditional images because we rarely blew them up big enough for the CA to be seen, and even then there were the limitations of the traditional enlarging process.
So, with this as background we can understand that just as a reduced frame 35mm digital camera is using the "sweet spot" of the lens, and thus avoiding any CA at the corners, this now applies as well to 645 reduced frame digital. And, of course, the center of the lens has the highest resolution so there is an overall greater impression of sharpness on prints from such systems.
When I started using the Pro Back I thought that I would find working with less than "full-frame" 645 to be problematic. Reduced frame in 35mm digital terms usually means a smaller and dimmer viewfinder. Not here. The reduced coverage area is defined by lines on the interchangeable focusing screen. No viewfinder brightness is lost, and in fact I found that being able to see outside the lines to be a real plus. Just as with an M Leica, one can judge the framing much more accurately because one is aware of what lies beyond as well as what's within. (The Sigma SD9 uses a technique of putting a dim mask around the part of the screen that isn't recorded, a worthwhile design for the same reason).
Kodak DCS Pro Back 645 — 100% detail
Canon EOS 1Ds — 100% detail
A colleague and I spent a lot of time shooting comparisons, making prints, and examining 100% views in Photoshop, comparing images from the DCS Pro Back and those from the Canon 1Ds. Compared strictly on the basis of resolving power (initially using Mamiya 645AF lens, and again a week later using Zeiss lenses on my Contax 645), I would judge them to be essentially equal,with maybe a slight edge to the Kodak.
Part of the reason that there may be a slight advantage to the Kodak back regardless of total chip size is that it lacks an antialiasing filter, which the Canon 1Ds has. An accessory AA filter is available for the Pro Back at a price of $US 1,450. My feeling is that fashion photographers are likely to either want or need to use one but that most other photographers will be just fine without one, and will be able to cope with occasional moire using software tools.
Do remember though that while resolution as compared with a full-frame 11MP or 14MP 35mm DSLR such as the Canon 1Ds or Kodak 14n is comparable, the overall usable size of the file is considerably larger with the Kodak back. I know that the following is going to be a controversial statement, but bear with me.
I find that there is about a 30% practical advantage to a 16MP square image as opposed to an 11MP rectangular one — at least that's the case for me and the way that I work. The reason is as follow. I rarely print a full frame in the 1.5:1 35mm rectangular format. I don't often find that this aspect ratio is the best for any particular shot, and often I haven't been able to either get close enough or to frame the subject appropriately. This means that I will crop the frame, and this reduces the amount of usable real estate in the image.
By having a square 37 X 37mm image to work with I can crop horizontally or vertically or even leave it square, or something inbetween. If you look at the hundreds of images on this site you'll see that a full frame 1.5:1 frame is a rare occurrence. For this reason I believe that the 16MP frame from the Kodak back, (or any other 16MP back for that matter) gives me roughly a 30% increase in real-world usable image real estate.
Not convinced by my argument? That's OK. If your style is to print every millimeter of the frame, including the rebate and frame numbers, just as Oscar Barnack intended it to be, more power to you. That being the case you may not realize the increase in image size and thus available resolution that I do. It works for me though.
Kodak DCS Pro Back
The above MacBeth colour charts were shot under open shade conditions. Each shot was metered by the cameras, based on a full-frame gray card reading. They were within 1/3rd stop of each other. Both files were RAW converted using Adobe Camera RAW and both were shot with AWB set. The Kodak image came in a 6200 Kelvin while the Canon was at 5340 Kelvin. I had heard that Kodak digital backs tended to be somewhat cool on their Auto White Balance setting and this bore it out. I set the gray point within Camera RAW and exported to Photoshop in 16 bit mode. There I set the White and Black points using the appropriate chart squares.
Though some of the colour differences are compressed here in web reproduction due to the use of sRGB, here's what they look like to me within Photoshop in the Adobe RGB colour space, using a profiled and calibrated monitor. (Please do not debate what I report below against what you see here. Web reproduction simply can't convey what I am seeing in a different colour space). I wanted to also do a Delta E measurement, but I'm working from my place in the country this summer and my spectrophotometer is at the office, so a visual comparison will have to do.
Overall I find the Kodak back's colour rendition to be somewhat more accurate than that from the 1Ds. Red in particular is much more accurate on the Kodak, with the 1Ds' reds being less saturated and "muddier". The 1Ds does a slightly better job with the blues, though purple is more accurate on the Kodak. I give a slight edge to the Kodak on the greens as well.
Overall both systems do a very fine job of colour reproduction, and unless one is doing product photography where absolute colour accuracy is necessary (in which case you'll need to profile the camera or back), neither system will let you down.
How Clean is it? Really Clean!
After the trials and tribulations of cleaning 35mm DSLR sensors, using a medium format digital back like the Kodak is an unmitigated pleasure. When the back is removed from the camera the imaging sensor is completely exposed (though always covered with either an IR or AA filter), and cleaning the filter is as simple as a wipe with a Pac*Pad, and if necessary a bit of Eclipse fluid. Nothing could be easier. This alone could be enough to cause some users to switch to medium format :-)
In fact the early test frames that I shot with the Kodak Pro Back were the absolutely cleanest images that I have ever dealt with — ever. Not one single dust spec visible over the entire frame at 100% magnification. If, as I do, you shoot 1,000 frames a month or more, this is a really big deal. Score one for medium format.
A Single Unit
What sets the Kodak Pro Back apart from any other medium format digital back to date is that it is a single integrated back. Imager, storage, and power in a single unit. No cables, and no computer needed to schlep along or trip over. Just like shooting with a 35mm DSLR.
Now, please realize that while this is important for the type of shooting that I do, it may not be for you. I travel widely and do a lot of hiking. Small size, low weight and lack of an attached computer, or storage device, or power supply, is a must. Your type of work may make this less important or not important at all.
Let me be polite. I'm not a big fan of Kodak's provided Photo Desk software. In fact I think it's dreadful. It is from the same mold as Canon's RAW conversion software — designed by someone who has no idea of the value of time. Every change that you make to the file during RAW conversion requires a complete recalculation of the file, taking about 30 seconds, even on a 2Ghz machine with 1GB of RAM. In other words, frustratingly slow and verging on the unusable. The software also has limited capabilities compared to the competition, and here I'm thinking of the fast, slick and full-featured image processing software from Phase One and Imacon.
During the first day that I had the Kodak back for testing I despaired of being able to get the job done because the software is so poor. But then I was chatting on the phone with my friend and colleague Uwe Steinmeuller of Digital Photo Outback and he asked, why wasn't I using Camera RAW? "You're kidding", I said, and within minutes my problems were behind me. I had not remembered that the Kodak back is one of the devices that Camera RAW supports, though not "officially". In other word the file format support is built in, but not supported by Adobe in this release. I found that it worked very well though and had no difficulties with it.
The back also allows the creation of JPG files as well as standard TIFFs. You can set the back to create these files as a background task when it's not doing anything else. This JPG file is in a proprietary Kodak format called ERI JPG that allows you to charge items such as colour temperature after the fact, just as if it was a RAW file, though this can only be done with Kodak's provided plug-in. Otherwise these JPG files are seen as normal files by other programs.
The back also allows you to save files as cropped verticals or horizontals, as well as native square images. I suppose that this will appeal to some types of photographers such as portrait shooters, but for most people this accomplishes little other than to save a bit of disk space, since it is no different than cropping the frame after the fact in Photoshop.
Camera RAW to the Rescue
In addition to having a superb integrated interface within Photoshop, Camera RAW in fact does a superior job of handing Kodak digital back files, ease of interface and faster operation aside. If you have a Kodak back, this is the software to use. Later in 2003 Photoshop 8 will be out and the capabilities of Camera RAW will be built in, so there is no software issue worth fretting about with the Kodak back.
Oh yes, someone is going to write and tell me that Kodak's Capture Studio (Mac Only) is better than Photo Desk. Yup, it is. Much better. In fact it's on a par with other leading RAW conversion software. But why Kodak in it's great yellow wisdom decided to only make it available for the Mac, when 85% of the computers in the world run under Windows, is a mystery. (Yes, I own and use a Mac. In fact it's my main Photoshop machine, so please don't write and tell me how it's better than a PC. You'd be preaching to the choir.)
Noise and ISO
Canon's CMOS technology has developed a well-deserved reputation for low noise at high ISOs. The D60 and 10D specifically are stellar in this regard, though the 1Ds is no slouch. How would the Kodak Pro Back compare?
Not at all bad, I'm pleased to report. I don't have a side by side with the 1Ds at this time, but here are three frames showing exposures taken with the Pro Back at ISO 100, 200 and 400. The area shown is a 100% enlargement of a very out of focus subject so that you can see what the noise alone looks like in both a medium and dark toned area. No sharpening has been applied to these frames.
I regard the Kodak Pro Back as being essentially noiseless at ISO 100. ISO 200 noise is more than acceptable, and any noise present at this speed is nearly invisible on a 20 X 24" print. ISO 400 noise is visible at that size, but no worse than seen from ISO 100 film grain. An application of Neatimage's magic and even that would become invisible. So much for noise.
The other aspect of shooting digitally that has potential for generating increased noise is long exposures. Because the Kodak back is not actively cooled, or have a built-in fan like the Imacon Ixpress, it will undoubtedly be noisy at long exposures. Kodak recommends that you turn on the camera's built-in noise reduction mode for exposures longer than 1/4 second. This creates a dark frame and then subtracts it from the exposure. But it also makes the post processing time as long as the exposure itself. This method is also used by several other digital backs and cameras and is the price you pay in some cases for in-camera noise reduction.
Moire? What Moire?
Contax 645 with 210mm f/4 Sonnar and Kodak DCS Pro Back @ ISO 100
I wish that I could show you a 20 X 24" print of this photograph! A JPG on the Web simply can't show you the detail that this image contains and how much resolution there is to enjoy. For example — see the truck on the wharf in the lower left hand corner? In a large print you can easily not only read the company name but also the telephone number in smaller type beneath it!
This amazing resolution is in large part due to there not being an antialiasing filter on the DCS Pro Back. Some $1,500 will buy you one that can be added on, but unless you're shooting lots of fabrics, why bother? Enjoy the resolution.
The trade off for this higher resolution is of course that moire occasionally rears its ugly head. The frame above shows what it looks like. But, and it's a big but, even in a 24 X 24" print it's virtually invisible. The enlargement you see is nearly 6 feet wide at screen resolution! At any smaller size the moire is all but invisible. I'll take the trade-off any time.
Hint — you'll find this grill roughly in the center of the frame showing the ship.
Contax 645 with Kodak Pro Back Vs. Canon 1Ds
Of course the inevitable question is — how do they compare, and which one should I get? I solved the dilemma but having both, and as I point out below I've been working with both medium format and 35mm for decades (as have many professional photographers), and each has its place. Nevertheless, here's my take on the pros and cons between these two excellent systems.
Kodak DCS Pro Back 645 Canon EOS 1Ds
If you crop the Kodak back's frame so that it is the same size as that from the 1Ds then image quality in terms of resolution (all other things being equal) will be roughly the same. But, if you are like me and want to have maximum versatility for framing and cropping, the extra real estate of the 16 MP vs. 11 MP sensor will provide a distinct advantage.
Colour Rendition and Dynamic Range
The Kodak back has slightly superior colour rendition, though only the most finicky user will be swayed by this small advantage.
High ISO Image Quality
The Canon has a strong advantage. After ISO 200 the Kodak starts to get a bit noisy. The Canon stays exceptionally clean to ISO 400, and is quite usable at ISO 800. The use of Neatimage can help in both cases of course and does tend to level the playing field.
Lens Choice and Lens Quality
The Canon has the widest choice of lenses by far, including wide aperture lenses, tilt / shift, Image Stabilized telephotos, zooms, etc. The Contax's lens choice is much more limited, but they are each superb. Zeiss glass is as good as it gets.
Full Frame and CA
The Canon 1Ds is a full frame camera and therefore can run into chromatic aberration at the edges, due to both lens limitations and the use of microlenses on the chip. The Kodak back has reduced coverage over full frame 645 and therefore is using the "sweet spot" of these already sweet lenses.
There's no contest. The Canon at 3 FPS for 8 second is the hands-down winner. The Contax / Kodak can do 6 frames in 15 seconds. Great for landscape work, portraits, some fashion, and the like, but not any form of shooting where rapid frame advance is required.
Dust & Sensor Cleaning
Like all 35mm format DSLRs the Canon 1Ds' sensor is a bitch to keep clean. No matter what you do or what tools you use the sensor is frequently speced with dust. The Kodak back, like all medium format digital backs, has an exposed sensor and keeping it clean is a trivial task. 10 seconds with a Pek*Pad and some Eclipse fluid and it's done — right to the corners. This advantage is not to be underestimated.
Because of the larger sensor size and thus file size one can only get 50 images on a 1 Gigabyte card with the Kodak back, while double that is possible with the Canon 1Ds. Obviously you'll need twice as many cards for the Kodak, but, will you shoot as much with this system as with the Canon? I don't think so.
Square Vs. Rectangular
This is almost a religious question. I've shot for more than 30 years with 6X6 square medium format, first with a Hasselblad 500C and EL, and then with a Rollei 6008. I like shooting square. The Canon 1Ds is, of course, 1.5:1 rectangular. I find that when I shoot square I end up not only cropping more creatively but also having more usable image real estate. You may think otherwise. Chaque a son gout.
Mechanical Switches vs LCDs and Buttons
This too is quasi-religious in nature. I'm totally comfortable with the LCD screens and buttons and modality of contemporary cameras like the Canon 1Ds. But, the Contax 645 is completely traditional in this regard, with mechanical switches, knobs and aperture rings. There isn't an LCD screen in sight (other than the one on the Kodak digital back). I like it and in many ways find it superior to buttons and LCDs. This is because there is no modality. By this I mean that every control just does the one thing that it was designed to do, and not several different ones depending on which mode you're in. When the light is changing quickly or the subject is fleeting there often isn't time to think about modes. If I have the choice I'll pick traditional mechanical controls every time.
Also, certain things that should be simple and quick to set, are. For example the Contax has a button for mirror lock up. Press it and the mirror locks up. The Canon 1Ds requires that you press buttons four separate times and consult an LCD screen to be able to turn mirror lock-up on, and then again off. I don't know what you prefer, but I can tell you which ones I think is superior.
Weight & Bulk
There isn't much to choose here. I won't even bother to give the weight specs. These are both heavy and bulky camera systems — about as big as one would want to work with all day in the field. A body and 2-3 lenses and accessories will fit in a Lowepro Minitrecker backpack, and even though I'm middle aged I can hike with this kit and a carbon fibre tripod for 3-4 hours at a time, so the portability issue doesn't come down more in favour of one than the other.
Features & Foibles
The Kodak back has no power switch. It is turned on automatically when you turn on the camera that it is attached to. But, it doesn't turn off when you turn off the camera. Instead you can set a turn-off time within the back's control software. But, the minimum time that you can set is 1 hour. This means that if you turn on the camera, take a shot and then turn the camera off, the back will remain "live", consuming battery, for a minimum of one hour. The drain seems small in this mode, but why not allow for a shorter turn off time? (A trick that I found for overcoming this is to pop the battery off and then reattached it. This makes the back forget that it's "on").
You can also program the back to turn off the review screen after a fixed amount of time. I've set mine to 30 seconds. But, the camera can not be set to automatically display a review image of the frame just shot. You have to explicitly press a button on the back to do so. Why not have it appear automatically if desired? This is simply a matter of bad programming on Kodak's part, as virtually every DSLR that I know of allows this.
The body and back communicate a great deal of information to each other. The EXIF data contains the shutter speed and aperture used. But what it doesn't contain is the focal length of the lens used. Since the camera knows this (it is passed to the back for imprinting when shooting film) why isn't it known by the Kodak back and made part of the EXIF data? It's a mystery, but I wish that Kodak's programmers had been a bit more rigorous with sweating details like this.
The LCD screen is not one of the best that I've seen. If you set the contrast so that the menus are readable, the review images are far too dark. Set the screen so that the review images are bright enough to view in daylight and the menus are washed out. The Kodak back does allow for different modes of displaying the review image, including full screen, full screen with magnification up to 1:1, and partial screen with histogram.
The back can be set to "flash" overexposed highlights on he LCD screen, but curiously this warning doesn't work when the display is set for histogram review. Another example of Kodak not sweating the software details as much as they might have.
After a week of intensive testing, what have I concluded? By way of comparison with the Canon 1Ds, two things. Firstly, that while the 1Ds' $8,000 price tag seems high to most people, it is in fact a hell of a deal compared to what one has to spend for anything comparable, let alone better. Is the Kodak DCS Pro Back 645 better? Yes. Judged strictly in terms of image quality (though not at the extremes of ISO settings, or frames / second). It's a subjective judgment, but I place the improvement at about 30%.
The back's price of $12,000 doesn't include a camera, so if you add a Contax 645, for example, you're at $16,000, which is double the price of a 1Ds. This simply goes to show that incremental improvements in image quality require significantly more money to achieve.
Further to the issue of price, some will blanche at the seemingly high cost of this type of gear. Bear in mind though that these are professional tools for people who make a living with them. Few pros are bothered by the cost of first rate gear because it is what allows them to remain competitive in their field. Its also a depreciatable business asset.
Since my interest in testing medium format backs was more than academic, I looked as well at what the other choices were. Compared to the Kodak Pro Back, there really weren't any. All other medium format backs of 16MP or higher are tethered, and as good as it is, my experience with the Imacon Ixpress showed that having anything other than a single piece unit didn't suit my style of shooting at all. The Leaf Valeo 22 offers a tempting alternative, but at $30,000 this 22 Megapixel back is out of my price range.
So, the Kodak Pro Back became my choice, and at the end of my week of testing I called Vistek and placed my order for a version to fit my Contax 645. From now on as I review future digital backs the Kodak will serve as my point of reference along with the Canon 1Ds.
And what of the 1Ds? Does my move to the Kodak Pro Back signal a switch away from the Canon and 35mm? Not at all! I have shot using film for 30+ years with both 35mm and medium format. Each format served its purpose and had its place for specific types of shooting. Now the same thing will simply apply to working completely digitally. As I stated in this article's title at the top of the page — medium format retains its edge.
There are two other full reviews of the Kodak DCS Pro Back on the Net that I am aware of; one at Naturephotographers.com and the other at Steves Digicams. Digital Photo Outback also has a brief report on the Kodak Pro Back and Contax 645 combination.
Update: There is a comprehensive report on PhotoNet by a photographer who compared a Canon 1Ds, Kodak Proback 645, Leaf Valeo 11 & Phase One H20. He ended up choosing the DCS Pro back and provides his reasons why.
In The Field
In early October 2003 I used the Contax / Kodak DCS Pro Back combination on a major shooting trip for the first time. In my write-up titled The Canadian Rockies I feature images from that shoot as well as well as a detailed report on my field experience with this equipment.
In early 2004 Kodak decided to exit
from the medium format digital back business.
Therefore, the DCS Pro Back 645 has been discontinued.