|Polaroid SprintScan 4000 Scanner
Polaroid's 4000 dpi scanner has resolution to spare, and fast operation to boot.
(Review first posted 05/31/2001)
||High end "personal", inexpensive "professional" film scanner|
||4000 dpi resolution (65 meg file from 35mm negative!)
||12 bits per channel
||High-speed SCSI interface
||Software with both "photographic" (RGB) and "prepress" (CMYK) scanning methodologies
When most folks hear the name Polaroid, they immediately think of instant print film. The company's experience runs quite a bit deeper than that though, and in fact they possess a great deal of intellectual property around the whole area of color management translation. They're not as widely known in the digital world as some of the other "film giants", but their film scanners have earned a good reputation for solid operation and good color.
The SprintScan 4000 that's the subject of this review has actually been on the market for a little while now, and in fact was the first 4000 dpi film scanner on the market anywhere close to its price range. It's positioned at the top of the "personal" scanner market, or as an affordable option for the professional realm. We see it meeting the needs of anyone wanting to get maximum detail out of their film, with a relative minimum of hassle and time. It doesn't offer some of the sophisticated defect-removal technology (dust and scratch elimination) that has appeared in some more recent models, but it proved itself to be a fast, capable performer in our testing. Despite its relative age, it competes very well against the current crop of scanners at or near its price point.
- Color or black and white 35mm negatives and positives, APS with optional adapter.
- 4000 dpi maximum input resolution
- 12 bits per channel digitization accuracy
- Claimed Dmax of 3.4 optical density
- High speed SCSI-2 interface
- Long-life cold cathode fluorescent light source
- Ships with PolaColor Insight and SilverFast Ai scanning applications
About the size of a shoe box, the SprintScan 4000 fits well on a desktop. Overall dimensions are 7" x 5.5" x 12.5 inches (17.8 x 14 x 31.8 cm), and it weighs in at 8 lbs. (3.6 kg). You'll need to leave up to a foot of additional space behind the scanner though, as the film carriers pass entirely through the scanner body in the process of scanning, and project out the back again. It thus needs a bit deeper work area, or a table not backed up against a wall, in order to provide clearance for the film carriers protruding from the back as successive frames are scanned.
The SprintScan 4000 connects to the host computer via a fast SCSI-2 interface, so you'll need to install a SCSI card in your computer, if you don't have one already. Older Macs (beige PowerMacs and before) typically came equipped with SCSI ports on them, but models since the blue/white G3s do not. Windows machines will pretty well always require the addition of an ASPI-compliant SCSI card.
The scanner ships with two software CDs, one containing a standalone application, PolaColor Insight, the second the widely acclaimed SilverFast Ai plug-in for Adobe Photoshop(tm), by LaserSoft. Both packages support both Mac and PC platforms. PolaColor Insight is an easy-to-use piece of software that works in RGB color space, while SilverFast is a good bit more involved, handles both RGB and CMYK color, and has many features oriented toward prepress scanning. (Scanning CMYK images for use in offset-printed publications.)
Scanning resolution can be as high as 4000 dpi. This produces maximum image sizes of 5619 x 3831 pixels with 35mm film, for a file size of 64.6 megabytes.
Bit depth is another important parameter for scanners, as a measure of both color accuracy and the maximum density range a scanner can recognize. (8 bits per channel is average 10 better, and12 quite good. A few scanners are now beginning to appear with 14 bits per channel of digitization accuracy.) The SprintScan 4000 captures a full 12 bits per channel, and furthermore allows you to import the full 36 bit image (12 bits in each of three color channels) into Photoshop.
Scanner Optics and Light Path
Film scanners have either fixed focus or variable focus optics in them. We're not sure which category the SprintScan 4000 falls into, but believe it to be a fixed focus design, since the software never offered an option to adjust the scanner's focus, and the scanner itself never seemed to go through a focusing cycle. Given the extreme resolution of most film scanners, we're surprised that their lenses can be designed with enough depth of field to insure sharp focus in the face of minor variations in the film plane position. We're surprised, but the fixed-focus approach nonetheless seems to work quite well, as evidenced by the performance of the SprintScan. Of course, the upside of a fixed-focus design is that focusing is no longer a concern, either in the form of twiddling a thumbwheel or by waiting while the scanner adjusts its focus for every scan. In our testing, the SprintScan produced sharp images every time, the sole exclusion being our unusual "USAF 1951" resolution target, which is a glass slide with the pattern deposited on one side of it. As with some other scanners we've tested, with the pattern facing one way, we got sharp results, but decidedly softer ones with it facing the other. Neither orientation was as sharp as it could have been though, and there was a lot of "flare", apparently caused by the great thickness of glass in the optical path. We saw no evident focus deficiencies while scanning normal slides or negatives.
The SprintScan 4000 uses a special fluorescent light source to illuminate the film. In the past, we've seen scanners with fluorescent illumination produce somewhat "softer" scans than those using more collimated light sources. With the SprintScan 4000 though, we saw no hint of softness in its scans, and in fact, it produced some of the most razor-sharp detail on our "House" image that we've seen yet.
Like most film scanners we've tested, the SprintScan 4000 uses sturdy plastic slide and filmstrip holders to carry the film through the scanner. Operation is simple, you first place the media to be scanned into the holder, then insert the holder into the scanner. The holders have slightly tapered front edges, to facilitate insertion into the scanner. You insert the holders slightly beyond where you feel slight resistance, at which point the scanner recognizes the presence of the holder, pulls it further in, and then moves it back and forth until it's properly registered and ready to scan the first frame. You can remove the holders at any time simply by tugging on them: There's a slight resistance, but it doesn't appear to harm the frame-advance stepper motor at all to override its resistance while the scanner is idle. The scanner body has openings on both ends, allowing the end of the film holder to project out the back as successive frames are scanned. (In the process, requiring a bit deeper work area.)
The film holder is a fairly standard clamshell arrangement, only this one is hinged at the front and opens lengthwise. ("Alligator mouth" instead of "clamshell"?) A series of raised bars on either side of the film opening position the film side to side, and a clever little sliding gadget with pins that fit the film's sprocket holes handles fine positioning along the length of the film. The film adapter worked well, but we did find that we had a bit of trouble with film that was badly curled lengthwise. It was hard to hold down the film while closing the clamshell, and the little ridges meant to guide the film laterally weren't always where they needed to be to catch the ends of the film and keep it aligned. (Our favorite design for film holders is to have a continuous recess running the full length of the adapter. This helps greatly with curled film.) The provision of a control to slide the film back and forth once it was loaded was a very nice touch though.
The slide holder has four recesses into which slides can be loaded. A spring-loaded finger presses one edge of each slide against sturdy ribs that cross the adapter side to side. There's about a millimeter of play between the edges of a standard slide mount and the sides of the adapter recess, allowing that much side to side adjustment of the individual slides. The spring-and-rigid-backstop arrangement provides for a very positive alignment of the slide to the adapter, but this turns out to be a bit of a two-edged sword. We've often encountered slide mounts in which the film was rotated slightly with respect to the cardboard or plastic mount. Some scanner adapters allow slight manual rotation of the slides to compensate for poor mounting jobs, correcting for the rotation of the film with a counter-rotation of the slide in the adapter. The SprintScan 4000's adapter permits no such adjustment, but the benefit is that there's virtually no chance of inadvertently rotating a slide in the holder. Another nice aspect of the 4000's slide holder is that it's very forgiving of unusually thick mounts, such as our glass USAF resolution slide, or bulky glass-and-plastic mounts.
Polaroid calls this scanner the "SprintScan", a name suggestive of speed. We found the allusion apt, as it seemed faster than some other high-end desktop scanners we've tested recently, although scanning with it is still an exercise in patience if you're used to the instant gratification of a digital camera.
Prescans (to produce low-resolution views of the film being scanned, to assist with cropping and color/tone adjustment) routinely took about 25 seconds. This is about midrange among scanners we've tested, with some taking as little as 12 seconds to generate a preview, and others taking upwards of a minute when their color management system was engaged. We generally found the prescan time less of an issue with the SprintScan, as we didn't find a need to repeat prescans very often while tweaking the scanning parameters.
For the scan itself, the SprintScan's processing involves five stages: Calibration, scanning, rotation, color correction, and file saving. Rotation, color correcting, and file saving will be very dependent on the computer the scanner is attached to, but the calibration and scanning stages should be about the same regardless of host. In our testing, we had the SprintScan connected to a slightly aging PowerMac G3 433 MHz CPU, with 192 MB of RAM, and the scanning software running in a 145 MB partition. We tested scanning speed with Polaroid's own PolaColor software. Here are the times we measured for a maximum-resolution RGB scan of our black/white resolution target film:
We were surprised that calibration took as long as it did at the beginning of each scan: This is pretty well a fixed time, regardless of how large a scan you're doing. The scanning itself was quite fast, particularly given the size of the files produced. Smaller scans are much faster: Our 1828 x 862 scan of the Musicians slide took only 75 seconds in its entirety, including 52 seconds for calibration. (No, we're not sure why calibration for that scan took 12 seconds less than the time reported above for a maximum resolution image. There seemed to be a good +/- 10% variation in the prescan times we saw with the unit.) You'll note that rotation of the scanned image takes a fair while on larger files: You may want to defer that operation to post-scan processing in Photoshop or other imaging software, as in our experience, you'll likely want to open the scans to retouch dust spots, make fine color adjustments, etc, as part of your normal workflow. The Color Correction item in the table refers to PolaColor's application of its IQA color management. This seems a good bit faster than other color management schemes we've seen used on other scanners we've tested.
For a full analysis of the results we obtained with the SprintScan 4000, check our sample pictures page for it. - You'll find a full analysis of each of our standard test scans there, as well as the sample images themselves. For now, a brief summary of what we found:
As one of the very first 4000 dpi desktop scanners available, the SprintScan 4000 led the market by a good 18 to 24 months. With other 4000 dpi models now becoming available, we were somewhat surprised by how well the SprintScan held up to the current competition. Color was excellent, dynamic range very good, and speed better than several more recent models. It was also notably easy to use, either with Polaroid's own PolaColor scanning software, or the excellent (but more prepress-oriented) SilverFast AI by LaserSoft.
We liked the SprintScan's speed, not only in the scanning, but in the workflow, which seemed to require relatively little repetitive prescanning as we made tonal and color adjustments. Scanning is still an exercise in patience (for us at least), but the SprintScan made the process relatively painless.
The SprintScan showed its age slightly when it came to handling very dense slides, as exemplified by our *very* dense "Train" image. Newer scanners with 14-bit A/D can reach a little further into the shadows, but not as far as we'd have expected: The SprintScan acquitted itself surprisingly well on this very tough test of dynamic range.
We were also very impressed with the SprintScan 4000's resolution. Not all 4000 dpi scanners are created equal, and the SprintScan showed some of the highest resolution we've seen to date. (June, 2001) Its (apparently) fixed-focus optics were also very sharp corner to corner. (We saw a little loss of definition in film grain patterns in the extreme corners of the image, but image detail didn't seem to suffer at all.)
Overall, we liked the SprintScan quite a bit. The only thing we'd like to see significantly improved was its dust removal function. It apparently uses a purely software-based approach that worked well on some subjects, and rather poorly on others. Competing systems using a combination of hardware (IR imaging of the dust and scratches, apart from the film emulsion itself) and software are much more sure-footed in their operation.
There's a lot more to say about the details of the test scans we captured, and we say it all on the sample pictures page. Check it out. This is quite an impressive scanner, and a good deal to boot, at current (2001) market prices.
The Bottom Line
Despite it's relative age in the marketplace, the SprintScan 4000 holds its own quite well against the current crop of offerings. It appears to offer a good price/value point between the latest "high end" desktop scanners, and lower-priced models with lesser capabilities. The SprintScan offers excellent scans, with good throughput and easy operation, at a competitive price.
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