Minolta Dimage Scan Multi Pro Film & Slide Scanner
4800 dpi, 16 bit A/D, and excellent optics: Minolta raises the bar on medium-format scanning!
(Review first posted 09/22/2001)
||High-end film scanner delivering professional results|
||Scans 35mm and medium-format film|
||4,800 dpi maximum resolution
3,200 dpi maximum resolutoin (medium format)
||8- or 16-bit scanning modes|
||Digital ICE, ROC, and GEM adjustments|
||Multi-sample scanning up to 16x|
Minolta is a company with long experience in the world of film, and extensive digital expertise previously applied in the areas of office electronics and imaging (copiers & printers). They made somewhat of a slow start in digital photography, although their scanner line has shown good performance and value for the dollar. The last year has seen Minolta achieve leadership status in digital cameras though, with the introduction of their high-end 5 megapixel Dimage 7 prosumer model, the high end of a line that also includes the 3 megapixel Dimage 5 and Dimage S304 models. Now, they've updated the high end of their scanner line with the Dimage Scan Multi Pro, a scanner with eye-popping specs that can handle film from 16mm to 6x9 cm and everything in between.
The Minolta Dimage Scan Multi Pro film scanner competes with a number of other medium format models in the marketplace. Of these, we've thus far reviewed only the Nikon Super Coolscan 8000 ED, which we'll make reference to later in the review as we discuss comparative specs. With a list price of $2,999, the Dimage Scan Multi Pro brings exceptional capability to the desktop scanner market at a relatively affordable price. We see the Dimage Scan Multi Pro fitting the needs of users ranging from well-heeled photo enthusiasts, to businesses and professional photographers looking for top performance on a budget. In support of this market, we found the Dimage software did a particularly good job of providing the power demanded by pros, while remaining very approachable for the amateur.
Following on the heels of the Dimage Scan Multi, the Dimage Scan Multi Pro is a surprisingly compact desktop device about the size of a shoebox. Measuring 6.6 x 5.03 x 14.8 inches (168 x 128 x 377 mm), and weighing about 8.8 pounds (4 kilograms), the Dimage Scan Multi Pro is slightly smaller than its predecessor (the Dimage Scan Multi) and dramatically smaller than the competing Super Coolscan 8000 ED from Nikon. Don't let the smaller size fool you though, the Dimage Scan Multi Pro is loaded with features and performed very well in our tests. Interface to the host computer is via either an Ultra SCSI or a much speedier IEEE-1394 FireWire interface, meaning you'll need to have such a port installed in your computer to use it. (The manual lists a number of Adaptec cards that are compatible.) The standard unit can scan negatives or slides, in either black and white or color, in any of six different film formats (counting 6x4.5, 6x7, and other medium-format sizes as separate formats).
The software CD shipped with the unit supports both Mac and Windows platforms. Standalone scanning applications are provided for both platforms, as well as a Photoshop acquire plug-in for the Mac, and TWAIN drivers for the PC. (NOTE: Minolta specifies that the scanner requires Windows 2000 Professional, so don't plan on plugging it into your Windows 98 or Me machine.)
Scanning resolution can be as high as 4,800 dpi, with an RGB trilinear CCD element that slides across the film in one pass. This produces maximum image sizes of 4,728 x 7,008 pixels for 35mm, or 10,692 x 15,840 pixels for medium format. (Those figures correspond to 99 and 508 megabyte files sizes respectively for 8-bit scan data, or 199 and 1016 megabytes (!) for 16-bit scans.) This is seriously a lot of data: We'll talk more later about how much information is actually extracted from the film.
Another important scanning parameter is "bit depth," a measure of both color accuracy and the maximum density range the scanner can recognize. The Dimage Scan Multi Pro is built around a 16 bit A/D, an exceptional spec in and of itself. (Although we'll see that its performance is about equivalent to the best 14-bit scanners we've tested in the past.)
(Some of)The Details
The Dimage Scan Multi Pro is one of the most capable scanners we've yet reviewed, but at the same time scores big in the ease-of-use department. As such, it will appeal to both professionals and well-heeled amateurs who work with both 35mm and medium-format film. We'll cover its features in detail, but thought it worth calling attention to a few of the Dimage Scan Multi Pro's key features at the top of the review. Overall, there's no question that it sets a high standard for scanners in this market segment. Here are a few of the key points:
4800 dpi Resolution
The Dimage Scan Multi Pro has the highest scanning resolution of any desktop scanner we've tested to date (September, 2001). As manufacturers have reached each new level of scanning resolution, we've constantly said "well, that's enough resolution, there just isn't any more detail to be had from the film." - And then the next generation of scanners proves us wrong. We confess we really weren't expecting to see any more detail from the Dimage Scan Pro than we'd previously seen in the 4000 dpi scanners we'd reviewed, but the Dimage surprised us: There's clearly more detail visible in its scans, although we really *are* getting down to the film grain at this point. While we're not ones to get excited by big numbers on spec sheets, we have to say that the resolution of the Dimage Scan Multi Pro impressed us. (You can see this for yourself - Just download the cropped images from our resolution targets and compare them against those from some of the 4000 dpi scanners we've tested: The differences are readily apparent.)
The "Digital ICE" (for Image Correction Enhancement, licensed from aptly-named Applied Science Fiction) defect-removal solution is one of our favorite scanning innovations. Under optimal circumstances, it can completely remove scratches, dust, and fingerprints from a slide or negative, while leaving the underlying image virtually untouched. The piece of film the scans below were taken from fell onto a cement floor and was literally walked upon. Even with this extreme level of damage, the results were quite noteworthy.
Digital ICE works by shining an infrared light through the film's emulsion, using the resulting scan information to create a "defect channel" showing where the dust and scratches are. The infrared light passes right through the layers of most color print or slide film, but is blocked by dust or scratches. (Note that this technique doesn't work with Kodachrome or black & white film, as those emulsions are either entirely or largely opaque to infrared light.) The scanner and its associated firmware/software then interpolates the surrounding image information to "fill in the gaps" shown by the defect channel.
Digital ICE shows different results on different scanners, depending on the particulars of each units optics and illumination system. On the Dimage Scan Multi Pro, the effect of Digital ICE seems to extend a bit further out from severe damage than on other units we've tested. The net result is that more of the worst scratches are removed, but at some cost to detail in undisturbed areas adjacent to the scratches.
We've found Digital ICE to be remarkably useful in routine scanning. While the tendency is to focus on extreme cases like the piece of film we showed above, its real usefulness comes in removing the little nits of dust and lint that are almost impossible to entirely eliminate short of a clean-room environment. With any volume of scanning work to do, you'll save literally hours of time in after-the-fact spotting and retouching. Very handy!
Digital ROC & GEM
In addition to the "Digital ICE" feature, the Dimage Scan Multi Pro also features "Digital ROC" and "Digital GEM." ROC stands for "Recovery of Color," and it does an incredible job of extracting the original color information from badly faded color negative film. We don't have suitable film to test this with ourselves, but we've seen any number of samples from the same technology on other scanners that demonstrate its capabilities.
GEM stands for "Grain Equalization and Management," and is a technology to remove the effects of film grain, without affecting image sharpness. While the Digital ICE and ROC features don't provide any adjustments in the scanner software, other than the ability to activate and deactivate them, Digital GEM allows you to control the intensity of the effect according to the amount of grain in the image. Once you set the amount of GEM to apply, the scanner scans a small crop of the image and displays it in a second preview window, allowing you to verify the results. Though the process can be quite time-consuming (I mean, go out for lunch while you're waiting), GEM can do a surprisingly effective job of cleaning up overly-grainy film.
Scanner Optics & Light Path
Film scanners tend to take one of two approaches in their optical design, providing either fixed- or adjustable-focus internal lenses. Given the extreme resolution of most film scanners, we're surprised that the 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 does seem to work, as evidenced by the performance of the Minolta's Dimage Scan Speed. The Dimage Scan Multi Pro, by contrast, goes the adjustable-focus route, offering both automatic and manual focusing options. In its default operating mode, the scanner autofocuses before each scan, increasing the scan time, but insuring that the resulting images are sharp. (You can turn this function off in the Preferences menu.) In our tests, we found that the manual focusing option (with its excellent and fast focus-feedback indicator) could routinely produce slightly sharper focus than the automatic system.
Normally, the scanner's autofocus system looks at the center of the frame to perform its focus adjustments. On the Dimage Multi Scan Pro, you can specify what specific point on the film you want it to adjust for, or what part of the film you want to manually adjust the focus based on. These are very useful features, in that we've sometimes seen scanner autofocus systems outfoxed by low-contrast, or poorly-focused originals. In the case of severely curled film, you may opt for sharp focus in one part of the frame, at the cost of poorer focus elsewhere. The Dimage Scan Multi Pro accommodates such situations with the aforementioned option of specifying the point of focus.
Optimum focus can be quite time-consuming to determine on a film scanner, particularly if you have to perform a full scan in between adjustments, to evaluate the results of your tweaking. The Dimage Scan Multi Pro uses a "live feedback" system that we found worked quite well, at least when given a nice contrasty chunk of image to work with. When using manual focus, a black and white "thermometer bar" graphic appears in the focus window. The black bar shows a measure of how good the focus currently is, while the white bar shows the highest level that's been reached since you opened the window. This makes it quite easy to adjust the focus back and forth until you find the optimum point. (With no tedious re-scanning in between.) The focus indicator will sometime jump around quite a bit from click to click on the adjustment slider, but the white bar makes it fairly easy to see when you've passed the best focus position, so you can come back. A nice implementation we wish more scanner manufacturers would adopt.
In common with other Minolta scanners we've tested, the Dimage Scan Multi uses a special fluorescent light source, producing strong spectral peaks in the red, green, and blue portions of the spectrum. We observed that this diffuse illumination source produced somewhat "softer" scans than some other scanners. The resulting scans had less of a razors-edge on fine detail, but were also much more forgiving of film defects and film grain. A good analogy (for those old darkroom aficionados out there) would be the difference between condenser and diffusion enlargers: The condenser optics tend to produce more contrasty images, but at the cost of greatly enhanced film grain, while diffusion enlargers create a softer look. Interestingly, we didn't feel that the Dimage Scan Multi Pro shared the slight softness of the earlier Minolta scanners we've tested, as detail and film grain seemed quite sharply resolved across the scanning area. (Look at our test scans for yourself, and compare them to the results we obtained from other scanners you might be considering buying - This is a somewhat subjective evaluation. To our eye though, it seemed that the Dimage Scan Multi Pro produced noticeably sharper results than its predecessor.)
The Dimage Scan Multi Pro uses slide- and filmstrip-holders made from heavy structural plastic to position the film inside the scanner. (Glass and plastic, in the case of the medium-format holder.) You first place the media to be scanned into a holder, then insert the holder into the scanner. When you insert a holder into the scanner, it slides easily until it reaches a click-detent. Once it's been inserted to the detent, the transport mechanism pulls it into the scanner body, and moves it back and forth into position so that the CCD can scan each frame. During scanning, the trilinear CCD moves slowly across the film. (The previous Dimage Scan Multi instead moved the film across the CCD sensor.)
The filmstrip holder can accommodate strips of 35mm film up to six frames in length, and the slide holder up to four slides. The medium-format holder can accept strips of film several frames long (depending on the specific format chosen), but only a single frame may be scanned without repositioning the film. An optional multi-format holder is sold separately, which employs user-cut masks to hold unusual film formats (such as 16mm movie film) in position.
We found all three holders (slide, 35mm film, and medium format) to be very effective and easy to use, with many small nuances of design that made them easier to work with. The 35mm film strip adapter is hinged, but only to the extent that a plate flips up to expose the side slot into which the film is laid. (Unlike many "clamshell" designs, the slot holding the film is a fixed structure.) The top pressure plate then hinges back down and latches, clamping the film flat. This arrangement did a particularly good job of handling curled or damaged film, regardless of whether the film was curled side-to-side, or along its length. Even 35mm film curled along its length was easy to deal with, thanks to a pair lips thoughtfully molded into the sides of the film recess, to help hold the film flat while the lid is closed. We also appreciated two other design touches in the 35mm strip holder. Perhaps as a response to earlier criticism, or possibly just a happy design "accident", slots in the film tray below the aforementioned "lips" allow access to the film sprockets, which greatly eases fine alignment between the frames of the 35mm film and the openings in the holder. (You can gently insert a slender probe (bent paper clip?) into the slot, and engage with the sprocket holes to nudge the film one way or the other.) The second minor design tweak that we really appreciated was the provision of finger holes on either side of the film strip, at both ends of the holder. These make it very easy to grab the film by its edges to remove or insert it. A minor point, but it's very handy being able to hold the film securely by the edges like this all the way into the holder. Finally, the film-holding slot is about a half-millimeter wider than the film itself, doing a good job of constraining the film position, yet still allowing minor side-to-side adjustments to be made for fine alignment relative to the limits of the scanning area.
The slide holder is also constructed of plastic, again in a clamshell design. Four recesses are provided in the base to lay the slides into, while the top pressure plate has plastic spring-fingers to apply pressure on the slide mounts, while accommodating a range of slide mount thicknesses. Depending on your mount (outside dimensions vary slightly), you should have enough space to correct for minor alignment errors between the film and the mount itself, by rotating the slide slightly in the holder assembly. (One or two degrees would be the maximum, but in our experience, this is enough to accommodate the normal range of variation to be found in commercially processed slides.) At the same time though, it's easy to get a perfect 90-degree square alignment between the mount and the holder, by pressing the slide against the sides of the recess.
The furnished medium-format holder is a more complex assembly, with two different sublets included one with and one without glass, both of which mount in a main carrier jig. The glassless holder has an opening that's 6x9 cm in size, to accommodate the largest commonly-used medium format film size. Movable bars top and bottom (slid partly in, in the product shot above) let you resize the opening to match the film size you're scanning, providing proper support all around the periphery of the film.
The glass-equipped holder has two pieces of anti-Newton coated glass top and bottom in it. As further protection against Newton's rings (colored interference patterns, usually in the form of concentric circles, that can appear when two flat, transparent objects are pressed tightly together), Minolta provides thin plastic masks matching popular medium-format film sizes. These masks are intended for use with the glass-based holder, and fit over pins in the holder body. They act as spacers, holding the two halves of the mount slightly separated, prevent the appearance of interference fringes.
One feature we missed from the previous Dimage Scan Multi model was the ability to make small rotational adjustments of the film after it was mounted in the holder. The new holder provides a very sure alignment between the film and holder body, but we liked the ability the older design offered to make small rotational adjustments in the holder itself. - This can be a huge time-saver, compared to trying to rotate a 500 MB file on your computer in Photoshop(tm).
For the really unusual film types like 16mm movie film and electron microscope negatives, Minolta offers the optional Multi-Format attachment. This is a two-piece affair, with a glass plate that mounts into the main carrier jig, and a separate hinged cover that attaches to the side of the jig. It's intended to be used with masks, the same as the glass-equipped medium-format holder, but the masks are included as uncut blanks, so you can customize them to the specific film you're working with.
System Interface and Included Software
The Dimage Scan Multi Pro uses an Ultra SCSI (mini-Amphenol connector) or IEEE-1394 FireWire connection to the host computer, providing the high speed data transfer necessary to handle the large amounts of data the scanner can generate. Minolta lists several models of Adaptec cards that the unit can be used with. (Adaptec is pretty much the standard for SCSI cards. You can find cheaper ones, but the Adaptec models are more likely to be compatible with a wide range of equipment. Note in particular, that some scanners, CD-ROM drives, and other equipment ships with low-cost SCSI cards included. In many cases, these are "dedicated" cards, that will only run the particular device they're shipped with. If you're buying a card to support the Dimage Scan Multi Pro, take our advice and get a "name brand" Adaptec unit. Speaking from personal experience, the hassle you'll save will be more than worth it!)
Once connected to the computer, the Dimage Scan Multi Pro is controlled through an excellent software interface that we'll describe in greater detail below. As noted earlier, the scanner-control software takes the form of standalone applications on both the Mac and PC, as well as a Photoshop plug-in on the Mac, and a TWAIN component on the PC. A particular strength of the Dimage software is the extent to which it provides powerful controls for experienced users, while at the same time offering a simple interface for novices.
Given sufficient memory (!), the Dimage Scan Multi Pro felt pretty responsive in use, even though it's scan times were a bit long. We mostly worked with it on our now-aging G3 PowerMac, connected to the system SCSI bus, but also did some timing tests on our PowerMac G4, via a FireWire connection. Working on the elderly PowerMac G3, where we did all the actual test scanning, we noticed two things. First, the scanner seemed to have to pause periodically, apparently to wait for data to be transferred over the SCSI bus. Second, we found that after a large scan, the computer spent quite a bit of time "thinking" about the data after the scanner was obviously through with its work. (The scan head had returned to home and stopped moving, but the computer left the progress bar up on the screen for as long as several minutes.) We thought that both of these delaying factors might be ameliorated by moving to our G4 Mac, which runs at 500MHz, and has a FireWire connection. We did limited timing testing on this platform, and have included the results in the table below. Note though, that we didn't perform any tests on a Windows platform: Times there could very well be quite different.
One thing that makes the Dimage Scan Multi Pro quicker to use is that tonal and color adjustments are faithfully reflected onscreen in the prescan image, greatly reducing the number of prescans you need to do before undertaking the full-res scan itself. This speeds workflow quite a bit. The scanner is also fairly intelligent about when it needs to do perform an autofocus operation: It autofocuses for the first prescan of any frame, but after that will generally not refocus for subsequent prescans of the same frame. (For instance, if you're wanting to double-check a particularly severe tonal or color correction.) As for the scans themselves, the Dimage Scan Multi Pro is pretty quick, and doesn't seem to spend quite as much time getting itself sorted out before each scan as many other devices we've tested.
So how does it do? Here's a table with timings from some of the scans we did. - Working on our now-aging 333 MHz PowerMac G3 (which has a SCSI interface), where we did all our test scanning, we noticed two things. First, the scanner seemed to have to pause periodically, apparently to wait for data to be transferred over the SCSI bus. Second, we found that after a large scan, the computer spent quite a bit of time "thinking" about the data after the scanner was obviously through with its work. (The scan head had returned to home and stopped moving, but the computer left the progress bar up on the screen for as long as several minutes.) We thought that both of these delaying factors might be ameliorated by moving to our G4 Mac, which runs at 500MHz, and has a FireWire connection. When we did further tests there, we found it was actually slightly slower than the SCSI-equipped G3. Note that we didn't perform any tests on a Windows platform: Times there could very well be quite different.
|Scan Operation/Condition (35mm film)
|Index scan, 4 slides||33s||34s|
|First Prescan (does autofocus)||33s||30s|
|Subsequent Prescans (no autofocus)||13s||13s|
|1200 dpi scan (1,752 x 1,182) w/AF||1m 2s||1m 45s|
|1200 dpi scan (1,752 x 1,182) no AF||43s||58 s|
|4800 dpi scan (7,008 x 4,728) w/AF, scan done||4m 55s||5m 34s|
|4800 dpi scan (7,008 x 4,728) w/AF, computer done||7m 3s||7m 49s|
|1200 dpi scan (1,752 x 1,182) no ICE||1m 49s|
|1200 dpi scan (1,,752 x 1,182) w/ICE||3m 47s|
|Scan Operation/Condition (6 x 7 film)
|First Prescan (autofocus)||45s||44s|
|Subsequent Prescans (no autofocus)||14s||13s|
|1200 dpi scan (3,312 x 2,673) (25.3 MB), scan done||1m 33s||2m 28s|
|1200 dpi scan (3,312 x 2,673) (25.3 MB), computer done||2m 19s||3m 31s|
|4800 dpi scan (13,248 x 10,692) (405 MB!), scan done||51m 41s (!)||57m 55s (!)|
|4800 dpi scan (13,248 x 10,692) (405 MB!), computer done||59m 1s (!)||64m 34s (!)|
When we did the maximum-resolution timing tests, we were a bit shocked at how long it took. - I mean an hour to scan a piece of film? Part of the reason we were shocked is that this really didn't seem to jibe with our experience of actually operating the scanner, as it seemed fairly responsive there. Comparing times with other scanners we've tested, we see that the scan times for comparable resolution range from about the same to nearly twice as long. (The 4800 dpi top resolution does produce a good 44% more data than the 4000 dpi of other high end scanners, so that explains some of the difference in scan times at maximum resolution.)
We think the reason we didn't notice the longer scan times all that much in our production testing was that the speed and ease of use of the software and user interface largely made up for it. In normal scanning (well, normal for us at any rate), we find we spend a lot more time messing with the user interface, tweaking tone and color settings and doing repeated prescans than we do on the actual scanning itself. Your mileage may vary, of course, but we found that the user interface of the Dimage Scan Multi Pro was so easy to work in that we got through what is for us the more time-consuming part of the scanning process (the setup) a good bit faster than normal, making up for the extra time we spent waiting for the scans to complete.
One thing that we felt to be a major defect of the scanning software, at least on the Macintosh platform, is that it isn't at all graceful about letting you do other things on the machine while the scans are proceeding. The scanning software insisted on being the front window no matter what, meaning that we couldn't follow our normal practice of working on other things while the scans were under way. - And when you're talking about an hour at a crack for maximum-resolution medium-format scans, that's a major hit on productivity.
This is now the fourth or fifth Minolta scanner we've reviewed, and we've liked Minolta's software from the start. The latest version has a few additional refinements that add a little power, without detracting from the ease of use. While we'd like a little more control in some areas, the software overall strikes an excellent balance between power and ease of use, and is one of our favorite scanning packages.
The Dimage Scan Multi Pro software interface runs standalone or as a plug-in to Adobe Photoshop. In either case, launching the software displays the main screen, where all scanning actions take place.
The main screen is divided into sections. Along the top of the screen are several control buttons and pulldown menus, while the bottom of the screen is divided into a preview area and utility window. A series of tabs above the preview area and utility window provide access to controls for different stages of the scanning process, and include Index, Prescan, Image Correction, and Digital GEM headings.
The top two pulldown menus set the film type and size, the first step in the scanning process. In between the two pulldown menus, a third pulldown menu allows you to select Glassless or Glass mounted film adapters (only activated when a medium format film size is selected). Two buttons are directly to the right of the Film Type pulldown menu. The first displays the Preferences window, and the second is the Custom Wizard button, which allows you to automate certain scanning processes into a "wizard" or access previously set up wizards. Below these menus and buttons, a row of icon buttons provide access to several scanner functions. From left to right, the button functions are:
The Index tab lets to view thumbnail prescans of each individual image in the 35mm film adapters. Pressing the Index Prescan button initiates a rapid, very low-res prescan, after which each thumbnail is displayed in order on the screen. You can select an individual image for scanning by clicking on it, which highlights the frame with a black border. Below the index tabs is a row of buttons which perform the following functions (from left to right):
On the left side of the Index tab is a window of image information. Here, you can set the image resolution, import a settings file from another scan, and set the output size. An Undo button in the bottom right corner removes the most recent change.
Clicking on the Prescan button activates the scanner to create a prescan preview of the selected image, and automatically opens the Prescan Tab. The larger preview image is then displayed in the preview window. The right window of the tab holds the same image resolution and size options, though the buttons that line top of the tab change. From left to right, their functions are as follows:
At the end of this row of buttons is the frame indicator as well as the RGB/CMY numerical display, which reports the color value numbers of specific points in the image as you scroll the mouse over the preview.
Image Correction Tab
Once you've adjusted the image resolution and size, as well as the orientation and cropping, clicking on the Image Correction tab allows you to perform prescanning corrections. The buttons across the top of the preview area again change, and from right to left perform the following functions:
Tone Curves and Histogram
Clicking on the Tone Curves / Histogram button displays the Tone Curves and Histogram window, which provides an easy way to adjust the white and black points of the image, stretching the tonal range as appropriate. You can also use the histogram sliders to control the "gamma" (midtone boost or cut) of all the color channels, either individually or together. This is our favorite way to quickly deal with color casts and poor tonal rendition.
We like the way this control panel combines the tone curve and histogram controls into a single interface, yet keeps them separate so you can see what you're doing. The two graphs are linked so that changes on either graph affect the other one, but you can use both independently. For some tough pieces of film, we found ourselves using the histogram to make the gross adjustments, and the curves tool to make fine tweaks in specific tonal ranges. Very slick.
At the top of the window is a pulldown menu which selects which RGB channel shown, or you can look at the main RGB channel. To view all four histograms at once, as in the image above, click on the RGB graph icon button just to the right of the pulldown menu, which expands the display. (You'll still need to switch channels for the Tone Curves.) You can adjust the Tone Curves either by creating points on the curve and dragging them. You can draw a freehand curve by clicking on the Freehand Curve tool (the pencil button to the right of the Tone Curves graph), which converts the cursor into a pencil draw tool. The Smooth Curves button, on the left side of the pencil button, smoothes out any points on the curve.
Directly below the Tone Curves graph is the Histogram, which plots the tonal distribution of the image, from black point to white point. The input and output values of the image are listed at the bottom right side of the histogram, and a slider bar allows you to adjust the shadow, midtone, and highlight points. Three eyedropper tools allow you to set black, midtone, and white points by clicking on the eyedropper and then clicking on a specific portion of the image.
At the bottom of the window are the Auto Setting (which tells the software to analyze the histograms and make its best guess as to the proper correction) and Reset buttons.
The Tone Curves and Histogram window is displayed on top of the preview area, meaning you can move it anywhere on the screen. Thus, you can immediately see the changes as you apply them. The shot above shows us applying both a histogram correction and a tone curve move.
Brightness, Contrast, and Color Balance Correction
As with the Tone Curves and Histogram display, clicking on the Brightness / Contrast / Color Balance Correction button displays an adjustment window that "floats" above the image. The window can be moved anywhere over the preview image, allowing you to see the effects of any changes made.
A curve at the top of the Brightness/Contrast window shows the changes made. Below the curve are adjustment sliders for Brightness, Contrast, and Red, Green, and Blue color balance corrections. A text box at the end of each slider bar reports the amount of change numerically, with a minus sign indicating a decrease. You can also type a numeric value into these text boxes. The Auto button at the bottom of the window applies any automatic adjustment, and any change can be undone by pressing the Reset button.
Hue, Saturation, and Lightness Correction
Clicking on the Hue / Saturation / Lightness button displays another adjustment window, which can likewise be placed anywhere on the preview area.
Three slider adjustment bars at the top of the window correct the Hue, Saturation, and Lightness, with the amount of change reported numerically on the right side of each bar. Two color strips below the slider bars report the pre- and post-adjustment color mapping. The Auto and Reset buttons are also at the bottom of the window.
We generally find that overall hue and lightness errors are best corrected with the histogram/tone curve controls. Often though, making large moves in the tone curves can adversely affect the color saturation in an image. This control lets you adjust overall saturation without affecting lightness or hue, a useful capability.
Variations Correction Tool
The Variations button pulls up the Variations correction window. This is perhaps the most "user friendly" adjustment control, ideal for relative novices to image correction. Three separate displays are available, dealing with color cast, contrast & brightness, and color saturation. In each case, a number of small thumbnails are displayed onscreen, with the central image showing the effect of any currently-selected image adjustments, and the surrounding thumbnails showing a range of possible adjustments. If you decide you like one of the surrounding options better than the current selection, you choose that adjustment by simply clicking on the thumbnail image. It then becomes the central image, representing the current state of the correction, and you're presented with a new range of alternative choices. A slider bar next to the pulldown menu adjusts the amount of difference between each variation. The "Display Limit" checkbox activates an indicator of the maximum level for each adjustment.
Using this interface, even complete novices can achieve pleasing results, since most everyone can at least tell whether they like one image more than another. It's still possible to get yourself "lost in the woods" though, since it can be difficult to judge color and tone accurately from small thumbnails like this. Likewise, novices are prone to make the images too contrasty or oversaturated, due to poor color judgement. Still, this is a very approachable interface that can get you "in the ballpark" quite quickly, with no detailed knowledge of color theory.
Selective Color Adjustment
This is a very powerful tool, hiding behind a deceptively simple interface. It's also one though, that requires some knowledge of how color works to be successful using it. The Selective Color Adjustment tool separates the color region into seven groups (Red, Green, Blue, Cyan, Magenta, Yellow, and Black), allowing you to adjust only the colors in the image that fall within the specified color ranges. As with the other adjustment windows, the control panel can be moved anywhere on the preview screen, just like the other adjustment windows.
Four slider bars adjust the amount of Cyan, Magenta, Yellow, and Black in each color, with the amount of adjustment reported at the end of the bar. This is the tricky part of this control, in that the adjustments are made in subtractive color space (CMYK), rather than the RGB additive color space most photographers and computer graphics users will be familiar with. The thing to keep in mind is that these colors are inverses of the ones you're familiar with. That is, adding cyan to an image is equivalent to removing red, adding magenta is the same as removing green, and adding yellow is the same as removing blue. Note that adding a subtractive color darkens the image, rather than lightening it as with the additive primary colors.
This tool can be very useful for "cleaning up" colors that the film and/or scanner reproduced poorly. For instance, this is a great way to brighten up the weak greens color negative film so often records. As powerful as it is though, we'd like to see it extended in two ways. First, we'd like the ability to select specific colors from within the image, so the correction could be applied to specific hues within the image. (Flesh tones, for example.) Second, we'd like to see a control that would affect how broadly the effect would be applied. (That is, to a very narrow range of colors around the one selected, or to a broader range of hues.) Despite our wish-list for the control, it's a very useful one as it stands, although it will take many users a bit of fiddling to become familiar with its operation.
Unsharp Mask Tool
The Dimage Scan Multi Pro offers an in-depth Unsharp Mask tool, which can be particularly useful for images that will be going directly into printed publications. (If you plan to manipulate the scanned images much on the computer, you're better off leaving the unsharp masking go until you're done with your retouching.) The structure of the USM controls in the Dimage software is very similar to that of Photoshop: The top slider bar controls the amount of the effect, from zero to 500 percent. The remaining bars control Radius, Threshold Level, and "Dark Part Protection Level." The Radius adjustment controls how large an area the sharpening function is applied to around contrast edges in the image. The Threshold Level control affects how large a contrast difference must be found between adjacent pixels before the sharpening operator will be applied. Finally, the Dark Part Protection Level prevents sharpening from being applied to dark areas of the image. This last is an enhancement beyond the capabilities offered by Photoshop, and is useful for avoiding sharpening noise in shadow areas.
The one thing we'd really like to see added to the Dimage Scan software's unsharp masking tool is an (optional?) preview window. As it is, short of repeated trial and error, there's no good way to tell the effect of adjustments you're making on the final picture. If you do a lot of the same type of scanning (that is, for the same output medium and reproduction parameters), you could probably develop a group of settings that could be applied blindly. In our experience though, USM is such a multivariate function, and frequently so subject-dependent that a preview option is almost mandatory.
Clicking on the Pre/Post Correction Comparison Display button allows you to check the image adjustments made against the original preview image. We've found this quite beneficial in the past, as it provides a complete perspective on each change. (We've seen some software packages that only show the changes relative to the last change you made. This is much less useful in our opinion, we prefer to see the reference back to the original, as shown here.)
Digital GEM Adjustment Tab
Clicking on the Digital GEM button at the top of the preview window enables this tab, allowing you to adjust the amount of the "GEM" processing that is applied. (Note that the Digital ICE and Digital ROC features do not have any adjustments available.) Digital GEM reduces the appearance of film grain in images. A slider bar at the top of the preview area adjusts the amount of Digital GEM applied, with values from zero to 100. The GEM button directly to the right activates a full scan of the selected portion of the image (indicated by a crop box which can be adjusted over the preview image). When the scan is complete, the cropped portion appears in the other preview window, allowing you to check on the GEM effect. NOTE though, that GEM apparently scans and processes the image at maximum res (in order to "see" the film grain), regardless of the resolution chosen for the final scan. Thus, this option takes a long time to preview or apply!
Clicking on the Preferences button in the preview window brings up the Preferences window, which lets you set a variety of scanning parameters. The following checkboxes and settings are available:
For a full analysis of the results we obtained with the Minolta Dimage Scan Multi Pro, 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:
Overall, we were very impressed with the Dimage Scan Multi Pro. As we've noted above, we liked its software interface quite a bit, and felt that it made it easy to achieve the results we wanted.
First and foremost, the Dimage Scan Multi Pro delivers an extraordinary level of detail, in this respect eclipsing all desktop scanners we've tested previously (as of September, 2001). In particular, the detail we observed in scans of our resolution test targets was the highest we've seen to date. The scanner's optics also seem to be of high quality, as the scans lost only a little sharpness in the corners of the film, less of a loss than we're accustomed to seeing. Chromatic aberration was also quite low, and we were surprised to see that flare in some images that we'd previously attributed to the camera lens was apparently at least partly caused by scanner optics: On the infamous Train slide, we didn't see flare that has been present in almost every other scan we've done of that target.
We don't have a quantitative test for the maximum film density that can be scanned, but the Dimage Scan Multi Pro seemed to do about as well as the best of other scanners we've tested up until this point. (Not better, as the 16-bit A/D might suggest, but at least as good as any others we've tested.) We did find though, that the electronics on the Multi Pro were very "quiet", so there was very little need to use its 16x multi-sampling feature to reduce noise in the scans. Scans were also very clean in the face of extreme tonal adjustments, with no need to restrict the scan head to single-line operation to get good
Preview scan accuracy was quite good, and we appreciated the fact that the effects of even fairly major tonal adjustments were pretty faithfully reproduced in the preview window, without necessitating another prescan.
We felt that the Digital ICE defect removal on the Dimage Scan Multi Pro was a bit of a mixed bag, removing more of the most severe damage on our brutalized test film, but also disturbing more of the unaffected area adjacent to the heavy scratches. For what it's worth though, it seemed to work pretty well with routine dust specks and light scratches in the emulsion.
Overall, we found a great deal to like about the Dimage Scan Multi Pro. We'd like to see faster scan and processing times, but we loved the user interface, and the image quality we obtained was first rate.
The previous Dimage Scan Multi model offered the capability to scan a variety of film formats, but suffered from reduced resolution when scanning medium-format film. The new Dimage Scan Multi Pro totally eliminates that limitation, and in fact sports the highest resolution we've yet seen on a desktop scanner, at least on 35mm film. (On medium format, it's still no slouch, at 3200 dpi, but isn't quite up to the 4000 dpi of some models.) At the same time, Minolta has greatly improved the electronics and made incremental enhancements to the scanning software. The net result is an exceptionally powerful scanner that is capable, fast, and easy to use. Image quality is first rate in every respect: This is a scanner that takes a back seat to no one in image quality, although it we found its scan times to be a little slow, at least on the Mac platform. The slow scanning was somewhat compensated for by the speed and fluidity of the user interface, but that's a very subjective issue - Other people may not like it as much as we did. All in all though, the Dimage Scan Multi Pro seems like an excellent choice for professionals and serious amateurs working with medium-format film, looking to bring their scanning in-house. Kudos to Minolta on this one!