EPSON Perfection 4990 Scanner: D?j? vu?

We would like to introduce to you a new model in the excellent photo scanner family line from EPSON. Selling at a pretty reasonable price, this solution offers all the benefits of the predecessors and boasts a few modifications. How revolutionary are they? Find out from our detailed performance and scanning quality analysis today!

by Sergey Samarin
05/12/2005 | 08:29 AM

In the middle of January EPSON introduced its newest flatbed scanner of the legendary Perfection family. Coming to replace the last-year top model, the Perfection 4990 scanner may ship in two versions: PHOTO and PRO. The difference between the two versions is small and mostly concerns the software included.


The top model of the Perfection series is – like all its predecessors – targeted at professional and amateur photographers as well as at all users who need a highest digitization quality. The new model’s distinguishing features are the improved optical density parameter and the ability to digitize transparent originals of virtually any format. Some of the formats supported are only typical for narrowly specialized slide-scanners, so the EPSON Perfection 4990 will surely take up the family tradition of leadership in the product class it belongs to, that is SOHO.

The update of the top model was in fact a long-planned event at EPSON, such updates habitually occurring each January. You may remember the names of the ex-tops: Perfection 4870 in 2004 and Perfection 3200 in 2003. And the Perfection 4990 is going to be replaced, too, somewhere after the next New Year holidays. The question we’re going to answer by this review is if the new scanner is a breakthrough or just a superficially improved last-year model.

The EPSON Perfection 4990 scanner came to replace
EPSON’s last-year top model

Technical Characteristics

Before discussing the distinguishing functional features of the Perfection 4990, I’d like to offer you a table that lists all the basic technical characteristics of the model. As usual, EPSON offers quite comprehensive information about its product.

We can’t overlook the fact that the optical density parameter has improved to 4.0Dmax. It means the scanner will now be better at digitizing negatives. It will most probably handle successfully “dark” film and even X-ray images. By the way, you now get additional film holders with the scanner.

Of course, high resolutions are necessary for digitizing transparent originals well. The EPSON Perfection 4990, like the ex-top model, sports an optical resolution of 4800dpi and a mechanical resolution of 9600dpi.

If you compare the characteristics of the new and previous top models, you will find that the new scanner is more reliable. The machine is now expected to last through 100,000 duty cycles against the previous model’s 30,000. In order to bring the scanner home safely, it is handed to you in its package which contains a lot of useful things.


The scanner in its package

The EPSON Perfection 4990 is packed into a colorful box, designed in the company’s corporative style. The box has a plastic handle and contains the following:

As I said above, the Perfection 4990 may come in two versions. So, the PRO version that is going to cost $100 more also includes the following software titles:


The EPSON Perfection 4990 is designed in a new way, dissimilar to the earlier top models. The case is made of rigid silver-color plastic with a few decorative details. One such detail can be found on the scanner’s lid – it is a bar indicator. When a transparent original is being scanned, a blue light is moving along this bar, indicating the movements of the slide-adapter’s carriage. I tried to picture this process at long exposure.

The transparent bar on the scanner’s lid is highlighted
when transparent originals are being scanned

The moving parts of the device – the scanning carriages – are protected with two transportation locks. So, after you’ve taken the scanner out of the package, you must remove these locks. The location of the locks is indicated by stripes of tape the whole case of the scanner is covered with. The first lock is situated at the left panel. It is a big cap with a groove in its top that you can turn around with a coin, for example.

The transportation lock is hidden under the sticker

Use a coin to unlock.
The coin is not included with the scanner :)

The second lock is on the scanner’s lid, protecting the moving carriage of the inbuilt slide-adapter.

The slide-adapter’s carriage is locked, too

You must open the locks immediately before connecting the device to the power grid lest you should damage its mechanics. The numerous stickers remind you about that, so you can hardly forget to perform this procedure.

Power and Scan buttons

There are only two buttons on the scanner’s front panel: Power-On and Scan. And a single LED indicator of the scanner’s status is placed next to them. I personally fully agree with the manufacturer that there shouldn’t be too many unnecessary buttons on the scanner.

Interface connectors

Following its best traditions, the company equipped the Perfection 4990 with two high-speed interfaces USB 2.0 and IEEE1394a (FireWire). You’ll find a USB cable enclosed, while a FireWire one is to be purchased optionally. The availability of two interfaces doesn’t mean you can attach the device to two computers at once. It is not intended for that.

Supported Technologies

This narration about the new scanner would be incomplete if I didn’t tell you about the exclusive technologies that make it a really perfect machine.

Mechanics: The scanner features a mechanical resolution of 9600dpi which is two times its optical resolution. Such a high parameter is made possible by the exclusive sub-scanning technology EPSON Micro Step Drive. Its point is not only in the use of a high-precision mechanism and a special stepping motor, but also in the controller employed.

Optics: The Perfection 4990 uses EPSON ColorTrue II Imaging System technology that combines the scanner’s hardware, optical system and image-processing system for a true representation of color with less digital noise.

The number of sensitive elements in the CCD array determines the scanning resolution, but the smaller the sensitive element, the less light it receives and the weaker the useful signal is. In all scanners from EPSON each of the three basic colors is scanned with two arrays shifted by half a pixel relative to each other. This helps to improve the scan resolution without diminishing the size of the pixel or worsening the color reproduction. The name of this technology is Matrix CCD.

There’s a dedicated microlens above each
light-sensitive element of the CCD array

A dedicated microlens is placed above each photo-receiver of the CCD array to focus the light into its center. This ensures a more efficient conversion of light energy into electrical energy. This technology is called On-Chip Microlens and is employed by many manufacturers of light-sensitive arrays.

Lighter: The greatest achievement of EPSON engineers is the extended optical density range supported by the new scanner. This parameter is now 4.0Dmax against 3.8Dmax of the last-year top model. You may be wondering how they managed to achieve this. They just noticed that the masking layer of negatives let pass the blue component of the spectrum badly. The lighter’s lamp located in the scanning carriage didn’t shine through the film well enough, and the blue filters of the array didn’t get the necessary amount of light. If, as a solution, we made the carriage move slower, it would shine through the film more and would “overlight” light areas of the film. So they found another solution: to optimize the digitization of transparent originals the manufacturer first improved the Dynamic Range Control system whose earlier version had reduced the scanner’s speed characteristics much. The improvements concerned the lighter type. The blue component of the spectrum of the cold-cathode lamp was intensified and this resulted in better scans of transparent originals as well as in higher digitization speeds.

With these good speed characteristics on hands, the manufacturer decided to bring further improvements to the digitization quality. The innovations slowed the scan process somewhat and also set up harder requirements to the hardware of the computer the scanner is attached to. Here are these resource-consuming technologies:

Digital ICE: Top Models’ Prerogative

The hardware/software technology Kodak/ASF Digital ICE made a good showing in the earlier top model, Perfection 4870, and was continued in the Perfection 4990. It is a creation of the people from Austin Development Center, a subdivision of Kodak, and is being actively promoted by a number of scanner manufacturers, EPSON among them. Digital ICE is mostly employed in specialized slide-scanners, ordinary flatbed scanners being a kind of exception. I covered the functional aspects of this technology in my article called EPSON Perfection 4870 PHOTO Scanner Review: There Is No Limit to Perfection! and illustrated it with actual scans. Here, I will dwell on some basic points. First, the purpose of Digital ICE is to automatically clean images from such defects as dust specks, scratches, etc. Digital ICE works with both transparent (Digital ICE for Films) and reflective (Digital ICE for Prints) originals.

Digital ICE for Films

If you have ever scanned film, you should know that you cannot safeguard yourself against dust specks whatever the conditions of the scanning may be. It’s simply impossible to have the original (as well as the scanner’s bed) absolutely clean. Film attracts dust due to electrostatic forces and all this results in your having to spend more time post-processing the image in the traditional way, i.e. in an image-editing program. Digital ICE for Films helps to spare you some of your time. This technology uses an additional fourth channel, the so-called defects channel, when scanning transparent originals. The surface of the original is additionally scanned in the infrared range to gather information about mechanical defects on the film. Basing on this info, the computer retouches the image where those defects occur. Digital ICE for Films doesn’t work with ordinary black-and-white film as well as with Kodachrome 64 Professional film.

Digital ICE for Prints

Photographs need to be cleared from dust, too, don’t they? Digital ICE for Prints works with opaque originals, searching for dust and scratches on their surface. To do that, the scanning is performed in two passes, with the help of two light sources. By the way, the placement of the two lamps can be clearly seen on the scanner’s carriage. Highlighted at two different angles, the surface produces different patterns of shadows cast by those surface artifacts. The data is then transferred to the computer that performs the necessary retouching. This technology shows its best if enabled to digitize old, horribly-looking photographs.

Both technologies require powerful hardware to run. The CPU, memory and hard drive now become relevant factors for determining the scanning speed. Below you can see the recommended hardware requirements for a normal operation of a scanner with Digital ICE:

The requirements to the hard disk drive are not about the speed but rather about the free disc space available before scanning with Digital ICE.

For users who don’t have a powerful computer but want to have tools for removing dust from their images, too, EPSON offers the following technology.

Digital ICE Replacement – Dust Removal

EPSON also offers the software-based Dust Removal technology to hide mechanical defects. It doesn’t require too much of system resources, but its quality is somewhat lower.

The above-described technologies are available from the scan program’s window. The user selects the desired cleaning method depending on his/her requirements to the quality and scan speed.

Software Bundle

The EPSON Perfection 4990 PHOTO is accompanied with a software bundle that occupies three CDs:

You must install the necessary software from the CD before attaching the scanner to the computer. The numerous stickers on the transportation locks and interface connectors remind you about that.

I have tested almost all the models that make up the big family of EPSON’s scanners. Be it a cheap or a most expensive scanner, one thing is common among them – the traditional unified software pack. From model to model the programmers from EPSON complement this software with features specific to the particular model, but the method for controlling the scanning process never changes greatly. And the most pleasant thing is that the user is free to choose a scan mode relative to his/her level of expertise. If you don’t feel like looking into all the fine-tuning options, you can scan in the full automatic mode even on a professional model.

There are three basic scan modes: Full Auto Mode, Home Mode and Professional Mode. I’ll give you a brief description of each. Since the interface of the EPSON Scan program has practically remained intact, you can read a more detailed description in our Perfection 4870 review.

Full Auto Mode

In this mode the EPSON Perfection 4990 will determine the dimensions of the original by pre-scanning it and choosing the optimal settings and will then finally digitize it. The user can only choose the parameters of the resulting file as well as some other options (the type of the original, the resolution, and the use of Color Restoration or Dust Removal).

Home Mode

This mode offers more setup flexibility to users who have some scanning knowledge.

Professional Mode

The experienced user is offered the professional scan mode. You have to set up all the parameters manually in the window’s three sections called Original, Destination and Adjustments.

Besides the scan program proper, several exclusive utilities are installed from the CD for making your work with the scanner easier.

These auxiliary programs are localized for a number of languages. Having installed the driver, you can proceed to install the Creativity Suite that includes the following utilities:

Choose your language for the Creativity Suite

Creativity Suite utilities

Testbed and Methods

We’ll use our traditional methodology to test the following aspects of the EPSON Perfection 4990 scanner:

We use one and the same computer for testing scanners in our labs. Its configuration always remains like follows:

Speed Characteristics

The speed qualities of a scanner are the first inquiry of the potential customers. Many people consider this as a key factor determining the appeal of the particular model. Yet the most important factor affecting the scan speed is the hardware configuration of your computer. So, choosing a scanner you may just make sure it’s equipped with a high-speed interface, your computer will be doing all the rest.

But back to our tests. When the user calls the scanner’s driver from the control program, the device must perform the pre-scan operation. A typical lamp warm-up time is about 25 seconds on this step. This is actually a standard warm-up time for all scanners with a white mercury-based fluorescent lamp. The warm-up time may increase greatly depending on the task (for example, if you’re scanning transparent originals). You should also keep it in mind that the lamp warm-up operation is performed several times if you’re scanning slides at the optical resolution with Digital ICE technology enabled. In this case the scanning speed goes up even higher.

I measured the time it took to digitize an original at resolutions of 300, 600 and 4800dpi. I didn’t scan an A4 original at the optical resolution since this operation would consume about 3.5GB of disk space as well as an enormous amount of time.

Speeds during originals digitizing


You’ve got a scanner already? And what were you looking at when choosing it? Besides the speed factor, many users guide themselves by the resolution parameter which is usually declared in the description of any scanner. The real optical resolution depends not only on the number of elements in the CCD array but also on the entire optical system. It is possible to practically check how well the scanner digitizes an original with numerous tiny details. Special patterns with alternating black and white lines are employed for such tests. The spatial frequency parameter of a pattern is determined by the number of line pairs per inch (lppi). A pattern looks like that:

Applied Image QA-69-P-RM test target

There are five patterns here with a differing spatial frequency: 30, 70, 95, 140 and 180lppi. I digitized them at the scanner’s maximum optical resolution (4800dpi in this case).

The CDF graphs of the two Perfections coincide almost perfectly. The deviation between them is really negligible. The test data confirm the accuracy and precision of my calculations at any rate.

Click to enlarge

Next I found the modulation transfer function for the five patterns – it is represented with sinusoidal functions in the diagram. To compare the tested scanner with some other models I took the min and max values and put them into the following formula:

So, we can compare the modulation transfer functions of the scanners. As you see, the Perfection 4990 is somewhat better than the others, but not too much. The three functions are close to each other, thus confirming that the scanners all belong to a class of devices with a high optical resolution.

Image Noise

The signal-to-noise ratio allows evaluating the tolerance of the scanner’s electronics to various kinds of noise. Noise can be random or correlated, so we have two test steps here.

Random Noise

The graphs below show the dependence of the amount of random noise on the reflecting capability of the areas of the Kodak IT8.7/2 Q-60R2 target.

The graph shows the dependence of the random noise value
on the reflective capacity of the original

The signal-to-noise ratio is the ratio of the median to the deviation on an area of the target. Bigger SNR values are better, indicating the scanner’s higher tolerance to noise. The delta SNR parameter is the sum of the measurements.

Correlated noise

Correlated noise shows up in images as regular patterns. Prevalence of such noise greatly reduces the SNR coefficient, which is found as the ratio of the median to deviation. The calculated coefficients are listed in the following diagram (bigger values are better):


In this section I will compare the colors of the original IT8.7/2 target with the colors produced after the digitization process. Finding such discrepancies is one of the functions of the Color Managing System whose main purpose is creating a profile (here, the scanner profile) to use it later to digitize standard originals. Using the numbers for each of the colors of the target, I construct a diagram with the scanner’s gamut range and calculate its area. I won’t describe this process at length – you can refer to my earlier reviews for details.

The gamut range identified as a triangle in the diagrams is a projection on the plane. It outlines the scanner’s palette in the visible light spectrum. Since we know the coordinates of the vertexes of the triangles, we can calculate their areas to estimate the absolute values of the ranges.

To give you some reference points the diagram above also contains the areas of the analogous triangles for the standard sRGB and Wide Gamut RGB color profiles (the former characterizes the gamut range of the majority of monitors, and the latter is the maximum area of the CIE La*b* space).

To build the next diagram I found the difference between the colors of the original target and the scan. The Color Difference value should not exceed 5.0 or the color discrepancies become visible for a majority of people.

The closer to X axis – the better

The results of the Perfection 4180 are shown in the diagram for the comparison’s sake. This scanner has the same optical resolution but a narrower optical density range (3.4Dmax). It can be easily seen that the Perfection 4180’s errors in reproducing colors fall on the darkest areas of the target, starting from the GS17 point, while the Perfection 4990 easily distinguishes between those zones. So, the specified 4.0Dmax is confirmed by the results of my tests.

Digitizing Quality

Now that we’ve gone through the “academic” part of our tests we can try the scanner with different typical originals. The first scan I’m going to show you is an X-ray image. This type of the original is the most difficult for a non-specialized scanner (in other words, for all SOHO class scanners). If you’re not in the know, the scanner must have a very high dynamic range or density range parameter to scan such an original successfully since X-ray images have the highest density (i.e. they are the darkest of all). Let’s see what we have here:

X-ray image scan

An ordinary scanner could hardly have passed this test because most SOHO devices typically have an optical of density of 2.4Dmax. The EPSON Perfection 4990, as you remember, boasts a density of 4.0Dmax. The processing of such difficult originals is made possible by the further optimization of the spectral characteristics of the scanner’s lamp. Why “further”? Because EPSON had made a jump from 3.4 to 3.0Dmax back in the last year with their Perfection 4870. The manufacturer had had to perfect the Dynamic Range Control system especially for that model and this had led not only to a wider density range, but also to smaller scan times with transparent originals! As you can see now, the EPSON engineering people didn’t stop, but spent the last year implementing further improvements.

The following is a medium-format transparent original scanned at the maximum optical resolution:

Medium format KODAK Ektachrome E100S film scan

Scan fragment of actual size

As another example I want to show you a scan of volumetric objects. These are a handful of markers scattered on the scanner’s bed. This image helps to evaluate the sharpness depth of the scanner visually.

Volumetric objects scan

Last go the scans of color targets. These will help you form your final opinion about the digitization quality of the scanner:

Reflective target – Kodak Q-60R2 (Auto Exposure)

Reflective target – Kodak Q-60R2 with Color Management activated

Reflective target – Kodak Q-60R2 without color correction

Transparent target – Kodak Q-60E1 (Auto Exposure)

Transparent target – Kodak Q-60E1 with Color Management activated

Transparent target – Kodak Q-60E1 without color correction

These are all the tests. My own opinion about the scanner, its pros and cons highlighted, comes in the next section.


It’s really very hard to be pushing the bar ever higher, releasing another top model each next year. This time, regrettably, I cannot say the innovations are revolutionary. On the contrary, the innovations are so insignificant that it probably doesn’t make sense to base a new scanner model on them. Well, see for yourself: they have extended the optical densities range, and that’s fine, of course. Next, they have put in more holders for scanning transparent originals. Good again. Next, they have added a bar indicator for the process of digitization of transparent originals on the lid. Well, that’s not a crucial innovation, because the scanner is yet rather noisy as to require such indication. These things have been packed into a new case and presented as a replacement of the previous top model. But it’s clear the Perfection 4990 had been planned long ago, and they just couldn’t but release it.

Due to the same minor innovations in the scanner, I didn’t repeat some tests I had made on the Perfection 4870. So, if you don’t find all the answers to your question in this review, take a look at our previous article called EPSON Perfection 4870 PHOTO Scanner Review: There Is No Limit to Perfection!.

The EPSON Perfection 4990 is a nice product on the whole. Its price also appears quite to be reasonable and appealing. You know, this machine is a full-featured alternative and replacement to slide-scanners which are not popular among home users mostly because of their very high price. More than that, the EPSON Perfection 4990 can digitize not only slides but also sheet originals, and it hardly has any competitors among the narrowly specialized slide-scanners in this respect.

This scanner can be recommended as a good buy, but you are likely to find it familiar if you have met the previous top-model. It’s just d?j? vu.