Testbed and Methods
I tested the scanners using our time-tested methodology that allows for an in-depth examination of all the properties of the devices. The configuration of the testbed remains the same, so you can compare the results with those we got in our earlier reviews.
- Intel Pentium 4 3.00GHz CPU;
- 1GB DDR SDRAM;
- Intel Bonanza D875PBZ mainboard;
- ATI RADEON 7000 graphics card;
- IBM DeskStar DTLA-307015 HDD;
- Samsung SyncMaster 757 NF monitor;
- Microsoft Windows XP Professional SP1.
I am going to evaluate the following parameters of the scanners:
- The real scanning speed when digitizing originals of two types (I will also examine any ways to increase the performance);
- Noise coefficients in the digitized images, which will be indicative of the scanner’s electronics’ tolerance to interference;
- Gamut ranges of the scanners with transparent and opaque originals;
- I will also construct graphs of the color difference between the color target and the scanned sample.
The time it takes to scan an original is among the key parameters of any scanner, and one that potential customers consider first. Slow machines hinder your creativity, making you wait till you start working with the images proper.
The designs of the two scanners don’t differ greatly, as I mentioned above. The similarities extend to the mechanical construction of the devices (drive mechanism, scanning carriage and so on). That’s why we can expect the two scanners to have the same scanning speed. I checked this theory out with a stop-watch. The speed characteristics were determined for originals of two types scanned at different resolutions (300dpi, 600dpi, 1200dpi and 2400dpi). Let’s view the results:
Time for digitizing a standard photograph (10x15cm or 4x6”)
Time for digitizing an A4 photograph (210x287cm)
You see two columns in the diagrams. The second – Performance – shows the scanning times with optimized settings. Users often ask how they can increase the performance of a scanner. One of the ways is a proper setup of the image-processing software you use to receive the data from the scanner. For example, this setup flexibility is available in Adobe Photoshop. Just launch Photoshop and enter the preferences menu (Edit - Preferences - Plug-Ins & Scratch Disks).
Plug-Ins & Scratch Disks
In the Scratch Disks section of the dialog box you should select the second physical drive of your system as the first scratch disk (by default, the drive you boot up the OS from is selected). This will increase the speed of disk operations in case you have two hard disk drives in your system (not two logical volumes). It is desirable that the drive you choose as the first scratch disc had a lot of free storage space. (Edit - Preferences - Memory & Image Cache)
Memory & Image Cache
The second dialog, in which you select the amount of memory to use, will help to increase the system performance even more. By default, the program uses 50% of memory. I chose 100% and achieved a nice performance bonus, especially in the highest scan resolutions.