A few scanning tips


Acer MiraScan 3.42

The MiraScan software came with an Acer 1240UT scanner, which is a 1200 dpi flatbed, USB interface, with a 5x7 inch transparency unit (film adapter). The scanner sells for $150 US. I was happy to see that it had a power switch, because other inexpensive models often omit it these days. I thought it was a lot of scanner for the price.

MiraScan is started from the File - Acquire menu of a photo editor program. MiraScan is very fully featured software, not missing anything. It has all the standard tools: histogram, curve, two color balance tools (below). These tools are enabled when the Auto Density option is turned off (to None). MiraScan can output either 24 or 48 bit images (to programs that can accept 48 bits).

Besides the conventional Color, Grayscale, or Line Art scan modes, there are scanner modes of Reflective (photo prints and documents), Transparent (slides), and Negative Film. Color negative mode offers Agfa, Fuji, Kodak, and Konica film types, to aid removing the orange mask in color negatives. The 1240UT has a real TMA in the underside of the lid, meaning when in film mode, the lower lamp goes out, and the motorized upper lamp in the lid is used. The scanner calibrates the CCD from that upper lamp. Such calibration is of course quite necessary for film mode, but some lesser film adapters don't provide it.

Color Wheel

Color Balance

Curve Tool

Nice tools!

The TMA in the lid has a black plastic cover, which otherwise provides a black background for scanning reflective work. There is also a plastic overlay for the 8.5 x 11.7 inch scanner bed, which has a cutout to identify the active area of the 5x7 inch TMA, and to also mark the TMA calibration area that must be kept clear of any obstruction.

Scanning 35 mm film is when you would use 1200 dpi, and in that case, you get an image size of about 1580x1000 pixels from full frame 35 mm, about 4.6 MB. That's too small to print 8x10 inch prints, but 5x7 and 6x4 inch prints are realistic from that size. And certainly these images are usable for any video screen purpose too.

MiraScan has a Job Manager (lower left in first image at top) to provide batch scanning. Up to ten scan jobs are possible, and each job may have very different scan properties if desired. Related to this, there is another thin plastic bed overlay that holds 6 mounted slides, and another for short film strips. There is an Auto Crop button (disabled if more than one job already exists, but you can easily delete any old jobs) that will automatically detect and crop the six slides (if the slide is bright enough) to create six jobs. Then the Scan button will batch scan all jobs. Same for film strips of negative s, it auto crops each frame and creates scan jobs for each.

When scanning line art, such as text documents, there is another histogram for setting line art threshold, which is a very nice feature. See Line art threshold.

The Auto Density mode works very well to automatically set image contrast. But one problem in manual mode is that when the scan area is very small (like 35 mm film size), the MiraScan histogram scale height was too small to really be usable. Histograms show the count of pixels, and small areas have few pixels, resulting in short bar graphs. When this area is very small, the height of the histogram data was near zero, and much of it is unseen. It would be desirable if that data height were scaled taller in the histogram window, to be more visible. However, this is not a problem scanning larger areas like photo prints, which are much larger areas than 35 mm film. And Auto mode still works fine of course, and if you use that, you won't see the histogram anyway.

USB scanners slow down when the image data size gets large. The following 1240UT timings were measured on an AMD 1.1 GHz 384 MB computer, and do not include a few seconds of calibration time for each scan.

6x4 inch RGB150 dpi1.5 MB0:19 Min:Sec
6x4 inch RGB300 dpi6.3 MB1:51
35 mm slide RGB1200 dpi4.5 MB0:37
8.5x11 inch Line Art600 dpi4.1 MB1:06
8.5x11 inch RGB150 dpi6.1 MB0:51
8.5x11 inch RGB150 dpiDescreen5:43
8.5x11 inch RGB300 dpi24.5 MB4:59

Generally, the MiraScan software is impressively versatile. The 1240UT is a very decent flatbed too, the results were good.   It should satisfy most purposes, and it is only $150.   Its TMA is a proper tool, not a toy, and I thought it did a surprisingly creditable job on film. However for serious film scanning, it should be realized that a $500 to $1500 dedicated film scanner will offer more for film.

Acer provides two copy utilities. Copier lets you specify number of copies, which printer, paper size and orientation, and color, gray, or line art for text. Copier also allows preview and scaling, in the upper right corner.

ScanButton is a one click tool, which scans one page from the scanner bed and routes the image to a specified destination. It adds an icon in the Windows tool bar, then one click launches it, or a Right Mouse button accesses its Settings screens. Those Settings allow mode, resolution, paper size, etc, to be unique for each destination. Or, you can elect to instead have the MiraScan driver interface shown to do the scan for that destination.

Copyright © 2001-2004 by Wayne Fulton - All rights are reserved.

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