VueScan does automatic cropping and automatic white balance, and then lets you use an external image viewer to tweak the cropping (if you desire) and tweak the color balance (if necessary). A lot of effort has been put into VueScan to make it accurately crop and white-balance scans, so the amount of manual adjustment needed is minimal - something you'll appreciate when batch scanning large numbers of images. You can also manually crop images by using the left mouse button to move the edges of the crop box in the Preview tab.
VueScan's user interface has a large number of options, but the only thing you normally need to do is set the frame number(s) to scan (in the Device tab) and then press the "Scan" button. If you've changed a lot of options and things aren't working right, just reset all the options to their default values with the "File|Default options" command.
There are two types of scans - a preview and a scan. The main difference between the preview and the scan is that no files are written when doing a preview. If you need to experiment with various options before writing the files, you can change options and see the effects of these changes by pressing the "Prev Mem" button. You can also turn off outputting files in the Files tab and then press the "Scan Mem" button.
A scan involves reading the raw scan data (from one of 3 sources), processing the raw scan data to get accurate colors, and writing the processed image data (to up to 4 destinations).
The raw scan data can come from one of:
The processed image data for a preview goes to the Preview tab. The processed image data for a scan can go to any combination of:
Note that there is only one memory buffer for the most recent preview, and only one memory buffer for the most recent scan. The usefulness of the memory buffer is that you can change options that affect the processed image and re-do the processing without needing to re-scan the film. Film is delicate, so you want to minimize how long it's in the scanner and how many times it's handled.
One of the most powerful features of VueScan is that you can save the raw scan data in a file (using "Files|Output raw file") when scanning from a film scanner. These raw scan files can then be reprocessed later (or with later, improved versions of VueScan) without needing to re-scan the actual film. You shouldn't ever need to scan the same piece of film twice.
The raw scan files are raw data straight from the CCD in the scanner, without any sort of color processing or modification. The only options that affect the raw scan files are in the Device tab and Crop tab. None of the options in the Filter or Color tabs affect the raw scan files in any way.
You only need to save raw scan files if you foresee a need to reprocess the image in a later session. In any case, VueScan always keeps the raw data from the most recent scan in memory, so you can always reprocess it without needing to rescan the image. The only time you'll need to rescan the image is if you want to scan at a higher resolution, or if you want to manually change the exposure or focus.
The preview window is primarily used to show the cropping that the automatic cropping is selected, and to let you change this cropping if necessary. It's also used to give you a rough idea of what the color and brightness will look like in the final scan.
VueScan uses color correction tables which have been derived from a Kodak Q60 calibration slide and which produce colors accurate to better than 1%. These color correction tables have been produced for each scanner that VueScan supports, and results in colors that are quite accurate.
Note that the images produced by VueScan from scanned negatives may vary in intensity and contrast from the prints you get back from a photofinisher. If you look closely at the prints, you'll probably see that the detail in the highlights of the image have been lost, and the detail in the dark parts of images can't be seen. VueScan tries to preserve the detail in the dark and light parts of images, and you can control how much detail in the dark and light parts is preserved by experimenting with the "Color|White point (%)" option. If you want to more closely duplicate the loss of detail in dark and light parts of images that you get when getting prints from a photofinisher, try setting "Color|White point (%)" and "Color|Black point (%)" to "5" and set "Color|Gamma" to "1.8".
You can use VueScan for batch scanning with the HP PhotoSmart, Minolta, Polaroid SprintScan 4000, Microtek ArtixScan 4000 and Nikon scanners. VueScan has been designed to scan as fast as possible, and to do post-processing of the images while the film ejects and while you prepare the next slide or negative to be scanned. This way you can do batch processing as fast as is practical.
You can significantly speed up batch scanning on some scanners by setting two options so the preview won't be done when you do a scan. To do this, set the cropping for all the frames, then turn off the "Crop|Auto crop" option. In addition, if the "Device|Auto exposure" option is displayed, turn it off and set "Device|RGB exposure" to either "1" or a value greater than one that won't overexposure any of the images.