BetterLight Scanning Guide
From UA Libraries Digital Services Planning and Documentation
Hello, this is the comprehensive guide to the use of the Betterlight overhead scanner. Let's begin scanning.
Turning on the machine: There are two power switches that need to be on for the computer to recognize the scanner
on the power supply located under the scan table on the small thin external scanning harddrive once these are on you will see a green light flashing on the scan back located in the camera
Turning on the lights: There is a red switch on the back of each hotlamp, flip these switches. The lamps take ten minutes to get heated up to a point that the spectrum of light they give off is stable and the correct color, be careful not to calibrate your colors before the lamps are hot.
Turning on the program: Open the Viewfinder 4.7.1 application. there is an shortcut icon in the program doc at the bottom of the screen that looks like a laptop and camera.
Preparing to make a scan
- Select crop tool and open the selected area to the full size of the preview area.
- Place your materials to scan on the scan table. along with the "focus card" and the "greyscale strip". Making sure to place those cards on the surface you want to image. These two cards also need to be placed in a horizontal orientation or the optical calibration will not work well.
- Click the "prescan" button. (you need to do this right off the bat when opening the program for the first scan of the session, viewfinder will not let you do much else untill you make a prescan.
- Once you have made a prescan of your materials on the scan table, click the crop tool again and size the scan area down by dragging one of the corner pips making a rectangle that better fits your materials.
- To set the folder where the scans will be saved, click the viewfinder dropdown menu at the top on the screen and select preferences. the window that will appear has fields for "save scan folder" and fields for the components of the naming convention, "File name", "Starting number", "Step by", and "Suffix Length". "Save scan folder" is self explanatory click the "Scan folder" button and browse to the appropriate folder."File name" also is strait forward, "Starting number" is the sequence number that Viewfinder will step forward as you make successive scans. if you are scanning the 1st scan in a sequence set this to 1, if you are starting at the 27th set this to 27. "Step by" is the number viewfinder will count to get to the next sequenced number, so if you are scanning every page in a manuscript, "Step by" should be set to "1", if you are scanning every other page, than "Step by" should be set to "2". "Suffix Length" is the number of digits that are total in the last segment of the auto generated file name. So if you set "Suffix Length" to 6, and "Starting number" to 241 the last segment of the file name will be "_000241". If set to 9 it would look like this "_000000241". you can ignore the rest of the stuff in the preferences window and close it down with the red button in the top left corner. now that you have set the file name you can view the filename that will be applied to the next scan in a field above the "Prescan" button.
- Click the spot color checker tool, and into a current preview of the materials containing the "greyscale strip" click a spot check marker onto the greytone that is associated with, "A", "2", "5", "M", "11", "14", "B", and "19". Eight spot check markers gives a very accurate calibration however you can use less.
- Select the "Color" menu on the right side of the viewfinder window under the "prescan" button to expose the "Auto Balance" button, click this to calibrate the color gamut. You will see the colors in the preview window shift slightly. You can click "Clear Meter" at this point to remove the spot check markers from the prescan window, however they will not effect anything if you dont.
- you now have a color space calibrated to "true" neutral pantone colors.
Size and DPI
- Click the "Size" menu next to the "Color" menu.
- This menu window has only one thing that we need to worry about "pixels/inch". this should be set to 600 for all scans done on the overhead!! (this is not a major concern since it dosent ever get changed however if you need to thats where it happens.)
- Click the "Tone" menu next to the "Color" menu.
- There are several tools within this menu that need to be addressed to adjust the tone of the preview image to make it as correct as possible, these tools are brightness (arrows under the "sun" icon), contrast (arrows under the black and white circle), line time (located above the file name field), and ISO (also above the file name field).
- Line time: is the duration of time the scanhead takes to scan a single row of pixels from top to bottom. you can think of it like shutter speed. the affect on tone is that the slower the line time, the more light is let into the CCD, the lighter the image will be, and vice versa. (CCD stands for Charge-coupled device, the technical term for the type of image sensor in the scanback.)
- ISO: is a way of mapping the value gamut onto the current colorspace. In film photography ISO is a scale for determining film speed, which is an analogous process to this digital one. You can get a sense of this by looking at the histogram that is overlapped onto the contrast/brightness curve present in the "tone" menu. as you click the ISO value up and down you can see the histogram of the greyscale values move across the tone curve. This movement will change the totality of greyscale values assigned to the current gamut across the tone curve. This tool is critical to the acquisition of correct tone but is something that you have to tweak back and forth to arrive at the best setting.
- brightness: moves the current colorspace up or down the valuescale. this action changes the range of greyscale tones the colorspace has access too. Lighter or darker.
- contrast: changes the steepness or speed at which the gradations of tone within the image pass through the current colorspace. This action will alter the ratio of grey to black&white. Duller to more rich tones
- You can also alter the tone curve its self however the best setting for the majority of jobs is the default. If your curve starts to get bumpy and is no longer a smooth slope from one side of the colorspace to the other open the dropdown that says custom and select default. (the default setting will change again to custom as soon as you make an edit.)
For more information on picking the right settings please view the page on visual assessment of images.
Viewfinder uses a realtime optical contrast detection tool to help focus the lens on the materials. For this tool to work well bright lights and crisp light on dark contrast edges will allow the machine to tell you when the lenses are at optimum focus.
- Click the "Focus" menu next to the "Tone" menu.
- Prepare a current prescan of your materials where the "betterlight focus card is placed on the surface that you want to be in focus. (this is important because the horizontal plane perpendicular to the scanback where the focus card is placed will become the plane that the focus tool attempts to set in focus. If you want to scan a book page then the card should rest on that page.)
- the height of the camera will determine focus and size of the materials that can be captured. there is a set of three buttons attached to the leg of the scan table these buttons will move the camera up and down with a motor. Use these buttons to roughly fit you materials into the frame of the prescan.
- You may have to move the camera and take a prescan several times to get the size right, you can also try starting a prescan and then as the camera is doing the capture use the buttons to move the camera and you can see in real time the size of the materials change.
- Using the camera move buttons during the prescan is a technique allowing you to see the changes happening, however the prescaned image is not updated unless you execute another prescan. this may seem counterintuitive since the tone ajusting tools immediately change the onscreen image. taking note of when you need to make a need prescan in your workflow will speed up production.
- Once the materials are framed up well with in the prescan window and the focus card is sitting on an appropriate part of the item. click the mouse on the horizontal lines portion of the focus card, the mouse pointer should look like a thick white plus sign.
- once you do this there will appear a tall skinny marque selection if this selection does not sit across only the horizontal lines please reposition it by clicking again or changing the magnification slider in the focus window to shrink or grow the selection until it covers a skinny strip across those horizontal stripes. this is the place that the scanback will look to find its contrast edges.
- Click the "Go" button you will see the three grey bars below the "Go" button turn into red green and blue bars with numbers under them. now you are ready to do the focusing.
- there are two black metal knobs "to the left" of the camera bellows, the ones on the right will make the camera fall on the ground... :( . the knobs on the left control the vertical position of the lens card and the cameraback. Twist the lower knob to move the lens card and watch the red green and blue bars get shorter and longer. the corrosponding numbers under these bars will also change. this is a representation of the level of contrast ratio which is a derivative of the level of focus that those contrast edges on the focus card are currently enjoying. The rule of thumb is that contrast is a factor of the tones brightness and gradations of what you are viewing with the camera and this will not be a constant set of components so the number that you are looking for will not always be the same, in some situations 1100 will be focused , and in another 400 will be focused, but higher is always better. You only have to monitor one of the R G B numbers since the difference in the three colored bars are accounted for in the pigment color compositions of the materials being scanned
- note* while the focus panel is active many of the other tools like the selection of tools at the top of the viewfinder window will be greyed out and unavailable for use. if during the process of getting an image ready for scan you need to get access to those tools and can not you may need to switch over to tone panel.
- Once you have achieved the highest number possible by moving the lower knob up and down, click the stop button, this will set the focus selection.
- Now check your focus level by clicking the check boxes next to "super" and "view", to the left of the "prescan" button, this will change the previously labeled "prescan" button into a "superview" button. It will also produce a small red rectangle on the preview window move this red box around by clicking a new center position for the box. (I find that a section that includes text or line work, and some type of surface material information like an edge of the page or book cover (or tear or hole) give the best sense of the level of focus you have achieved. if this focus is not to your liking you can tweak the focus knob ever-so-slightly and do another superview prescan to observe if the focus level is improved.
- Turn superview off by unclicking the boxes"view" and then "super".
- once you have arrived at a focus that is to your satisfaction then click the "Scan" button and the scanback will do a final scan, save it to the defined folder and automaticaly open photoshop so you can begin the optimization process for that image.
- note* the preview scan image will not update as the final scan is taken, take this into consideration as you make successive scans so as not to be come confused with old information.
please see the optimizing in photoshop tutorial for more information on preparing images for ContentDM.