Difference between revisions of "BetterLight Scanning Guide"
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Revision as of 16:16, 7 August 2008
Hello, this is the comprehensive guide to the use of the Betterlight overhead scanner. Lets 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 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.
Turning on the program: Open the Viewfinder 4.7.1 application
Preparing to make a scan
- Select crop tool and open selected area it 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 are done with preferences close the window. now that you have set the file name you can view the filename that will be applied to the next can 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 greytone, "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 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.
- ISO: is a way of mapping the value gamut onto the current colorspace. 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 bumby 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.)
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.
- 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 pointed should look like a thick black 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