User’s Manual4-12GrayDocument Type: Choice: Normal, Photo, DocumentThree options of document type are provided when you chooseGray as the image type for your scanned document. Choice:Normal, Photo, Document. Document: Choose Document if your original containspure text or a mixture of text and graphic since it is anoptimal setting for regular business document. Whenusing Document, only Threshold can be adjusted. Photo: Choose Photo if your original contains photo toreproduce your photo in vivid grayscale image. Whenusing Photo, no Threshold and Contrast can be adjusted. Normal: When using Normal, Threshold, Brightness, andContrast can be adjusted.Threshold: The value ranges from 0 to 255. The default is230. A low threshold value produces a lighter image, and canbe used to subdue backgrounds and subtle, unneededinformation. A high threshold value produces a darker image,and can be used to help pick up faint images. Adjust thethreshold setting by dragging the Threshold sliding bar to theleft or right to achieve the desired threshold setting.