Is there a way to utilize this scanner's full bed?

I have a CanoScan 8800F that's not scanning the full bed which measures 8.75" x 12". It seems to max out at the LTR (upper left) and A4 (bottom right) markers shown in below pic, causing whatever exceeds those markers to be cut off. My previous Canon scanner did the same thing. Is there a way to utilize the entire width and length of the bed? After all, there is glass there, so it seems like the scanner should be able to scan beyond the limits of LTR/A4.

Question by oscilatingcretin on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.