If you are shooting on film, scans are done on a drum scanner, and are digitally dustspotted with minor imperfections corrected.
Scan sizes are based on film size for ensuring retrieval of all the usable information.
90mb - $35.00
150mb - $65.00
250mb - $120.00
For B&W grayscale, I scan at 720dpi to size. Piezography utilizes fully files of this size.