Jan Hinsch wrote an excellent review article “About the Use of Digital Single Lens Reflex Cameras on Microscopes” in 2004 for the web journal Modern Microscopy, http://www.modernmicroscopy.com/main.asp?article=33&print=true. The purpose of this article is to demonstrate the capabilities of the new Olympus Evolt E-330 DSLR for use with older design microscopes to capture the full diagonal of an 18 mm field number eyepiece that is not high eyepoint. This camera can be fitted with OM mount film camera lenses using the Olympus MF-1 adapter. A key requirement I had before purchasing a DSLR was that critical focusing must be possible at the full resolution of the sensor. I asked the Olympus Precision Instruments Group whether Olympus would have a DSLR available with this capability, and learned from them that the new E-330 DSLR would allow a selected area to be displayed at full resolution from the main CMOS sensor for critical focusing. This 7.5 megapixel sensor measures 13 by 17 mm.