I responded to a post today in an interesting forum discussion about the new Pentax 645D “medium format” (or, as I prefer to call it, “mini MF” format) digital camera. This is a potentially game-changing camera. I has a 33mm x 44mm 40MP sensor and a body-only price of under $10,000. Its cost is far below that of competing mini MF bodies and a fraction of the cost of recent larger MF systems – and the price isn’t much above that of the high end full frame DSLR systems. While larger is not always better, for some types of photographers this puts a level and type of digital camera performance within reach.

In the discussion forum thread I referred to above, a writer had suggested that the 1.7x size differential between the Pentax 645D and full frame DSLRs would not be significant. In a sense he is right – it will not be significant to most photographers, and I surely cannot imagine why anyone would get one in order to make family photos to post on the web. However, I thought I’d share what I wrote concerning why I think that this might be significant for at least some photographers. My response (slightly edited) follows:

Photosite density is rarely the limiting factor when it comes to maximum print size from DSLR originals. As [the other poster] points out, “technique” stuff tends to be much more critical. Enlargement limits are more likely the result of stuff like camera movement, slight mis-focus, lens issues, etc.

I disagree that the size difference between the 24mm x 36mm full frame DSLR sensor and the 33mm x 44mm “mini MF” sensor isn’t significant. There are several reasons I feel this is the case: Continue reading More Thoughts About the Pentax 645D ‘mini MF’ Camera →