Bulent’s recent question about a possible foray into large-format film photography, primarily for macro shots, yielded several comments about how one gets a shallower depth of field with Large Format (LF). I seen that, heard that before. One or more of the 645z reviews I’ve seen made a big deal about how the medium format (MF) niche was crippled if not doomed by the inherently shallow depth of field. I remember in the early days of APS-C and smaller sensors, some were moaning about the difficulty of getting shallow enough depth of field.
OK, so it seems that the general consensus is that moving from LF to MF to FF to APS-C to smaller sensor carries with it a corresponding increase in depth of field. But what does this mean? Really? I understand that lenses with longer focal lengths have shallower depths of field. So a 75mm lens will have shallower depth of field than a 50mm. And I understand that a 75mm lens on a 645 format will have the same effective field of view as a 50mm on a FF 35mm format. Is this why the larger formats are considered to have shallower depth of field? Because I need to use a longer lens to achieve the same field of view? What if I had a 100mm macro lens that could be adapted to fit on the 645z and a K-mount FF and a K-mount APS-C. Since the lens and its focal length are constant, does the depth of field remain constant, with only the effective field of view changing? Or does the depth of field also change? In short, I think my question is whether the accepted relationship [LF & MF = shallower depth of field] really has anything to do with the sensor format. I am guessing that people are talking about a practical issue (need to use longer lenses to get the same field of view on a LF) rather than a physical issue of the interaction between sensor size and lens. But I can’t tell... stan -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
