Archived posting to the Leica Users Group, 2000/02/29
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]drodgers@nextlink.com wrote: > Austin > > You wrote: > > >>Since the 'lux opens up more than the 'cron, the 'lux is capable of far > less depth of field than the 'cron.<< > > Technically, because the 'cron has a closer mimimum focusing distance, it > is capable of creating a photograph with less depth of field than the 'lux. > For instance, a 'cron will at it's minimum focusing distance (approx 1/3 > meter) and maximum aperture (f2) have less depth of field than a 'lux at > it's minimum focusing distance (approx 1 meter) and maximum aperture > (f1.4). > > So in theory the 'cron is capable of less depth of field than the 'lux. DOF > is a function of focusing distance, not just aperture setting. The closer > the plane of focus, the less depth of field. > > However, I'd agree that if both 'cron and 'lux were wide open and focused > at, say, 10 feet, the 'lux could provide less depth of field with f1.4. > > David David. This is a trifle confusing to me. Why would anybody find it an advantage, to have less depth of field at a close distance. Especially when comparing an opening of f2 and faster. The way I see it, lenses of f2 and faster where not developed to provide a small as possible depth of field , but to offer the possibility to be useful at lower light levels. Hence the name Noctilux and Summilux and not, for example, Nodepth or Summilodepth. This high speed lenses aren't even well corrected for close up (below about 1m or 3 foot). When I use my Noctilux wide open, I try to make sure, that I have a reasonable distance from the object, to get some sort of useful depth of field. Why would you guys want to have the least amount of depth of field from a 50mm lens? Even for a portrait anything larger than F2 does not make sense. At least not with good light. And then, surely not to get less depth of field. The only thing I can think of is for somebody who collects nose only shots. " The nose collection. 10 thousand different hooters. " Of course, all lenses with the same focal length used at the same distance, have the same depth of field, when operated at the same f-stop. Regards, Horst Schmidt