Archived posting to the Leica Users Group, 2012/07/22
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]If you remember film SLR cameras, they all had a focusing aid in the center of the screen, implying that just focusing on a ground glass was sometimes difficult. The first kind I saw were a couple of shallow crossed prims in the center, giving the effect of a split image rangefinder. Years ago, I did a calculation that I don't think I'm competent to repeat now, but the calculation showed that the image separation of the simulated rangefinder was equivalent to that of a true rangefinder whose base was the diameter of the lens aperture--i.e. piss poor. Then a better thing showed up, a large cluster of micro prisms in the center. The hand shake of even the steadiest photographer was enough to make an out of focus image shimmer. However, on a tripod, this system was useless. So, a viewfinder display derived from the image on the sensor would be at best equivalent to that on a ground glass. To be practical, this would have to be supplemented by a display of the kind of signal that actuations auto-focus systems, for example, an indication of local contrast, which decreases when going out of focus. Herb >Can't be THAT hard. It would amaze you what can be done in SW, and then >implemented in HW. > >If you make it a priority of your design team...... > >But let me go back to basic RF cameras..... > >If you employ LiveView in the VF ( which I believe is called EVF or >something like that), and you use a really good LCD/LED display for the >image, you are basically looking through a SLR camera. Better than that is >the fact that you are actually looking at the "film" plane . No more out of >focus adjustment cameras or lenses.... WYSIWYG. Period. Make the LCD a >really good one, and it would make a surprisingly good focusing system. >Noctilux capable..... > >Did I mention cheap? I should have..... > >And the implementation of AF is pretty easy, but then again, how do you make >the M mount lenses move in and out for focusing? Move the mounting plane? > >Personally, I like the idea of an EVF..... > >I do not like the idea of a big honking rear mounted LCD that is my primary >focusing and viewing device... Ii think those are insufficient to promote >good technique. > >Let's just hope Leica actually makes a M10 at a price point we can >afford.... God knows, the M9 MSRP was way above mine..... > >( Thanks John.....!) > >Frank Filippone >Red735i at earthlink.net > > > > >_______________________________________________ >Leica Users Group. >See http://leica-users.org/mailman/listinfo/lug for more information -- Herbert Kanner kanner at acm.org 650-326-8204 Question authority and the authorities will question you.