Archived posting to the Leica Users Group, 2004/08/22
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Douglas, There are several aspects to your question. When you refer to the lens spatial frequency response exceeding the sensors limits you are really addressing the Nyquist theorem. This has been covered years ago: specifically look up Austin Franklin posts. Essentially, the sensor must resolve twice the frequency of the information striking it. One of the exciting breakthroughs in chip design is the gradual reduction in pixel pitch and a reduction in noise levels. The low pass filters have been a way to lower the information coming off the lens to half what the sensor can resolve. Kodak at least has appeared to eliminate the filter on their D14n in its various incarnations so it appears that hardware software combinations are almost there in terms of digitizing light. It also appears that fabrication techniques are being created to place lenses on the pixels that can handle the skew rays coming off wide angle lenses. Another way to look at wide angle lenses is that the lens designers have a new opportunity to produce sensor friendly 6mm lenses that will have incredible DOF and we will have the opportunity to spend money on them. Don dorysrus@mindspring.com -----Original Message----- From: lug-bounces+dorysrus=mindspring.com@leica-users.org [mailto:lug-bounces+dorysrus=mindspring.com@leica-users.org] On Behalf Of Douglas M. Sharp Sent: Sunday, August 22, 2004 7:48 AM To: Leica Users Group Subject: Re: [Leica] Re:Do you like a rookie [R-D1] This is something I was wondering about, according to my knowledge the limits of the focal lengths of lenses to be be used successfuly is between 32 and 75mm. Above this your focussing accuracy is not on, below there are problems with sensor coverage. Another aspect appears, IMO, to be being ignored (or I missed it) AFAIK if the resolving power of a lens is above the resolving power of the sensor then you start getting moire and artefacts on your images. The basic reason for a low pass filter in digital cameras. As we all know the resolving powers of Leica lense are legendary. Facit, is the RD-1 really to be recommended for use with lenses of this quality ? Could this be the cause of those "out of focus " images we've seen, the low pass filter causes a degree of fuzziness which compensates or removes the effects mentioned above. Could the low pass be so strong as to blur the images ? Could this be the problem that Leica have been trying to solve for so long ? The fact that their lenses are too good. Douglas MIKIRO schrieb: > Hi, Richard, > > The range-finder is accurate enough as far as I have used 35/2 and > 50/2.8 at wide open, but I myself have not yet tried faster lenses. > The physical base-length of R-D1 range-finder is 38.2mm, while that of > Leica M is 69.2mm. Thus, in theory, R-D1 (1x) is as accurate as 0.58x > M cameras. One photographer who uses R-D1 extensively told me that he > only occasionally fails in focusing with 35mm at f1.4 but quite often > with 90mm at f2.8. > > The sound of the metalic vertical travel shutter of R-D1 has a higher > pitch and may not be as quiet as that of M. It is nonetheless > comfortable to my ears and helps create a rhythm in taking pictures. > In this respect, I prefer R-D1 to Hexar RF and Contax G2. It is a > matter of taste, though. > > The buffer memory takes two RAW images. Writing data to my SD card > (Sandisk) takes four seconds for one image and six seconds for two. > With JPG, you do not have to wait in real shooting. > > I hope this helps. > > Best regards, > > MIKIRO > Japan > > > Richard F. Man wrote: > >> At 07:50 AM 8/21/2004, mikiro@yahoo.fr wrote: >> >>> ... >>> R-D1 is larger, heavier, and, most importantly, more solid than >>> Bessa R2. Indeed, if you have a close look, you will find that it >>> shares only a few parts with Bessa. The 1x viewfinder is at least as >>> clear as that of Bessa R2. The shutter is much quieter. The shutter >>> charge lever is a unique feature of this camera and makes you feel >>> that you use a mechanical film camera. It is much smoother than the >>> film advance lever of Bessa. Even in a single shooting session, you >>> can use R-D1 and M cameras interchangeably with no stress. >> >> >> >> Hi Mikiro, how do you find the rangefinder focusing accuracy? Many of >> the early pictures on the web seem to be misfocused but look like it >> may be just due to the shooters? Also, the R-D1 has a short RF base, >> but I believe someone says the 1x viewfinder makes it effectively >> much longer. Is that the case? >> >> How quiet is the shutter subjectively, say, compare to the M? >> >>> In terms of image quality, R-D1 is in the same league with my Pentax >>> *istD (and probably other D-SLRs with similar sensors). In-camera >>> jpg images look a bit dull, and RAW may give you additional details. >>> The colour is very neutral. Epson people aim that its images reveal >>> characters of lenses by minimising filters and retouches in the >>> camera. In this respect they seem to be successful. More work will >>> be needed to confirm it. >> >> >> >> How fast can you take RAW pictures? Does it have a larger enough >> buffer so that you basically don't need to worry about it? >> >> Thanks! >> >> >> // richard (This email is for mailing lists. To reach me directly, >> please use richard at imagecraft.com) >> >> >> ------------------------------------------------------------------------ >> >> _______________________________________________ >> Leica Users Group. >> See http://leica-users.org/mailman/listinfo/lug for more information > > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information > -- Ihre bevorzugten Shops, hilfreiche Einkaufs-Hilfen und gro?artige Geschenk Ideen. Erleben Sie das Vergn?gen online einzukaufen mit Shop@Netscape! http://shopping.netscape.de/shopping/ _______________________________________________ Leica Users Group. See http://leica-users.org/mailman/listinfo/lug for more information