wlaidlaw Posted June 25, 2006 Share #21 Posted June 25, 2006 Advertisement (gone after registration) With the way sensors are improving, it gives a lot of scope to produce smaller aperture lightweight lenses. My Sony DSC-R1 has a usable 3200ASA on its APS-C CMOS sensor - certainly no noisier than the 400ASA on my previous Digilux 2. One year on, the sensor for the DM, whoever is making it, should hopefully be even better. If ASA400 or even 800 are completely usable with little perceptible noise, then an f4 or even f5.6 lens for occasional use is no hardship. On the zoom front, if Kyocera/Zeiss could get one to work on the Contax G2 ten years ago, then why could not Leica now. I know the viewfinder on the G2 is a bit small but again things must have moved on in ten years. Stepper/piezo motors are now tiny, current efficient and cheap. The whole viewfinder/rangefinder system could be run by them rather than mechanical links and then there would be no problems using a pair of moving curtains to link with any lens, including zooms, coupled via a passive transponder chip (no battery) in the lens to the body - maybe on the DM Mk2. Wilson Link to post Share on other sites More sharing options...
Advertisement Posted June 25, 2006 Posted June 25, 2006 Hi wlaidlaw, Take a look here Digital M. I'm sure you'll find what you were looking for!
lct Posted June 25, 2006 Share #22 Posted June 25, 2006 A Leica M with zoom? Ouch! Anyway, those liking shallow DoF will still need fast lenses and even faster ones to compensate the crop factor. Best, LCT Link to post Share on other sites More sharing options...
johnbailey Posted June 25, 2006 Share #23 Posted June 25, 2006 Just regarding the shutter on the digital M - can someone explain to me why a (mechanical) shutter is required at all? I can see why it would be there in the R9/DMR combo (because the R9 already has one for film use), but in an exclusively digital camera could they not have the sensor permanently exposed and just take a timed electronic 'slice' of the signal? I note that on my Nikon D70 aside from the flipping mirrror, the sensor is permanently exposed. No shutter. John. Link to post Share on other sites More sharing options...
stunsworth Posted June 25, 2006 Share #24 Posted June 25, 2006 John, are you sure about there not being a shutter on the D70? Anyhow returning to your question two things imeadiately come to mind. Heat build up - heat = noise, and battery life. I'm sure there are other issues as well but I'm not an expert in these matters :-) Link to post Share on other sites More sharing options...
adan Posted June 25, 2006 Share #25 Posted June 25, 2006 John, the D70 does indeed have a mechanical shutter in front of the sensor - sure you're not seeing the secondary mirror for the AF system (reflects the image down into the floor of the camera for focusing)? If it were easy to leave out the physical shutter in an SLR, it would not have taken Olympus (and Panasonic) so long to come up with 'live view' in the Evolt 330 and L-1 cameras. Another reason for a shutter on interchangable-lens cameras is dust protection. Link to post Share on other sites More sharing options...
adan Posted June 25, 2006 Share #26 Posted June 25, 2006 "On the zoom front, if Kyocera/Zeiss could get one to work on the Contax G2 ten years ago, then why could not Leica now" Because the Contax G cameras did not use a superimposed-image mechanical rangefinder. Only autofocus - or autofocus-measured "manual" focus. The viewfinder window of a Leica M is solid glass from the front all the way to the eyepiece (split diagonally with semi-silvering to reflect the framelines and RF image). A zoom finder requires several optical elements AND a lot of empty space to slide them back and forth in. No empty space in the Leica viewfinder, thus no zoom! Link to post Share on other sites More sharing options...
adan Posted June 25, 2006 Share #27 Posted June 25, 2006 Advertisement (gone after registration) Here's Leica's own illustration of their viewfinder. See the solid pale blue mass at left? - that is the main viewfinder - and there is no space in there for the 5-10 moving pieces of glass that a zoom viewfinder would require. In case the image doesn't show up (first ime uploading on this forum for me) here's the URL http://www.leica-camera.com/kultur/mythos/innovationen/messsucher/index_e.html Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/140-digital-m/?do=findComment&comment=1289'>More sharing options...
johnbailey Posted June 25, 2006 Share #28 Posted June 25, 2006 John, the D70 does indeed have a mechanical shutter in front of the sensor - sure you're not seeing the secondary mirror for the AF system (reflects the image down into the floor of the camera for focusing)? If it were easy to leave out the physical shutter in an SLR, it would not have taken Olympus (and Panasonic) so long to come up with 'live view' in the Evolt 330 and L-1 cameras. Another reason for a shutter on interchangable-lens cameras is dust protection. Ah.. I see it now! Yes, it does have a shutter. Apologies for propogating my ignorance. John. Link to post Share on other sites More sharing options...
stunsworth Posted June 25, 2006 Share #29 Posted June 25, 2006 But suppose instead of the framelines being etched on a small plate as they are at present they were drawn electronically on a LCD. That way they could be electronically varied almost infinitely provided the lens could communicate to the body. Link to post Share on other sites More sharing options...
lct Posted June 25, 2006 Share #30 Posted June 25, 2006 ...there is no space in there for the 5-10 moving pieces of glass that a zoom viewfinder would require... Andy, do you think there could be enough space to insert a magnification lens that one could remove by any means to get two different magnifications? Best, LCT Link to post Share on other sites More sharing options...
adan Posted June 25, 2006 Share #31 Posted June 25, 2006 Stun (for short): That might work. The zebra-code on new lenses should be enough to identify field of view. A zoom lens would require a variable zebra-code, though (flashing lights? LCD spots that lighten and darken on the lens?) LCT: Hmm- I don't know WHICH pieces of glass in the viewfinder get changed between the various magnifications. But you would have to change magnification for both the main window and the rangefinder image (the dark blue line) or they would no longer align correctly for focusing. Link to post Share on other sites More sharing options...
lct Posted June 25, 2006 Share #32 Posted June 25, 2006 ...you would have to change magnification for both the main window and the rangefinder image... Yes of course, would it be difficult to do? Link to post Share on other sites More sharing options...
calshot Posted June 25, 2006 Share #33 Posted June 25, 2006 And I've heard it will be named M8. Wim I think we have called it that(M8) Rob Link to post Share on other sites More sharing options...
ed_oneal Posted June 25, 2006 Share #34 Posted June 25, 2006 I still don't understand why there has to be a shutter at all since the LCD display will be active only AFTER the shot is taken (a welcome feature, which, among other things saves battery power). It seems to me that the image capture could be entirely electronic. Link to post Share on other sites More sharing options...
adan Posted June 25, 2006 Share #35 Posted June 25, 2006 LCT - I don't know. If the change requires working with the glass bits in the middle of the RF/VF, it would certainly require going back to the factory (not something a user could change). And the viewfinder frames would have to vary (via Steve's method or some other) to keep the framing consistent with the magnification. I.E. you'd need to reduce the 50mm frame mask by 20% if the magnification was reduced by 20%. ------- NOT just for LCT: My own take is - the Leica M RF/VF does what it does (focus and frame fast prime lenses from 28-135mm) very well as it is. No one, including Leica, has come up with improvements (or even matched it, except perhaps the new Zeiss Ikon) in the last 50 years. Rather than screw it up trying to add things it is not really designed for (zoom, AF, variable magnification) - buy a camera that IS suited for those tasks (R9, Sony, Nikon, Canon). Link to post Share on other sites More sharing options...
adan Posted June 25, 2006 Share #36 Posted June 25, 2006 Ed: The image sensor itself draws power and produces heat whenever it is on (it's a silicon chip just like any other). Power drain reduces batery life and heat increases noise in the image. There are no or almost no digital cameras that do not use a mechanical shutter - even digicams like the Digilux 2 or the Sony R1/H1/N1 have a leaf shutter in the lens. Dust is already something of a problem with DSLRs - even though the sensor is only uncovered for fractions of a second with each exposure. If it were permanently uncovered it would have a terrific case of dandruff within a few minutes from the attractive charge of the "Charge" coupled device. Link to post Share on other sites More sharing options...
ed_oneal Posted June 25, 2006 Share #37 Posted June 25, 2006 Good point about "dandruf". I'll have to think about a solution to that problem. Given the issue of the sensor having a hard time responding rays at oblique angles, covering the sensor with another piece of protective glass seems impractical if you want to keep the same case dimensions. As far as having the sensor on all the time, why not have it off until you press the "shutter release" button half way down? That gives the system time to see the image and settle down. This should take only milliseconds. After you get an indication (green light?), you press the button all the way down to capture the image. Again, the "dandruf" problem may be difficult but a shutter will only be able to do so much. Ed Link to post Share on other sites More sharing options...
lct Posted June 25, 2006 Share #38 Posted June 25, 2006 ...No one, including Leica, has come up with improvements (or even matched it, except perhaps the new Zeiss Ikon) in the last 50 years... I wonder if digital will change those good old things, Andy... AFAIK a .72x finder magnification will not be large enough to focus 90/2 and 75/1.4 lenses at full aperture due to the crop factor and consequent reduction of circle of confusion. .78x could fit but i don't see how the 21mm frame (28mm FoV) could be visible in the finder then, assuming that the mechanical base length of the rangefinder will remain the same as that of classic M cameras (goggles oblige i guess). Hence my question... Link to post Share on other sites More sharing options...
marknorton Posted June 25, 2006 Share #39 Posted June 25, 2006 Sensors which provide a continuous output are called Interline sensors and differ from the full frame sensors which require a mechanical shutter. In an Interline sensor, a built-in "electronic" shutter samples the image for the required time, the longer the time, the greater the effective exposure. Full frame sensors behave much more like film. When the shutter fires, the sensor is exposed and the data is read out once the shutter is closed. If you look at the Kodak web-site and the different sensors available from this manufacturer, you'll notice Interline sensors tend to be smaller and have lower pixel counts. If you want larger sensors and larger pixel counts (such as their 39MP, 61mm diagonal sensor), full frame is the way to go. The D2 mechanical shutter that you hear "click" actually operates AFTER the exposure and covers the sensor instead of exposing it. It seems this sensor needs to be in the dark while the data is being read out. As Andy points out, having the sensor on all the time increases its temperature and drains the battery which affects image noise. Noise doubles for every 10 degree C rise in temperature, so you want to minimise the amount of self heating. It would even be a good idea to provide a Peltier heat pump to cool the sensor below ambient for best noise performance. The same effect is used in the "business end" of satellite receiving dishes where the electronics are cooled dramatically to minimise the noise level and enhance the extraction of the signal from deep space. As for the zooming viewfinder, I agree it would be next to impossible to make it a zooming viewfinder and retain the quality we expect. My little Sony P&S has one, but the quality is poor. But, Leica have this fundamental problem. The standard 0.72 viewfinder has its own "sweet spot", let's say working with 35 - 75mm lenses and the combination of viewfinder magnifiers, 0.58 and 0.85 magnifications, aux finders have been introduced in the past to move that sweet spot to accomodate 21mm to 135mm lenses. They're all klutsy solutions and in the ideal world, the M8 would support 21 to 90 directly without any of these add-ons and key to that would be to allow the user to change the viewfinder magnification. The LCD panel could certainly be used to draw the frame lines and open a "window" for the rangefinder patch and it could also carry other viewfinder information such as AE shutter speed. Further, the frame lines and patch could move under software control as you focus, something that is now done mechnically. There is no need for a rewind knob in the M8 so there is some space available but it all comes down to their budget. Has it all gone on the digital sensor and processing with the shutter carried over from the R9 and the viewfinder/rangefinder from the M7, or have they dug deep and come up with a new design? Link to post Share on other sites More sharing options...
highlander Posted June 25, 2006 Author Share #40 Posted June 25, 2006 And I've heard it will be named M8. Wim Hi, Can you give any information on what Leica mean by "Optimisation of the lenses " with this zebra code, are our existing lenses out or will they have to be coded ? (at another cost). Link to post Share on other sites More sharing options...
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