carstenw wrote:
I am not sure if better DR is really realistic (although digital does appear to have better DR if nothing clips in ugly ways), but I think that one thing which is absolutely crucial to the success of this camera is to have loads of highlight headroom. Clipped highlights would kill a digital B&W immediately, in many cases.
clipped highlights in digital are much less problematic in b&w than they are in color. i purposely clip highlights when i'm shooting for b&w all the time. what makes b&w film so beautiful is usually low dynamic range and a very non-linear tone curve. i'm curious to see what leica is doing here as i see the channel mixer of color digital as a real advantage for b&w.
I hear ya, cputeq. I just wonder if loosing the control in normal b&w of adjusting color channels is worth it. I could see the advantage to IR shooters, but I'm not so sure for regular b&w shooters. I'm sure that Leica shooters who do buy the camera will be convinced it is a worthwhile tradeoff.
the truth is that Leica is still making a high quality product, and as long as the lenses continue to be what they are (I mean, is there something as good and as fast as the 28/2 ASPH or the 50/1.4 ASPH that you could theoretically buy off the shelf?) there will be a market for the lenses.
there are MF backs out there that only shoot monochrome and they make the M9 look like a blue light special.
In my M2, M3, M4 days, I shot nothing but black and white. It "made" me see the world in terms of black and white. It is purely a psychological thing, but I would love to have a camera where black and white was the only option. My black and white photography has never been as good with a dslr, simply because the default presentation is color (and yes, I know I can have a black and white jpeg preview showing on the lcd screen when shooting, but not quite the same as no color option), and it has made me rather lazy, looking for black and white after the fact in post, rather than fully concentrating on making the most of the light, shadow, form and texture as I compose.
So for me, bring it on! Maybe I can save enough for this black and white body, and recover my old 35/50/90/135mm kit I adored so much in my Leica M film days.
douglasf13 wrote:
I hear ya, cputeq. I just wonder if loosing the control in normal b&w of adjusting color channels is worth it. I could see the advantage to IR shooters, but I'm not so sure for regular b&w shooters. I'm sure that Leica shooters who do buy the camera will be convinced it is a worthwhile tradeoff.
I would define 'regular B&W shooters' to be B&W film shooters, who never had the luxury of Channel Mixer for their post. That's where I see this still theoretical camera aimed, at convincing the film hold-outs there might be a good enough reason to go digital.
Besides, wouldn't the benefit of shooting with a red, orange, yellow, green, etc. filter on a monochrome camera be that the pixels all respond equally to such a filter? Rather than having a CFA that means only 25% see actual red, 50% green (obviously without a color filter over the lens)... I'm sure there's some math in the interpolation that removes some of the difference, but my impression from all the digital cameras I've owned has been that the red and blue channels are always noisier than the green and when doing extreme attempts at emulating a red filter in B&W, tended to result in less optimum results. Of course, if you have to shoot with a filter, that means the need to be more deliberate with your work at the time of exposure since there will be less room for tweaking in post.
Maybe B+W talked them into it to help kick some life back into the low demand (my guess) for B&W filters.
I have never been satisfied with "filter emulation" for black and white in post. Red filter emulation as stated, always leaves much to be desired (dark line artifacts around tree branches when blue/cyan luminosity is diminished). Iusually resort to using a polarizer, then boosting red luminosity, and lowering green luminosity when trying to emulate. If the proposed sensor had a "typical" spectral response akin to an "average" modern panchromatic film, it would be nice to put those 39mm filters back into service
rscheffler wrote:
I would define 'regular B&W shooters' to be B&W film shooters, who never had the luxury of Channel Mixer for their post. That's where I see this still theoretical camera aimed, at convincing the film hold-outs there might be a good enough reason to go digital.
Besides, wouldn't the benefit of shooting with a red, orange, yellow, green, etc. filter on a monochrome camera be that the pixels all respond equally to such a filter? Rather than having a CFA that means only 25% see actual red, 50% green (obviously without a color filter over the lens)... I'm sure there's some math in the interpolation that removes some of the difference, but my impression from all the digital cameras I've owned has been that the red and blue channels are always noisier than the green and when doing extreme attempts at emulating a red filter in B&W, tended to result in less optimum results. Of course, if you have to shoot with a filter, that means the need to be more deliberate with your work at the time of exposure since there will be less room for tweaking in post.
Maybe B+W talked them into it to help kick some life back into the low demand (my guess) for B&W filters. ...Show more →
I'm just not convinced the tonality will be a huge upgrade. Everything I read about these b&w sensors is in regards to detail, not being more b&w film-like in terms of tonality. It's still a digital sensor, after all. I'd certainly be curious to try one.
Have you guys tried shooting red filters on our current digital cameras?
I think dynamic range on color cameras is limited sometimes due to the whitebalance.
With a monochrome sensor there is no problem there. So even with a normal monochrome sensor the dynamic range is increased a bit, for example in artificial light.
Because the effort to have a monochrom camera for a manufacturer is very small, it is a good niche camera for a company like Leica that is used for smaller production numbers. It would be even the same small effort to have a camera without microlenses. Kodak / Truesense sensors offers different models of most of their sensors.
Up to here this is nearly no additional effort for the R&D department, most work for marketing and book-keeping :-)
I suppose that Kodak / Trusense would even produce a sensor with increased dynamic range with ND filters on part of the pixel for Leica. This would be a great :-)
Another part of the better monochrom tonality could be a better matched spectral response. Or even matched exchangable filters for different film spectral response (like human vision day-correct, human night vision, orthochromatic, IR,..).
douglasf13 wrote:
I just wonder if loosing the control in normal b&w of adjusting color channels is worth it
That adjusment can be done before you snap the image, using color filters just as in the good ol' days. Probably with muuuuch better results as well.
douglasf13 wrote:
Have you guys tried shooting red filters on our current digital cameras?
No, but it's probably no idea at all. Put a red 25A filter on the lens and the green and blue pixels will not "see" anything since they already have their filters. You could instead just scrap those channels, leaving you with only 1/4 of the information from a full color image.
I sometimes try to get the same tonality in B&W as I can get with film, but it always ends up with terrible noise and low sharpness if I alter the channels too much. So I stick with a wite balance fairly close to 5500K in most cases, which is a bit limiting. This would not be the case with a monochrome sensor and filters.
Edit: Then probably the monochrome sensor will have a character, not having 100% linear response to photons of any wavelength, just like one film differ from an other.
douglasf13 wrote:
I'm just not convinced the tonality will be a huge upgrade. Everything I read about these b&w sensors is in regards to detail, not being more b&w film-like in terms of tonality. It's still a digital sensor, after all.
+1 @ more detail
As to tonal range ... a total elimination of the CFA would render all pixels capable of recording the same amount of light energy, but wouldn't the range of a pixel's response to the light energy still be limited to the individual pixel's capabilties. In that regard, it would seem that the DR wouldn't be significantly greater ... but the transitions within that DR would have more accurate/precise increments than those interpoplated from from the RGB CFA (with different energy response @ R vs. G vs. B). To me, this is where the gain would be.
Even though we can currently convert the color to B&W, and play with it greatly in PP, the initial values are a guess/reverse engineering of the light that has passed through the CFA. Without the CFA ... it is no longer a reverse engineering effort, but rather a direct response. To me, that would render the accuracy/precision greater from the onset, leading to Deming 101 principles.
Here's a twist that might be interesting. Given the use of the RGB CFA approach ... consider if you were to use a variable-NDFA, somewhat similar to Fuji using the multi-size pixel approach in their super-CCD, or the variable-sized grain structure of some films, that yielded greater DR than their contemporaries. In doing so, you might be returning to a semi-interpretive approach, but it could offer some ability to handle those scenes that exceed the pixels DR for protecting highlights.
If the non-NDFA pixels are not "clipped", then the amount of ND could be offset accordingly via the algorithm. If the non-NDFA pixels are clipped, then the algorthm could utilize the NDFA pixels "as is". A profile could easily be used for on/off in simple form, or even better programmable to those pixels @ varying ND value.
It'll be interesting to see how much DR can be improved without a CFA (assuming it will not be replaced with an NDFA). My expectation is the improvement in tonality "within" the DR more so than the expansion of the DR. Of course, both would be nice.
Now, I just need to get the patent for my variable-NDFA finished, so I can start collecting my royalties. Of course, I have to finish working on my tilt-shift sensor patent first.
douglasf13 wrote:
Have you guys tried shooting red filters on our current digital cameras?
I tried a blue filter for correcting tungsten lighting once, figuring that I would get less noise in the blue channel this way, but in the end, due to the filter factor, I had to go up one stop in ISO, and got the noise anyway, so I gave that up. On a tripod, balancing the light with filters makes sense, I guess.
@Rusty: Regarding your NDFA idea: you could just put an LCD (without color filters) in front of the sensor and regulate the light per pixel. Ofc, you need a polarizer filter as well so you'd lose a lot of light there, and you might get problems with color shift even more.
An NDFA would mean a reduction in resolution. With a CFA you still get luinosity values per pixel. Not so with an NDFA as it's the luminosity you're changing. So if you did some kind of fuji-style random distribution with two exposure levels per output pixel an 18 megapixel sensor would be reduced to 9 megapixel. If you did a symmetrical thing like the GRGB of the CFA you'd end up with four exposure levels and 4.5 megapixel.
Don't you just record the brightness for one specific color band in a CFA at each location? I mean, you cannot draw any conclusion about the "Red brightness" from a sensel with a green filter in front.
Luka, as far as I am aware, the green intensity is used as the luminance value, and red and blue only contribute to their own colour channel information. All colours are interpolated from the Bayer Matrix. The same could be done with ND pixels, but the recombination would be different, I guess.
And unlike the RGB guessing (i.e. color noise), the ND would be a known value for accurate algorithm correction specific to the ND pixels only in the event that the ND was not needed/wanted. Not unlike making a manual exposure compensation when using a linear polarizer (i.e. from a known value).
Anyway ... I still think that the gains will be most noticeable within the DR, rather than an expansion of DR (hoping for both). Of course, being a Leica ... my "beer budget" will preclude me from owning it, just drooling at others more fortunate. Still, will be good to see what they've come up with.
