M9M spectral sensitivity

[Jamie Roberts]

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Jamie,

 

Well, really, if Leica get the color sensitivity of yet another M-series camera wrong, then we need to send the entire R&D department for eye tests or something.

 

But no, they couldn't, really, not again!!

 

Could they?

 

Regards,

 

Sandy

 

"Not again" is the key phrase there

 

Ironically, I for one would be happy if they could reproduce the M8's "false colour" spectral response for BW, but I can't see how they're going to do that without interpreting the raw file in a way they certainly haven't disclosed. And even there you generally want to tweak spectral response in way that a monochrome file can't.

 

We'll see

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[sandymc]

Erwin Puts said green sensitivity was a good thing, as lenses perform best at green. Fwiiw.

Btw, for what reason should the camera mimic the spectral response of film? Just because our eyes are habituated to the panchromatic convention?

 

Well, you can make a good argument that the spectral response should be indeed be green biased as Erwin suggests, and not just to make the lenses work at their best - the classic formula is

 

Y = 0.2126 R + 0.7152 G + 0.0722 B

 

aka 71% of luma is green, rather than a flat response. That BTW is approximately what you would get in a conventional color to mono conversion in LR or C1. But a bare sensor would, I'd suggest, have too much red sensitivity to do a good job no matter what view you take on what the ideal should be.

 

Sandy

[Jamie Roberts]

{snipped}

Btw, for what reason should the camera mimic the spectral response of film? Just because our eyes are habituated to the panchromatic convention?

 

Jaap--

 

Really? We are talking about the art of monochrome photography.

 

It's not that our eyes are habituated to "panchromatic convention," actually. But it's demonstrable that effects of tonal difference make for more compelling monochromatic variance. In fact, without hue, all you have *is* that variance. Some of a preference, then is cultural, I'm sure, and some is conventional too, but art works through convention.

 

And again, anyone who works with film, as I mentioned in another thread, knows the difference between Tech pan and TriX and tMax and Agfa panX:)

 

Universally panchromatic raw files--essentially a desaturation--are just boring, visually.

 

So for the very reason that this is still "photography" and not something else, we can't just ignore the tonality of film. The authenticity of an HCB print comes as much from the overal capture tonal response as anything else.

 

I don't know if you have access to Sean R's site, but the HCB image at the top of the review is so much more interesting, consistent and effective--due to the tonal variances in faces, in particular--than any sample I've seen from the MM so far.

 

The grain of the MM might be Tmax but the tonality looks downright muddy in skin, trees and skies so far.

 

Sandy though has given me hope that this is precisely what Leica might be working on. We'll see. Heaven knows whatever remains of Kodak *should* be able to help them there.

 

But it won't be firmware, I don't think, unless they're doing something they're not telling in front of the sensor.

[Jamie Roberts]

{snipped} That BTW is approximately what you would get in a conventional color to mono conversion in LR or C1. But a bare sensor would, I'd suggest, have too much red sensitivity to do a good job no matter what view you take on what the ideal should be.

 

Sandy

 

And would I be correct in saying when you say a "conventional colour to mono conversion" you mean a desaturation? That's all that C1 does "out of the box"--though of course the strength of the conversion comes from the ability to mix colours... for mono rendering...

[sandymc]

And would I be correct in saying when you say a "conventional colour to mono conversion" you mean a desaturation? That's all that C1 does "out of the box"--though of course the strength of the conversion comes from the ability to mix colours... for mono rendering...

 

Jamie,

 

Yes, just so - no ability to color mix is the reason why I wouldn't a buyer for the M Monochrom, as fascinating a concept as it may be - I use channel mixing all the time......my favorite tool....

 

Regards,

 

Sandy

[jaapv]

All nice and theoretical. I'll think I'll go home and see what I can do with a bunch of DNGs I have. :) I hope I have some spare time this weekend. I'll start off with Andreas.

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...anyone know how the photos (models & portait etc.) of people look with blue eyes?

[gjames9142]

The mystery to me is, if the file is so neutral and you can't mix colousr, why (and how) is there the possibility in the menu to choose cool, sepia or selenium ? I have put my name down for one, but if it is to have only one hue, count me out. I suppose the other option is to use dedicated piezography inks. I have one friend who has three dedicated BW printers for different tonalities. You are going to have to be serious to use this camera, but maybe that is the point.

[tgray]

The mystery to me is, if the file is so neutral and you can't mix colousr, why (and how) is there the possibility in the menu to choose cool, sepia or selenium ?

 

It's the same idea of how toning is done with traditional B&W materials. You take your monochrome image and selectively tone that. So instead of a gradient from black to white, you have a gradient of brown to white. You can easily do this in photoshop, but I guess it's nice they included it as an option for the in camera jogs.

[01af]

I'll think I'll go home and see what I can do with a bunch of DNGs I have.

Do you have any you took with the intention to convert to b/w?

[pico]

Erwin Puts said green sensitivity was a good thing, as lenses perform best at green.

 

That must have something to do with the digital sensor. Blue light produces sharper images, but the aesthetic is limited. A trick some of us did to get better detail in B&W images under canopy jungles and forests was to use a blue filter. The printer loved it.

 

I really don't understand Puts' assertion, but there is a lot I do not understand yet.

[Guest Holy Moly]

...anyone know how the photos (models & portait etc.) of people look with blue eyes?

 

This I already asked at May 10th.

The given spectral sensitivity of the sensor might expose blue eyes like in portraits on collodium wetplates =harsh, very fair and agressive. Oversensitivity of blue (f.e.always blown sky and/or brown tan)

 

No answer yet due to the rubbish photographs from the 30 minutes loaners.

[01af]

I have put my name down for one, but if it is to have only one hue, count me out.

You have three tones to choose from in camera, and more than 16 million choices in post-processing (okay—you don't want most of these ... but there are always more than you can shake a stick at). If you include duotone and tritone then the number of useful choices quickly approaches infinity.

[Jamie Roberts]

The mystery to me is, if the file is so neutral and you can't mix colousr, why (and how) is there the possibility in the menu to choose cool, sepia or selenium ? I have put my name down for one, but if it is to have only one hue, count me out. I suppose the other option is to use dedicated piezography inks. I have one friend who has three dedicated BW printers for different tonalities. You are going to have to be serious to use this camera, but maybe that is the point.

 

We are talking about two separate things:

 

• the tonal or spectral response of the sensor which will show certain tones lighter or darker in response to their colour (bw films had certain responses to, say, skin tones that are typical
  
• an overlay tone as a gradient to use with the tones in the image.
  

 

Sepia or selenium simply "overlay" the whole file and add a colour. You are toning or tinting the image. You can select as many of those overlays in post as you like, and a number in the camera.

 

The tonal or spectral response of the camera will likely be fixed by the physical attributes of the sensor. In other words, the way the camera represents yellow as opposed to red in terms of monochrome tones will be "cooked" in the camera; you can't "colour mix" to get a different look.

[AlanG]

Erwin Puts said green sensitivity was a good thing, as lenses perform best at green. Fwiiw.

Btw, for what reason should the camera mimic the spectral response of film? Just because our eyes are habituated to the panchromatic convention?

 

No I think it should be infra red and maybe use compound lenses like flies have.

 

Most successful b/w photographers put in countless hours understanding how to shoot on b/w with various filters, process the negatives for the correct contrast and density for that image, and print it using a certain contrast paper along with dodging and burning in for impact. (Maybe even use Polycontrast paper and burn it with a different contrast filter.) You can't simply expect to shoot a typical scene and let the camera arbitrarily record in greyscale and expect it to look great.

[luigi bertolotti]

I have a vague wonder about this question of spectral sensitivity... but am not sure if it has solid roots, because still miss some points about the MM worflow...

 

1) I have read that the RAW (DNG) from MM is a 14 bit file

2) Which gives LOT of graytones, a wide "room to maneuver"

3) Which RAW converter will be used for such files ? I mean, is there the possibility that, in the RAW processing session, one can select, looking and remembering the scene, some setting like "green dominated pic" or "blue dominated pic" to "tune" the RAW processing to achieve a result, in term of distribution of graytones, that gives the "optimal" result for a certain scene ?

 

Sorry if this a silly question.

[tgray]

I mean, is there the possibility that, in the RAW processing session, one can select, looking and remembering the scene, some setting like "green dominated pic" or "blue dominated pic" to "tune" the RAW processing to achieve a result, in term of distribution of graytones, that gives the "optimal" result for a certain scene ?

 

No. The spectral sensitivity will be fixed on manufacture. The only way to change it will be to put a colored filter over the lens before taking a shot. You'll be able to change the contrast and relationships of the tones after the fact. It will be very, very similar to shooting B&W film in many respects.

[gjames9142]

Jamie,

 

Thank you for that clear explanation. I personally wouldn't point to HCB as a great printer/technician. Most of his life he sent in the film, and had it printed by Gassman in Paris. In the late 60s, via my dear friend Sam Tata of Montreal, he gave me a print of In Front of the Gare St. Lazare, which I still enjoy looking at, but I think that the gravure reproduction in The Decisive Moment is a richer interpretation of the image. If you are in Toronto, there is some work of HCB and some other great photographers at MoccA on Queen street. For me the real revelation is Leon Levenstein, a tremendous photographer. Many of the HCB prints are early ones and quite nice.

 

Geoffrey James

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Hallo,

Look here: Leica M

[jaapv]

No I think it should be infra red and maybe use compound lenses like flies have.

 

Most successful b/w photographers put in countless hours understanding how to shoot on b/w with various filters, process the negatives for the correct contrast and density for that image, and print it using a certain contrast paper along with dodging and burning in for impact. (Maybe even use Polycontrast paper and burn it with a different contrast filter.) You can't simply expect to shoot a typical scene and let the camera arbitrarily record in greyscale and expect it to look great.

I have a hard time correlating your answer to the post you quoted.

[brianv]

1) I have read that the RAW (DNG) from MM is a 14 bit file

2) Which gives LOT of graytones, a wide "room to maneuver"

3) Which RAW converter will be used for such files ? I mean, is there the possibility that, in the RAW processing session, one can select, looking and remembering the scene, some setting like "green dominated pic" or "blue dominated pic" to "tune" the RAW processing to achieve a result, in term of distribution of graytones, that gives the "optimal" result for a certain scene ?

 

.

 

 

The camera will record light hitting the sensor with an efficiency dictated by the spectral response of the detector used in it. Kodak worked for years to improve the spectral response of their detectors, especially with respect to the blue portion of the spectrum. On my first-generation monochrome camera- "what blue".

 

There is no point in inputting "green dominance" or "Blue dominance" unless you are hand-coloring the image. What you do, as is done for black and white film, is use color filters and color correction filters. This will take some experimentation, and the LCD on the camera allows results to be checked instantly. Using some "ancient" filters in new ways will be interesting, a type "A" filter, 81 series filters, and 82 series filters in addition to the traditional filters used for black and white.

 

https://www.schneideroptics.com/pdfs/filters/B+WHandbookFull.pdf

 

I'm betting that Schneider is happy to see this new camera.