M9M spectral sensitivity

[giordano]

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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.

 

Thank you for the B+W link. I've just posted along similar lines in a different thread, with this link to detailed information on the transmission curves of all(?) the Wratten filters. It seems to me that there's a role for some of the CC filters as well as the ones you cite.

 

But I doubt whether the LCD preview, particularly viewed in daylight, will be good enough to judge the subtle effects we're talking about.

[jaapv]

Well, it will be better than waiting for film to be developed and printed. You can always plug the card into your laptop.

[brill64]

Here is an IR time exposure with a 'black' filter. The bluffs and topography in the far distance could not be seen due to the persistent haze. Medium Format. (It is film, but the principle is basically the same.)

 

beautiful!

[jaapv]

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

MM ones cannot be converted, but yes, about 20 % of my images are taken with the intention to be converted, I have a user setting for DnG/B&w Jpeg on my M9 and M8.

[brianv]

But I doubt whether the LCD preview, particularly viewed in daylight, will be good enough to judge the subtle effects we're talking about.

 

I flip out viewing hood attachment that slides into the hot shoe mount would be nice. I can cup my hand over the LCD screen of the M8 and M9 when testing lenses that I convert to Leica Mount. I have no problems determining if I hit the shim to the last 0.01mm using the viewscreen. If "Eyes" are the main intend, a quick zoom in to that region is all that is necessary. My original monochrome DSLR did not have an playback feature. You did not know what was recorded onto the built-in disk drive until downloading across a SCSI interface.

 

It's the 21st century. No flying cars, but a Monochrome Digital camera that can use my lenses from the 1930s! I'll settle for that.

[giordano]

I have no problems determining if I hit the shim to the last 0.01mm using the viewscreen.

 

Judging sharpness is one thing, judging and comparing subtle tonal effects is another.

[AbbeyFoto]

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I was told the Bayer filter was replaced by a clear filter.

 

Can I ask a dum question? Does the M9 have a Bayer and an IR filter? If so, we can assume the MM retains the same IR filter?

[giordano]

Can I ask a dum question? Does the M9 have a Bayer and an IR filter? If so, we can assume the MM retains the same IR filter?

 

Yes; yes; no. We can be sure it has an IR-cut filter, but it may be slightly different from the one on the M9 in order to tweak the spectral sensitivity of the sensor to produce better-looking monochrome results. Comparison of test shots of identical subjects using the M9 and MM may eventually reveal whether or not this is the case. Early days!

[brianv]

Judging sharpness is one thing, judging and comparing subtle tonal effects is another.

 

Then just bring a palm computer with you. Better screen than any other digital camera. Small enough to drop into the field case. Get a Luigi bottom plate that allows access to the SD card. Think of it as a Polaroid, but much faster and no goo.

[pico]

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.

 

That is just so wrong. I am disappointed and with that I leave this forum, and not because of your posit, but the whole thing has gone overboard with people who express opinions that serve nothing in terms of real-world outcomes, but just more impressionistic Internet bullshit.

.

Ta.

[jaapv]

Yes; yes; no. We can be sure it has an IR-cut filter, but it may be slightly different from the one on the M9 in order to tweak the spectral sensitivity of the sensor to produce better-looking monochrome results. Comparison of test shots of identical subjects using the M9 and MM may eventually reveal whether or not this is the case. Early days!

 

According to LFI it is the same IR filter.

[AlanG]

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

 

Because you said this, "Btw, for what reason should the camera mimic the spectral response of film? "

 

So if the MM is not going to mimic the spectral response of film (which mimics human vision) what could it mimic? Insects?

 

So I said if you use filters you can adjust the spectral response and that is what serious b/w photographers have always done.

 

As I said elsewhere a big limitation of the MM that I see is that it makes doing b/w photography similar to color slide photography. In that if highlights are blown out, you can't recover them. Whereas negative film has more dynamic range towards the over exposure side.

 

With b/w film photography, burning in the sky and other highlights is a pretty important tool to have.

[250swb]

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. .

 

Make the MM file RGB and you can add any hue you like in post processing, including, as O1af has said, making them duotine, tritone or quadtone. The files have to be RGB anyway or the bundled Silver Efex software can't be used.

 

I think this is one of the things that is going right over peoples heads when discussing the weird rendering of native MM files. B&W has never been literally black, white and a series of neutral grey tones. Greyscale is largely an invention of the computer age and has never been an aspect of creative photography. All prints have some sort of hue to them if they come from a wet darkroom. So you are right to question it, it is needed, but post processing will come to the rescue.

 

Steve

[jaapv]

I still fail to see where film comes into the equation. Neither digital nor film is a perfect match for the human eye. The reference should be direct, not a copy of a copy. Which film should it mimic? No two have the same response.

Because you said this, "Btw, for what reason should the camera mimic the spectral response of film? "

 

So if the MM is not going to mimic the spectral response of film (which mimics human vision) what could it mimic? Insects?

 

So I said if you use filters you can adjust the spectral response and that is what serious b/w photographers have always done.

 

As I said elsewhere a big limitation of the MM that I see is that it makes doing b/w photography similar to color slide photography. In that if highlights are blown out, you can't recover them. Whereas negative film has more dynamic range towards the over exposure side.

 

With b/w film photography, burning in the sky and other highlights is a pretty important tool to have.

[giordano]

According to LFI it is the same IR filter.

 

In that case, it seems that one of the following must be true:

 

• There will be no change in spectral response between the pre-production MM's seen so far and the prodution models.
  
• The "clear" layer that we have been told takes the place of the Bayer array is actually - or will be replaced by - a colour filter that tweaks the MM's spectral response.
  

[AlanG]

I still fail to see where film comes into the equation. Neither digital nor film is a perfect match for the human eye. The reference should be direct, not a copy of a copy. Which film should it mimic? No two have the same response.

 

It has nothing to do with a copy of a copy. Film companies and Kodak in particular put in decades of research learning what most people preferred when viewing b/w photos. The result of this research was used to adjust the properties of various b/w films and their associated processing and printing recommendations. This included the understanding and adjustment of characteristic curves and changes in spectral response to typical colors in a scene. Now of course these are just starting points and the use of filters and processing variations are employed by photographers in order to reproduce tones in particular ways. So it isn't as if film came into being with a certain look and people just got used to seeing b/w images this way. The look was finely crafted over time as new information about what viewers preferred came out.

 

So if you are going to disregard all of this information you will need to start from square one and do new research rather than emulating a look that has already proved successful. Most likely this new research will find the same results that Kodak and other film companies found. Since the MM is a monochrome panchromatic system, the default characteristics are baked in (you can't change film) and need to be rather broadly acceptable but with the expectation of further adjustment by the user. E.g. it has a fairly open look and does not filter out any part of the visual spectrum.

 

Whether there is anything about the system in the MM and its associated raw processing that precludes it from emulating a particular b/w look is something I'm not qualified to answer.

[brianv]

Film companies and Kodak in particular put in decades of research learning what most people preferred when viewing b/w photos. The result of this research was used to adjust the properties of various b/w films and their associated processing and printing recommendations.

 

Kodak used this research to formulate the spectral response of their detectors. If you look at how the spectral response of the KAF series full-frame detectors has evolved over the past 20+ years, you can see it. The original detectors responded very poorly to Blue and had a much higher IR repsonse. Kodak developed the "e" series with extended blue, and brought down IR. I seem to recall "tin" being added to the detector chemistry. ("Google is your friend" it was 'indium-tin oxide'.) response to Red and Infrared is still high, and this is where "color correction filters" and IR-cut filters come in. The alternative is to get away from Silicon to another material, such as Gallium Arsenide. Before "Blue" SPD's became so cheap, some cameras used Gallium-Arsenide photo-detectors for the metering system because the spectral senstivity was closer to film. But Gallium Arsenide is expensive, uses more power. Gallium Arsenide used with Indium and Phosphate (InGaAsP) is used in Infrared detectors. A 320x200 camera from Sensors Unlimited cost $25K about 10 years ago. It was Monochrome.

[IkarusJohn]

Film companies and Kodak in particular put in decades of research learning what most people preferred when viewing b/w photos. The result of this research was used to adjust the properties of various b/w films and their associated processing and printing recommendations.

 

Presumably, Truesense, as a successor to Kodak, understands this?

 

I would expect them to be aware that there is a limit to what you can achieve in post-processing a monochrome image, and to apply some of that film learning to the MM sensor. Perhaps it's early days for this sort of fine tuning.

 

Cheers

John

[AlanG]

Presumably, Truesense, as a successor to Kodak, understands this?

 

I would expect them to be aware that there is a limit to what you can achieve in post-processing a monochrome image, and to apply some of that film learning to the MM sensor. Perhaps it's early days for this sort of fine tuning.

 

Cheers

John

 

If you can't get the look you want via post processing, I don't see what else TrueSense or Leica can do about it other than suggest you use filters when shooting. If they alter the spectral characteristics of the sensor enough to make much of a visual difference, (e.g make it less sensitive to one color range) it won't work for all situations and you won't make too many people happy with it.

 

C1 version 6 has a nice channel mixer that goes from color to b/w. I think after using it, I would have a hard time using a monochrome sensor.

 

I made a post about it here:

 

http://www.l-camera-forum.com/leica-forum/leica-m9-forum/238887-reason-m-monchrome-7.html#post2079015

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Hallo,

Look here: Leica M

[IkarusJohn]

If you can't get the look you want via post processing, I don't see what else TrueSense or Leica can do about it other than suggest you use filters when shooting. If they alter the spectral characteristics of the sensor enough to make much of a visual difference, (e.g make it less sensitive to one color range) it won't work for all situations and you won't make too many people happy with it.

 

C1 version 6 has a nice channel mixer that goes from color to b/w. I think after using it, I would have a hard time using a monochrome sensor.

 

I made a post about it here:

 

http://www.l-camera-forum.com/leica-forum/leica-m9-forum/238887-reason-m-monchrome-7.html#post2079015

 

I think you misunderstood my post, Alan.

 

I'm comfortable with a good starting point (with the sensor from Leica and Truesense), adjusting the tone with filters, taking a picture and then dealing with the results in post-processing.

 

What I was responding to was the discussion here and throughout the Monochrom threads that the starting point from the Monochrom (neutral, in Silver Efex Pro 2) was not as appealing as film. It seems to me that is a matter of adjustment by Truesense and Leica as they finalise the camera. Once they have settled on a good starting point, it's a question of experimenting with filters and processing to ge the look you want. I have no problem with that.

 

I don't buy the suggestion that Tri-X or any other film is perfect. It's one version of what has been successful. I'm hoping the release Monochrom will represent a good and workable starting point which moves us on from a blind following of film - they have the skills and the knowledge, don't they?

 

Cheers

John