M9M spectral sensitivity

[Manicouagan1]

Advertisement (gone after registration)

As folks accumulate experience with the Monochrom Leicas in the wild, I am interested in its ability to cut through atmospheric haze using a red or orange filter, its response to different skin tones, and its response to different colors in follage. The spectral response of the ccd should be a lot different than panchromatic silver hailide films which is typically flat in the visible range with a sharp cut off around 650 nm. Theoretically an unfiltered Monochrom Leica landscape should show a lot of haze due to the extended UV response. The peak in the typcial ccd response is in the green so images of follage should be anomalously light. The question are these theoretical differences significant in real images.

 

I've proceess a lot of my M9 landscapes to simulate the effect of a red or orange filter. Will the Monochrom Leica do significntly better job of cutting through haze than I can do by manipulating my M9 images?

[manolo]

no idea but is a good question.

[Advertisement]

The Leica Q3 is available for pre-order at B&H Photo Video and Adorama

[pico]

[...]Will the Monochrom Leica do significntly better job of cutting through haze than I can do by manipulating my M9 images?

 

Yes. When you mimic IR or red filters in software, the effect of haze remains even if the color cast is removed. When photographing with real red filtration, the short waves are simply not admitted into the camera. Unfortunately, red is a relatively poor band to capture great detail, especially in 35mm, but some don't mind.

.

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.)

[el.nino]

"And, in a final note on tonal rendition, in a discussion with Leica engineers I was told that the M Monochrom is very close to panchromatic in its native response, but that a light yellow filter will bring it even closer to that goal if desired."

 

Leica M9 Monochrom

[squarenegs]

"...very close to panchromatic..."

 

 

So, the coloured filters from my days shooting black and white can be used on

the new Leica M&M but the rendering will only be kind'a ...sort'a like on film,

but not really like on the pan films that all B&W shooters are familiar with.

 

Hmmm... sounds like a black and white version of the issues

my M8 has rendering colour without the cut filters.

 

The introduction of pan film was a major step forward

in photographic image capture technology.

Did the Leica brain trust forget that?

[ho_co]

In regard to the question "How film-like will the M Monochrom be?" please note this from another thread:

 

... the color response curve will be adjusted to match panchromatic film even more closely....

 

So there'll be more tweaking in firmware before the camera is shipped.

Edited May 11, 2012 by ho_co

[Manicouagan1]

Advertisement (gone after registration)

I know of no software/firmware approach that could change the spectral response of the sensor. To my knowledge the only way to tune the spectral response of the sensor is to vary the optical filter in front of the sensor. Possibly the filter in front of the Monochrom M sensor is different from the one on the M9, which is certainly different from the one on the M8. Possibly the Leica folks and the sensor provider are still working on the filter.

[ho_co]

Agreed. Somewhere I've seen (from Michael?) that the M9's color filters are replaced by clear ones on the M Monochrom.

 

Anyway, the new LFI is under way; we'll soon have all the details.

[sblitz]

What happens if you use a color filter on the m9 and shoot bw jog?

[jaapv]

I asked. The same as on B&W film, albeit with slight differences in the intensity of the effect. One needs to experiment a bit to get the desired result. All the dealers that sold off their remaining stock of black and white filters at dumping prices are gnashing their teeth now.

[jaques]

I collected and traded vintage film camera for 10 years or so... along the way I must have accumulated around 200 (or more) colour filters for B&W photography. So if the M9 Monocrom takes off I should finally be able to get rid of them- and at a profit!

[tgray]

So, the coloured filters from my days shooting black and white can be used on

the new Leica M&M but the rendering will only be kind'a ...sort'a like on film,

but not really like on the pan films that all B&W shooters are familiar with.

 

Remember most B&W films don't have the same spectral sensitivity. Leica isn't going to just say it's exactly like the sensitivity to T-Max, and piss off all the Tri-X fans. Sub in any two B&W films for T-Max and Tri-X. And that's if they could get it exactly like those films in the first place. The sensitivity of the M-M is probably pretty close to the 'average' panchromatic film, with a bit more IR and UV sensitivity, depending on what Leica does with the IR filter glass. And slapping a yellow filter will probably give an output very similar to but not the same as slapping a yellow filter over T-Max or Tri-X.

 

Hopefully some enterprising reviewer will get his hands on an M-M and shoot some color checkers and other targets, it side by side with our favorite films, so we can get a sense of how close/far it is from those films. I'd be much more interested in that than a comparison with the M9.

[Paulus]

I asked. The same as on B&W film, albeit with slight differences in the intensity of the effect. One needs to experiment a bit to get the desired result. All the dealers that sold off their remaining stock of black and white filters at dumping prices are gnashing their teeth now.

 

I was thinking the same! Am I glad that I saved all my filters, because I'm still shooting B&W film. I knew shooting B&W would be rewarding in the end.

[pico]

"...very close to panchromatic..."

 

 

So, the coloured filters from my days shooting black and white can be used on

the new Leica M&M but the rendering will only be kind'a ...sort'a like on film,

but not really like on the pan films that all B&W shooters are familiar with. [...]

 

Even modern panchromatic film is not as the human eye sees. A K2 filter in daylight can bring it closer. Of course, we are waiting for someone to measure the spectral response of the MM to get better approximations.

.

[pico]

I collected and traded vintage film camera for 10 years or so... along the way I must have accumulated around 200 (or more) colour filters for B&W photography. So if the M9 Monocrom takes off I should finally be able to get rid of them- and at a profit!

 

Unlikely. How many customers will you have? How many MMs will be sold? Filters are everywhere, filling camera store's back shelves and junk drawers.

[jaapv]

Even modern panchromatic film is not as the human eye sees. A K2 filter in daylight can bring it closer. Of course, we are waiting for someone to measure the spectral response of the MM to get better approximations.

.

A bit difficult right now, as the spectral response is still up in the air on the preproduction cameras, which are all that are available at the moment.

[lars_bergquist]

The question is: Do we want exact spectral sensitivity? And, equal to what?

 

Let's return to the primordial yellow filter question. If we photograph a scene with white clouds on a blue sky, and somehow, by whatever means, produce a print where we can show by photometry that the luminance of the sky and the clouds are exactly as in nature – we will find that print flat. The reason is that in the original scene, we see not only luminance contrast, but we do also percieve the colour contrast, and our visual sense does inevitably add them together. So our spontanous perception of the scene will be that it was more contrasty than that print.

 

Ergo the Y filter which holds back the blue sky a little more (and also brightens deciduous foliage a bit, which we appreciate because we do not only have our maximum sensitivity in green, we are also more alert to information in the green band.)

 

There is also the fact that the landscape will inevitably have a far larger luminance range than any print made to be viewed in reflected light. So the mid-tones need a boost. In most cases a Y filter does indeed somewhat increase mid-tone separation.

 

The old man from the Age of the Yellow Filter

[lars_bergquist]

And by the way don't forget that the MM sensor still has an infrared filter in front of it. How strong we do not yet know, but it is there. It has to be.

 

It may of course be as weak as in the M8, which was a useful IR camera with an appropriate deep-deep red filter.

 

The old man from the Kodachrome Age

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!

[lars_bergquist]

I find that Leica have already answered that question here http://www.l-camera-forum.com/leica-forum/leica-m9-forum/238391-m-monochrom-ir-sensitivity.html

 

So, sorry, but no go.

 

The old man who had to sell his M8

[Advertisement]

Hallo,

Look here: Leica M

[brianv]

Use color correction filters if you want a different spectral response. This might take some experimentation to get a particular tone to your images. 81, 82, "CC" filters, etc.

 

For "cloud" shots, vegetation, contrast enhancement, use filters just as you would with black and white film. "Pre-process" the image rather than post-process digitally. As close as the M9 is to using a film camera, this monochrome M9 will be even closer. And more fun.

 

I wonder how much it would be to have the IR absorbtion filter replaced by clear glass.