A question about Leica M8 and IR Cut filter for monochrome shooting

[peterm1]

I have now had my M8 for quite a few years and have recently begun using it once more - this time for black and white images - which up to now I have been doing by shooting color then converting in post when I feel that a specific image may look better in black and white. Now I will actually shoot in mono.

The thing is because I have habitually only shot mono images in full color first and then converted in post due to the greater flexibility provided by this method, I am not sure of the regime when shooting directly in black and white. But since I am not otherwise getting much use of my M8 these days I might as well treat it as a dedicated camera for black and white it it produces good images as people claim it does.

My main question is this: Should I use an IR cut filter when shooting mono or is it better to leave it off? I have heard comments suggesting it is beneficial to leave it off when not shooting color but am not clear on this. I think the suggestion was that the sensor's sensitivity to IR provides mid range advantages in the images.

If it comes to that should I also use dedicated black and white contrast filters (also, or instead of IR cut). I used to use these regularly when shooting film back in the day (yellow, orange, red, apple green and deep green - for both 50mm Summicron/ Summitar and 50mm Summarit) and so am in the fortunate position of having a nice collection of such filters (mainly Leica but some B & W etc) for my Leica lenses. They would cost a small fortune these days. I presume they works the same way as they did for film providing greater contrast depending upon the color of filter mounted.

I have been shooting monochrome in JPG but also with RAW turned on so I have the option of having a full color, full resolution image in the event that I decide I need it either because I want a color version of the final image or because I want to reinterpret the black and white image that came from the camera as a JPG, or because of dynamic range considerations etc. The only downside of shooting this way is it is slow to save images with both turned on.

 

[dfdann]

I am very interested in this thread as I regularly shoot in color and convert to B&W with my M8. Have had very good results at up to ISO 1250. Prints up to 11X14 very good.
Cheers, Dan

 

[willie_901]

It seems likely the answer is –*it depends.

If there isn't any IR light present, it can't matter.

If there is a lot of IR light present it could be bad or good.

For instance, blood vessels near the skin will render with a heat signature which might look odd when there is no filter. Or, a landscape rich in foliage might render better without the IR filter.

As far as "yellow, orange, red, apple green and deep green" lens filters go, I suggest the same rendering can be achieved during raw-file, post-production rendering. The color temperature parameter and, or selective changes luminance levels (using Lightroom slider terminology) have a profound effect on monochrome rendering of completely desaturated raw files. A different approach (I don't use) is LR CC has a B&W Mode where one can adjust Color Mix. Obviously, other post-production platforms have similar tools.

While claiming essentially identical results by rendering raw files with selective hue adjustments or using optical filters may not feel right, it makes sense. Does it matter if selective, visible-light frequency contributions are affected during capture or afterward? In principle no. Though, it could be tedious to invest time re-creating the look of different lens filters. However using a raw file where all the frequency information is available does provide more flexibility.

The frequency response of lenses, sensor color-filter arrays and differences in raw rendering algorithms are important. Different people may have different experiences due to these variables.

 

[f16sunshine]

It does indeed depend.
Mostly it depends on the presence or lack of IR present in the scene.
Sometimes maybe it seems to open up shadows to remove the filters....more shadow detail is a plus.
I found it made the images look a bit soft and out of focus at times.

The focus distance of IR is different than visible light.
A subject that is reflecting a great deal of IR can appear slightly out of focus in those wavelengths while being in focus in the visible wavelengths.... giving a sort of fuzzy glow to the subject.
Here is an image where this is occurring.
It's a color image yes but one can imagine what it would look like in mono.
It's the only set I have online with unfiltered lenses.

BTW
When I used the M9 it seemed also to benefit from IR cut filters. Images seemed to be more crisp.
Some also are using IR cut filters to improve the M240 output as well.
I don't use Leicas at the moment but I have saved a few IR cut filters in the event I pick up an M240 sometime in the future.

 

[peterm1]

OK

So this is what I take from those answers (thanks by the way guys). I need to find out if someone has yet invented an IR Cut filter using the principles displayed in the Shrodinger's Cat "Gedankenexperiment" (thought experiment).

So, just like the guy checking to see if the cat is alive or dead, I will need to view the image to see if my image is alive or dead in terms of outcome. 🙂🙂😀

I guess the question I am getting at is what is your practical / personal experience in terms of IR-Cut filter for black and white shots out of the M8? Do you guys use one or not for this purpose and in either event are you happy with results you generally get. Acknowledging of course that IR may or may not be present in a specific image so results will vary when a filter is not used depending upon that and how it affects the resulting.

In a general sense I tend to prefer "character" lenses and images over "technically precise" ones so I am guessing that the presence of IR might be beneficial here, at least sometimes. Such as in the color photo below which would seem to be likely to produce a nice glow when rendered in black and white.

 

[dfdann]

I leave the filters on that I received when I bought the camera new for both B&W and color.
Good results on both. I convert to B&W in lightroom.
Cheers, Dan

 

[jaapv]

There are two aspects.
If you leave the IR filters off when shooting for B&W, the shadows will be lifted slightly due to the IR, which some photographers find pleasing.
However, depending on the IR focus shift of the lens, there will be an unsharp IR component in your image at approx. -5 stops, deteriorating microcontrast and sharpness to a small extent. It all comes down to a personal preference.

 

[jaapv]

It does indeed depend.
Mostly it depends on the presence or lack of IR present in the scene.
Sometimes maybe it seems to open up shadows to remove the filters....more shadow detail is a plus.
I found it made the images look a bit soft and out of focus at times.

The focus distance of IR is different than visible light.
A subject that is reflecting a great deal of IR can appear slightly out of focus in those wavelengths while being in focus in the visible wavelengths.... giving a sort of fuzzy glow to the subject.
Here is an image where this is occurring.
It's a color image yes but one can imagine what it would look like in mono.
It's the only set I have online with unfiltered lenses.

BTW
When I used the M9 it seemed also to benefit from IR cut filters. Images seemed to be more crisp.
Some also are using IR cut filters to improve the M240 output as well.
I don't use Leicas at the moment but I have saved a few IR cut filters in the event I pick up an M240 sometime in the future.

The M9 and M240 do show some IR sensitivity. The M8 passes about 50% of IR light, the M9 about 20% and the M240 about 30%.
That means that images shot in light with high IR content will certainly benefit from an IR-cut filter on all three cameras.