AlanG Posted March 25, 2015 Share #81 Posted March 25, 2015 (edited) Advertisement (gone after registration) Actually, nobody ever doubted the effectiveness of colour manipulation at B&W conversion.... I just read over the thread and several people have doubted the effectiveness and results. Some even said that the same thing could be done with filters... which clearly is impossible if you study the range of effects in my examples. Which one of my examples above would come out better by using a filter in front of the camera? BTW working at 100% I saw no change in noise when moving the color sliders to a lighter position but reducing a pretty extreme amount can make posterization depending on which color is darkened. Which figures. Edited March 25, 2015 by AlanG Quote Link to post Share on other sites More sharing options...
Advertisement Posted March 25, 2015 Posted March 25, 2015 Hi AlanG, Take a look here Yellow Filter On An M9, Good Idea?. I'm sure you'll find what you were looking for!
Lenshacker Posted March 28, 2015 Share #82 Posted March 28, 2015 (edited) This is with the Orange filter on the lens. M1015792 by fiftyonepointsix, on Flickr I will be posting test images and discussion on Leicaplace, Experiments in Monochrome Conversions | Leica Place - Leica User Group With the Orange filter over the lens, the Blue channel response curve is close to green, except not as efficient. The conversion "equalizes" the blue and green channels and uses the blue pixels as if they were green. Instead of red-green-blue, it generates Green/Blue and Red. I wrote a new Fortran function that parses DNG Tags from the "Image File Directory", and will be able to try some M9 files. The M9 uses a more complex structure to store the "thumbnail" and "Main image" in the same file. The code will modify the main image, correct the IFD to make it monochrome-linear, and keep the thumbnail unchanged. Edited March 28, 2015 by Lenshacker 1 Quote Link to post Share on other sites More sharing options...
AlanG Posted March 28, 2015 Share #83 Posted March 28, 2015 (edited) And your goal is??? I can't see why I'd want a photo that looks like this. Is this a Fortran exercise or does it have something to do with actual applied photography? Btw, don't the M9 files still have to be converted to b/w in a raw processor? Have you tried the color sliders yet in C1 as I've suggested? In seconds you can run through various looks for your conversion to see what you like for a given image. Edited March 28, 2015 by AlanG 1 Quote Link to post Share on other sites More sharing options...
Lenshacker Posted March 28, 2015 Share #84 Posted March 28, 2015 (edited) If anyone is interested in having a discussion on the OP's original post, and using color filters for monochrome conversions- we can discuss it on Leicaplace. Alan will handle C1 discussions here. I have no interest in C1 sliders, and will not be discussing them. For the M9 - I will use the same Raw processor that I wrote for the M8, the dimensions of the image are parameters passed into the routines. Run-time array dimensions. - Brian Edited March 28, 2015 by Lenshacker Quote Link to post Share on other sites More sharing options...
AlanG Posted March 28, 2015 Share #85 Posted March 28, 2015 (edited) Hi all, I know that yellow filters on a Monochrom is just as worthwile as on a film camera, but how about on an M9? Is there any benefit or point to it, or is it best to just add the effect in post? Anyone else tried colored filters on M8/M9 etc? He asked if there was a benefit to using a yellow filter or if it was better to do it in post. Clearly it is far better to do it in post. And you have to do post conversions and perhaps use the color sliders even if you shoot through a filter. Now if you and others want to still shoot through filters as some kind of experiment, go for it. Fyi, I went to the trouble to shoot through some filters so perhaps you might reconsider trying out C1 for conversions and compare the results to using filters. I can't recall seeing filter companies promoting using their filters this way. Edited March 28, 2015 by AlanG Quote Link to post Share on other sites More sharing options...
pgk Posted March 29, 2015 Share #86 Posted March 29, 2015 He asked if there was a benefit to using a yellow filter or if it was better to do it in post. Clearly it is far better to do it in post. And you have to do post conversions and perhaps use the color sliders even if you shoot through a filter. Alan, can I suggest a step back for a moment. Not everyone is as comfortable using software as others (and some are obviously very comfortable). For some I can see that using a yellow filter (interesting comments by Lenshacker on the sensitivity of the sensor here) might prove to be a more predictable and usable method of pre-visualising and obtaining a specific result, even if it is not perhaps the nest technical solution. So I wouldn't dismiss it as an unusable solution. Its not for me but in some circumstances it might well be a viable way to operate. I would agree with you that I'd prefer to use software which IMO will yield a 'technically better' result and is as you have demonstrated, far more versatile. [i studied PS as I believe you did in PCL? So we come from a highly technical background, but not everyone does.] 1 Quote Link to post Share on other sites More sharing options...
Lenshacker Posted March 29, 2015 Share #87 Posted March 29, 2015 (edited) Advertisement (gone after registration) [i studied PS as I believe you did in PCL? So we come from a highly technical background, but not everyone does.] Color Postscript, Printer Control Language, HP Graphics Language, PGC, added all of them to my custom image processing software in the 1980s. The nice thing about writing your own code, you can try things out. Never know what you will find until you try. Plus now, I have all of my edge detection, Fourier, and Wavelet processing code ready to go for the M8 and M9. The next thing to try is raster-vector, then convert the vector back to raster to ease the edge and line demosaic artifacts. Edited March 29, 2015 by Lenshacker Quote Link to post Share on other sites More sharing options...
AlanG Posted March 29, 2015 Share #88 Posted March 29, 2015 (edited) Alan, can I suggest a step back for a moment. Not everyone is as comfortable using software as others (and some are obviously very comfortable). For some I can see that using a yellow filter (interesting comments by Lenshacker on the sensitivity of the sensor here) might prove to be a more predictable and usable method of pre-visualising and obtaining a specific result, even if it is not perhaps the nest technical solution. So I wouldn't dismiss it as an unusable solution. Its not for me but in some circumstances it might well be a viable way to operate. I would agree with you that I'd prefer to use software which IMO will yield a 'technically better' result and is as you have demonstrated, far more versatile. [i studied PS as I believe you did in PCL? So we come from a highly technical background, but not everyone does.] I understand the thought but a yellow filter is only predictable if you understand the light and color of your subjects. The effect is often relatively small. My suggestion is for digital photographers to appreciate the medium and not look at things as if shooting film. Yes one needs to use software to convert to b/w but they have already made that choice. So learning how to use conversion software is something they should embrace as a skill to develop just like learning how to use filters with film is a skill. Or b/w printing is a skill. The color sliders are very intuitive with instant feedback and you can learn how to use them very quickly. I think if you care enough about your photos to buy expensive cameras your work will really improve if you develop good post processing skills. . Edited March 29, 2015 by AlanG Quote Link to post Share on other sites More sharing options...
pgk Posted March 29, 2015 Share #89 Posted March 29, 2015 I think if you care enough about your photos to buy expensive cameras your work will really improve if you develop good post processing skills. An interesting concept;). But as with cars, the ability to afford a fast and expensive model, and even enjoying owning and using it, does not necessarily mean that it will be used well or with understanding. Quote Link to post Share on other sites More sharing options...
BerndReini Posted March 29, 2015 Share #90 Posted March 29, 2015 If you go so far as to use color filters on the M9, then please go out and by a Monochrom. If you care so much about black and white image quality, then you are certainly someone that will appreciate the MM. The benefits of a yellow filter on an M9 have to be marginal compared to what you gain from shooting with an MM. Quote Link to post Share on other sites More sharing options...
Lenshacker Posted March 29, 2015 Share #91 Posted March 29, 2015 If you go so far as to use color filters on the M9, then please go out and by a Monochrom. If you care so much about black and white image quality, then you are certainly someone that will appreciate the MM. The benefits of a yellow filter on an M9 have to be marginal compared to what you gain from shooting with an MM. I bought the Monochrom when they first came out. It's the second Monochrome Digital camera bought in 22 years for me. What caught my interest, and I wanted to investigate: how close to the behavior of the Monochrom can an M8 or M9 come by using a raw processor designed for use with color filters. Quote Link to post Share on other sites More sharing options...
AlanG Posted March 29, 2015 Share #92 Posted March 29, 2015 An interesting concept;). But as with cars, the ability to afford a fast and expensive model, and even enjoying owning and using it, does not necessarily mean that it will be used well or with understanding. I'm sure many people don't get the most out of what they own. (You surely don't want to hear me play the piano.) If they are researching things on various forums, presumably they are open to learning. So I'd hope that if they have the interest to consider using filters to achieve a certain b/w affect they are a bit sophisticated and have some further interest in understanding the process. The examples I posted are extremely simple to learn how to do. I have been serious about photography for quite a long time and have a lot of darkroom experience of all types. I am amazed by what is possible with raw converters and post processing and see that as the major difference between film and digital photography. Now everybody has easy access to this technology should they care to learn it. Quote Link to post Share on other sites More sharing options...
Lenshacker Posted March 30, 2015 Share #93 Posted March 30, 2015 (edited) Red filter, 1934 5cm F2 Sonnar, Leica M8. M1015819 by fiftyonepointsix, on Flickr M1015835 by fiftyonepointsix, on Flickr Blue channel equalized with green channel, both are sensitive above 600nm to contribute to the image. This is where the 14-bit samples give plenty of room to boost the signal. Batch processed from the color-DNG to the monochrome-DNG, Lightroom used to set Black-Level and to convert to Jpeg. I can set Black-level in the Tag in the IFD, will most likely do so. Edited March 30, 2015 by Lenshacker Quote Link to post Share on other sites More sharing options...
BerndReini Posted March 30, 2015 Share #94 Posted March 30, 2015 I wanted to investigate: how close to the behavior of the Monochrom can an M8 or M9 come by using a raw processor designed for use with color filters. What is the verdict? And is it different with different lighting conditions such as mostly tungsten or fluorescent? I would be interested to know how much different the M9 is from the MM with different raw processing in general. I see more midtone tonality in the MM files, but I have been asked whether this could not be compensated for in processing. My answer is not in Lightroom, but would a completely different raw interpretation close the gap? Quote Link to post Share on other sites More sharing options...
Lenshacker Posted March 30, 2015 Share #95 Posted March 30, 2015 (edited) What is the verdict? And is it different with different lighting conditions such as mostly tungsten or fluorescent? I would be interested to know how much different the M9 is from the MM with different raw processing in general. I see more midtone tonality in the MM files, but I have been asked whether this could not be compensated for in processing. My answer is not in Lightroom, but would a completely different raw interpretation close the gap? No verdict yet, still experimenting. I uploaded full-resolution jpegs to my Flickr account. The results with the Red filter are better than I thought they would be, better than what I got simulating a Red filter with Silver-Efex2 with the M9. Lighting that is weighted for Red will improve the response of the blue/green: push them more towards the Red and require less boost. Fluorescent- I need to try it. The image will never be as sharp as with the Monochrom, as some interpolation is required. The highlights are better preserved with the color camera as the Blue/Green response is low and does not saturate as quickly as the unfiltered Red channel. I uploaded the source code used for the Orange filter on Leicaplace; the Red filter is the same except scales the Blue/Green by 3. I have a couple more things to try, will do a direct compare with the Monochrom in the next week. The white value of the Monochrom is '3fff'x, with my raw processor the combined channels call white 'bfff'x with the red filter in place. C THE VALUES ARE 14-BITS PER PLANE. WE WANT TO ADD THEM, THEN SCALE TO C 16-BITS. DO 25 J= 1, ROWS DO 25 I= 1, COLUMNS BIGVALUE= RED( I, J) BIGVALUE= BIGVALUE+ GREEN( I, J)* 3 IF( BIGVALUE .GT. Z'BFFF') BIGVALUE= Z'BFFF' IMAGE( I, J)= VALUE( 1) 25 CONTINUE RETURN END Edited March 30, 2015 by Lenshacker Quote Link to post Share on other sites More sharing options...
Lenshacker Posted April 4, 2015 Share #96 Posted April 4, 2015 This will only work with the M8, B&W 090 Red filter. The IR cut filter of the M8 lets ~5% ir through. Software pulls Blue and Green up to same intensity levels as Red. Then Blue/Red are swapped. I1015897 by fiftyonepointsix, on Flickr Blue channel is Infrared; Green channel is Red and Infrared; Red channel is Red. Quote Link to post Share on other sites More sharing options...
Lenshacker Posted April 7, 2015 Share #97 Posted April 7, 2015 This is with the Yellow Filter and the custom Fortran software, Blue and Green are equalized and combined into one layer, Red is interpolated. The two channels are added. I will take the M8 and Monochrom out together on the next Sunny weekend. M1015730 by fiftyonepointsix, on Flickr M1015734 by fiftyonepointsix, on Flickr 100% crop. M1015734_crop by fiftyonepointsix, on Flickr This is with Silver-Efex2, neutral conversion to monochrome. L1015734-Edit by fiftyonepointsix, on Flickr Quote Link to post Share on other sites More sharing options...
Lenshacker Posted April 13, 2015 Share #98 Posted April 13, 2015 (edited) M1012668 by fiftyonepointsix, on Flickr This is with the Yellow filter on the 28/2.8 V3 Elmarit-M, on the Leica M9. Converted using the Fortran program. The DNG file as written by the M9 has the thumbnail picture and main picture. I modified the main picture to be linear-DNG, but did not modify the Thumbnail. Photoshop can process the file, but LR "Hiccupped". They probably took some shortcuts in assuming the second image had properties of the first, ie color paired with color. This has all been a very interesting learning experience for reading, modifying, and writing DNG files. Edited April 13, 2015 by Lenshacker Quote Link to post Share on other sites More sharing options...
Lenshacker Posted April 17, 2015 Share #99 Posted April 17, 2015 I figured out how to modify the DNG file for Lightroom and Windows Explorer to treat the M9 files as Monochrome, including pre-view image. Having the M Monochrom DNG file handy helped, they play an interesting "trick" with the Thumbnail image. The "Colormatrix" information is stored in the IFD used for the Thumbnail. LR must assume it is valid for the Sub-IFD, PS does not make that assumption. Quote Link to post Share on other sites More sharing options...
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