Photographer and author, LaNola Stone, shares with us thoughts on being behind the lens while photographing children with this celebration of mothers of all kinds.
Digital post-process manipulation is a great way to fix any problems with the
actual picture as well as to improve an already existing shot. Color can be
changed within seconds, as opposed to minutes and hours in a conventional
darkroom.
I found digital manipulation to be a great way to learn the basics of color
and contrast as well as saturation. Digital was perfect in my eyes until they
were opened to the lack of black and white options. I was not happy with shooting
black and white from my digital camera by turning it to grayscale mode. This
worked but then left me stuck. I finally did some research and found that I could
make a color image black and white. All description below are done from
Photoshop.
The Wrong Way
I started to create black and white by going to
image>adjustments>desaturate. This did make the image into black and white,
but gave me no control. I couldn't decide whether the reds became black, gray, or
white. This technique was not for me. I needed control.
The Solution
After a little more searching I discovered that each Red, Green, and Blue
channel created a grayscale image when isolated and each image portrayed the
color differently. I decided then that I had to learn how to use this knowledge
to control the color to grayscale conversion. I soon realized that I could do
this in the channel mixer.
Here's how I do it.
Getting An Idea
This step can be skipped but I find it to be useful.
Before you decide to change an image you should look at each individual
channel representation of the image. To do this go to the "channels" palette,
located with the "layers"
Click on each channel and see how it looks. See the images below for an
example.
Color
Red
Green
Blue
With this particular image I like the look of the red channel. On some photos
I like the green and the blue but hate the red. Make sure you take note of the
channel you like.
The Actual Conversion
At this point you select the RGB channel in the palette. You should also make
a snapshot so that you can revert back if you change your mind. If you want you
can make an
adjustment layer instead of the snapshot.
With RGB selected go to image>adjustments>Channel Mixer. In the
channel mixer select "monochrome" and start moving the channels. The trick is
that you must adjust the channel sliders to what you want but they must add up
to 100 if you do not want to change the lightness of the image. When I do
this I usually adjust it until I like it and the exposure looks about right
then I do the math and make small changes.
I generally just do 100% of a channel I picked earlier when I was getting an
idea but sometimes I would take 70% green and 30% blue if I liked the green more
than the blue channel but still liked the blue channel effect. This is up to you.
Below is how I chose to do this photo.
Move your mouse over the photo to see it in
color
I chose these setting because I hated the way the green channel made the
flowers black and I liked the red channel. I didn't see any reason to mess with
the blue in this particular case. This image is easy to convert because it has a
many colors and each channel looks drastically different. Some images do not look
very different. In this case I just play around until I like it.
Adjustment Layers
In Photoshop adjustment layers are just layers which do the same as the
regular control but make it a removable effect in the form of a layer. There
isn't much more to say about them except that they are good if you tone images in
RGB color mode with Color Balance because it allows you to change the intensity
(opacity). A few people swear by them because you can remove what you did
without going back in the history palette and losing work up to the
adjustment.
To create an adjustment layer go to Layer>New Adjustment Layer and select
the type you want. It is very simple!
Some Notes
I did this in Photoshop 7.0. I don't know about being able to see the
different channels ahead of time in other editors, but most any photo
editor has a channels mixer. I know both PSP (Paint Shop Pro) and PWP
(Picture Window Pro) have the option.
I would highly suggest making copies of images in Photoshop and playing
around. Its the best way to get practice.
Text and pictures, Copyright (c) 2002-2003 Justin
Winokur.
Jwink@email.com
The photo at the top is one my photos I feature on my website:
www.photosbyjustin.com
More ideas to play: First, establish a white point, a grey point and a black point. Second, you can do all this things locally. Third, an advise, no matter how horrible it looks like in color, think always about the final black and white results.
Manuel.
PD: If you only use one channel or one and a half of the full three, you will see increased noise and lack of detail. Try always the most similar to the three original channel.
For much more control and flexibility look at Russell Browns tutorial "Seeing in Black and White" at
http://www.russellbrown.com/body.html or
http://www.russellbrown.com/tips/pdf/colortoB&W.pdf
An alternate, possibly more effective, way is to do the conversion in Lab mode. Image>Mode>Lab Color, and then pick the Brightness (L) channel. Discard the rest. This technique preserves luminance better, I find.
Color theory is fascinating. I work in the graphics hardware industry designing computer hardware to render graphics and I deal with color spaces and color conversion all the time. What I think Justin has "discovered" is that the three color components - red, green and blue - have different tonal ranges.
When you do a conversion from a color image to B&W, what typically happens is that the RGB is converted to luminance using the following equation (or a similar one)...
Luminance (B&W) = (0.299 x RED) + (0.587 x GREEN) + (0.114 x BLUE)
As you can see, the green channel gets far more of a weight than the red or blue channels. In practical terms, this means a 100% fully saturated blue will appear much darker - tonally - than a 100% fully saturated green (for example) when converted to monochrome. In this way, an image that has a lot of contrast in the form of different highly saturated colors can actually look quite "flat" when converted to monochrome.
Controlling exactly which of the R, G and B channels has the highest contribution to the conversion is a good way of maintaining the contrast level in the image. *HOWEVER*, the equation I quoted above is based on studies of visual perception and how we interpret the intensity of various colors. If you decide to play around with that mix - you may get a more pleasing result, but it may have a rather strange appearance when compared to the original color image. But artistically - I don't think this is an issue.
It would be nice to convert the color photo to B&W with the same sensitivity to colors as B&W film does. This involves more than only mixing the R, G and B channels to B&W. I think there is at least one plug-in available that does this. However they do not give you much control and you can not make your 'own B&W film'.
I have an idea, and worked it out a bit, to give the user such control. I am quite sure that this is feasable. If there are any plug-in programmers that are interested to help me I would like to discuss this further. I do a lot of programming, but PhotoShop plug-in's are not my speciality :-(.
Interesting article. I've tried the method before but now go about it slightly differently.
I copy and paste the colour channels into layers. Choose the preferred (new) layer as the "original" and hold it @ 100%. That's the base layer. Above that comes my next preferred layer, the one that builds in the contrast : this might be at 20 - 40% opacity. Sometimes the third layer (a previous RGB channel) is unnecessary; if included it would have an opacity less than the middle layer.
Linear burn of 4-8% applied to the composite is sometimes good for tonal value; depends.
"To Jeff how can you convert to InfraRed
- Anh Tran, March 6, 2003"
Sorry Anh Photoshop can do wonderful things, but it only apears to add things to the image. In fact it can only modify or take away. You can take one color and copy it and change it to another color to restore a lost or faded color, but you can't really add things that aren't there. That incredible sharpness you can get from infa-red film is blurred by the ultra-violet and visable colors when the image is stored. One thing that photoshop does not do very well is to restore blurred images. This is because the information to restore the detail is lost forever.
Photoshop is a great tool but to get the detail, sharpness and tonal range, you still need a fine grain b&w film, properly exposed and developed.
Since digital cameras have pretty well caught up with 35 mm color film, we will see more and more people letting their 35 mm SLR sit while the digital camera gets used. One thing about the CCD sensor that the digital camera uses is that it is sensitive to infa-red light. I don't know anybody that has experimented with red filters for that infa-red effect with a digital camera. This should reduce blurring the image with the shorter wavelengths that tend to scatter more. Some camera anf filter combinations may work better than others,
You can't convert an image to IR, but you can manipulate it such that it looks something like an IR image might look by working with the three available (R-G-B) color channels.
Though digital sensors are intrinsically IR sensitive, most (in fact all) digicams use IR blocking filters since most people don't want IR images and if you didn't block it it would affect the other color channels (mainly the red channel). Some of the blocking filters are sharper than others, so some digicams can be induced to give mild IR images by using an external visible-block/IR-pass filter (e.g. R72).
In theory instead of the usual Red/Green/Blue image sensor you could make an Infrared/Red/Green/Blue sensor with four color channels, but nobody does and none of the existing software could handle the four color files it would generate. The demand for such digital IR systems would be so small in the consumer photographic world that it just wouldn't be worth doing it. For scientific applications, where cost isn't a big issue, it's quite possible.
Another way to convert to B&W would be using the Hue/Saturation mask, but treating each color separetly, desaturating and changing the Lightness of each of them. This gives great freedom to get the better look of the image. <p>
On the other side, some (or much...) experimentation is required, compensated by the chance of leaving an image half way between a color and a B&W one, that could be an interesting option.
Whatever process you follow, the expectations must be low. The results are much much worse that what you can do with 35mm, two filters and a Tri-x or Tmax. I would welcome any example to support the contrary.
Manuel.
I have been shooting with an EOS D30 (my first EOS body) for a couple of years now and have been using the channel mixer for B&W work. I recently bought an Elan 7 film body partly as a back up but primarily to shoot B&W negative film. Shooting digital and converting to B&W loses one of the major advantages of B&W negative, the contrast range that can be captured which appears to be about twice that of the D30. I am using Ilford XP2 Super chromogenic since it is cheaper to process and easier to scan (compatible with the ICE scratch and dust removal).
THere is a great plug-in by The Imaging Factory (http://www.theimagingfactory.com/) called convert to B&W Pro which does it's conversions based on several film types and allows for a LOT of control over your conversion.
The one drawback I have with this plug in is that it can't be added to an action to be able to process a whole folder of images equally.
Fred Miranda www.fredmiranda.com has created an action to convert an RGB image to a simulated IR. It works quite well and is only $8. Go to his site and click on actions and you should see this and many other actions (the step interpolation rivals if not surpasses Genuine Fractals at enlarging images as well as the image sharpening action)
For those who use Macintosh under system 9, the finest conversions to black and white can be accomplished by a plug-in known as Colleen's Photoshop Fun Pack available at http://pw1.netcom.com/~kawahara/photoshop.html It allows the red, green and blue signals to be changed by percentage with contrast and brightness adjusted independently. A full frame image allows one to quickly see the effects of change. It also has a superior blur control. It is completely free, so give it a try. I am avoiding system X because I use this one plug-in so much.
Why not just do "mode->grayscale"? This would convert the RGB image to B&W. But if you do this what is the % of red, green & blue that goes in the final image?
Some readers have asked if it is possible to reproduce the b&w film colour conversion. I suppose the cheapest way may be to take a picture in colour and one with your b&w film of choice. Convert the colour image to gray with Justin's method by varying the % of red, green & blue to reproduce the b&w film photo and see if it works.
However I think that the problem may be the spectral transmission of the red green and blue filters which are placed before the ccd. Each filter has a transmission that varies with wavelength (i.e. green is transmitted with a different efficiency w.r.t yellow). When the image is taken this transmission curve is fixed on the digital data and cannot be altered because, for each pixel, you end up with 3 colours (red, green and blue), not 3 spectral curves. You would need a software that was able to mix the % of red, green and blue for each colour in the image separately: e.g. a particular shade of yellow gets associated with a specific b&w intensity, another shade of yellow gets associated with a different b&w intensity etc.
As far as I know in the b&w film the silver grains get exposed depending on (i.e. the image intensity depends upon) the light intensity arriving on them and therefore depending on the % reflectance of each original colour. This means that to convert a colour image to b&w film you need a matrix with the % reflectance values of each colour. Is this possible?
I am not sure whether there are rgb or cym filters in the b&w emulsion. If there are, then it may be possible to measure (or ask the manufacturer) the spectral transmittance of each of them separately and then program this into a software for conversion to b&w.
Am I going right or am I going wrong? Help me on this.
Charles
I'm going in support of Wayne Young's point of view, there
are already well defined standards for Color->B&W convertion
around (e.g. in computer graphics hardware, in Television/video
broadcast, etc). These standards (and color chanel wheighing
factors) can be found in standard textbooks on Computer Graphics
like Foley's "Fundamentals of interactive computer graphics" and
they are the starting point for a "realistic" conversion.
I used the techniques described here for quite a time, and have found that there is still a more flexible way to accomplish a classical b/w look in photoshop:
Create a new layer on top of the image you want to "desaturate" and fill it with plain white or black. Now turn the layer mode of that layer to 'saturation'. That way the output image is desaturated, but the color information in your original image layer stays intact.
Now select the image layer and use the curves (ctrl-m) tool to adjust the color channels. Just adding midpoints to the curves of channels and rising or lowering them would result in images near to those created with the layer mixing technique, you may just want to correct the overall lightness a bit afterwards with the levels tool. Now by using the curves, you can select exactly, which color distribution of the original image is going to affect the b/w value of the output image. Its possible to achive a very realistic high contrast b/w look that way, even with rather dull original images. The trick is to fully exploit the slightest tonal contrasts in the original and to translate them to a high-contrast b/w output.
NIK makes a plug in filter pack that includes a B&W conversion that is excellent. you can change a slider and have the effect of any filter yuo want, not just R,G,B.
Well first of all, in a professional point of view, the technique with the channel mixer is by far the best one someone with photoshop skill AND traditional photographic experience should used, precise and pretty close of a filtered picture. And to answer someone who ask < how do you do a IR version of it >
well martin evening in is book (personaly THE only professional, straight to the point photoshop book people should buy) photoshop for photographer, show you that, if you go in channel mixer, boost the green to 200%, red -30% and Blue -70%, then go to the green chanel, gaussian blur (5 to 10) and finnaly sharpen your image and ad noise to it ...you should get something pretty close to what a IR B/W should look.
Here's a method that I use that works quite well. As mentioned above, the luminance channel in lab color preserves a touch more detail. The process is quite simple, and I will happily email the ps action to anybody who requests it.
convert image to lab color
delete channels a & b
duplicate the remaining layer
got to layer options > blending mode > multiply
adjust blend opacity to suit. I find that between 45 & 70 % works bests depending upon the effect I'm looking for.
flatten image, convert to grayscale
Here is an example, original color and then grayscaled using this method, blend layer opacity at 60%:
i find this article very helpfull...I have exhibited that the desaturation in ps has not got the quality when you shot it in camera...I would recommend channel mixer for this or u can use also sponge tool to find the right tone you are searching...Regards
after initially downloading a photoshop plugin for black and white conversion from digidaan.nl it found out, that it did not work with my software. I reprogrammed it and wrote a PDF manual. You can download both from my website with the following links:
www.wolfsson.de/Tom Wolfsson's Digital Darkroom.atn
www.wolfsson.de/manual.pdf
I think the method of creating Hue/Saturation adjustment layers is much more complicated and not as visual. By adding flexibility, this method also reduces the predictibility of an adjustment. The channel mixer technique is in my opinion far superior to an artist.
Black and White conversion is usually done well through the color channels panel. Pick either Red, Green, or Blue. (Certain colors are good for certain things. . .skies can look good in the red channel).
After you've picked a color channel that is closest to the look you want, go to Image > Mode > Grayscale.
You can save your image now if you like the results, or to fine tune the tones, navigate to Image > Adjustment > Levels.
Move the gray, white, and black sliders on the bottom to adjust the tones and brightness of the greys, whites, and blacks.
Don't forget to 'save as' when you're finished so you don't erase the original color photo.
Hi to all,
Only after few adjustments, (levels curves) a colour photo can be easily transformed into a B&W by using Layer palette. Hue & Saturation method gives a better control of manipulation with extraordinary results.
1. So, in Layer palette click on to the round circle, the adjustment layer, (half white, half black), choose Hue&Sat then click OK. A new diagram will come up on the Layer palette.
2. Step 2 is the same as 1, but this time reduces Saturation to 0 (zero value). Click OK again. On the Layer palette will come now two diagrams with the actions 1&2.
3. Change mode to Colour, click twice on the first diagram created; the Hu&Sat will come up, and then play with hue until happy?.
I personally find this method the best?
See sample ...
apart from using channels u can use different curves for different parts of the photo. for example cahnge contrast of the whole photo with a curve then erase with the eraser tool one area of the photo that u want to change it differently and then use another layer of curve for that particular area of the photo and erase other areas wit eraser tool. this is like using split filtering in darkroom thechniqes which u change contrasts of dofferent parts of the photo differently