Mono Conversions - How to get the best from your RAW.
Part one with part two below.
It's a thorny old subject this. One look around the various internet forums and you can come away feeling very confused indeed as to the best way to get really good mono images from your RAW capture.
In order to give you the best start point, we really need to go right back to the original time of capture and have a look at exposure and file type.
RAW Bit Depth
Most DSLR cameras are now fitted with 12-bit sensors. This means that if you shoot RAW, then you have the possibility to capture 4096 tones. This compares to 256 for an 8-bit JPEG.
In simple terms, even before you have opened your image in Photoshop or any software processing package, and if you capture in jpeg, then you are immediately at a disadvantage. Why? Well in order to achieve a good monochromatic image that has the subtlety of tones we have become accustomed to seeing in great black and white photographs darkroom printed using a traditional silver gelatin process, it is essential that we shoot RAW. 
Exposure.
We also need to look closely at our exposure to ensure we have the optimum tonal range from our capture. If we under expose our photograph, (see example left) then we may lose as many as 2000 of these 4096 available tones, overexpose and you risk losing highlight tone, texture and detail.
You soon start to realise that we walk a very fine line with digital exposure. Trying to get the balance right to maximise the potential of any image. It also highlights the need to get it right in camera. Post production should be just that and not image rescue!
For the purposes of this tutorial, we will assume you have a nicely exposed histogram. That is to say that it is as far right as possible, without losing the highlights.
We are going to look at the optimum workflow through Lightroom and analyse the individual steps in the processing to ensure that you get the most natural looking mono conversion possible.
Lightroom
Probably one of the best RAW processing packages currently available and regarded by many as one of the easiest and intuitive to use.
There are however a couple of things you need to be aware of when using Lightroom. Not just for mono work, but also for your colour images too.
Presets
Are you aware that Lightroom automatically adds brightness, contrast, a tone curve at also a basic level of capture sharpening to your RAW file preview?
Not many people do, so in order to have the best start point, you need to reset everything back to zero. This is essentially how your image was captured in camera and it will look flat and bland. You could actually refer to this process as 'make my image look terrible' routine. However as the photographer of the image, you would have pre-visualised how that photograph would look after post production. It is essential therefore, that you remove any 'default' adjustments to give you the best starting point.
Luckily, Lightroom has a pre-set that allows you to do this with the click of a button. If we look at the screen grab below.
We can see the preset that will allow us to get back to the original unmolested capture.
Now hit that button and see just how flat your image can actually look! This is where you now will start making your image look as it was intended at point of capture.
You must now get the balance between exposure, highlight recovery (recovery)shadow recovery (fill light) and blacks just about right. You may also want to add in some clarity (mid range contrast) and apply an adjustment in the tone curve to give you the level of snap required.
Take some time to experiment with these settings and if you are unaccustomed to processing your images this way, then it is appropriate we keep the rest back to part two, where we will be looking at Grayscale adjustments and also a look at the new black and white conversion in Photoshop.
Part Two
In part two, we will take the following image and look at the different methods of black and white conversion available through both Photoshop and Lightroom.
In our starting image below, captured on a Nikon D3 during one of many sunrise shoots, we can see that there is a good tonal range and the exposure at capture is spot on.
One interesting side topic on the D3, although it has the option to expand the ISO down to 100, you actually lose a whole stop of dynamic range in the process, which defeats the purpose in many ways!
We are now going to scroll down the tool bar on the left until we find the HSL tools. (Hue, Saturation and Luminance).
Following our own instructions above, we end up with something that looks like this:
It is interesting to see how different your monochrome image can look with some minor adjustments on the colour sliders.
One of the benefits of lightroom is in its parametric adjustment of all images - this compares very well to other image adjustment software where any adjustment is usually destructive. I always imagine images like a piece of playdough, where each and every adjustment stretches the dough until eventually it snaps - this does not happen in Lightroom and is why it is my preferred choice for most of my post production work.
If we now take the same colour image and send it over into Photoshop CS3, we can have a look at the new Black and White conversion tool.
Thomas Knowles has kindly given us a new toy to play with and a very good one it is too - there are also some interesting pre-sets that we can have a look at too.
The default settings are actually not too bad, but again you can experiment with moving the sliders until you get the final images that was what you pre-visualised when you originally captured the photograph.
We will now look at the various preset filter options too see how different the effects look. CS3 offers a range of filter simulation options to replicate the effect of using a coloured filter with traditional black and white film. Have a look at the results below to draw your own conclusions.
In the final image, we have opted for a variation on the default conversion, however with most post production work, it is always season to taste and many will no doubt prefer one of the presets or a variation there of.
What is important to remember is that the point of capture is critical to ensure we have the tonal range to provide us with the smooth gradations from dark to light that all good monochromatic images have.