Making Conversions to Infrared

QUESTION:
I have been trying to follow a tutorial for converting my color images to Infrared using Channel Mixer. After moving my Blue slider to said position (-200), the image becomes VERY pixelated and low-res, while the original looked crisp and clean. The magazine mentions nothing about possible pixelation. How can I prevent this ugly pixelation?

ANSWER:
Short answer: You can't. At least not using that exact method with this particular image.

What is probably happening (and this is a PURE GUESS based on looking at the channel information in about 50,000 images and not having seen this image) is that the blue component of the RGB image has some voluminous JPEG artifacts and/or noise present, as sometimes happens, and that is introduced to the result by mixing in the blue component. By going -200 on Blue in the Channel Mixer, it doesn't mean you are removing the influence of the blue component, but you are INVERTING the influence -- and quite strongly. The result will be that any ugliness/damage/compression/artifacts in the blue component will be enhanced in the result.

[ For Elements users, you will need to use at least a component separation to extract RGB or the Hidden Power Channel Mixing tools found on the Hidden Power website http://hiddenelements.com ]

SO, the first thing I would do is check the RGB components and have a good look at the Blue component, and I think you'll see why this technique makes for a bad IR conversion -- at least with that particular image. I have seen images before where the blue component had more compression artifacts than the rest of the components before. You can likely tone it down. For example, you could potentially use a Luminosity and Color (or LAB) conversion to isolate the tone and then perhaps blur the color a little (perhaps not at all). This will lower image color noise.

[ Again, Elements users will probably want to seek the help of Hidden Power tools in making Luminosity and Color separations ]

There are MANY different ways to make an IR conversion, and I have pioneered one myself in my B&W and IR Custom Conversion tool for color images ( see http://hiddenelements.com/elements5_tools.html ). The tool was built for Elements users, but can be used in Photoshop just as well by extracting the files and loading the actions into the Photoshop Actions palette. The places where I think Channel Mixing conversions fail to imitate real infrared is that they don't address standard qualities in IR photos, like black skys, film grain, glowing skin. The conversions may work on one image type and not another, and any conversion that works that was is, more-or-less, an accident that just makes things look a little different than you are used to. Even with compensations, all you get is a mock result: an imitation of infrared and never the equivalent of the real thing.

The only real way to make IR images is to shoot IR exposures, because IR wavelengths are not just a calculation of other image components, they are a completely separate set of qualities that are part-and-parcel of the infrared spectrum. Many digital cameras filter out the IR wavelengths so they don't taint exposure results. Some digital cameras can be modified to remove filters and capture IR light in a more traditional fashion, and/or when used with proper lens filters (e.g., infrared filters that block visible light or key to favor orange or red wavelengths), you may get passible IR results.The results, however, will depend on your camera's ability to capture IR light, as well as the filter you use (more opaque IR filters limit the exposures more to infrared light qualities).

Your end result can only be as good at imitating infrared as your initial capture...or rather it can be better in the end (because you can make heroic adjustments), but you need to have the right info in the initial capture to give you the image information you need to make fabulous infrared images. The choice to filter or not, or modify or not will lead to you needing to use different techniques in adjustment to achieve your desired results. But images with inherent damage (such as a highly compressed blue channel) will likely lead to bad results using any process without further processing to correct the image.

The new Hidden Power Infrared and Custom B&W tool will help you make customized B&W conversions and mock IR. See some sample images with conversions made with the tools here:

http://www.hiddenelements.com/infrared5_tool_samples.htm