May 22, 2008

Software Review: SilkyPix

The following was written by special guest writer Wayne Beaumont.

Virtually all digital SLRs available today are able to output in RAW format. This also extends to many manufacturers’ high end or enthusiast level point and shoot cameras. I was recently given a Canon G9 which falls into the enthusiast category and provides the option of outputting it’s files in RAW format.

I consider myself to be a casual photographer, taking more than what I would consider snapshots but certainly falling short of fine art photography. Being recently introduced to a camera with RAW capability, I started looking into the pro’s and con’s of this format. The pro’s include the ability to adjust camera parameters such as white balance, sharpness, noise reduction , and exposure (to some degree) using computer software. Allowing these to be adjusted to suit your own taste and possibly correcting errors in the original photo. The con’s are related primarily to camera performance. RAW files tend to be large. Canon G9 RAW files typically exceed 12MB. As a result, shot to shot performance on the G9 suffers and the number of files you can put on a memory card is drastically reduced. With today’s multi-GB SDHC cards, this s not of too much concern since 4GB and up cards are available at reasonable cost. The G9 also allows you take both jpg and RAW files at the same time. I find this to be a great option since I can use the camera jpg as a reference when processing the RAW file.

For point and shoot cameras, RAW provides the ability to provide a level of image quality that often is not attainable from jpg‘s. This is particularly true when using the camera in less than ideal lighting conditions. Modern point and shoot cameras typically stuff a lot of pixels on a small sensor. The result is highly detailed pictures when taken in bright light, but as the light drops, the small pixels limited light gathering capability results in pictures containing a lot of noise. Usually appearing as colored speckles throughout the picture, particularly in shadow areas. Camera manufacturers combat this by applying in-camera noise reduction which effectively reduces the visible noise but often leaves details that are smeared. In extreme cases, the photo can take on an almost watercolor appearance. Since RAW files contain all the information provided by the camera’s sensor, you can make the decision regarding how to apply processing after the fact. You can decide how much noise reduction you are willing to apply and balance this against lost detail.

One other downside to RAW files is that their format is not standardized across the industry. RAW format is different not only from manufacturer to manufacturer but also from camera model to camera model. This means that if you look for a RAW processing program other than that supplied by the camera manufacturer, you need to make sure that your camera’s format is specifically included. Software publishers stay pretty much on top of what is available on the market, but if you purchase a camera that is new to the market, the number of available RAW software packages may be limited.

RAW converters are not to be confused with photo editing software. A photo editing software package may contain a RAW processor, but it is usually a distinctly different program from the editor itself. RAW converters apply modifications to the entire picture, not to selected portions of it. Also RAW converters really allow you to control how the photo is to be displayed. If you like what you see, the results can be saved to another file, typically jpg or tiff. RAW converters do not modify the original RAW file.

SilkyPix is a RAW converter only. If you want to process a photo further, you will need a photo editing package. As a RAW converter, SilkyPix provides extensive control over how a RAW file is interpreted. Opening the software, the user is presented with an array of controls. Many of which are self explanatory, but some have odd names and appear to be included in odd locations. To process a RAW file though is made straightforward with a large collection of presets. Any of the presets can be selected, then further modified to suit your taste.

The default screen lists a logical progression of available controls. Starting with exposure, then going on to white balance, contrast, color (hue and saturation variations) , and noise reduction/sharpness. At the very top of this list is a pull down menu listing what SilkyPix refers to as ‘tastes’. Tastes is SilkyPix’ term for defined presets. The presets may be global or limited to a subset of adjustments. You can save you own set of presets under a new taste, allowing you to apply the same set of actions to a series of photos individually or in batch mode.

SilkyPix provides an extensive amount of control over how RAW files are processed. Among these are a lens aberration tool that includes not only controls for lens distortion but a really nice tool for removing chromatic aberrations. Chromatic aberrations are typically a red/blue halo around high contrast area in a photo. These are pretty well controlled on the G9 but can be seen in some instances. This tool makes this easy to fix. These show the before and after effects:

Noise reduction goes beyond just sliders for luminance and chroma. SilkyPix combines sharpness and noise reduction into a set of related controls.

These controls interact with each other so some experimentation is in order. It is important to draw a balance between how much sharpness you want along with how much noise you’re willing to accept. With the G9 when dealing with hi ISO pictures (ISO 400 - 800), I am not looking to eliminate all of the noise. My goal is to reduce the noise to what looks like film grain, which I don’t find objectionable, and keep a fairly high level of detail. This is a 100% view of an ISO 800 photo with no sharpening or noise reduction being applied.

After applying noise reduction and sharpening:

Again, you have to decide what level of noise reduction and sharpening you think is appropriate for your photo. SilkyPix gives extreme control over just how much is applied and provides tools for restoring lost detail due to applied noise reduction.

SilkyPix includes a unique highlight controller which allows you to recover and blend in or emphasize overexposed areas. This is done through two sliders labeled Chroma/Ludminance and Saturation/Hue. Blown highlights can also be tamed with the supplied dynamic range expander. It’s good to have the histogram displayed as you apply dynamic range expansion. You will be able to see the exposure pull in on the right side of the histogram. It is suggested that this control be used in conjunction with others and to use sparingly

Once you are satisfied with your changes, you can hit Ctrl-S. SilkyPix will then bring up the file save dialogue:

Here you can specify the output type (JPEG or TIFF). In the case of TIFF, you may select 8 or 16 bit format. In addition, you can change the saved file resolution, apply sharpening, and the quality level if saving in JPEG. If saving for further work in a photo editor, select TIFF format. You may want to save more than one copy using different levels of noise reduction. By combining these in a photo editor, you can then decide where different levels of noise reduction are most appropriate.

The software also includes photo management and batch processing capability.

One issue I do have is the time it takes to process files for both display and saving. To save a file took upwards of 20 seconds . This was on a modern laptop with a dual core processor. A desktop may be slightly faster due to a higher performance disk drive. Displaying photos in the converter took time also. Any changes made required an inordinate amount of time to display. This may be circumvented by choosing the software option to display modifications in zoom (preview) mode only.

With this criticism aside, I find SilkyPix to be an excellent application. It offers an enormous amount of flexibility and can be fun just to see what can be done with processing RAW files. Compared to the jpg files straight out of the G9, RAW files exhibit greater dynamic range, and detail along with the ability to further push the camera’s limits and the possibility to recover what may have been a blown shot.

This has touched briefly on a few features of SilkyPix. The software is available on a 2 week trial basis from their website located at The package is priced to make it reasonable for a casual photographer and is a worthwhile option to anyone shooting RAW. The software manual is available for download, but some patience is required as the English translation leaves a little to be desired..


Anonymous said...

excellent review! definitely a worthy software to take a look at

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