Raw processing on Android devices with Photo Mate R2
Lars Rehm | Published: Jan 17, 2014 at 18:25 UTC76
Photo Mate R2 uses the open-source software dcraw for decoding Raw files but all editing algorithms are specific to the app. So if you convert a file "as shot" the final result will be identical to a conversion in dcraw but of course the whole point of Raw conversion is being able to change shooting parameters in post-production. This also means that once new camera models are compatible with dcraw their files will also work in Photo Mate R2.
In this section we have processed a few Raw images with Photo Mate R2 and, for comparison purposes, with Adobe ACR 8.2 to show you what the image results look like.
Below we have processed the ISO100 Canon EOS 70D Raw file of the dpreview studio shot in Photo Mate R2 and compared it to the out-of-camera-JPEG and the Adobe ACR conversion at default settings. As you can see the Photo Mate output is a little flatter and less contrasty than the JPEG file. It is also softer, with less sharpening applied. Nevertheless, there is very sightly more detail in the image, especially in the shadow areas.
Like the Photo Mate output the Adobe ACR shows some more fine detail than the out-of-camera JPEG but has some more contrast and sharpening applied, giving it a more "punchy" appearance.
In this test we tried to get maximum detail out of a Raw file in Photo Mate. The only two sharpening parameters offered by the app are the sharpening amount and radius. With its Detail and Masking sliders Adobe's ACR offers better control over sharpness but with some small-radius sharpening applied Photo Mate R2 squeezes a tiny amount of additional detail out of the Sony Raw file and generates a less processed looking image. The warmer color response is also noticeable.
Recovering highlights and lifting shadows is another useful application of Raw conversion. This image was taken on a hike on a sunny day. The in-camera JPEG processing struggled with the very high contrast between sunny and shaded areas in the forest. In Raw processing a more balanced result can be created by recovering highlights and applying some fill light to the shadow areas.
With highlight recovery set to the maximum the Photo Mate R2 output looks more balanced and natural than the out-of-camera JPEG but Adobe ACR manages to recover even more detail in the highlight areas.
White Balance Correction
The Auto White Balance systems of digital cameras tend to create unnatural color casts under artificial light. This ISO 12800 shot was taken under candle light illumination with a Pentax K-30. The out-of-camera JPEG has a very strong orange cast that we tried to soften and make look more natural in Photo Mate. This is easily done by moving the white balance sliders in the app but no way of checking the color values in an image means you have to judge your result by eye and trust the display of your Android tablet.
Photo Mate R2 is the only fully-fledged Raw converter for Android we are currently aware of. It comes with a remarkably comprehensive feature set that is not far off some desktop packages. Enthusiast and professional users might miss lens profiles or the ability to read color values but overall Photo Mate R2 covers a large proportion of your Raw processing requirements.
Most users are more likely to feel limited by their tablet hardware than the app's feature set. Photo Mate R2 offers a function for screen calibration but the screens of most current Android tablets don't come close to a carefully calibrated IPS monitor in terms of color accuracy, contrast and tonal range. Given the size of Raw files it's also advisable to use Photo Mate with one of the current high-end Android tablets such as the Google Nexus 10 or the Samsung Galaxy Note 10.1. On the latter single file conversion takes approximately 25 seconds, so processing a batch of images can take a while.
Photo Mate R2 uses the Raw decoding algorithms of dcraw and is therefore compatible with most current cameras. That said, in our test it occasionally had some trouble displaying files from the Pentax K-30 and flat out refused to convert a couple of files from the Nikon D800. I would recommend you try the app with files from your camera straight after installation, so you can make use of Google Play's 15 minute return policy if necessary.
Despite some minor quibbles at just under $10 Photo Mate R2 is a no-brainer for Raw shooters who already own a decent Android tablet and a more than viable backup solution for photographers who usually prefer to process Raw files on a laptop or desktop. Thanks to the compact dimensions and low weight of tablets it could also be the software of choice for Raw shooters who like to travel light.