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Fujifilm X-Trans matrix and raw converters

Olleg Samoylov | Software/App Reviews | Published Feb 13, 2013

Hi all, I am a happy owner of a Fujifilm X-E1. This camera has an innovation CMOS matrix X-Trans with a non-standard color filter array pattern. And there was a great surprise for me that support of my Adobe Lightroom 4.3 for X-Trans matrix is bugged. Now I am going to test the support of several raw converters for the X-Trans raw to choose my new one.

I have choosen the next three photos for the tests: 

This photo was taken at extreme light condition. There was an exhibition of ice sculptures lighted by artificial night light. This couple was lighted by the bright violet projector at the front, behind there was an ice sculpture with the snow and the night around. May be this photo is not good, but due to it's badness it's good to test how convertors work at extreme conditions. :)  Raw is here.
This is a sample image from the X-E1 dpreview review for ISO 200. You can take the raw from the review article. But I've found strange settings recorded in raw. First the noise reduction was changed from Std to Hi, even for ISO 200. I've recreated the jpeg with standard noise reduction. Second, WB was set by grey sample and latter was manually shift to the cyan (WB shift is R -3 B 0). That's why the sample image is so bluish.
 The same raw image, but with fixed WB shift to the default (R 0 B 0). Much warmer. Some converters reveals cold colors as in raw WB+WB shift settings, some warm as this WB without WB shift. Thats why I'll keep both to be compared.
 The same image with ISO 6400 and the raw WB shift R -3 B 0.
 The same image with ISO 6400 and the default WB shift.

 I will converts this 3 photos in each converters in 2 variants. First variant will be with settings to preserve camera WB and exposition and with defaults for all others settings. Second will be with auto correction of brightness and WB. Jpeg quality is set to 95 where it's possible.

 I'll test the next software:

Adobe DNG Converter ver. 7.2.0.46

DNG Converter is distributed by Adobe for free to convert a proprietary raw formats to open standart of format for raw files called DNG (digital negative). It's not suited to process final jpeg images, but it makes demosaicing too to create jpeg preview embedded into DNG files. That can be extracted later for test purpose (I used "dcraw -e *.dng"). Also I want to test how it's good in conversion of such non-standard X-Trans raw files to DNG. 

Adobe Photoshop Lightroom ver. 4.3

Perhaps Lightroom is the most popular raw convertor. But it's support of X-Trans raws is far from ideal, that's why I began this tests.

Raw File Converter EX powered by Silkypix ver. 3.2.13.0

This Raw File Converter EX is an official Fujifilm converter distributed for free. Looked like old version of Silkypix Developer Studio with support of new Fujifilm cameras.

Silkypix Developer Studio Pro ver. 5.0.32.0

This is the latests commercial variant with new algorithms for colour processing, so looked different. I downloaded Silkypix DSP 5 trial from the Silkypix site.

Capture One Pro ver. 7.0.2

Capture One Pro is well known raw converter, I downloaded trial to test.

DxO Optics Pro ver. 8.1.2

I like how DxO lab tests cameras and lenses, so I downloaded latest trial of DxO Optics Pro 8. But this program does not support X-E1. You can see RAF files in the file browser of DxO, but all of them marked as "uneditable". Okey, I thought, let's test linear DNG on it. But... It doesn't show in file browser any converted DNG (by Adobe converter) at all with any compatibility settings. But it fine works with DNG created by Pentax K-5 camera (DNG become Pentax standard for raws). That's why it wasn't tested.

ACDSee Pro ver. 6.1

ACDSee Pro is a known name and has a trial. But ACDSee does not recognize X-E1 RAF files.

Dcraw ver. 9.17

Dcraw is a very small free open-source program written in ANSI C and thus can be compiled on almost any operational system. It has simple interface of "command prompt" and thus is not convenient for a common user. But there is a lot of GUI program (open source and commercial) based on it and due to this it's interesting to test this software. Dcraw was compiled and tested under Debian Linux. I used "dcraw -w -W" for image with camera settings and "dcraw -a" for autocorrection.

Raw Therapee ver. 4.0.9.50

Raw Therapee is a well-known open-source free program based on tweaked Dcraw. It exists for Windows, MacOs and Linux. I downloaded version for Windows 64-bit. But it crashes when I tried to open X-E1 RAF files.

I didn't test Aperture and Raw Photo Processor because I have not MacOS. 

Extreme violet light

 This is recreated jpeg by the camera converter with default settings, Provia film emulation and automatic WB. This is a preview (thumbnail) jpeg that Adobe DNG Converter embed into DNG files. It's roughly the same as generated by others Adobe software, Lightroom for instance, reduced to 1024 pixel width. Thus I'll show result jpeg from Adobe DNG Converter only once.
Lightroom with default settings (WB set to camera). I hope you can understand now why I am so motivated to look for a new converter. :) Lightroom with WB set to "Auto" and "Auto tone" pressed. Somewhat better, but still awful.
This is a Fujifilm official converter RFC EX. For X-E1 it automatically rises parameter DR in the highlights controller to 0.4EV. WB set to camera, EV compensation 0. RFC EX with auto correction of exposition and WB.
Silkypix DSP5.  For X-E1 it automatically rises parameter DR in the highlights controller to 0.4EV. WB set to camera, EV compensation 0. Silkypix DSP5 with auto correction of exposition and WB Auto(Absolute).
Capture One 7. First time jpeg from a converter is as good as the one from the camera.  Capture One 7. It does not only change brightness by auto correction but also makes some magic with levels. Image heavy rebuilded and lost the night charm, but still looks not bad. I say more, this is very close to what I can remember about this scene. Sure I saw all brighter, as on this photo.
dcraw -v -w -W

dcraw -a
Dcraw has very primitive algorithm for AWB, but it worked better than some sophisticated commercial  alternatives. But to tell the truth, the correct colour was violet but not tan.

And... I can't understand... Dcraw is a very small program written by 1 programer in free time. The program is a single file 352 KiloBytes size. Why such program show better result than programs of such huge giants as Adobe?

ISO 200 sample

Recreated jpeg with camera default settings, standard noise reduction. WB set as it was in RAF: "custom" (by grey sample) with manual WB shift R -3 B 0. The same, but with AWB setting in the camera converter. To test AWB function of the camera too. The camera raw converter doesn't have an exposure auto correction.
Lightroom with default settings. Camera WB detected as Temp 4650K Tint +63.  Lightroom with auto corrections. WB set to Temp 4700K, Tint +30.
This is a Fujifilm official converter RFC EX. For X-E1 it automatically rises parameter DR in the highlights controller to 0.4EV. Detected camera WB is Temp 5355K Tint 0. RFC EX with auto correction exposition and WB. WB set to Temp 5039K Tint 4.
Silkypix DSP5.  For X-E1 it automatically rises parameter DR in the highlights controller to 0.4EV. Detected camera WB Temp 4779K Tint 19. Silkypix DSP5 with auto correction of exposition and WB Auto(Absolute). WB set to Temp 5418 Tint 6.
Capture One 7 without autocorrection. Camera WB  detected as Temp 4549K Tint 23. There is a color moire on the engraving. It can be fixed by the "moire" tool (Amount=75, Pattern=12). Capture One 7 with auto correction and AWB. WB set to Temp 4551K Tint 20.7.

 dcraw -v -w -W

Too dark. IMHO this is because X-E1 always underexposure for 0.4EV, to get better dynamic range.

dcraw -a

It's cold as the camera AWB, but better than some commercial alternatives.

ISO 6400 sample

Recreated jpeg with camera default settings, standard noise reduction. WB set as it was in RAF: "custom" (by grey sample) with manual WB shift R -3 B 0. The same, but with AWB setting in the camera converter. To test AWB function of the camera too. The camera raw converter doesn't have exposure auto correction.
Lightroom with default settings (WB set to camera). The denoiser isn't automatically adjusted in lightroom by default with high ISO, but you can create automatic profiles for each ISO by youself. Lightroom with auto corrections.
This is a Fujifilm official converter RFC EX. For X-E1 it automatically rises parameter DR in the highlights controller to 0.4EV. In hight ISO RFC EX automatically rise denoiser. RFC EX with auto correction.
Silkypix DSP5. For X-E1 it automatically rises parameter DR in the highlights controller to 0.4EV. In high ISO DSP5 automatically rise denoiser. Silkypix DSP5 with auto correction of exposition and WB Auto(Absolute).
Capture One 7 without auto correction. But even without auto correction it automatically changes parameters of sharpness and denoiser for the high ISO.  Capture One 7 with auto correction and AWB.
dcraw -v -w -W

dcraw -a

Dcraw has a primitive denoiser, but it was not used. What is interesting, that X-E1 ISO 6400 raw image can be used as is, without any sharpness and denoise. Sure, noise exists, but it is almost invisible when I look at this image scaled by image viewer to my 1600x1200 monitor. It's looked like a little grain.

DNG size

DNG raw can be two types: "mosaic" and "linear". The mosaic DNG is a common raw as is. The linear DNG means that color interpolation already processed by the DNG converter. It's suitable, for instance, for raw converters which don't understand a non-standard color pattern.

Adobe DNG Converter has several parameters for conversion responsible for compatibility with other programs. They can be set at once as preset, for instance "Camera Raw 7.1 or higher compatible". Or can be set explicitly: version of DNG specification (1.4, 1.3 or 1.1), linear or mosaic,  compressed or without compression. Let's see how this parameters changes the size of the DNG file.

Mode\Photoextreme ISO 200  ISO 6400
RAF size 25 MB 25 25
Camera Raw 2.4 48  54  54 
Camera Raw 4.1  48  54  54 
Camera Raw 4.6  48  54  54 
Camera Raw 5.4  48  54  54 
Camera Raw 6.6  48  54  54 
Camera Raw 7.1  16  20  18 
mosaic, compressed  16  20  18 
mosaic, non-compressed  32  32  32 
linear, compressed  48  54  54 
linear, non-compressed  94  94  94 

As you can see Adobe DNG Converter creates mosaic DNG only in the mode "Camera Raw 7.1 or higher compatible" and linear DNG with roughly 3 times more size for the other compatibility modes.

Compatibility with tested converters

 mosaic  linearRAF

Adobe Photoshop Lightroom ver. 4.3

(results exactly the same)

 yes  yes yes 

Raw File Converter EX powered by Silkypix

ver. 3.2.13.0

don't see don't see  yes

Silkypix Developer Studio

Pro ver. 5.0.32.0 

reject  yes  yes 

Capture One Pro ver. 7.0.2 

yes, but without the profile of X-E1 don't see  yes 

DxO Optics Pro ver. 8.1.2 

don't see  don't see  reject

ACDSee Pro ver. 6.1 

broken jpeg (wrong colors)  yes  reject 

Dcraw ver. 9.17 

broken jpeg (wrong colors)  yes  yes 

Raw Therapee ver. 4.0.9.50 

broken jpeg (wrong colors)  yes  crash

As  you can see the proprietary RAF format much better supported, than open standard DNG. Thus don't use DNG if you don't need it.

Examples

ACDSee Pro + mosaic DNG ACDSee Pro + linear DNG
dcraw -a + mosaic DNG dcraw -a + linear DNG
Raw Therapee + mosaic DNG Raw Therapee + linear DNG
Captire One + mosaic DNG Capture One + RAF (for comparison)

As you can see sometimes DNG can be useful. For instance, if you prefer ACDSee Pro or free Raw Therapee.

Conclusion

Only Capture One shows accurate result comparable to the camera jpeg. And it has the promising auto correction tool. Also I was surprised by power of Dcraw, but this program is inconvenient for serious work.