Last week we published 36 sample images taken with the new Olympus E-P3 compact system camera in Large SuperFine JPEG+RAW format. So far neither Olympus nor any of the major third-party software developers have updated their raw converters to support the new camera; but as we have found out, RawTherapee is capable of opening, editing and converting the E-P3 ORF files.

Below you can find a comparison of some out-of-camera JPEGs and ORFs developed with RawTherapee, with noise reduction turned off. Do note that without a dedicated Olympus E-P3 camera profile available, it is not possible to recreate the exact colours of the camera-original JPEGs, but that is not the main focus of this comparison anyway.

Low-ISO Comparison

First and foremost, we were interested in seeing if there were any major differences in sharpness and detail at low ISO settings. Some of you have expressed disappointment at the level of detail seen in the out-of-camera JPEGs, even though we made a point of shooting the samples with the Noise Filter set to “Off” and in-camera sharpening left at its default level. We therefore thought it would be worth checking what you could eke out of the raw files using currently available software.

Our first sample photo was taken using the new 12mm f/2 lens  at a sensitivity setting of ISO 200 and aperture of f/8. This is a sharp, high-grade prime lens, and the image was captured at a fast shutter speed, meaning any blurring attributable to camera or subject movement is out of the question.

First, the full frame - JPEG on the left, raw conversion on the right.

What’s immediately obvious here - aside from the differences in colour - is that lens distortion is auto-corrected in the out-of-camera JPEG, while the image converted with RawTherapee is uncorrected. This is most easily noticed in the row of buildings in the background. Of course this distortion correction robs you of some field of view - you can see how the image converted from raw gets a little bit more of the scene in - and alters somewhat the size and shape of individual image details, as evidenced in the crops below.

Let’s now move on to the assessment of sharpness and detail at 100% magnification. (Again, JPEG - left, raw - right.)

The camera-original JPEG shows considerably higher contrast, while the raw conversion has arguably better tonality. The leaves in the background are better defined in the RawTherapee conversion, while the orange shoulder strap appears to hold more detail in the OOC JPEG.

This crop, taken from the bottom-left part of the photo, shows how much the in-camera distortion correction alters the size and shape of image elements near the borders of the frame - but more importantly, it also demonstrates differences in the appearance of shadow noise at low ISO settings. There’s a bit of luminance noise in the JPEG, while the raw conversion has some tightly-grained chroma noise. This difference is probably attributable to different interpretations of the binary image data by the in-camera JPEG engine and RawTherapee.

These crops, taken from the centre of the image, appear to show that there is more detail in the raw files than what you can see in the OOC JPEGs. How much of this is actual detail remains open for debate, but we it’s clear that the image converted from raw would produce a crisper print at large sizes.

Our second low-ISO sample was taken with the 14-42mm lens at the 14mm end, sensitivity of ISO 200 and aperture of f/5.6.

Out-of-camera JPEG

Image converted with RawTherapee

The above pair of images show the effect of in-camera lens distortion correction even more dramatically (which is no wonder given that a kit zoom at the wide end is expected to have more distortion than a high-end prime).

These crops lead more or less to the same conclusions drawn from the previous pair of pictures - you can definitely achieve much crisper-looking results by shooting raw, but the actual amount of detail may not be that much higher, and you may also run into aliasing issues.

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