Shading Compensation

Another optional image filter available on the E-1 is 'Shading Compensation'. This filter is designed to remove the dark corners we sometimes see in images taken at wide angles and maximum apertures (this is known as lens shading). This problem mostly effects very wide angle lenses Curiously however we found this feature to be virtually ineffective in our tests, the samples from which you can see below. The only lens which exhibited noticeable corner shading was the E 14-54 mm at full wide angle (14 mm) and maximum aperture (F2.8). Enabling the 'Shading Compensation' filter appeared (to us at least) to have virtually no effect.

Settings: Sharpness 0, HQ JPEG, +1.3 EV compensation, Manual WB

Shading Compensation off	Shading Compensation on
ED 50 mm Macro F2.0 @ F2.0
E 14-54 mm F2.8-F3.5 @ 14 mm (F2.8)
E 14-54 mm F2.8-F3.5 @ 54 mm (F3.5)
ED 50-200 mm F2.8-F3.5 @ 50 mm (F2.8)
ED 50-200 mm F2.8-F3.5 @ 200 mm (F3.5)

RAW

Like all digital SLR's (and several prosumer level digital cameras) Olympus provides a RAW format option on the E-1. RAW simply means data direct from the sensor (12 bits per pixel) which hasn't been processed in any way. Additionally the current camera settings (such as parameters, exposure etc.) are recorded in the header of the RAW file. Olympus uses the .ORF extension for RAW files.

RAW vs. JPEG: Resolution & Quality

The optional Olympus Studio application provides a choice of 'RAW Development Engine', you can select between 'High Speed' or 'High Function'. The included Olympus Viewer application appears to always use the 'High Function' engine, ensuring maximum image quality but with a performance tradeoff. Conversion using the 'High Speed' option was approximately three times faster than 'High Function' but image quality suffered in the former mode.

The 'High Function' RAW Development Engine is clearly more sophisticated than the 'High Speed' with better resolution, lower artifacts and lower visible moiré. The 'High Function' RAW Development Engine also appears to improve color response, contrast and dynamic range. The 'High Speed' RAW Development Engine seems to be identical to the engine used in the camera to produce JPEG's or TIFF's, and I think it's interesting to see how much better the E-1's images could look if Olympus could have squeezed the 'High Function' engine into the camera.

Resolution (100% crops)

JPEG (SHQ) *	RAW (High Function) **	RAW (High Speed) ***

* In-camera, ** Olympus Viewer and Olympus Studio, *** Only Olympus Studio

Quality (100% crop)

Place your mouse cursor over the labels shown below the crop to see the image processing differences between in-camera JPEG and RAW converted using either the 'High Function' or 'High Speed' RAW Development Engines.

JPEG (SHQ) *	RAW (High Function) **	RAW (High Speed) ***

* In-camera, ** Olympus Viewer and Olympus Studio, *** Only Olympus Studio

RAW vs JPEG: Noise levels

When we performed our ISO noise tests (page 15) we also shot the test in RAW and processed the images (to TIFF) using Olympus Studio with both the 'High Speed' and 'High Function' RAW Development Engines. Below you can see a comparison of luminance noise between JPEG and RAW using the two different RAW Development Engines with and without Noise Filter.

It's very interesting (and revealing?) to see that noise levels above ISO 400 are actually quite a bit higher using the 'High Function' RAW Development Engine compared to the 'High Speed' engine and which produced results virtually identical to in-camera JPEG. In resolving an image with more detail the High Function RAW Development Engine also appears to reproduce more of the noise from the original image data.

Luminance noise graph (ISO 100 - 3200)

Indicated ISO sensitivity is on the horizontal axis of this graph, standard deviation of luminosity (normalized) on the vertical axis. The (NF) suffix indicates that Noise Filter is enabled.

RAW latitude (digital exposure compensation)

With additional samples we have reevaluated the available latitude in RAW images and found it to be fairly disappointing, perhaps in the range of 0.3 to 0.5 EV, lower than we would expect from a professional level digital SLR.

RAW	RAW -1.0 EV (digital exp. compen.)