Sensor sizes seem to fall into two distinct size categories: large DSLR sensors and a second class of much smaller sensors found in compact cameras. Most serious compacts, those with full manual control, seem to have sensor sizes at the upper end of the group of small sensors.

The diagram below illustrates the relative sizes of the two sensor groups. The cropped DSLR sensor group is shown in orange tones, the compact sensor group in blue tones.

As evident in the diagram, there is a big gap in sizes between the largest compact sensor, the now rarely used 2/3” (8.8 x 6.6mm) sensor, and the smallest DSLR sensor, the 4/3 (18.0 x 13.5mm) sensor. This gap is much larger than the size difference between individual sensors in each of the two groups.



Sigma’s DP1 has used a sensor in the first group of large DSLR sensors. The price of having a very large sensor in a compact body is a not very bright, nor versatile, fixed 28mm lens. All other serious compacts to date (late May 2008) use the much smaller sensors typical in compact cameras. Except for Ricoh’s GRD I/II, all these cameras feature versatile zoom lenses that are at least fairly bright at the beginning of their respective zoom ranges. Because their sensors are small, noise and noise reduction remain an issue in all but the best lighting conditions.

The question is why there isn’t an intermediate size of sensor for serious compacts: a size that fits between the DSLR and compact sensor sizes. These sensors could offer better image quality than those sensors in the compact group while they wouldn’t be so large as to preclude zoom lenses. An intermediate size would be 12.0mm x 9.0mm, which I’ll call the “S/C” sensor. This hypothetical sensor has approximately half the area of the 4/3 sensor and about twice the area of the 2/3” sensor. This sensor should allow for reasonably compact lenses and camera bodies.

Making a sensor for just one class of camera or model seems feasible if we take Panasonic’s LX2/D-LUX 3 as an example. Its unique 16:9, 8.8mm x 4.8mm, was only ever used in that particular camera model. As of May 2008, Fuji’s 2/3” Super CCD HR sensor is also only used in one model: the FinePix S100fs.

So perhaps a new intermediate sensor size could provide a better balance between image quality and a compact form factor.

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Pt. 1 - Appearance and Zoom Range
Pt. 2 - JPEG Noise
Pt. 3 - ISO 80 JPEG Crops at 35mm & Full Aperture
Pt. 4 - Flare Performance
Pt. 5 - Noise Performance Revisited
Pt. 6 - G7 Default JPEG vs GX100 Silkypix Conversions
Pt. 7 - Key Timings
Pt. 8 - Build Quality, Quality Control, and Battery Life
Pt. 9 - Conclusion

Thanks to quick shipping by PopFlash, I have the GX100 in my hands. This one seems to be a good copy, focusing properly in my initial tests. I am super busy these days and so rather than waiting to complete testing of this camera, I will be posting frequent, short updates.

I have chosen to compare these three cameras, Canon Powershot G7, Ricoh Caplio GX100, and Leica D-LUX 2, because I think they are all excellent choices for those seeking a compact camera with manual controls. In many cases, these are at the top of the list for DSLR users seeking a second, more compact camera. The D-LUX 2, which is essentially the same as the Panasonic DMC-LX1, has been replaced by the D-LUX 3 (LX2), but I will be using the earlier camera for comparison since it is the one I have available. In some ways, it may be the more appropriate model for my style since Panasonic has apparently applied considerable noise reduction to even the RAW files on the D-LUX 3/LX2. I discussed this issue here.

Here are some comparison photos of the three:











Here are a few resized photos taken from the same vantage point to show the effective zoom focal length range of these three cameras, which in my opinion is a key differentiating feature between them. These photos obviously should not be used to judge image quality, only zoom range.

First, the GX100 at the wide end, 24mm (35mm film equivalent):



Next, the D-LUX 2 at its widest setting, 28mm (available only in 16:9 aspect ratio):



Finally, the G7 at its widest, 35mm:



Now the telephoto comparison, starting with the GX100 at 72mm equivalent:



D-LUX 2 at full telephoto, 112mm equivalent:



G7 at full telephoto, 210mm equivalent:



Quite a difference. More to follow soon!

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