Weather-Sealed DSLR Camera Comparison
All these digital SLRs have sophisticated metering systems. Each one specifies its multi-segment metering differently. The K20D and K200D use 16 segments, the 7D uses 63, the E-3 uses 49, the K-7 uses 77 and the D300S uses 1005 pixels. It is not possible to use the number of segments alone to know which one is better because the decision depends on what is done with the data. Of all these cameras, only the 7D shows consistently less reliable exposure than others. The K20D has the more conservative exposure while the D300S gives mostly well-balanced results.
Center-weighed metering is fixed on all but the Nikon. It can weigh 75% of its metering on a 6, 8, 10 or 13mm circle. Most people probably would not know which of these options to choose, so having them in the first place is unimportant. The most useful setting however lets the D300S turn its center-weighed metering into average metering. The Olympus E-3 has two additional and rather interesting metering modes, a highlight and a shadow-bases spot meter. This allows to meter on a highlight or shadow respectively, something which is much easier than identifying and 18% mid-tone.
Images can be tuned by controlling various internal processing parameters specified in arbitrary units. These parameters do not normally apply to RAW images which are unprocessed. Some cameras have more increments than others but since the units are unknown, it is impossible to know which camera gives more latitude. In terms of sophistication, the K-7 wins hands down with 3 different sharpening functions, each having 9 steps of adjustment and independent control over shadow, overall and highlight contrast.
|Table 6 -Image Parameters|
|Canon EOS 7D||Sharpness 0-7, Contrast +/-4, Saturation +/-4, Color Tone +/-4.|
|Nikon D300S||Sharpness 0-9, Contrast +/-3, Saturation +/-3, Hue +/-3, Brightness +/-1.|
|Olympus E-3||Contrast, Saturation, Sharpness: All in 5 steps.|
|Pentax K-7||Sharpness +/-4 on 3 scales (27 total settings). Saturation, Hue, Hi/Low Key, Contrast, Highlight contrast, Shadow contrast: All +/-4 (9 steps).|
|Pentax K20D||Saturation, Hue, Contrast: All +/-4. Sharpness in 9 steps on 2 scales.|
|Pentax K200D||Sharpness, Saturation, Hue, Contrast: All +/-4.|
While every DSLR camera on the market supports RAW files, Pentax DSLRs have the option to save the data in its purely unprocessed RAW format and Adobe's DNG format which promises to be more portable. In-camera RAW development is available on the Pentax DSLRs as well. This means that a RAW shot can be converted to JPEG directly in the camera, no software installation needed. Other than Olympus and Nikon, each camera here has a dedicated RAW button that toggles the camera in and out of RAW mode (or RAW+JPEG).
No camera in this roundup is too sophisticated to have a built-in flash and they all are equipped with a hot-shoe for using external flashes of their respective manufacturers. They almost all have a Sync-Port connector, something which is less used these days because hot-shoe adapters and wireless triggers exist.
|Table 7 - Built-In Flash|
|Canon EOS 7D||Guide Number 12 @ ISO 100
|Nikon D300S||Guide Number 12 @ ISO 100
Guide Number 13 @ ISO 100
Guide Number 13 @ ISO 100
Guide Number 11 @ ISO 100
Guide Number 13 @ ISO 100
Each camera features automatic image review, playback and a camera status display. For playback, magnification, zoom and automatic rotation are standard features. Histograms come in both RGB and luminance. All these cameras except the E-3 allow you to delete an image during automatic image review.
Among these cameras, SD and SDHC cards are used by all the Pentax models, while all other models work with Compact Flash Type 2 memory cards. The Olympus E-3 also has a second slot which accepts xD cards. Presently more cameras are moving to SDHC which is the cheapest type of memory. It remains that Compact Flash cards have an advantage in size and speed, as the fastest CF cards beat the fastest SDHC by a wide margin. Given the hefty buffers on all by the K200D, memory card limits should be not an issue.
The last difference is portability. Obviously, none of these are pocket size and they all gain weight when a lens is mounted. The lightest and smallest camera here is the Pentax K200D. Despite its small size, it is very comfortable to use, although you have to make due with fewer external controls and the smaller viewfinder. The K-7 is heavier but amazingly close in size to the K200D, particularly considering the K-7 features a larger 100% coverage viewfinder and many more controls. The K20D is a step wider and more comfortable to hold. The three remaining models are noticeably bulkier and heavier. Note that a heavy lens can make any camera heavy but if the lens is much heavier than the camera, it may feel imbalanced.
|Table 8 - Size & Weight|
|Canon EOS 7D||5.8" x 4.4" x 2.9"||860g|
|Nikon D300S||5.8" x 4.5" x 2.9"||938g|
|Olympus E-3||5.6" x 4.6" x 3"||890g|
|Pentax K-7||5.2" x 3.8" x 2.9"||750g|
|Pentax K20D||5.6" x 4" x 2.8"||800g|
|Pentax K200D||5.3" x 3.7" x 2.9"||690g|