Digital Cameras - Pentax Optio 330RS Test Images
(Original test posting: 09/22/02)
| I've begun including links in our reviews to a Thumber-generated index page for our test shots. The Thumber data includes a host of information on the images, including shutter speed, ISO setting, compression setting, etc. Rather than clutter the page below with *all* that detail, I'm posting the Thumber index so only those interested in the information need wade through it! |
| Outdoor Portrait:
Somewhat magenta color cast, but good exposure and detail. The extreme tonal range of this image makes it a tough shot for many digicams, which is precisely why I set it up this way, and why I never shoot it with fill flash or a reflector to improve the lighting. The object is to hold highlight and shadow detail without producing a "flat" picture with muddy colors, and the Optio 330RS did pretty well, although it did lose some highlight detail. The shot at right was taken with a +0.7 EV exposure compensation adjustment to brighten midtones, but pushes the highlights a bit. (In retrospect, I should have shot a series here using the 330RS' contrast adjustment, as it's likely that the low contrast setting would have helped hold the highlights in check.) I chose the Auto white balance setting for the main series, though it produced similar, magenta results to the Daylight setting. Alternatively, the Manual setting resulted in a yellow cast. Due to the strong magenta cast of the Auto white balance, Marti's skin tones are pinkish, as is the white shirt and house siding. The blue flowers in the bouquet are dark and a little purplish (a common problem with this shot). Detail is strong in the flower bouquet, as well as Marti's features, with good detail in the shadows. There's image noise in the shadow areas, but I'd classify it as "moderate." To view the entire exposure series from zero to +1.0 EV, see files O33OUTAP0.HTM through O33OUTAP3.HTM on the thumbnail index page. |
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Results are similar to the wider shot above in terms of color and exposure, and the Optio 330RS' 3x zoom lens helps prevent distortion of Marti's features. The level of visible fine detail increases with this close-up shot, even in the dark shadows. The shot at right was taken at the default exposure setting, and still loses detail in the white highlights of the shirt collar. Contrast is a little high from the bright sunlight as well. To view the entire exposure series from -0.3 to +0.7 EV, see files O33FACAM1.HTM through O33FACAP2.HTM on the thumbnail index page. |
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Indoor Portrait, Flash:
Underexposed by the flash, and magenta color cast from the room lighting. The Optio 330RS' built-in flash underexposed this shot, and there's no way to correct it, as the camera's exposure compensation adjustment doesn't seem to affect flash exposures. The darker exposure, combined with the Auto white balance setting, results in a strong pink cast, while the household incandescent lighting produces a slight orange cast on the back wall (and on Marti's hair). |
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Indoor Portrait, No Flash:
Excellent color with Manual white balance. This shot is always a very tough test of a camera's white balance capability, given the strong, yellowish color cast of the household incandescent bulbs used for the lighting. The Optio 330RS' Manual white balance setting produced the most accurate results here, though with a slight yellow cast. Auto white balance resulted in a very strong orange cast, while the camera's Incandescent setting produced warm, sepia-like results. The main image was taken with a +1.0 EV exposure compensation adjustment, which results in an even exposure. Anything higher produced bright highlights. (Here is a sample image at the default exposure.) Skin tones look about right, but the blue flowers are dark and purplish (a common problem with this shot). Though slightly dark, overall color looks pretty good here. To view an abbreviated exposure series from +1.0 to +1.7 EV, see files O33INMP3.HTM through O33INMP5.HTM on the thumbnail index page. ISO Series:
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House Shot:
Good color and resolution, slightly soft details, significant corner softness. The Optio 330RS' Manual white balance setting produced the most accurate color here, with the most natural overall color balance and a good white value on the house trim. The Auto and Daylight settings produced slightly warm images, though both were nearly accurate. Resolution is moderately high (reasonable for a three megapixel camera), with some leaf detail visible in the tree limbs and shrubbery. Details are slightly soft throughout the frame, and appear to be defined more by high contrast than sharpness. Image noise is high, and some artifacts are present in the vertical and horizontal details of the house. There's a significant amount of softness in the corners of the image, a good bit more than I'm accustomed to seeing in the cameras I test. |
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Far-Field Test 
Really excellent resolution for a 3 megapixel camera. This image is shot at infinity to test far-field lens performance. NOTE that this image cannot be directly compared to the other "house" shot, which is a poster, shot in the studio. The rendering of detail in the poster will be very different than in this shot, and color values (and even the presence or absence of leaves on the trees!) will vary in this subject as the seasons progress. In general though, you can evaluate detail in the bricks, shingles and window detail, and in the tree branches against the sky. Compression artifacts are most likely to show in the trim along the edge of the roof, in the bricks, or in the relatively "flat" areas in the windows. This is my ultimate "resolution shot," given the infinite range of detail in a natural scene like this, and the Optio 330RS captures an excellent level of detail for a three megapixel camera. The fine foliage in front of the house has strong detail in the leaves and branches, as do the tree limbs over the roof. The bright sunlight on the white paint of the bay window causes the Optio 330RS to lose almost all highlight detail there, but the shadow areas above the front door and in the shade of the trees fare much better, showing stronger detail in the bricks and leaves. Overall color is quite good, with accurate hue and correct saturation (It looks a bit undersaturated, compared to many cameras' handling of this image, but it's actually more faithful to the original than much of the competition. The table below shows a standard resolution and quality series, followed by sharpness, contrast, and saturation series. Resolution Series:
Sharpness Series:
Contrast Series:
Saturation Series:
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Lens Zoom Range Typical 3x zoom range - sorry I forgot to shoot these... :-( I routinely shoot a series of images to show the field of view for each camera, with the lens at full wide angle, at maximum telephoto (3x, in this case), and at full telephoto with the digital zoom enabled. Unfortunately, I forgot to snap them while I had the 330RS. The Optio 330RS' lens is equivalent to a 37-111mm zoom on a 35mm camera, very slightly shifted toward the telephoto end, relative to the 35-105mm range of most 3x zooms on consumer digicams. |
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Musicians Poster
Magenta color casts, but good detail and resolution. This shot is typically a tough test for digicams, as the abundance of blue in the composition often tricks white balance systems into producing a warm color balance. All three white balance settings had trouble here, producing strong magenta casts. The Manual setting appeared the most natural, with the best skin tones and overall color. Both Auto and Daylight settings were warmer and had stronger magenta tints. The blue background is purplish, and the blue robe has purple tints in the deep shadow areas. (This is a difficult blue for many digicams.) Resolution is moderately high, with good detail in the embroidery of the blue robe. (The somewhat coarse details on the poster used for this shot tend to favor cameras with 3 megapixels or less, so the P330RS is helped a bit by that here.) Corner softness is again pronounced on the left side of the frame, but remaining details are fairly sharp. |
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Macro Shot
Slightly large macro area, flash is uneven. The Optio 330RS performed less than average in the macro category, capturing a fairly large minimum area of 5.4 x 4.1 inches (137 x 102 mm). Resolution is fairly high in the center of the frame, but there's a lot of softness in the corners. The Optio 330RS' flash throttles down for the macro area reasonably well, though coverage is uneven with dark corners. Overall, acceptable for occasional closeup shots, but probably not your camera of choice if you need to do a lot of macro work. |
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"Davebox" Test Target
Good color with Manual white balance. The Optio 330RS' Manual white balance setting resulted in the most accurate color balance here, though it still produced a slight warm cast. Both the Auto and Daylight settings resulted in warmer images. The shot is slightly overexposed, resulting in some flare around the highlight areas and some loss of detail in the white gauze. (Focus is also unaccountably a little soft here.) The camera picks up the subtle tonal variations of the Q60 target well, up to the "B" range. The large color blocks are about right, though slightly warm, and their saturation is about right. Moderate detail is visible in the shadow area of the charcoal briquettes, but with high noise and a pronounced green cast to the deepest shadows. Contrast Series:
Saturation Series:
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Low-Light Tests Sensitive enough for average city street lighting and darker. The Optio 330RS features a full manual exposure control mode, though its maximum shutter speed is only four seconds. In our tests, the camera captured bright, clear images at light levels as low as 1/8 foot-candle (1.3 lux) at the ISO 250 setting, though the target remained visible but dim at 1/16 foot-candles (0.67 lux). At ISO 125, the camera captured bright images only as low as 1/2 foot-candle (5.5 lux). Color balance is warm from the Auto white balance setting. Typical city street lighting equates to about one foot-candle, so the camera should be able to capture darker images well (though focus is slightly soft at the lower light levels). Noise is low at ISO 125, increasing to a moderate level at ISO 250. The table below shows the best exposure I was able to obtain for each of a range of illumination levels. Images in this table (like all of our sample photos) are untouched, exactly as they came from the camera.
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Flash Range Test Bright as far as nine feet from the target, then progressively darker. The Optio 330RS' flash was brightest to about nine feet from the test target. Intensity decreased gradually from that point on, becoming quite dim at the 14 foot distance. Below is our flash range series, with distances from eight to 14 feet from the target.
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ISO-12233 (WG-18) Resolution Test 
Strong detail to 1,050 lines/picture height. The Optio 330RS performed very well for a three megapixel camera on the "laboratory" resolution test chart. It started showing artifacts in the test patterns at resolutions as low as 600 lines per picture height vertically and as low as 500 lines horizontally. I found "strong detail" out to at least 1,050 lines. "Extinction" of the target patterns occurred at about 1,200 lines. Optical distortion on the Optio 330RS is fairly high at the wide-angle end, where I measured a 0.99 percent barrel distortion. The telephoto end fared much better, as I measured a 0.016 percent barrel distortion. (Essentially imperceptible.) Chromatic aberration is moderate, showing about three to four pixels of coloration on either side of the target lines. (This distortion is visible as a very slight colored fringe around the objects at the edges of the field of view on the resolution target.) The strongest visible distortion was some corner softness, along the left side of the frame. Resolution Series, Wide Angle
Telephoto
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Viewfinder Accuracy/Flash Uniformity Tight optical viewfinder and loose LCD monitor. The Optio 330RS' optical viewfinder is tight, showing about 87 percent of the frame at wide angle and approximately 85 percent at telephoto. The LCD monitor turned out to be just slightly "loose," as my standard lines of measurement were very slightly outside of the frame in both shots. The LCD monitor is close to 100 percent accuracy though, so the 330RS' LCD finder is about as accurate as you'll find. Flash illumination at wide angle is uneven, with strong falloff in the corners of the frame. At telephoto, flash coverage is more even, but the dim intensity results in a pink cast.
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