Digital Cameras - Pentax Optio 430RS 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!|
Daylight white balance setting for
the main series, though it produced a slight magenta cast. Both the Auto
and Manual settings produced greenish images,
with the Manual setting producing the strongest cast. The magenta cast of
the Daylight setting makes Marti's skin tones a little pinkish, as well
as her white shirt and the house siding. The blue flowers in the bouquet
are slightly dark, but the color is spot-on, without any strong purple tints.
(This is a difficult blue for many digicams to get right, and the Optio
430RS gets it almost exactly right.) Resolution is high, with a lot of fine
detail visible in the flower bouquet as well as on Marti, although details
in her hair are flattened somewhat, probably by the camera's noise-suppression
processing. Shadow detail is moderate, but noise is rather high.
To view the entire exposure series from zero to +1.3 EV, see files O43OUTDP0.HTM through O43OUTDP4.HTM on the thumbnail index page.
Higher resolution and detail, with good sharpness.
Overall results are similar to the wider shot above, and the Optio 430RS' 3x zoom lens helps prevent distortion of Marti's features. As is typical with this close-up shot, detail is much stronger in Marti's face and hair. The shot at right was taken with a +0.3 EV exposure compensation adjustment, which loses some highlight detail in the white shirt collar, but keeps the skin tones where they should be. The shadow areas show good detail, though noise is again high.
To view the entire exposure series from +0.3 to +0.7 EV, see files O43FACDP1.HTM
through O43FACDP2.HTM on the thumbnail index page.
Indoor Portrait, Flash:
Slight underexposure, and a magenta cast from the room lighting.
The Optio 430RS' built-in flash is reasonably bright, but was tricked by the high-key subject here a bit, underexposing slightly. The strong incandescent lighting in the room produces a magenta cast. - Easy enough to get rid of in an image editing program, but I'd hope for a little less cast from the camera itself.
Indoor Portrait, No Flash:
Very good 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 430RS' Manual white balance setting produced the very good results here, with just enough warmth left in the scene to suggest the original lighting. Auto white balance resulted in a very strong orange cast, while the camera's Incandescent setting produced yellowish results. The main image was taken with a +1.3 EV exposure compensation adjustment, which is higher than normal on this shot. (Here is a sample image at the default exposure.) The blue flowers are dark and purplish (a common problem with this shot, due to the very warm-toned room lighting), but overall color is quite good.
To view an abbreviated exposure series from +1.0 to +1.7 EV, see files O43INMP3.HTM through O43INMP5.HTM on the thumbnail index page.
Good color, moderate detail, but rather soft overall
The Optio 430RS' Manual white balance setting produced the most accurate color here, with the most natural overall color balance. Both the Auto and Daylight settings produced warm images, with the Daylight setting resulting in the strongest cast. Resolution is fairly high, with good detail in the tree limbs and shrubbery in front of the house, but details are rather soft across the frame. The brick pattern on the house appears soft and slightly blurred in some areas, but detail in other areas is strong.
A fair amount of detail, but rather soft overall.
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 430RS picks up quite a bit of detail, but once again all of it is rather soft. (For what it's worth, it looks like the 430RS has a rather aggressive noise-suppression algorithm that ends up "suppressing" a lot of the fine detail in the image as well.) The bright sunlight on the white paint of the bay window tricks the Optio 430RS, causing it to lose a fair amount of detail in this area. (I probably should have used the 430 RS' low contrast setting for this shot.) 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, but noise is a good bit higher there as well. Overall color looks good, though a bit warm and yellow. The table below shows the standard resolution and quality series, followed by sharpness, contrast, and saturation series.
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 430RS. The Optio 430RS' lens is
equivalent to a 38-113mm 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.
Slight warm cast regardless of white balance setting, but good color overall.
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. The Optio 430RS fell victim to this trap, producing slightly warm casts with each white balance setting. That said, overall color isn't too far off the mark in any of the shots. I found the best results with the Manual setting. Auto and Daylight settings were just a hint warmer. The warm cast produces a greenish cast on the blue robe, which also has very slight purplish tints in the deep shadows (a common problem with this shot). The embroidery of the blue robe has a lot of fine detail, as do the beaded necklaces and flower garland.
The Optio 430RS came in a bit below average in the macro category, capturing a fairly large minimum area of 5.44 x 4.04 inches (138 x 103 millimeters). Resolution is high, with a lot of fine detail in the dollar bill, coins and brooch. Corner softness is more noticeable in this shot, though details are sharper in the center of the image. The Optio 430RS' flash throttles down for the macro area reasonably well, but coverage is uneven this close, with dark corners.
"Davebox" Test Target
Slight color casts with each white balance setting, good color otherwise.
The Optio 430RS' Manual white balance setting
resulted in the most accurate color balance here, though it still showed
a very slight warm cast. The Auto setting resulted
in a greenish cast, while the Daylight setting
had more of a yellow cast. Exposure is bright, causing some flare around
the strongest highlights, particularly noticeable in the small res target.
The camera does pick up the subtle tonal variations of the Q60 target
well though, up to the "B" range. The large color blocks are
a little warm but generally accurate, although the green square looks
a little weak, and the yellow square is a little reddish. Contrast is
high, but the shadow area of the charcoal briquettes holds onto a fair
amount of detail. Image noise is high, however, particularly in the shadow
Sensitive enough for average city street lighting, but strong color casts any darker than that.
The Optio 430RS 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 200 setting, though the dim lighting resulted in a strong magenta cast. At ISO 100, the camera captured bright images only as low as 1/4 foot-candle (2.7 lux), again with a pinkish-purplish color cast. Color is normal, though warm, at the one foot-candle (11 lux) setting. Typical city street lighting equates to about one foot-candle, so the camera can capture darker images, albeit with a strong color cast. (Using the flash might be a better option.) Noise is fairly low at ISO 100, increasing to a moderate level at ISO 200. 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.
Flash Range Test
Bright as far as nine feet from the target.
The Optio 430RS' 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.
ISO-12233 (WG-18) Resolution Test
Strong detail to 1,100 lines/picture height.
The Optio 430RS performed a bit below average for its 4.0-megapixel category on the "laboratory" resolution test chart. It started showing artifacts in the test patterns at resolutions as low as 500 lines per picture height vertically and as low as 400 lines horizontally. I did find "strong detail" out to 1,100 lines, but there were odd "fuzzy" artifacts along the edges of the target elements. "Extinction" of the target patterns occurred at about 1,250 lines.
Optical distortion on the Optio 430RS is higher than average at the wide-angle end, where I measured a 0.91 percent barrel distortion. The telephoto end fared much better, as I measured only 0.02 percent barrel distortion. (Almost undetectable.) Chromatic aberration is high, showing about eight or nine 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.)
Resolution Series, Wide Angle
Viewfinder Accuracy/Flash Uniformity
Slightly tight optical viewfinder and slightly loose LCD monitor.
The Optio 430RS' optical viewfinder is tight, showing about 87 percent of the frame at both wide angle and telephoto lens settings. (Slightly better than the 85% that seems standard on consumer cameras.) Images framed with the optical viewfinder are shifted toward the lower left corner of the frame, with extra space along the top and right sides, something you'd need to get used to and learn to account for in using the camera. The LCD monitor turned out to be just slightly little "loose," as my standard lines of measurement were just outside of the frame in both shots. The LCD monitor is thus very close to 100 percent accuracy, something I like to see in a camera. Flash illumination at wide angle is uneven, with pronounced falloff in the corners of the frame. At telephoto, flash coverage is even, but the low intensity produced a pink cast.
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