Digital Cameras - Pentax Optio 450 Test Images
|I've begun including links in our reviews to a Thumber-generated index page for the test shots. The Thumber data includes a host of information on the images, including shutter speed, ISOsetting, compression setting, etc. Rather than clutter the page below with *all*that detail, we're posting the Thumber index so only those interested inthe information need wade through it!|
|Outdoor Portrait: |
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 shoot it with no fill flash or reflector to open the shadows. The object is to hold both highlight and shadow detail without producing a "flat" picture with muddy colors, and the Optio 450 had a little trouble with the high contrast lighting, although its color is very good.
The shot at right was taken with a +0.7 EV exposure compensation adjustment and the contrast set to low. Midtones are still a little dark, and even at this low contrast setting, the highlights are quite bright. I chose the Daylight white balance as the most accurate overall, despite a quite noticeable magenta cast. The Auto setting resulted in a rather greenish look, while the Manual setting was quite warm-toned.
Skin tones look pretty good, although the blue flowers in the bouquet are a little darker than in real life. This is a very difficult blue for many digicams to get right, but the Optio 450 does pretty well with it. For reference, the flowers are actually a light navy blue, with just slight hints of purple in them. The camera handled the strong red and green tones quite well, and color looks very good throughout the rest of the frame. Resolution is very high, with sharp details in Marti's features as well as in the flower bouquet and house siding. Detail is also good in the shadow areas, with low noise.
To view the entire exposure series in the Daylight white balance from zero to +1.0 EV with the low contrast adjustment, see files O45OUTLCDP0.HTM through O45OUTLCDP3.HTM on the thumbnail index page.
Excellent resolution and detail, although again slightly high contrast.
Overall exposure and color balance are similar to the wider shot above, and the Optio 450's 5x zoom lens prevents any distortion of Marti's features in a closeup like this. Detail is stronger and more well-defined in this shot, especially in Marti's face and hair. (Probably more than Marti would like to see full-screen.) The shot at right was taken with a +0.3 EV exposure compensation adjustment. Contrast was again high at the default setting, so I shot with the low contrast adjustment. Shadow detail is excellent, with low noise.
To view the entire exposure series from zero to +0.7 EV, see files O45FACLCAP0.HTM through O45FACLCAP2.HTM on the thumbnail index page.
Indoor Portrait, Flash:
A lot(!) of positive exposure compensation for the best exposure, but good overall color.
The Optio 450's flash drastically underexposed this shot at the default exposure setting, looking almost like the flash hadn't fired at all. I found the best exposure with a +2.0 EV exposure compensation adjustment, which is much higher than average for this shot. The background incandescent lighting results in an orange cast on the back wall, which also spills onto Marti's features and parts of the flower bouquet a little, but overall color is pretty good.
To view the exposure series at zero and from +1.3 to +2.0 EV, see files O45INAFP0.HTM and O45INAFP4.HTM through O45INAFP6.HTM on the thumbnail index page.
Indoor Portrait, No Flash:
Excellent color with both the Auto and Manual white balance settings, but quite a bit of exposure compensation required.
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. Both the Optio 450's Manual and Auto white balance options produced excellent color here, though I preferred the slightly pinkish tone of the Auto setting to the slight green tint of the Manual setting. (The Incandescent setting resulted in a strong warm cast.) Skin tones are very good, although a little pink, but the blue flowers are quite purple. (A common problem with this shot.) The main shot required +1.7 EV exposure compensation, a fair bit more than this shot typically requires. (Here's a shot at the default exposure.)
Slight color casts with each white balance tested, but great detail and resolution.
The Optio 450's Auto and Daylight white balance settings produced pretty similar results here, with slight reddish casts. As I found the Manual setting to be a hint too cool, I chose the Daylight setting for its slightly lesser red cast. Resolution is very high, with practically all the detail to be found in this target visible in the tree limbs and shrubbery. (Cameras like the Optio 450 stretch the limits of this poster, even though it was made from a 500MB scan of a 4x5 negative shot with a tack-sharp lens.) Details are also quite sharp, though the top corners are soft.
Excellent resolution and detail, though slightly high contrast.
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 450 performed very well. (Apologies for the slight tilt in the images!) Detail is excellent in the tree limbs over the roof and in the fine foliage in front of the house, with great definition in the leaf patterns. Details are also sharp throughout the frame, although the top corners of the frame are just slightly soft. (Still, the degree of softening in the corners is much less than I'm accustomed to seeing from digicam lenses on this shot.) The shot is slightly underexposed with the camera's default settings, and the contrast is a little high to boot. The result is that the shadow areas are rather dark, although there's almost no noise present. Even with the underexposure though, I was surprised to see that the camera held onto the detail in the strong highlight on the front of the bay window. Color is about right, although the underexposure makes it a bit more saturated than it might be otherwise. The table below shows a standard resolution and quality series, followed by ISO, sharpness, saturation, and contrast series.
Lens Zoom Range
Excellent 5x zoom range.
I routinely shoot this series of images to show the field of view for each camera, with the lens at full wide angle, at maximum telephoto (5x, in this case), and at full telephoto with the digital zoom enabled. The Optio 450's lens is equivalent to a 37.5-187.5mm zoom on a 35mm camera. That corresponds to a moderate wide angle to a pretty substantial telephoto. Following are the results at each zoom setting. (Apologies again for the slightly tilted images here!)
Slight color casts with each white balance setting, and a slight underexposure, but good resolution.
This shot is often a tough test for digicams, as the abundance of blue in the composition frequently tricks white balance systems into producing a warm color balance. Despite the reddish cast, the Optio 450's Daylight white balance setting produced the best overall color here. The Auto setting fell prey to the problem described above, producing strong warm cast, while the Manual setting was quite cool and blue. The red cast of the Daylight setting creates purple tints in the blue background, as well as in the deep shadows of the blue robe. Skin tones are quite red as well. Resolution is very high, with great detail in the embroidery of the blue robe. The original data file for this poster was only 20MB however, so the Optio 450 can definitely show more detail than the poster has in it.
Really excellent macro performance.
The Optio 450 did really well in the macro category, capturing a very small minimum area of just 1.2 x 1.6 inches (30 x 40 millimeters). Resolution is very high, with great detail in the dollar bill, coins, and brooch. Details are also quite sharp, with only slight softness in the corners. (Of course, the tops of the coins and the brooch are soft, due to the shallow depth of field this close.) Exposure is pretty good as well. The Optio 450's flash had surprisingly little trouble throttling down for the macro area, producing only a slight overexposure.
"Davebox" Test Target
Very slight color casts with each white balance setting, some underexposure though.
Both the Auto and Daylight white balances produced similar, warm color balances, though the Auto setting appeared the least strong. (The Manual setting was a little greenish.) The 450 somewhat underexposed this shot with its default exposure setting, but it distinguishes the subtle tonal variations of the Q60 target well. The large color blocks are dark, with moderate saturation, but the color is fairly accurate. Despite the underexposure, detail is good in the shadow area of the charcoal briquettes, with very low noise.
Pretty good low-light capabilities, sensitive enough for average city street lighting at night and a bit darker.
The Optio 450 has a maximum exposure time of four seconds, and a variable ISO setting, which handle low-lighting fairly well. In my testing, the 450 produced clear, bright, usable images down to the 1/8 foot-candle (1.3 lux) light level, with good color at the 400 ISO setting. (Though just slightly dim, you could arguably use the image taken at the 1/16 foot-candle, 0.67 lux, light level.) At ISO 100 and 200 however, the brightest images were obtained at the 1/4 foot-candle (2.7 lux) light level. Since average city street lighting at night equates to about one foot-candle (11 lux), the Optio 450 should have no trouble handling slightly darker situations. As I noted in some of my other shots, the Optio 450 does an excellent job controlling image noise, as even at ISO 400, noise is only moderate. 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 sample photos) are untouched, exactly as they came from the camera.
Flash Range Test
A tendency to underexpose, but fairly consistent all the way to 14 feet from the test target. (It looks like the camera is boosting its ISO somewhat though.)
In my testing, the Optio 450's flash illuminated the test target all the way out to 14 feet, with only a very slight decrease in intensity. Flash illumination was a bit dim from the start, but maintained a nearly consistent level. - It looks like the camera is "cheating" a little bit, boosting its ISO when shooting with the flash. (My EXIF reader doesn't read the 450's ISO values properly, but the amount of image noise in these shots suggests that they were shot at an ISO of 200 to 400. This practice of surreptitiously boosting ISO to get better flash range has become fairly common with consumer digicams.) Below is the flash range series, with distances from eight to 14 feet from the target.
High resolution, 1,100 lines of "strong detail." Slightly less than average barrel and pincushion distortion.
The Optio 450 performed very well on the "laboratory" resolution test chart. It started showing artifacts in the test patterns at resolutions as low as 800 lines per picture height, in both horizontal and vertical directions. I found "strong detail" out to at least 1,100 lines. "Extinction" of the target patterns didn't occur until about 1,350 lines.
Optical distortion on the Optio 450 is slightly less than average at the wide-angle end, where I measured an approximate 0.6 percent barrel distortion. The telephoto end fared a little better, as I measured a 0.4 percent pincushion distortion. (Overall, this represents a shift of the distortion toward the telephoto end. Most digicams I test show on the order of 0.8% barrel distortion at wide angle, but very little if any pincushion at the telephoto end.) Chromatic aberration is very low, showing only very light color on either side of the target lines in the corners. (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.) I also noticed some corner softness in a few shots, strongest in the top corners of the frame.
Resolution Series, Wide Angle
Resolution Test, Telephoto
Viewfinder Accuracy/Flash Uniformity
A tight optical viewfinder, and nearly accurate LCD monitor.
The Optio 450's optical viewfinder proved quite tight, showing about 78 percent frame accuracy at wide angle, and about 84 percent at telephoto. (Note that images framed with the optical viewfinder are also shifted toward the upper left corner in the final image.) The LCD monitor was much more accurate, showing approximately 98 percent accuracy at wide angle, and about 99 percent at telephoto. Since I generally prefer LCD monitors to be as close to 100 percent accuracy as possible, the Optio 450's LCD monitor performed well here, but I'd really like to see a more accurate optical viewfinder. Flash distribution is uneven at wide angle, with a lot of falloff at the corners and edges of the frame. At telephoto, flash distribution is more uniform, but dimmer.
O450 Sample Pictures
O450 "Picky Details"
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