Minolta DiMAGE A1Minolta updates their revolutionary five-megapixel electronic SLR with faster shutter speeds, an Anti-Shake mode, 14-bit A/D, and a tilting LCD monitor, among other improvements.
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A1 Sample ImagesReview First Posted: 08/08/2003, Updated: 11/10/03
Digital Cameras - Minolta DiMAGE A1 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 DiMAGE A1 performed very well, particularly when I used its contrast-adjustment option.
The shot at right makes use of virtually the full range of image adjustments the A1 offers, including a +1.0 EV exposure compensation adjustment, a -2 unit contrast tweak, and a +1 unit saturation boost. The net of all this is a better-than-average handling of the extreme contrast caused by the harsh lighting of this shot, accurate color, and good saturation. The contrast adjustment does just what you'd want it to, holding down the strong highlights, and pulling up the deepest shadows, making it a very useful adjustment to have. - All in all, one of the better jobs I've seen of handling this very tough shot.
I chose the Daylight white balance as the most accurate overall, though the Auto setting produced similar results. The Manual setting was close, but had a slight reddish tint. Skin tones look good, and the blue flowers in the bouquet are only a little dark, but quite hue-accurate. (This is a very difficult blue for many digicams to get right, but the A1 gets them almost perfect. For reference, the flowers are a fairly pure light navy blue, with just hints of purple in them.) Color looks good throughout the rest of the bouquet as well, and the strong red flowers have good saturation (bordering on being too intense, but holding good shape nonetheless). Resolution is excellent, with a lot of fine detail visible throughout the frame, even in the shadows. Details are also sharp, and image noise the shadows is quite low. An excellent job all around.To view the entire exposure series from zero to +1.7 EV, see files A1OUTAP0.HTM through A1OUTAP5.HTM on the thumbnail index page. (There's also a full series from 0 to +1.3 EV, with the contrast set down to -2 and the saturation up to +1, as A1OUTCM2SP1AP0.HTM - A1OUTCM2SP1AP4.HTM, and a series from 0 to +1.0 EV with the contrast set down to -5 and the saturation up to +2, as A1OUTCM5SP2AP0.HTM - A1OUTCM5SP2AP3.HTM)
To view the entire exposure series at the default contrast and saturation settings, with exposure adjustments from zero to +1.7 EV, see files A1OUTAP0.HTM through A1OUTAP5.HTM on the thumbnail index page. There's also a full series from 0 to +1.3 EV, with the contrast set down to -2 and the saturation up to +1, as A1OUTCM2SP1AP0.HTM - A1OUTCM2SP1AP4.HTM, as well as a series from 0 to +1.0 EV with the contrast set down to -5 and the saturation up to +2, as A1OUTCM5SP2AP0.HTM - A1OUTCM5SP2AP3.HTM
Excellent resolution and detail.
Color and overall exposure are similar to the wider shot above, though this shot was taken with the Auto white balance setting. The A1's 7x zoom lens helps prevent distortion of Marti's features, important in close-up shots like this. Detail is outstanding, with sharp details in Marti's face and hair. (More detail than Marti would probably care to see, I don't show her these ultra closeups 1:1 on the screen. ;-) The shot at right was taken with a +0.3 EV exposure compensation adjustment, which loses some highlight detail, though midtones are bright. I chose not to use the contrast adjustment here, as I didn't care about losing detail in the highlight on the shirt collar, and felt that the range of brightness in Marti's face was OK. Shadow detail is again strong, with only moderate noise.
To view the entire exposure series from -0.3 to +1.0 EV, see files A1FACAM1.HTM through A1FACAP3.HTM on the thumbnail index page.
Indoor Portrait, Flash:
Slightly more than average underexposure with the default settings, but good color and illumination with an exposure boost.
The A1's built-in flash illuminates the subject well, albeit with more than the usual underexposure at the default exposure setting. I obtained the best exposure with a +1.3 EV exposure compensation adjustment, which is slightly more than the +1.0 EV this shot typically requires. Color in the flower bouquet and on Marti's features is pretty good, although the background incandescent lighting results in an orange cast on the back wall (which also spills onto Marti's features slightly). I also shot with the camera's Slow-Sync flash mode, which combines the flash with a longer exposure to allow in more ambient light, to balance the light coming from the flash. The default exposure setting again produced a rather dim image, but this time it took only a +0.3 EV exposure adjustment to produce a good exposure. (Although this shot still looked slightly dark, the +0.7 EV adjustment was a little too bright for my taste.) The orange cast is again present, but overall color isn't too bad. Overall, a good performance, with just a bit more exposure compensation than is typically required.
Indoor Portrait, No Flash:
Very good color with both the Incandescent and Manual white balance settings, good exposure as well.
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 A1's Manual and Incandescent white balance settings produced good results, though I chose the Manual setting as the most accurate overall. The Auto setting had trouble, however, and produced a strong orange cast. Marti's skin tone is pretty good here, though slightly pale. The blue flowers came out quite dark, with faint purple tints, a common problem with this shot. The shot at right has a +1.0 EV exposure compensation adjustment, which is about average for this subject among the cameras I've tested. A good job overall.
Great resolution, detail, and color.
The A1's Manual white balance setting produced the most accurate white value on the house trim, with good overall color as well (just slightly cool). The Auto setting also produced very good results, but the Daylight setting was just a hint warm. Resolution is very high, with good detail in the tree limbs and shrubbery. (The A1's 5.0-megapixel CCD is actually starting to stretch the limits of this poster as a test target, and can likely pick up more detail than the poster has in it.) Details are fairly sharp throughout the frame, without any strong indications of corner softness, though some of the shrubbery appears to be defined more by contrast than in-camera sharpening.
Excellent resolution and detail, though a slightly limited dynamic range.
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 A1 performed very well. The tree limbs over the roof and fine foliage in front of the house show strong detail, with good definition in the leaf patterns. In-camera sharpening does a good job here, as details are sharp, with very little "halo" from the sharpening algorithm. The image is also quite sharp from corner to corner, with very little evidence of softening in the corners, evidence of a very high quality lens. Despite it's slightly high native contrast, the camera picks up pretty good detail in the bright white paint surrounding the bay window, a trouble spot for many digicams. On the flip side though, detail is not quite as strong in the shadow area above the front door, and there's a fair bit of noise there. Overall color looks good, although the image is slightly underexposed and the contrast is a little high. The table below shows a standard resolution and quality series, followed by ISO, sharpness, color, filter, contrast, and RGB series.
The DiMAGE A1 offers a wide range of adjustment options for both color and contrast, with very fine steps along the way. As a result, it gives you an excellent ability to "tweak" its images to suit your own particular tastes. Minolta was something of a pioneer with fine-grained image adjustment like this. While other manufacturers have followed suite to some extent, the DiMAGE A1 offers superior control in this area relative to virtually all of its competitors.
Color Adjustment Series:
Lens Zoom Range
An excellent 7x zoom range, extending to wider angles than most competing models.
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 (7x, in this case), and at full telephoto with the digital zoom enabled. The A1's lens is equivalent to a 28-200mm zoom on a 35mm camera. That corresponds to a wider angle than that offered by most digicams to a pretty good telephoto. Following are the results at each zoom setting.
Color balances shifted slightly toward magenta/purple, but good overall results.
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. The A1's Daylight white balance produced the best overall results here, with pretty good skin tones, though a very slight magenta color balance overall. The Auto and Manual settings were cooler, with more of a magenta/purple tint. The slight magenta cast of the Daylight white balance gives the blue background purplish tints that aren't in the original image. The blue robe also looks purplish in the shadow areas, but isn't bad overall. Resolution is very high, with great detail in the embroidery of the blue robe. (The original data file for this poster was only 20MB though, so cameras like the A1 are definitely capable of showing more detail than the poster has in it.)
Very tiny macro area with great detail.
The A1 performed well in the macro category, capturing a tiny minimum area of only 1.96 x 1.47 inches (50 x 37 millimeters). Resolution is very high, with strong detail in the dollar bill. The coins and brooch are soft due to the very short shooting distance, an optical fact of life at such short shooting distances, and not the fault of the camera. There's some softness in the corners of this shot, mainly in the top left corner of the frame, but not bad when compared to the results produced by most cameras I test. (The soft coins and brooch make it difficult to determine corner softness in the remaining corners.) The A1's flash does a very good job throttling down for the macro area, and exposes the shot evenly (although exposure is just slightly bright). An excellent performance overall, particularly with the flash.
Slight underexposure, but good color.
Both the A1's Auto and Daylight white balance settings produced slightly warm color balances here, but the Manual setting produced a pretty accurate color balance. The target is just slightly underexposed (likely less than the 0.3 EV minimum adjustment though), which helps the A1 easily distinguish the subtle tonal variations of the Q60 target. Colors are about right in the large color blocks, but a little dark from the underexposure. The shadow area of the charcoal briquettes shows a lot of detail, with moderate noise. Overall, a good performance.
Excellent low-light performance with good color and low noise, and a surprisingly sensitive autofocus system.
The DiMAGE A1 offers full manual exposure control, and a maximum exposure time of 30 seconds. It thus does very well under dim lighting, especially given its adjustable ISO and Noise Reduction features. The A1 produced clear, bright, usable images down to the 1/16 foot-candle (0.67 lux) limit of my test, with good color at all four ISO settings. The camera's Noise Reduction feature did a good job of controlling image noise, although noise is still pretty high at the 800 ISO setting. Still, a very good job overall. The A1 doesn't have an autofocus-assist illuminator, but I found its AF system to be surprisingly sensitive, focusing at light levels as low as 1/4 foot-candle (about a quarter of the brightness of a typical city night scene). I did find though, that the AF system sometimes became confused when it was near its low-light limit, indicating focus when it wasn't even close. Fortunately though, in those situations, I could almost always tell that it was out of focus, simply by looking at image in the LCD display. 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.
(Note: If you'd like to use a light meter to check light levels for subjects you might be interested in shooting, a light level of 1 foot-candle corresponds to an exposure of 2 seconds at F/2.8 and ISO 100.)
Flash Range Test
A powerful flash, without any strong falloff at the furthest test distance, but the camera automatically sets its ISO to 200 when the flash is in use.
In my testing, the A1's flash illuminated the test target all the way out to 14 feet, without any significant decrease in intensity, but to achieve that result, it apparently automatically boosts its ISO setting to 200 whenever the flash is in use. This practice is increasingly common with digicams, opting for higher image noise in exchange for greater flash range. Below is the flash range series, with distances from eight to 14 feet from the target.
High resolution, 1,150 lines of "strong detail." High barrel distortion, but low pincushion.
The A1 performed pretty well on our "laboratory" resolution test chart. It started showing artifacts in the test patterns at resolutions as low as 800 lines per picture height vertically, and as low as 600 lines horizontally, but I found "strong detail" out to at last 1,150 lines both vertically and horizontally. "Extinction" of the target patterns occurred around 1,350 lines. One odd note though: For some reason, there were a large number of tiny black specks between the target lines. (These were most visible between the finely-spaced diagonal and horizontal lines, although they were also quite evident between the lines of the hyperbolic resolution wedges.) Given the regular spacing of these artifacts, I have to assume that they somehow result from the A1's image-processing algorithms. I didn't notice these artifacts in any of my "natural" test subjects, perhaps because they only appear to be triggered by very finely spaced, high-contrast detail in the subject.
Optical distortion on the A1 is somewhat high at the wide-angle end, where I measured approximately 1.0 percent barrel distortion. The telephoto end fared much better, as I found only 0.3 percent pincushion distortion there. While the distortion at wide-angle is higher than average, the overall results are quite good for a long-ratio zoom lens, as such lenses generally tend to show much higher distortion levels than lower-ratio zooms. Chromatic aberration is very low, showing only very faint 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 A1's images are also unusually sharp from corner to corner, with very little of the softness in the corners that I've come to expect from digicam lenses. All in all, the A1's lens appears to be of unusually high quality.
Resolution Series, Wide Angle
Resolution Test, Telephoto
Viewfinder Accuracy/Flash Uniformity
Excellent accuracy from the electronic viewfinder.
The A1's electronic "optical" viewfinder (EVF) is very accurate, showing almost exactly 100 percent of the final frame at both wide angle and telephoto zoom settings. The LCD monitor is likewise very accurate, since it shows the same view, just on a larger screen. Given that I like LCD monitors to be as close to 100 percent accuracy as possible, the A1's LCD monitor is essentially perfect in that regard. (The A1's EVF is also nice, in that it works down to unusually low light levels, avoiding a common failing of electronic viewfinders.) Flash distribution is fairly even at wide angle, with just a little falloff at the corners and edges of the frame. At telephoto, flash distribution is more uniform.
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