Digital Cameras - Minolta DiMAGE G400 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!|
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 G400 did a pretty good job, with its contrast adjustment dialed down a notch.
The shot at right was taken with a +1.0 EV exposure compensation adjustment, about average for this shot. Midtones are bright, though at the expense of highlight detail. Contrast is high from the strong lighting, but midtone detail is still good. I chose the Daylight white balance as the most accurate overall, as the Auto setting was actually quite warm.
Marti's skin tones look about right, and the blue flowers in the bouquet are rendered almost perfectly. (Many digicams have trouble with this blue, but the G400 gets it almost exactly right.) The strong red flowers are bright and a little oversaturated, and the greens are a little undersaturated, but the yellows look about right. I'd rate the overall color accuracy as very good though. Resolution is high, and detail is strong in the flower bouquet, as well as in Marti's features and hair. Shadow detail is moderate, although there's some noise there. All in all, a very good performance.
To view the entire exposure series from -0.7 to +1.3 EV, see files G40OUTDM2.HTM
through G40OUTDP4.HTM on the thumbnail index page.
Stronger resolution and detail, but high contrast limits shadow detail.
Overall results are similar to the wider shot above, with high contrast but good color. The G400's 3x optical zoom lens does a good job preventing any strong distortion in this close-up shot, and captures fairly sharp details. The shot at right was taken with a +0.7 EV exposure compensation adjustment, which captures good midtones (although again at the expense of the strongest highlight detail). Detail and resolution are both higher in this shot, although the high contrast limits shadow detail greatly.
To view the entire exposure series from -0.7 to +1.0 EV, see files G40FACDM2.HTM
through G40FACDP3.HTM on the thumbnail index page.
Indoor Portrait, Flash:
A bright flash, with good coverage in its normal mode, and good color.
The G400's built-in flash proved quite bright, almost too bright in its
normal mode. Coverage is pretty even on Marti's
features, though so strong that shadows are harsh on the back wall. Color
is good, however, without any strong tints from the room lighting. I also
shot with the G400's Night Portrait mode, which
employs a longer exposure to allow more ambient light into the image.
Flash coverage is good, though with a lesser intensity. Color balance
is quite warm due to the longer exposure, which allows more of the incandescent
background lighting into the image. Reds are oversaturated (the red roses
look almost electric), and Marti's skin tone is quite orange.
Indoor Portrait, No Flash:
Not a great performance: Color casts with both white balance settings tested, and some underexposure, even with high exposure compensation boosts.
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 G400's Auto and Incandescent white balance settings had a little trouble here, producing slight color casts. The Auto setting had a strong yellow cast, while the Incandescent setting had more of a reddish tint. Since the Incandescent setting had the least cast of the two, I chose it for the main series (I'd consider this right about on the borderline of acceptable coloring for this shot. - It'll look a bit better printed than it does here on-screen.) The shots at right were taken with the ISO set to 200, and the exposure compensation adjusted to +1.3 EV. (At ISO 100, the shot was still quite dim even at a +1.7 EV exposure compensation adjustment.) Marti's skin tones are red from the color cast, and the blue flowers in the bouquet are very dark and purplish (a common problem with this shot, due to the strong color cast of the household incandescent lighting used in it). Image noise is high at ISO 200, though it's only slightly lower at the ISO 100 setting. I also snapped an image with the camera's Night Portrait mode (this time without the flash), which produced a very dark image with a strong yellow cast.
To view the entire exposure series from zero to +1.7 EV, see files G40INI20TP0.HTM
through G40INI20TP5.HTM on the thumbnail index page.
High resolution with strong detail, though high contrast and a warm color cast.
Though slightly warm and yellowish, the G400's Daylight
white balance setting produced the best overall color here, with the most
accurate white value on the house trim. The Auto
setting also resulted in a warm cast, which was slightly more stronger
(though both are actually fairly strong). Resolution is very high, and
detail is strong throughout the frame, especially in the tree limbs above
the roof, front shrubbery, and house brick pattern. Details are fairly
well defined, considering this is a shot of a poster, but the camera's
somewhat contrasty tone curve tends to make detail in some areas look
a bit more crisp than it perhaps actually is. The image is impressively
sharp across the entire frame, with only a little softness in the corners,
mainly noticeable in the lower corners of the frame.
High resolution with strong detail. High contrast means limited dynamic range, but good color.
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
DiMAGE G400 performs well. Detail is strong in the tree limbs over the
roof, as well as the fine foliage in front of the house, with good detail
in the brick pattern also. Details are just slightly soft, though still
quite well defined, and there's relatively little of the softness that
I've come to expect in the corners of digicam images.- The G400's lens
seems to be of unusually good quality. The camera loses most of the detail
in the bright white paint surrounding the bay window, a trouble spot for
many digicams. Detail is also only moderate in the shadow area above the
front door, with fairly high noise. Overall color looks very good with
the both the Auto and Daylight white balances. The table below shows a
standard resolution and quality series, followed by ISO, sharpness, saturation,
contrast, and color series.
Lens Zoom Range
A typical 3x 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 (3x, in this case), and at full telephoto with the digital zoom enabled. The G400's lens is equivalent to a 34-101mm zoom on a 35mm camera. That corresponds to a moderate wide angle to a moderate telephoto. Following are the results at each zoom setting.
Somewhat warm, reddish color balances, but good detail and 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. The G400's Auto and Daylight
white balance settings both produced warm color casts, and it was a bit
of a toss-up choosing between the two. The reddish color cast gives the
blue background purplish tints, and affects the deep shadows of the blue
robe in a similar manner. Skin tones are warmer than in reality, but are
still believable. Resolution is very high, and detail is strong in the
embroidery of the blue robe, as well as in other fine detail areas such
as the instrument strings, beaded necklaces, and flower garland.
A small macro area with good detail in the dollar bill. Flash actually throttles down a bit too much, underexposing slightly.
The G400 performed well in the macro category, capturing a minimum area
of only 2.74 x 2.06 inches (70 x 52 millimeters). Resolution is very high,
and detail is strong in the coins, brooch, and dollar bill. Details are
sharp, with only a little softness in the corners, this latter amounting
to a better performance than I'm accustomed to seeing from mid-range digicams.
Color balance is warm and yellowish from the Auto white balance setting,
but exposure is about right. The G400's flash
throttles down a bit too much for the macro area, underexposing the shot.
(I'm guessing that the flash exposure sensor was fooled by a glint off
a coin or the brooch, so don't hold the underexposure too much against
"Davebox" Test Target
Nearly accurate exposure, but rather warm color balance, limited shadow detail, and high image noise.
Given how well the G400 did on some of my other shots, I was surprised
to see how warm the color balance was on this shot, with both the Auto
and Daylight white balance settings. Because
the Auto setting had the strongest cast, I chose the Daylight setting
for the main shot. Exposure is about right, and the G400 distinguishes
the subtle tonal variations of the Q60 target well. The large color blocks
are warm and yellowish, although saturation is pretty good. The large
red and blue color blocks, are oversaturated a little though. The shadow
area of the charcoal briquettes shows limited detail, with a high noise
Pretty good low-light performance, with good color and exposure down to the lowest light level at the higher ISO settings. Limited low-light autofocus capability though.
The G400 produced clear, bright, usable images down to the 1/16 foot-candle (0.67 lux) limit of my test at the higher (200 and 400) ISO settings. At ISO 100, images were bright as low as 1/8 foot-candle (1.4 lux), and at ISO 50, images were bright only as low as 1/4 foot-candle (2.7 lux). Color balance was good, if slightly warm. Image noise was low (barely perceptible) at the ISO 50 setting, but as always, increased steadily with increasing ISO, becoming quite strong at ISO 400. The biggest weakness of the G400 for low light shooting is its autofocus system. It was a little hard telling what the low light focus limit was, as the camera actually seemed to do better than it "thought" it did. - It would blink its AF-warning icon in the LCD viewfinder at light levels even higher than the 1 foot-candle my test starts at. Despite this, it seemed to achieve accurate focus down to levels below 1 foot-candle. My recommendation though, would be to not rely on it for accurate autofocusing in any sort of dim lighting, instead using one of the fixed-focus settings available in Manual mode. 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 one foot-candle corresponds to a normal exposure of two seconds at f/2.8 and ISO 100.)
Flash Range Test
Limited flash range at ISO 50, good range with Auto ISO setting, but higher image noise as a result. Not too bad overall though.
In my testing, the G400's flash illuminated the test target all the way
out to 14 feet, without any significant decrease in intensity with the
ISO set to its "Auto" position, which boosted it to 200. The
good flash range came at the cost of rather high image noise though. With
the ISO set to 50, noise was lower, but the subject was underexposed even
at the 8 foot minimum distance. Overall though, the results aren't too
bad for a compact camera. Below is the flash range series, with distances
from eight to 14 feet from the target.
High resolution, 1,100 lines of "strong detail." Lower than average barrel distortion, and low pincushion as well.
The G400 performed pretty 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 occurred at between 1,350 and 1,400 lines.
Geometric distortion on the G400 is a bit lower than average at the wide-angle
end, where I measured approximately 0.6 percent barrel distortion. The
telephoto end did better yet, as I measured approximately 0.2 percent
pincushion distortion there. Chromatic aberration is good to moderate,
showing just a few pixels of coloration that ranges from faint to moderately
bright 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.) Corner to corner sharpness is
also a good bit better than average, with less of the softness I've become
so accustomed to seeing in he corners of the frame. Taken together, these
results point to a fairly high quality lens on the G400, consistent with
the results of my other test images.
Resolution Series, Wide Angle
Resolution Test, Telephoto
Viewfinder Accuracy/Flash Uniformity
A tight optical viewfinder, but pretty accurate LCD monitor.
The G400's optical viewfinder is quite tight, showing only about 82 percent of the final image area at both wide angle and telephoto zoom settings. The LCD monitor did much better though, showing approximately 98 percent frame accuracy at both zoom settings. Given that I like LCD monitors to be as close to 100 percent accuracy as possible, the G400's LCD monitor does very well indeed. - But I'd really like to see a more accurate optical viewfinder. Flash distribution is uneven at wide angle, with a fair bit of falloff at the corners and edges of the frame. At telephoto, flash distribution is a little more uniform, but the target is a bit underexposed.
G400 Test Images
G400 "Picky Details"
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