Digital Cameras - Contax TVS 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, ISO setting, compression setting, etc. Rather than clutter the page below with *all* that detail, we're posting the Thumber index so only those interested in the 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 TVS did a pretty good job in that respect.
The shot at right was taken with a +0.3 EV exposure compensation adjustment (less than most cameras require), which resulted in slightly high contrast, though the midtones do show a fair amount of detail. Highlights are quite hot, however. I chose the Daylight white balance for the main series, despite a very slight magenta cast (most noticeable in the white shirt and house siding). The Auto setting produced a warm cast, while the Manual setting resulted in a greenish image.
Marti's skin tone is rather pink from the magenta cast, but the blue flowers in the bouquet are nearly right. (This is a very difficult blue for many digicams to get right, and there's only the slightest trace of a purple tint in places. The TVS does a great job here.) The strong reds and greens also look good, though the brightest areas of the red flowers appear oversaturated. Still, detail is good in the petals.
Resolution is very good, with a lot of fine detail visible throughout the frame, even in the shadows. Sharpness is about average for a five megapixel camera: Not as good as the best I've seen, but still pretty good. Details are also fairly sharp, and image noise the shadows is moderately low.
To view the entire exposure series from zero to +1.0 EV, see files TVSOUTDP0.HTM through TVSOUTDP3.HTM on the thumbnail index page.
Excellent resolution and detail.
Overall results are similar to the wider shot above, and the TVS' 3x zoom lens helps prevent distortion of Marti's features. Detail is very good, with a lot of detail in Marti's face and hair, although the finest elements are again rendered just a little coarsely. The shot at right was taken at the default exposure setting, which produced a moderately well-balanced exposure, albeit with lost detail in the strongest highlights, and somewhat deep shadows. Shadow detail is again strong, with only moderate noise.
To view the entire exposure series from -0.3 to +0.7 EV, see files TVSFACAM1.HTM through F717FACAP2.HTM on the thumbnail index page.
Good intensity and coverage with the built-in flash, excellent color as well.
The TVS' built-in flash illuminates the subject quite well, even at the default exposure setting, though I chose an exposure compensation adjustment of +0.3 EV for the main shot. Coverage is bright and even across Marti's features, and color is well-saturated and generally hue-accurate. The background incandescent lighting results in a orange-pink cast on the back wall, which spills onto Marti's hair and parts of her shirt, but overall color is good. I also shot with the camera's Slow-Sync flash mode, which brightens the image by combining the flash with a longer exposure. The best exposure in this mode was obtained at the default setting. The orange cast is much stronger here, affecting Marti's skin tone quite a bit, though overall lighting is more even.
The shots below show the results of different exposure settings with each of the flash options I tried:
Most accurate color with the Manual white balance setting, and good overall exposure.
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 Auto and Incandescent white balance settings produced nearly identical results here, with warm, reddish casts. - Not as bad as some cameras I've tested, but still a bit too much cast to be considered accurate. However, the Manual setting did a very nice job, with excellent color. Marti's skin tone looks pretty good, but the blue flowers are just a little dark, albeit without any strong purple tints. The best exposure was obtained with a +1.0 EV exposure compensation adjustment (about average for this shot), though the highlights are on the verge of being too bright. (Actually, results weren't too bad at the default setting, just slightly dim.)
To view the entire exposure series from zero to +1.3 EV, see files TVSINMP0.HTM through TVSINMP4.HTM on the thumbnail index page.
Great resolution, detail, and color, though with some softness in the corners.
The TVS' Daylight white balance setting produced the best overall results here, with the most accurate white value on the house trim. The Manual setting was nearly accurate, though the white trim had a slight greenish cast to it, and the Auto setting produced a reddish cast. Resolution is very high, with a lot of fine detail in the tree limbs and shrubbery, as well as in the house details. (In fact, the 5.0-megapixel TVS stretches the limits of this poster as a test target. Even though the poster was made from a 500MB scan of a 4x5 negative shot with a tack-sharp lens, the TVS comes close to extracting all the detail that's to be found here.) Details are reasonably sharp throughout the frame, though softness is present in all four corners (most prominent in the top right corner).
Excellent resolution and detail, with good 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 TVS performed very well. The tree limbs over the roof and fine foliage in front of the house show well-defined, strong detail, with great definition in the leaf patterns and tree bark. Details are a little coarse though, in a way that I'd normally attribute to overzealous in-camera sharpening, but that which here I concluded is due to a lack of sharpness in the image delivered to the sensor. (I base this conclusion on the fact that I could achieve only modest improvements in detail when I played with unsharp masking in Photoshop, starting from a camera image shot with the minimum sharpening setting.) The good news is that the image is equally sharp from corner to corner: If corner softness is present here, it's very faint. The camera also picks up a moderate amount of detail in the bright white paint surrounding the bay window, a trouble spot for many digicams because of the harsh lighting. Detail is also moderately strong in the shadow area above the front door. Overall color looks good too, although the exposure is just a little bright. The table below shows a standard resolution and quality series, followed by ISO, sharpness, 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 TVS' Carl Zeiss lens is equivalent to a 35-105mm zoom on a 35mm camera. That corresponds to an average wide angle to a moderate telephoto. Following are the results at each zoom setting.
Good color with the Manual white balance setting and good detail, although the images are slightly overexposed.
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 TVS' Manual white balance setting did the best job here, though skin tones were just slightly pinkish. All three white balance settings are close to the mark though. The slight red cast of the Manual white balance creates purplish tints in the blue background that aren't in the original image. The blue robe looks nearly right, however, with only a faint trace of a purple tint in the deep shadows. Exposure is a little bright, as the white flowers in the Asian model's hair are washed out, and the highlights of her skin are very light. 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 TVS are definitely capable of showing more detail than the poster has in it.)
A good performance: A small macro area with good detail, color, and resolution.
The TVS did a bit better than average in the macro category, capturing a minimum area of 3.12 x 2.34 inches (79 x 59 millimeters) at its closest shooting distance (7.0 centimeters). Resolution is very high, with strong detail in the dollar bill. The coins and brooch are slightly soft due to the reduced depth of field at such a close shooting range. There's much more softness in the corners in this shot, extending the length of both sides of the frame. (This is a very typical failing of digicam lenses in macro mode, caused by the optical phenomena of curvature of field.) The TVS' flash throttles down fairly well for the macro area, with some falloff in the corners of the frame. (Sorry, I don't know why the flash shot was taken at such a great distance, I'll reshoot and update this section of the page.)
A slightly bright exposure with high contrast, but good color.
The Auto white balance produced good color here, with the most accurate white value in the mini-resolution target and large, white color block. Both the Manual and Daylight settings produced similar images, with warm casts. The TVS slightly overexposed this shot, but still managed to distinguish the subtle tonal variations of the Q60 target well. Colors are bright and vibrant in the large color blocks, verging on oversaturated, although the bright yellow block is actually a bit undersaturated. Though quite dark, detail is actually pretty good in the shadow area of the charcoal briquettes, with low noise, and the last steps of both gray scales are barely distinguishable. A very good performance overall.
Good low-light performance with good color even at the darkest limit of my test, but significant hot-pixel noise.
Although the TVS generally operates under automatic exposure control, it does offer longer exposure times through its Record menu, with a maximum exposure time of eight seconds. Thus, the camera fared pretty well on my low-light test, helped along by its adjustable ISO. The TVS produced clear, bright, usable images down to the 1/16 foot-candle (0.67 lux) limit of my test, at both the 200 and 400 ISO settings. At ISO 100, images were bright as low as 1/8 foot-candle (1.3 lux), and at ISO 80, images were bright as low as 1/4 foot-candle (2.7 lux). The camera's autofocus gives up at considerably brighter light levels however, becoming unreliable somewhere around 1/2 foot-candle. Color was slightly warm with the Auto white balance, but still pretty good overall. Noise was low at the lower ISO settings, but increased to a moderately high level at ISO 400. The grain pattern was brighter and more visible at ISO 400, with multiple white specks from "hot pixels". Still, the TVS did a good job. (See Mike Chaney's Qimage software for a program that can help deal with hot pixel noise.) 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 |
Rather limited flash range, particularly at the telephoto setting.
In my testing, the TVS' flash illuminated the test target best at the eight foot distance, then decreased in intensity from there. This would be consistent with Contax' rating of the unit, which specifies a flash range of a bit under 6 feet (1.8 meters) at the lens' telephoto setting. (About 10 feet at wide angle.) A 10-foot range (3.3 meters) is reasonable, but less than 6 feet is awfully short. Below is the flash range series, with distances from eight to 14 feet from the target.
Very high resolution, 1,200 lines of "strong detail." Average barrel distortion, though no pincushion distortion.
The TVS performed very well on the "laboratory" resolution test chart. It started showing artifacts in the test patterns at resolutions as low as 1,000 lines per picture height, in both horizontal and vertical directions. I found "strong detail" out to at least 1,200 lines, although you could perhaps argue for as high as 1,250 lines. "Extinction" of the target patterns didn't occur until about 1,450 lines.
Optical distortion on the TVS is about average at the wide-angle end, where I measured approximately 0.8 percent barrel distortion. (This is about average among cameras I've tested, but I'd really like to see much less geometric distortion in digicam images than that.) The telephoto end fared much better, as I didn't find so much as a single pixel of pincushion or barrel distortion. Chromatic aberration is low, showing only slight 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
Resolution Test, Telephoto
Viewfinder Accuracy/Flash Uniformity
A slightly tight optical viewfinder, but nearly dead-on LCD monitor.
The TVS' optical viewfinder is only a little tight, showing approximately 86 percent frame accuracy at wide angle, and approximately 84 percent at telephoto. (This is about average among cameras I've tested, but still less accurate than I think adequate.) The LCD monitor proved much more accurate, showing nearly 100 percent at both wide angle and telephoto settings. Given that I like LCD monitors to be as close to 100 percent accuracy as possible, the TVS' LCD monitor does an excellent job here. Flash distribution is fairly even at wide angle, with only a small amount of falloff at the corners of the frame. At telephoto, flash distribution is even more uniform.
TVS Sample Pictures
TVS "Picky Details"
Up to Imaging Resource digital cameras area