A reddish color balance and high contrast, but good resolution in the flower bouquet, and good colors in the flowers.

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 color temperature and main/fill balance here closely match that of summer sunshine here in North Georgia.) The object is to hold both highlight and shadow detail without producing a "flat" picture with muddy colors. The EasyShare DX7440 did pretty well, but its contrast level was pretty high.

The shot at right was taken with a +0.3 EV exposure compensation adjustment. This left the midtones a little dark, but I couldn't go any brighter without totally losing highlight detail. Despite a reddish cast, I chose the Auto white balance setting as the most accurate overall. The Daylight setting was a bit warmer and yellow.

Skin tones are a little red from the overall color cast, and the blue flowers in the bouquet are darker than in real life. (Many digicams have trouble with this blue. The DX7440 gets the hue nearly right, but the tone is a fair bit darker than the flowers actually are.) The strong greens look about right, and the red flowers are pretty accurate, though a little oversaturated. Resolution is high, and detail is strong in the flower bouquet, though shadow detail is limited and image noise is moderately high.

To view the entire exposure series from -0.3 to +1.3 EV, see files 7440OUT2BAM1.HTM through 7440OUT2BAP4.HTM on the thumbnail index page.

Saturation Series:
I forgot to shoot a series showing the effect of the 7440's color saturation adjustment with our new test setup, but here are some examples with the old setting. The saturation control covers a fairly broad range (a bit broader than I'd like actually), but is still within the range of what I'd consider photographically useful.

Saturation Series
Low	Normal	High

Excellent resolution and detail, though again high contrast.

Overall results are similar to the wider shot above, with high contrast. Midtones are slightly dark, and highlights are strong. The shot at right was taken with a +0.3 EV exposure compensation adjustment. The DX7440's 4x zoom lens does a good job of preventing any geometric distortion of Marti's features. Resolution and detail are much higher in Marti's face and hair, with pretty good definition.

To view the entire exposure series from -0.3 to +1.0 EV, see files 7440FAC2BAM1.HTM through 7440FAC2BAP3.HTM on the thumbnail index page.

Normal Flash +0.3 EV

Only slight exposure compensation required to produce very good results. A slightly warm color balance from the strong room lighting.

The DX7440's built-in flash produced a good image at the default exposure setting, though overall results were just a trifle dim. With a +0.3 EV exposure compensation adjustment, the exposure was brighter with good coverage. (At +0.7 EV, the exposure was much too bright.) Overall color is just slightly reddish from the Auto white balance, with a hint of an orange cast on the back wall and on Marti's hair from the Incandescent room lighting.

Auto White Balance

Incandescent White Balance

Generally good color, with only slight color casts with both settings, and 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. The DX7440's Auto white balance setting resulted in a slightly reddish color balance, while the Incandescent setting produced a stronger yellow cast. While neither white balance setting was dead-on, both are within the range of what I'd consider acceptable, and I selected the Auto setting for the main example for this shot. The red cast increases the pink in Marti's skin tones, and makes the blue flowers dark and purplish, but the results overall are quite good when compared to most cameras' auto white balance photos on this test. The shot at right was taken with a +0.7 EV exposure compensation adjustment, a little less than what's required by most cameras.

To view the entire exposure series from zero to +1.0 EV, see files 7440INAP0.HTM through 7440INAP3.HTM on the thumbnail index page.

ISO Series:
Image noise is present but quite low at the 80 and 100 ISO equivalent settings. As the ISO increases, the noise levels remain fairly low, but that's because the camera makes a heavy tradeoff with subtle subject detail to suppress the noise in the final images. The net effect isn't too bad at ISO 200, but the ISO 400 shot looks almost like a watercolor painting in places. - Don't shoot with the DX7440 at ISO settings over 200 if you care about subtle detail in your photos.

Auto White Balance

Daylight White Balance

Good resolution and detail, but not up to the levels of the best 4-megapixel models. Slightly reddish color balance.

Though slightly red overall, the DX7440's Auto white balance setting produced the most accurate overall color, as the Daylight setting had a warmer cast. Resolution is high, with good detail in the tree limbs above the roof and in front shrubbery. The brick pattern also shows good detail, but the image overall isn't quite as sharp as the best (and admittedly considerably more expensive) four-megapixel digicams. Plenty of resolution for sharp 8x10 prints, but true "enthusiast" shooters will probably want to look for a camera that snaps sharper images. Despite the slight softness overall though, details are equally sharp throughout the frame, from corner to corner, something I look for in a digicam.

Limited dynamic range, but good resolution and detail.

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 DX7440 does a great job in that respect. The tree limbs over the roof and fine foliage in front of the house have good detail, with clear definition in the leaves (and in my cameo appearance in the side yard!). Details appear reasonably sharp from corner to corner. Again, while the DX7440's image sharpness isn't quite up to the levels of the best 4 megapixel digicams, it's not too far off the mark, certainly adequate for sharp 8x10 prints. The camera slightly overexposed this image with its default settings, and the combination of minor overexposure with the camera's high native contrast resulted in the loss of essentially all detail in the bright white paint surrounding the bay window, evidence of a limited dynamic range from the bright exposure. The slight overexposure did help detail in the shadows above the door though. There's also some evidence of lens flare in the tree limbs against the sky, but the overexposure there produce visible flare on all but the most elite camera lenses. Overall color looks good with the Auto white balance setting. The table below shows a standard resolution and quality series, followed by ISO, sharpness, saturation, and color series.

Resolution Series:

ISO Series:

Sharpness Series:
This sharpness series below reveals that some of the softness in the DX7440's images may be the result of heavy-handed in-camera sharpening. - Applying strong, tight unsharp masking in Photoshop(tm) to the "Soft" image below results in much better subject detail.

Saturation Series:
A good range of color saturation adjustment.

Saturation Series
Low	Normal	High

Color Series:

Color Series
Black and White	Sepia

Lens Zoom Range

A good 4x 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 (4x, in this case), and at full telephoto with the digital zoom enabled. The DX7440's lens is equivalent to a 33-132mm zoom on a 35mm camera. That corresponds to a range from a fairly wide angle to a moderate telephoto. Following are the results at each zoom setting.

Auto White Balance

Daylight White Balance

A slightly reddish color cast, but great 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. Both the DX7440's Auto and Daylight white balance settings produced reddish color casts, Daylight more so than Auto. Skin tones are a little red, and the blue background has a purple tint (as do the deep shadows of the blue robe), but the overall color with the Auto white balance setting isn't too bad. Resolution is high, and detail is strong in the embroidery of the blue robe, as well as in the beaded necklaces, flower garland, and other areas of fine detail.

Standard Macro Shot

Macro Shot with Flash

An average size macro area, with some softness in the corners but overall good detail. A slight reddish color balance with the photoflood lighting, and the flash is tricked by the shiny coins.

The DX7440 turned in about an average performance in the macro category, capturing a minimum area of 2.99 x 2.24 inches (76 x 57 millimeters). Resolution was high, with clear, sharp details in the brooch, coins, and dollar bill. As with the macro modes of most digicams I test, there was some softness in each of the four corners, but it didn't extend very far into the frame. Color balance was pinkish with the Auto white balance setting, but exposure was good. Undoubtedly tricked by the reflections from the coins and the brooch, the DX7440's flash throttled down a little too much for the macro area, producing a dim exposure. (With less reflective subjects though, the DX7440's flash should work well for macro shooting.)

Auto White Balance

Daylight White Balance

Auto WB, Low Saturation

Correct exposure but high contrast. A slightly warm color balance and high saturation. (The "Low Saturation" option is actually very close to accurate.)

The DX7440's Auto white balance setting produced a warm color balance here, though overall results were better than the stronger red cast of the Daylight setting. Exposure is about right, although contrast is high, yet the camera distinguishes the subtle tonal variations of the Q60 target fairly well. Colors are generally hue-accurate, but pretty oversaturated. (My results from Imatest show an average saturation of 120%, quite a bit higher than usual.) Shadow detail is minimal in the charcoal briquettes, with high image noise. Most consumers tend to like highly saturated color, so the DX7440's images may in fact appeal to the average user. To its great credit though, while the DX7440 really pumps up bright colors, it seems to be much more careful with pastels, particularly Caucasian skin tones. Another positive note is that the DX7440's "low saturation" setting actually produces very accurate color, good for users more interested in accurate reproduction than snappy-looking photos.

The results in the tests below mirror those seen above in other test shots. The test series are repeated here without further comment, for the benefit of our more quantitatively-oriented readers.

ISO Series:

Saturation Series:

Saturation Series
Low	Normal	High

Color Series:

Color Series
Black and White	Sepia

Low-Light Tests

Excellent low-light performance, with good color and exposure in almost total darkness. Very good low-light focusing as well.

With a maximum exposure time of 64 seconds and full manual exposure control, the DX7440 is well-suited for low-light shooting. The camera 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. Noise was very low at the 80 and 100 ISO settings, and only increased to a moderate level at ISO 200. Even at ISO 400, image noise is lower than I'd expect, but as we saw earlier, the way the DX7440 achieves its low noise levels at high ISO settings is by trading away a lot of subtle subject detail. 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 our 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.)

	1 fc 11 lux	1/2 fc 5.5 lux	1/4 fc 2.7 lux	1/8 fc 1.3 lux	1/16 fc 0.67 lux
ISO 80	3 sec f3.4	6 sec f2.8	12 sec f2.8	32 sec f2.8	64 sec f2.8
ISO 100	2 sec f2.8	4 sec f2.8	12 sec f2.8	24 sec f2.8	48 sec f2.8
ISO 200	1 sec f2.8	2 sec f2.8	6 sec f2.8	12 sec f2.8	24 sec f2.8
ISO 400	1/2 sec f2.8	1 sec f2.8	3 sec f2.8	6 sec f2.8	12 sec f2.8

Flash Range Test

A low-intensity flash, with significant falloff beyond 8 feet or so.

In my testing, the DX7440's flash illuminated the test target all the way out to 14 feet, although its intensity dropped markedly from 8 feet on out. Flash power remained bright to about nine feet, but fell off significantly as the distance increased. Below is the flash range series, with distances from eight to 14 feet from the target.

8 ft	9 ft	10 ft	11 ft	12 ft	13 ft	14 ft
1/125 sec f4.8 ISO 80	1/125 sec f4.8 ISO 80	1/125 sec f4.8 ISO 80	1/125 sec f4.8 ISO 80	1/125 sec f4.8 ISO 80	1/125 sec f4.8 ISO 80	1/125 sec f4.8 ISO 80

ISO-12233 (WG-18) Resolution Test

High resolution, 1,150 lines of "strong detail." Lower than average barrel distortion.

The DX7440 performed 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 1,150, arguably 1,200, lines. "Extinction" of the target patterns didn't occur until about 1,400 lines.

Looking at this target with Imatest, the results were a little confounded by the 7440's high contrast and strong in-camera sharpening, which caused the images to saturate on both ends of the tonal scale. Bottom line, though, the uncorrected average resolution using the "MTF 50" criteria was 1187 LW/PH, dropping to 904 LW/PH when corrected to match the edge profile of a standard 1-pixel radius sharpening.

Optical distortion on the DX7440 is very low at the wide-angle end, where I measured only 0.2 percent barrel distortion. The telephoto end fared about the same, also with an 0.2 percent barrel distortion. Both numbers are quite a bit lower than average. Chromatic aberration is very low, showing at most about four pixels of 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.) Finally, the DX7440's lens seems to hold sharpness very well out into the corners, with less of the softness there that I'm accustomed to seeing in digicam images.

Resolution Series, 50mm

Wide Angle	"Fine" JPEG	"Normal" JPEG
2,304 x 1,728	7440RES2304F	7440RES2304N
2,048 x 1,536	7440RES2048	-
1,656 x 1,242	7440RES1656	-
1,200 x 900	7440RES1200	-

 

Resolution Test, Zoom Series

Sharpness Series

Sharpness Series
Soft	Normal	Sharp