The Olympus Stylus 790 SW is a digital
camera targeted to point-and-shoot photographers and replaces the Stylus 770 SW.
It retains a 7.1 megapixel resolution on a 1/2.33 in.
CCD image sensor, and a 38-114mm (35 mm equivalent)
3x internal optical zoom lens, with an aperture
range of F3.5(W)–F5.0(T).
We find the overall image quality of the Olympus
790 SW to be good with low noise and images retaining most of the details
at ISO 80.
3x Optical Zoom
Range
Wide-angle 6.7mm
[38mm, 35mm equivalent]
Telephoto 20.1mm
[114mm, 35mm equivalent]
The Olympus 790 SW provides 3x optical zoom.
In the above pictures, we show the coverage for
38mm and then 114mm (35mm equivalent).
Besides Programmed AE (P) mode and easy-to-use Scene Modes,
the Olympus 790 SW also has Digital Image Stabilization
(DIS) mode. DIS attempts to reduce blur caused by camera shake and/or subject movement by using a high ISO, which in turn hopefully results in the camera using a high enough shutter speed to negate the camera shake and subject movement.
Digital Image Stabilization
DIS = OFF
DIS = ON
The use of a high ISO results in higher noise in pictures, but sometimes DIS can be useful, as demonstrated by the above two pictures. (The train schedule was posted way up high and I just could not read it so decided to take a picture and enlarge it on the LCD screen.) This is especially true if you intend to produce only small prints and/or use them for Web only display.
The camera also provides exposure compensation
(no Auto Bracketing) and displays previews (Perfect Shot Preview feature) of the resulting effect on the LCD for you to select from. The screen is divided into 4 smaller rectangles and sometimes it can be challenging to tell the difference between them.
Shutter speed ranges from
1/2-1/1,000 sec. in all modes (4 sec. in Night
scene mode). There are no other long shutter speeds.
Super Macro
Super Macro
9.1mm [51.8mm], P, Spot
1/2.5 sec., F4.0, ISO 400
The Olympus 790 SW lens allows you to focus as
close as 7cm (2.8 in.) at wide-angle in Super
Macro mode. AF locks precisely and fast; without an AF Illuminator, AF locks well on subjects with good contrast but subjects with low contrast might
be difficult to get a focus lock in low-light.
Fortunately, there is a LED light that can function as a light source by throwing extra illumination on a close-up subject to facilitate AF lock. There is iESP AF that will focus on subjects that
is not in the center of the frame, but you cannot
manually select the AF Frame you want the camera
to focus at.
White Balance
Indoors
AWB
WB = Tungsten
As the above pictures show, the auto white balance
is not quite accurate indoors under artificial
light [using two ordinary tungsten
bulbs]. There is no Custom/Manual WB, so I select
Tungsten, which is accurate enough. Outdoors,
under natural light, the AWB works very well.
ISO
Comparisons
ISO 80
ISO 100
ISO 200
ISO 400
ISO 800
ISO 1600
You can set the ISO on the Olympus 790 SW from
80 to 1600 (ISO 2500 in Candle and Available Light
scene modes at 2048x1536 pixels only). The 100%
crops above (area delimited by the white square)
demonstrate that images at ISO 80 is quite clean
with low noise. Above ISO 80 and ISO 100, there
seems to be very aggressive noise reduction. At ISO
200 and 400, noise has been reduced but at the expense of image detail; they would be usable in small-sized 4x6
in. prints and for Web display. Above ISO 400,
the presence of noise is quite visible.
[Note: I used flash in the pictures above because the usual low-light ISO shots resulted in severely under-exposed images.]
Chromatic
Aberrations
CA is not a problem in everyday shots. In the
high contrast shot above, the area delimited by
the red square at middle left, and reproduced at
100% crop at bottom right, shows minimal purple
fringing.
Long Shutter
Speed
9.1mm [51.8mm], Night Scene,
Spot, 4 sec., F4.0, ISO Auto (160)
WB=Tungsten, Self-Timer (12 sec.), Tripod
Used, 100% Crop
The Olympus 790 SW allows the use of a long shutter
speed of up to 4 sec. but only in Night scene
mode. Generally, with CCD image sensors, noise
usually becomes more prominent at slow shutter
speeds.
To test this noise reduction algorithm, we take
a low-light indoors shot using the Night scene
mode. Noise reduction seems to work quite well and the AF was able to lock despite the low lighting.
Overall, good image quality for
a 7.1MP digital camera. Despite the availability of high ISOs, the Stylus 790 SW is not a low-light
camera, but for its intended purpose of sunny
beach, boating, and rough outdoors, the Olympus
790 SW can be expected to capture good image detail and colours.
The pictures in the Olympus Stylus 790 SW
Photo Gallery page provide a good sample of
what the camera is capable of. I have provided
samples at 800x600 pixels (compressed to Quality
60/100 in Photoshop Elements) as well as the original
3072×2304 pixels version.
You can safely assume that most macro shots
and slow shutter speed shots required the use
of a tripod. Any image that is adjusted for levels
in Photoshop has "_adjusted" appended
to the file name.
I have defaulted the image size to 800x600 pixels.
For those who have their monitor resolution set
to 1024x728 pixels, everything should snugly fit
and you should not have to scroll to see the whole
image. If your monitor is set to 800x600 pixels
resolution, start the slide show and then scroll
to the right to position the image within your
screen width. Then, press F11 (if you are using
Internet Explorer) to switch to full screen mode,
and the image should fill your screen nicely.
Press F11 again at any time to switch your monitor
display back to normal mode.
To return to this page from the Photo Gallery,
click on the animated graphics of the camera.
Please open and download the original size version
only if you need to and only once
to your hard drive -- and save me some precious
bandwidth. Thanks!
