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Pentax Optio S4 Digital Camera

Camera QuickLook
Review Date 10/31/03
User Level
Novice to experienced amateur
Product Uses
Family / Travel / Special Events
Digicam Design
Manual Control / Point and Shoot
Picture Quality
High, 4.-megapixel CCD
Print Sizes
4x6, 5x7, 8x10, 11x14
Suggested Retail Price


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Sample Pictures

Pentax has found a niche for themselves in the digicam market, specializing in stylish, compact models. The Pentax Optio S4 is the latest such camera, an update from last year's Optio S. Sporting a 4.0 megapixel CCD, the Optio S4 literally fits inside an empty Altoids tin, giving Pentax a competitive edge in the portable digicam market. Pentax has also enhanced the Optio S4 with buffer memory for faster shot to shot speed and minor but welcome interface improvements. Read on for more details, this cool little design just got cooler!

Camera Overview

With an amazingly tiny size (it actually fits inside an Altoids mint tin), the Optio S4 is an exciting example of miniaturization in the digicam marketplace. Measuring a Lilliputian 3.27 x 2.04 x 0.78 inches (83 x 52 x 20 millimeters) and weighing just 3.9 ounces (113 grams) with the battery and SD memory card, the Optio S4 will fit into even the smallest shirt pocket. There's no question this camera is meant to go places, and the retractable lens keeps the camera front flat, making it quick on the draw. A built-in lens cover conveniently slides out of the way whenever the camera is powered on, allowing the lens to telescope outward in a matter of seconds. The 4.0-megapixel CCD (4.23 total megapixels) produces high resolution, print quality images, as well as lower resolution images better suited for email. The camera offers a host of creative features and functions, as well as manual control over focus and white balance (if desired), proof that small size doesn't have to cramp your style.

The Optio S4 has a 3x zoom, 5.8-17.4mm lens, the equivalent of a 35-105mm lens on a 35mm camera, just like its predecessor, the Optio S. The lens is where Pentax made a real innovation with the Optio S, in that its internal elements actually "unstack" as the lens retracts, arranging themselves side by side within the camera body. When the lens telescopes back out again, the optical elements shuffle back into normal alignment. I have to admit that I expected to see some pretty horrific optical trade-offs resulting from such a shoehorned lens design, but the Optio S-family lens is of surprisingly high quality. It loses some sharpness at closer shooting distances and the corners of its images are a little soft, but overall there seem to have been fewer trade-offs made than in many subcompact models I've seen.

The lens' aperture ranges from f/2.6 to f/4.8, depending on the zoom position, and focus ranges from 1.31 feet (0.4 meters) to infinity in normal shooting mode, with a Macro range extending from 7.08 inches to 1.64 feet (0.18 to 0.5 meters). A Super Macro mode gets even closer, focusing from 2.36 to 7.87 inches (0.06 to 0.2 meters) at the middle-zoom lens position. In addition to manual and automatic focus control, the Optio S4 also offers Spot and Multiple AF area modes. Plus, an Adjustable AF mode lets you select the AF area manually using the Multi-Controller. The camera's autofocus system uses a TTL contrast-detection method to determine focus, based on a seven-point area in the center of the frame. A maximum of 4x digital zoom is available in addition to the optical zoom, but keep in mind that digital zoom generally decreases the overall image quality because it simply enlarges the center pixels of the CCD image. To frame shots, the Optio S4 features a very tiny, real-image optical viewfinder as well as a 1.6-inch, color TFT LCD monitor. The optical viewfinder is unfortunately very "tight," showing only about 70% of the final image area, forcing you to use the LCD for even mildly accurate framing. Fortunately, the LCD viewfinder is spot-on 100% accurate. The LCD monitor reports limited camera information, including camera mode, the number of available images, focus mode, date and time, and battery power, among various other mode information. An expanded histogram information display not only puts a small histogram on-screen for checking exposure, but also reports more exposure details, such as white balance, quality and resolution, ISO, and metering mode.

Exposure remains under automatic control, although the Optio S4 does provide a lot of options. Shutter speeds range from 1/2000 to four seconds, but note that longer shutter speeds are only available in the "night" shooting mode. An On/Off button on top of the camera powers the camera on, and the down arrow of the Multi-Controller accesses the camera's Mode menu. The Mode menu appears like a virtual dial, as the left and right arrow keys "turn" the dial to the desired position. Available modes are Program AE, Picture, Night Scene, Movie, Panorama Assist, 3D Image, Digital Filter, and User.

Program mode is the default operating mode, providing access to all of the camera's exposure options, such as Exposure Compensation, White Balance, metering, etc. By default, the Optio S4 uses a Multi-Segmented metering mode, which reads the entire image area to determine exposure. Through the Record menu, Center-Weighted and Spot options are also available. Exposure Compensation is adjustable from -2 to +2 exposure equivalents (EV) in one-third-step increments. An ISO adjustment offers an Auto setting, as well as 50, 100, and 200 equivalent settings. White Balance options include Auto, Daylight, Shade, Tungsten, Fluorescent, and Manual settings. The Optio S4 also features sharpness, saturation, and contrast adjustments.

The remaining modes on the virtual dial are intended for special shooting situations. When the Picture mode is highlighted on the virtual dial, pressing the down arrow key accesses seven presets or "shooting scenes," which include Landscape, Flower, Portrait, Self-Portrait (for holding the camera in front of you), Surf and Snow, Autumn Colors, and Sunset. The camera's separate Night Scene mode allows you to capture bright images in relatively dark settings. Movie mode captures a maximum of 30 seconds of moving images and sound per clip, at 320 x 240 pixels. Through the Record menu, a Fast Forward Movie option slows down the frame rate, so that when movies are played back, the action appears sped up (like time-lapse photography). Speed-up ratios of anywhere from 2x to 100x are available in Fast Forward Movie mode. In Panorama Assist mode, the Optio S4 captures a series of images to be joined together as a single panoramic image on a computer. When this mode is highlighted on the virtual dial, pressing the down arrow lets you select which direction the panoramic series will go in (up, down, left, or right). A semi-transparent display of the previous image in the panoramic series helps you align each subsequent one. 3D Image mode produces three-dimensional images similar to old-fashioned stereographs. The camera captures two images of the same subject (one just slightly off-center from the other) and combines them to achieve a 3D effect. A transparent display of the first image captured remains on the LCD monitor, so that you can align the second image to it. A 3D viewer comes with the Optio S4, and works when viewing 3D images in either Parallel or Cross formats. In Digital Filter mode, the camera offers Color and Slim filter settings. Pressing the down arrow when the Digital Filter icon is highlighted on the virtual dial accesses the available filters. Color filters include black and white, sepia, red, pink, violet, blue, green, and yellow filter effects. The Slim filter lets you "squeeze" your subject in eight steps vertically or horizontally. Finally, the User setting lets you customize a set of camera functions, such as flash mode, white balance, etc., which can be instantly recalled.

The Optio S4 also features a Self-Timer mode that provides a 10-second delay between the time the Shutter button is pressed and when the camera actually takes the picture, allowing you to get into your own shots. A remote control is available as an accessory. For shooting fast action subjects, the camera's Continuous Shooting mode captures a rapid series of images for as long as you hold down the Shutter button, much like a motor drive on a traditional 35mm camera. The amount of available memory space determines the maximum number of images the camera will capture in the series, and details like image size and shutter speed determine the shooting interval. The camera's flash operates in either Auto, Off, On, Auto with Red-Eye Reduction, or On with Red-Eye Reduction modes, and is effective from 7.87 inches to 11.48 feet (0.2 to 3.5 meters) at wide angle with a sensitivity of ISO 200.

If you press the Power switch more than two seconds, the Optio S4 turns into a voice recorder. The lens retracts and the LCD shows remaining recordable time and elapsed recording time. Press the Shutter button to toggle recording through the built-in microphone on the front of the camera. Alternately you can hold the Shutter button down for the duration of the recording. Pressing the Menu button while recording adds an index to the sound file. Sounds are saved as monaural WAV files.

The Optio S4 stores images on SD / MMC memory cards or in its 11 megabytes of internal memory. My evaluation unit came with a 16MB SD card, but the box contents don't list a memory card as part of the standard offering. You should thus plan on purchasing a large-capacity card along with the camera. The camera utilizes a D-LI8 rechargeable lithium-ion battery pack for power, which is included along with the necessary battery charger. Since the Optio S4 does not accommodate AA batteries in any form, I highly recommend picking up an additional battery pack and keeping it freshly charged. The optional AC adapter might also useful for preserving battery power when reviewing and downloading images. A USB cable accompanies the camera for quick connection to a computer, as well as a software CD containing ACDSee software for both Mac and PC platforms.

Basic Features

  • 4.0-megapixel CCD.
  • Real-image optical viewfinder.
  • 1.6-inch color TFT LCD monitor.
  • Glass, 3x, 5.8-17.4mm lens, equivalent to a 35-105mm lens on a 35mm camera.
  • 4x digital zoom.
  • Automatic exposure control, plus a range of preset Scene modes.
  • Shutter speeds from 1/2000 to four seconds.
  • Maximum aperture of f/2.6 to f/4.8, depending on lens zoom position.
  • Built-in flash with five modes.
  • SD/MMC memory card storage, although no card is included in the box.
  • 11 megabytes of internal memory. (So you don't absolutely have to have a card.)
  • Power supplied by one D-LI8 rechargeable lithium-ion battery pack or optional AC adapter.
  • ACDSee software and USB drivers included for both Windows and Mac platforms.

Special Features

  • Movie with sound mode.
  • Voice Recorder mode.
  • Continuous Shooting mode.
  • 3D Image and Panorama Assist modes.
  • Night Scene photography mode, plus seven preset Scene modes.
  • 10-second Self-Timer for delayed shutter release.
  • Remote-Control mode for use with optional remote-control.
  • Adjustable color mode eight color filters and a Slim filter setting.
  • Macro and Super Macro (close-up) lens settings.
  • White balance (color) adjustment with six modes, including a manual adjustment.
  • Image Contrast, Sharpness, and Saturation adjustments.
  • Multi-Segment, Center-Weighted, and Spot metering modes.
  • Sensitivity setting with three ISO equivalents and an Auto setting.
  • Adjustable autofocus area and available manual focus control.
  • DPOF (Digital Print Order Format) compatibility.
  • USB cable for connection to a computer (driver software included).


With its tiny size and multitude of features, the Optio S4 is a great camera for people on the go. Although it operates mainly as a point-and-shoot style digicam, it offers an abundance of color and exposure controls for creative shooting. The 4.0-megapixel CCD delivers high quality images, good for printing or distributing via email. The ultra-compact design makes the Optio S4 an excellent candidate for travel, fitting easily into a shirt pocket or small purse. It's also great for novices who want to have fun with their digital picture-taking, but get good quality images as well, and have a few features to grow into.



The Optio S4 is easily one of the most feature-packed, subcompact cameras ever manufactured. Its sleek, smooth styling is free from any notable protrusions except for the lens, which telescopes outward about an inch when powered on. The camera is so small, it actually fits inside an empty Altoids tin (making for a very inexpensive camera case!). Measuring 3.27 x 2.04 x 0.78 inches (83 x 52 x 20 millimeters), it's well-suited for shirt pockets, hip pockets, and small evening bags. Despite its attractive metal body, the Optio S4 weighs only 3.9 ounces (113 grams) with the battery and SD card. The small size and smooth case design will make it a little difficult for larger hands to hold onto, but an included wrist strap will provide some security if it slips through your fingers. The camera also has textured body panels that help provide some traction for fingers, and an indented thumb rest on the back panel.



The front of the camera features the lens, flash, optical viewfinder window, flash sensor, self-timer lamp, and remote control sensor. There's also a tiny microphone, just under the lens barrel. A shutter-like, retractable lens cover protects the lens whenever the camera is powered off, sliding quickly out of the way when the camera is turned on. The lens then telescopes out from the camera body about an inch. The front of the Optio S4 is flat without any finger grips, so keep the wrist strap securely around your wrist when holding the camera.



On the right side of the camera (when looking from the back) are the DC In and dual-purpose PC/AV connector jacks, each protected by a flexible, rubbery flap that remains tethered to the camera. The metal eyelet for attaching the wrist strap is also on this side of the camera.



The opposite side of the Optio S4 is featureless and smooth.



The camera's top panel is flat with only slight protrusions from the Shutter and Power buttons. An illuminated ring surrounds the Power button, lighting green in Camera mode and Red in Voice Recorder mode. Some reviewers have commented negatively about the position of the power switch on the top panel, feeling that it would be too easy to confuse it with the shutter button. In practice although, I didn't find this to be an issue at all. The power switch is slightly recessed, and takes a deliberate effort to actuate, while the shutter button is raised slightly above the surface of the case. In shooting hundreds of shots, none of us at IR ever had any trouble confusing the power switch with the shutter button. (Well, none of us except newsletter editor Mike Pasini. Used to one button on top, he would at first turn the camera off as he tried to capture an image. But he was eventually able to train himself to feel for the bigger button after turning the camera on to avoid the problem.)



Only a handful of external controls dot the camera's rear panel, along with the optical viewfinder eyepiece and 1.6-inch color LCD monitor. Two LEDs next to the optical viewfinder report the camera's status, such as when focus is set, when the flash is charged, etc. Lining the bottom of the LCD display are the Menu, Display, and Playback buttons. A small Multi-Controller button in the center of the rear panel navigates through settings menus, and accesses the camera's Mode menu via the down arrow. The up arrow accesses the Remote Control, Self-Timer, and DPOF functions. Just above the Multi-Controller are the Flash/Erase and Focus/Protect buttons. The Zoom lever is in the top right corner. Also on the back panel is a small speaker, for playing back audio.

I found one improvement in the control design on the Optio S4 that I personally appreciated. When you're in playback mode, pressing the center of the rocker button on the back of the camera can trigger the camera to record an audio clip to attach to the photo you're currently viewing. Whether just from general ham-handedness or not, with the original Optio S, I found myself occasionally recording an audio clip by accident when I was just trying to scroll through the pictures on the card. On the S4, there's a menu option to disable the voice memo mode, making it easy to avoid this problem.

On the bottom panel of the Optio S4 are the tripod mount and memory card / battery compartment. The plastic, threaded tripod mount is just off-center from the lens because of the camera's small size, but provides a stable mount, centered along the panel. The memory card / battery compartment features a locking door, flexibly hinged with rubber but too close to the tripod mount to allow quick battery changes while working from a tripod. However, I doubt that this will be of much concern to most you, as the Optio S4 is clearly designed for on-the-go shooting rather than tripod work.


Camera Operation

The camera's user interface is very straightforward, with only a fewexternal controls and an easily navigable LCD menu system. For standardpoint-and-shoot operation, the most basic features (such as flash,focus mode, and zoom) all feature external controls. The Mode settingallows you to quickly set the camera's operating mode, using theMulti-Controller. When it is necessary to enter the LCD menu system,you'll find it simple to navigate. Three menus are available,delineated by subject tabs at the top of the screen, with the Playbackand Setup menus available in any mode. The arrow keys of theMulti-Controller scroll through each selection, and the OK button inthe center of the pad confirms any changes. It shouldn't take much morethen half an hour to an hour to become familiar with the basic camerasetup, as it's fairly intuitive.

Record-Mode Display
In Record mode, the LCD monitor optionally displays just the subject,the subject plus a partial information overlay, the subject plus a fullinformation overlay that includes a histogram, or nothing at all (thatis, the LCD may be turned off).

Playback-Mode Display
In playback mode, the LCD display options mirror those in Record mode,but expand to include thumbnail or zoomed views. The LCD can show thecaptured images alone, with a limited information overlay, or with afull overlay that includes a histogram. Pressing the wide-angle side ofthe zoom control takes you to a nine-image thumbnail view of images onthe card, letting you quickly scan through them. Pressing the telephotoend of the zoom control zooms in on the captured image, up to a maximumenlargement of 4x. When zoomed in, you can use the Multi-Controller toscroll around the enlarged display.

External Controls

Power Button
: Placed unobtrusively on the camera's top panel, thisbutton powers the camera on and off. If you press the Play button whilepowering the camera on, the lens does not extend, and the camera comesup in Playback mode. If you hold the Power button down for two secondsat startup, the lens does not extend, and you enter Voice Recorder mode.

Shutter Button
: To the left of the Power button on top of thecamera, this button sets focus and exposure when halfway pressed, andfires the shutter when fully pressed.

Zoom Toggle Button
: Located in the top right corner of the backpanel, this button controls the optical and digital zoom in any recordmode.

In Playback mode, this button controls the digital enlargement ofcaptured images, as well as the index display mode.

In Audio Playback mode, this button serves as the volume control,with the wide-angle side decreasing the volume and the telephoto sideincreasing it.

Focus / Protect Button
: Directly to the left of the zoom togglebutton, this button cycles through the available focus modes: Autofocus(no icon), Macro mode (flower symbol), Super Macro mode (flower symbolwith an "S"), Infinity focus mode (mountain symbol), Manual Focus mode("MF"), and Adjustable AF mode (AF with arrows), which lets you pickthe AF area manually. In Manual Focus mode, a numeric scale indicatesthe current focus setting in meters, but only a few distances aremarked, making it difficult to accurately estimate the focusingdistance you've selected. Also, there's no enlarged display modeavailable to assist you in setting focus visually. Overall, nice tohave a manual focus option, but its implementation leaves something tobe desired.

In Playback mode, this button marks the currently selected image asprotected, or removes protection. ("Protection" simply means that theimage cannot be altered in any way or deleted, except from cardformatting.)

Flash / Erase Button
: Just on the left of the Focus / Protectbutton, this button cycles through the available flash modes in anyrecord mode. Flash modes include Auto, On, Off, Auto/Red-Eye Reduction,and On/Red-Eye Reduction.

In Playback mode, pressing this button displays the Erase menu,which allows you to erase all images on the card or individual images,one at a time. (Press it once and the camera will ask you if you wantto erase the current image, press it a second time and you'll be askedif you want to erase all the images.)

: Right about center in the camera's rear panel,this multi-directional rocker button features four arrows and a center"OK" function. In any settings menu, the arrow keys navigate choicesand the OK button confirms selections.

In Record mode, the up arrow key accesses the Self-Timer, RemoteControl, and Continuous Shooting modes. In Playback mode, this buttonpulls up the DPOF on-screen menu, allowing you to mark individual orall images for printing as well as establish the number of printcopies, crop the image, and activate a time and date stamp.

Also in Record mode, the down arrow displays the Mode menu, withoptions for Program, Picture, Night Scene, Movie, Panorama Assist, 3DImage, Digital Filter, and User modes. In each mode selected, thevirtual dial shows which of the arrow keys are available. For example,when Picture mode is highlighted, the down arrow key is added to thearrow display. Pressing the down arrow again lets you select betweenthe seven available preset scene types (Landscape, Flower, Portrait,Self-Portrait, Surf and Snow, Autumn Colors, and Sunset).

This button is also configurable via a Setup menu option. Bydefault, pressing the right or left arrow directions in Record modechanges the exposure compensation setting. (A handy feature, as this isa very frequently used setting, in my experience.) In the Setup menu(on the third screen of options), you can change the "Fn Setting"selection to let the left/right arrow keys control the resolutionsetting, JPEG quality, white balance, focusing area selection, AEmetering pattern, ISO sensitivity, instant review setting, or FastForward Movie option. Very slick!

Menu Button
: Below the lower left corner of the LCD monitor, thisbutton displays the settings menu in any record mode, as well as inPlayback mode.

Display Button
: To the right of the Menu button, this Displaybutton controls the information and image displays on the LCD monitor.In Record mode, pressing this once calls up a histogram display of thesubject area (a graphical representation of the light and dark valuesin the image), as well as a readout of basic settings such asresolution, quality, white balance, etc. A second press dismisses thehistogram and information display, showing just the image area, and athird press disables the LCD monitor entirely.

In Playback mode, pressing the Display button pulls up the samehistogram and information display, pressing it a second time clears allinformation overlays, showing just the image.

Playback Button
: Beneath the lower right corner of the LCDmonitor, this button puts the camera into Playback mode.

Camera Modes and Menus

Record Mode: In Record mode, the camera can capture stillimages or movie files. The Mode menu (accessed via the down arrow ofthe Multi-Controller) selects between Program, Picture, Night Scene,Movie, Panorama Assist, 3D Image, Digital Filter, and User modes, whichprovide varying levels of control over the exposure.

Playback Mode: This mode lets review captured images on thememory card, erase them, protect them, set them up for printing, addvoice annotations, or play them back in a slide show.

Menus: The following settings menus appear in anycamera mode. However, not all Record functions are available in allRecord modes.

  • Record Mode Settings
    • Recorded Pixels: Sets the image size to 2,304 x 1,728; 1,600 x 1,200; 1,024 x 768; or 640 x 480 pixels.
    • Quality Level: Sets the JPEG compression level to Good, Better, or Best (one star being Good and three stars being Best).
    • White Balance: Adjusts the overall color balance of the scene. Options include Auto, Daylight, Shade, Incandescent, Fluorescent, and Manual. (Manual being a very unusual and welcome option for a subcompact camera like the Optio S4.)
    • Focusing Area: Designates the area of the frame that the camera determines focus from, either Spot or Multiple (seven-point AF).
    • AE Metering: Chooses how the camera determines exposure, choices are Spot, Center-Weighted, and Multi-Segment.
    • Sensitivity: Adjusts the camera's light sensitivity, options are Auto, or 50, 100, or 200 ISO equivalents.

    • Digital Zoom: Turns the 4x digital zoom on and off.
    • Instant Review: Turns the Instant Review function off, or sets the review time on the LCD screen to 0.5, 1, 2, 3, 4, or 5 seconds.
    • Fast Forward Movie: Adjusts the frame rate of Movie mode to create a time-lapse effect. Options are Off, x2, x5, x10, x20, x50, and x100.
    • 3D Mode: Puts the 3D recording mode into Parallel or Cross formats, which dictate how the 3D images will line up for viewing.
    • Memory: Specifies which camera settings are saved when the camera is powered off.
    • Sharpness: Adjusts the overall image sharpness to Normal, or to plus or minus settings.

    • Saturation: Controls the level of color saturation, with three adjustment levels. (An unusual and welcome feature in a subcompact digicam.)
    • Contrast: Adjusts overall image contrast to one of three settings. (Another unusual and welcome feature.)
    • EV Compensation: Lightens or darkens the overall exposure from -2 to +2 EV in one-third-step increments.

  • Playback Settings
    • Copy Image and Sound: Copies files between the built-in memory and the SD card.
    • Resize: Changes the size of captured images to any resolution smaller than the original file.
    • Trimming: Allows you to crop captured images and save a new copy.
    • Alarm: Allows you to set up to three alarms. When the alarm goes off, the camera beeps and you can set a certain image to be displayed.
    • Slide Show: Activates an automatic slide show of images on the card. You can set the image interval time.
    • Record Voice Memo: Lets you toggle the voice recording option during playback on or off.

  • Setup
    • Format: Formats the SD or MMC card, erasing all files (even protected ones).
    • Sound: Controls the volume of the camera's startup, shutter, button operation, and playback sounds.
    • Start-up Screen: Sets what image appears on the LCD monitor when the camera starts up.
    • Date Style: Cycles through available date formats.
    • Date Adjust: Sets the camera's internal date and time.
    • World Time: Allows you to set the time for another city, so that you can display the time in London, for example, on the LCD monitor. A full list of cities is in the manual.

    • Language: Changes the menu language to English, French, German, Spanish, Italian, or Japanese.
    • Video Out: Sets the Video Out signal to NTSC or PAL.
    • Sleep Timeout: Turns the Sleep function off, or sets the camera to go to sleep after 30 seconds, or one or two minutes.
    • Auto Power Off: Turns this feature off, or sets the camera to shut off after three or five minutes of inactivity.
    • Quick Delete: Activates a Quick Delete option, which automatically selects "Delete" on the Delete screen, rather than the "Cancel" option.
    • Quick Zoom: When activated, this function enlarges the captured image to the maximum size with only one press of the Playback Zoom button. (If off, the button gradually enlarges the image.)

    • Fn. Setting: Allows you to select one function to be adjustable by the right and left arrows of the Multi-Controller in Record mode so you don't have to access the menu. The default function to control is Exposure Compensation. Other options include resolution setting, JPEG quality, white balance, focusing area selection, AE metering pattern, ISO sensitivity, instant review setting, or Fast Forward Movie option, sharpness, saturation, contrast, EV compensation.
    • Reset: Resets all camera settings to their defaults.

In the Box

Packaged with the Optio S4 are the following items:

  • D-LI8 rechargeable lithium-ion battery pack.
  • Battery charger with AC plug cord.
  • Video cable.
  • USB cable.
  • Wrist strap.
  • Software CD.
  • 3D image viewer.
  • Operating manual and registration card.

Recommended Accessories

Recommended Software: Rescue your images!
Just as important as an extra memory card is a tool to rescue your images when one of your cards fails at some point in the future. I get a lot of email from readers who've lost photos due to a corrupted memory card. Memory card corruption can happen with any card type and any camera manufacturer, nobodies immune. A surprising number of "lost" images can be recovered with an inexpensive, easy to use piece of software although. Given the amount of email I've gotten on the topic, I now include this paragraph in all my digicam reviews. The program you need is called PhotoRescue, by DataRescue SA. Read our reviewof it if you'd like, but download the program now, so you'llhave it. It doesn't cost a penny until you need it, and even then it'sonly $29, with a money back guarantee. So download PhotoRescuefor Windows or PhotoRescuefor Mac while you're thinking of it. (While you're at it,download the PDF manual and quickstartguide as well.) Stash the file in a safe place and it'll be there whenyou need it. Trust me, needing this is not a matter of if, butwhen... PhotoRescue is about the best and easiest tool forrecovering digital photos I've seen. (Disclosure: IR gets a smallcommission from sales of the product, but I'd highly recommend theprogram even if we didn't.) OK, now back to our regularly scheduledreview...



See camera specifications here.


Picky Details

Cycle times, shutter lag, battery life, etc. can be found here.


User Reviews


Sample Pictures

See the full set of my sample pictures and detailed analysis here. The thumbnails below show a subset of my test images. Click on a thumbnail to see the full-size photo.


Indoor Flash






Viewfinder Accuracy



Test Results

In keeping with my standard test policy, the comments given heresummarize only my key findings. For a fullcommentary on each of the test images, see the Optio S4's "pictures"page.

As with all Imaging Resource product tests, I encourage you to letyour own eyes be the judge of how well the camera performed. Explorethe images on the pictures page, to see howthe Optio S4's images compare to other cameras you may be considering.

  • Color: Very good color, but a tendency to oversaturate strong reds and blues. Capable manual white balance, but trouble with highlights under strongly-colored lighting. Overall, the Optio S4 delivered very good color. It tended toward a slightly warm color balance in many cases, from the harsh outdoor lighting to the more controlled lighting of the studio. Depending on the light source, it was a toss-up between the Auto and Manual white balances. In some cases, the Auto setting appeared more natural, and in others, the Manual. Apart from the tendency toward slightly warm casts, its color was generally hue-accurate, and reasonably well saturated. Bright reds and blues tend to come out slightly oversaturated, while other strong hues are a little undersaturated. Caucasian skin tones came out very well although, and the always-difficult blue flowers in the bouquet in my Outdoor Portrait test were nearly spot-on. The manual white balance setting handled the very difficult household incandescent lighting of the Indoor Portrait very well, but boosting the exposure compensation to produce an acceptably bright image resulted in odd "electric" greenish tinges in highlight areas. On balance although, color rendition was very good.

  • Exposure: Accurate exposure, good dynamic range. The Optio S4 did a good job overall with exposure, even in the high-key Outdoor Portrait. Shadow detail was limited in the darkest areas, but midtone details were fairly strong. On my "Davebox" test, the Optio S4 distinguished the subtle pastel tones on the Q60 target well, although shadow detail in this shot was again limited. The indoor portraits required about average positive exposure compensation (+1.0 EV), although this resulted in slightly odd-looking highlights on Marti's shirt, as noted above.

  • Resolution/Sharpness: Good resolution, 1,150 - 1,200 lines of "strong detail." High barrel distortion at wide angle. The Optio S4 performed fairly well on the "laboratory" resolution test chart. It started showing artifacts in the test patterns at resolutions as low as 600 lines per picture height horizontally, and about 700 lines vertically. I found "strong detail" out to 1,200 lines in the horizontal axis and 1,150 lines vertically. "Extinction" of the target patterns didn't occur until about 1,400 lines.

  • Close-Ups: Excellent performance with the Super Macro mode, standard macro is about average. Flash has trouble up close. The Optio S4 performed surprisingly well in the macro category, capturing a minimum area of only 2.76 x 2.07 inches (70 x 53 millimeters) in the normal macro mode. In Super Macro mode, the minimum area was only 1.66 x 1.24 inches (42 x 32 millimeters). At the normal macro setting, details were soft throughout the frame, with a lot softness in the corners. However, in Super Macro mode, details were sharper, although corner softness was again visible. The camera's flash throttled down for the macro area pretty well, although the brooch reflected the light right back into the lens (not really the camera's fault). - Overall, a surprisingly strong macro performance for a subcompact digicam. - A good choice for photographing very small objects.

  • Night Shots: Pretty good low-light performance for a point-and-shoot digicam, with bright exposures at light levels just under below that of typical city street lighting at night. The Optio S4 operates in Program AE mode at all times, meaning that the camera is always in charge of shutter speed and aperture. With a maximum exposure time of four seconds, the S4 is slightly limited when shooting at night. Still, the camera fared pretty well on my low-light test, capturing bright images down to the 1/4 foot-candle (2.7 lux) light level with good color at the 100 and 200 ISO settings. At ISO 50, images were bright only as low as 1/2 foot-candle (5.5 lux). At the darker light levels, the target was still visible, but the underexposure resulted in a strong magenta/purplish color cast. Since average city street lighting at night corresponds to about one foot-candle (11 lux), the camera should be able to handle slightly darker situations quite well. Noise is low at the 50 and 100 ISO settings, but becomes moderately high at ISO 200.

  • Viewfinder Accuracy: A very tight optical viewfinder, but very accurate LCD. The Optio S4's optical viewfinder is very tight, showing approximately 70 percent frame accuracy at wide angle, and approximately 73 percent at telephoto. The LCD monitor is much more accurate, and actually a hair loose, as the viewfinder shows just a little over 100 percent of the frame. Given that I like LCD monitors to be as close to 100 percent accuracy as possible, the Optio S4's LCD monitor is pretty near perfect, but the optical viewfinder definitely needs some work.

  • Optical Distortion: Higher than average distortion at wide angle, no distortion at telephoto. Some trouble with softness in the corners of images. Low chromatic aberration. Optical distortion on the Optio S4 is higher than average at the wide-angle end, where I measured an approximate 1.0 percent barrel distortion. (Average is about 0.8%, still much too high, IMHO.) The telephoto end fared much better, as I couldn't find even a single pixel of pincushion or barrel distortion. Chromatic aberration is surprisingly low, as there's relatively little color around the target elements. (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.) As noted above, it seemed that the Optio S4's lens tended toward the soft side for relatively close shooting, also showing a fair bit of softness in the corners at distances of 10 feet or less. Shooting more distant subjects outdoors, the images seemed a good bit sharper.

  • Image Noise: Higher than average image noise, but fairly typical for a high-resolution subcompact. It's an unfortunate fact of life that higher resolution and smaller cameras invariably result in higher image noise. The Optio S4 is no exception here, as you'll find image noise levels that are generally about twice as high as those of the best full-sized cameras. (That is, the S4's image noise at ISO 50 is close to that of many full-sized digicams operating at ISO 100.) How you feel about this will depend a lot on how you intend to use the S4's images: If you're mainly interested in prints 5x7 inches in size or smaller, I suspect you won't notice the noise at all. On the other hand, if you're addicted to 8x10 enlargements with significant cropping, you may want to consider a larger camera with lower noise levels. Check my sample pictures, to see for yourself how the Optio S4 performs.

  • Shutter Lag and Cycle Time: Quite good for a subcompact, a 2-frame buffer memory helps greatly. The original Optio S was very slow from shot to shot, but the S4 adds two frames of "buffer" memory, which lets you grab two full-resolution images in a bit under two seconds. (Provided that the image review function is turned off.) Shutter response is also surprisingly fast, only 0.44 seconds with full autofocus and the lens set to its wide-angle position, and 0.81 seconds at telephoto. "Prefocus" shutter response is a astonishingly fast 0.01 seconds.

  • Battery Life: Surprisingly good battery life for a subcompact. Battery life on the Optio S4 is surprisingly good for such a tiny camera. Worst-case life (capture mode with the LCD turned on continuously) is about 93 minutes. With the LCD off, continuous run time stretches to over two hours. Best of all, when the camera is in "sleep" mode, its power drain drops dramatically, to the point that it will run for well over 6 hours. Still, my standard recommendation of purchasing a second battery along with the camera stands.


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As you may have gathered from some of my comments, I was quite impressed with the Optio S4. I've become accustomed to seeing significant compromises in image quality and feature sets, in order to cram cameras into ever-smaller packages. To my great surprise although, first the Optio S and now the S4 seem to have avoided almost all such compromise, delivering very good color and image quality, along with a really surprising level of features and special functions.

Some compromise is evident in the lens design in that it isn't as sharp when shooting at close distances (say, up to 10 feet or so) as it is when shooting at a distance, but the amount of softening at close range isn't too severe, and overall optical performance is quite good when compared to other ultra-compact digicam. (So far, all the ultra-compact digicams I've tested show the same sort of corner softness as does the Optio S4.) One significant improvement relative to the original Optio S is that the S4 now has two frames of buffer memory, dramatically improving cycle time relative to that of the earlier model. About the only significant complaint I had to make about the S4 was its image noise: In common with other subcompact digicam models, the smaller sensor used in the S4 results in more image noise than you'll typically find on a full-sized camera of the same resolution. How you feel about image noise will depend a lot on how you use your photos: If your primary use is to make prints 5x7 inches or smaller, you likely won't notice it. Overall, the Optio S4 is amazingly full-featured for a subcompact model, delivering good color and tone in an incredibly tiny package. If you're looking for the ultimate in a "take anywhere" camera, the Optio S4 could be just what you've been waiting for. Definitely a "Dave's Pick," kudos to the engineers at Pentax!


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Pentax Optio S4, Pentax Digital Cameras, Digital Cameras

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