DCRP Review: Pentax Optio S4i
by Jeff Keller, DCRP Founder/Editor
Originally posted: June 5, 2004
Last Updated: June 5, 2004

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When discussing ultra-small cameras, the Pentax Optio S-series always comes up. The latest iteration of these popular models is the Optio S4i ($350), which has a 4 Megapixel CCD, 3X zoom lens, and of course, that ultra compact body. The differences between the S4i and its predecessor (the S4) are few. The only major changes I can see between the two models is the larger LCD and included charging cradle on the S4i.

Is the S4i the king of the "micro cameras"? Find out now!

What's in the Box?

The Optio S4i has an average bundle. Inside the box, you'll find:

  • The 4.0 effective Megapixel Pentax Optio S4i camera
  • D-LI8 rechargeable Li-ion battery
  • Battery charging cradle
  • Wrist strap
  • USB cable
  • A/V cable
  • CD-ROM featuring ACDSee software + drivers
  • 136 page camera + PC connection manuals (both printed)

Instead of including a memory card, more and more camera companies are hard-wiring memory right into the camera. The S4i has a paltry 10MB of on-board memory, which won't hold many 4 Megapixel photos. With that in mind, purchasing a memory card is a requirement. The Optio S4i has a slot for Secure Digital cards, which are available as large as 512MB at the moment. I'd suggest 128MB as a minimum size.

The S4i uses the same D-LI8 lithium-ion battery as the Optio S and S4. This battery packs just 2.6 Wh of energy, which is not a whole lot. Pentax estimates that you can take about 180 pictures (with 50% flash use) per charge, or spend 110 minutes in playback mode. These days I'd call that below average.

I'm not a huge fan of proprietary batteries, but they're impossible to avoid on cameras like this. Another one will cost you $40 -- and I do recommend having a spare battery. (Those who like the S4i but want something that uses AA batteries may find the slightly larger Optio S40 to be interesting.)

The Optio S4i has a rather unique battery charger -- it's like a dock, but it's used only for battery charging (as opposed to hooking to a TV or transferring images to your PC). Drop the camera in the dock and the battery will be fully charged in about 100 minutes.

But wait, there's more. You can charge the battery itself, without having the camera in the dock. This is handy for those with extra batteries.

The Optio S4i has a built-in lens cover, so there is no lens cap to worry about. As you can see, this is one small camera!

There are a few accessories available for the S4i. The most interesting of the bunch is the O-WP2 waterproof case (around $200), which lets you take the camera up to 40 m underwater. Other optional items include an AC adapter ($45), remote control ($15), and camera case ($20). Oh, and Pentax is also selling the 3D image viewer ($10) that they once included with the camera.

ACDSee 1.6 for Mac OS X

ACDSee 5.0 for Windows

Pentax includes ACD System's ACDSee for both Mac (v 1.6) and PC (v 5.0). While it's not equal to Photoshop, this is still pretty good software. It runs in both Mac OS X and Mac OS 8/9 environments. There's also a program called ACD PhotoStitcher which assembles panoramic shots for you. It's not Mac OS X native, but runs in Classic.

While complete, the manual included with the Optio isn't what I'd call "user friendly". You'll find what you're looking for, after wading through bullet points and fine print.

Look and Feel

If you've been following digital cameras for the last year or two then you already know about the Optio S-series' design. Compact, mostly-metal, and very stylish. And did I mention that it fits into a tin of Altoids? One thing you need to watch out for on all these metal cameras is that they scratch very easily.

The camera can fit in any pocket and can easily be operated with just one hand. Build quality is good in most areas, which leads to some disappointment when you see the flimsy plastic door over the memory card and battery compartment.

Here's how the S4i compares in terms of size and weight with some of the competition:

Camera Dimensions (W x H x D, excluding protrusions) Volume (bulk) Mass (empty)
Canon PowerShot S410 3.4 x 2.2 x 1.1 in. 8.2 cu in. 185 g
Casio Exilim EX-Z40 3.4 x 2.2 x 0.9 in. 6.7 cu in. 121 g
Konica Minolta DiMAGE Xt 3.5 x 2.6 x 0.8 in. 7.3 cu in. 120 g
Kyocera Finecam SL400R 3.9 x 2.5 x 0.6 in. 5.9 cu in. 125 g
Pentax Optio S4i 3.3 x 2.0 x 0.8 in. 5.3 cu in. 105 g
Pentax Optio S40 3.5 x 2.3 x 1.0 in. 8.1 cu in. 125 g
Sony Cyber-shot DSC-T1 3.6 x 2.4 x 0.8 in. 6.9 cu in. 180 g

As you can see, the S4i takes the crown for both size and weight. I should also point out that the Casio EX-Z40 has a lot in common with the S4i, including the lens.

Let's being our tour of this unique camera now!

The Optio's lens design is is quite a feat of engineering -- especially when you see how far it sticks out when you turn on the camera. This F2.6-F4.8, 3X optical zoom lens has a focal range of 5.8 - 17.4 mm. That's equivalent to 35 - 105 mm. Not surprisingly, there are no lens accessories available for this camera.

To the upper-left of the lens is the built-in flash. The flash has a working range of 0.2 - 3.5 m at wide-angle, and 0.1 - 2.0 at telephoto, which is on the small side.

To the left of the flash is the remote control receiver and self-timer lamp. Below the flash is the microphone. There's no AF-assist lamp on this camera.

The Optio S4i has as larger LCD than its predecessors (1.8 vs. 1.6 inches). Unfortunately, the resolution of the screen is not so hot, with just 85k pixels (compare that with 118k pixels on the PowerShot S410's 1.5" display). Even so, the resolution didn't seem low in actual use, so it's not a huge deal. The screen brightness is not adjustable. In low light, the screen was quite dark, so you may have to resort to the optical viewfinder.

Directly above the LCD is a pretty tiny optical viewfinder. It lacks a diopter correction knob (to focus), but so do most cameras in this class.

To the right of the viewfinder are three buttons followed by the zoom controller. The three buttons have the following functions:

  • Quick (green) mode - puts the camera in a fully automatic mode, with all options locked up
  • Flash (Auto, flash off, flash on, auto w/redeye reduction, flash on w/redeye reduction)
  • Focus (Autofocus, macro, super macro, infinity/landscape, manual focus, focusing area)

Manual focus

I'll cover the macro mode later in the review. The manual focus feature lets you use the four-way controller to set the focus yourself. The camera will put a distance meter on the LCD, and will also enlarge the center of the frame so you can make sure you're properly focused. The focusing area option lets you use the four-way controller to choose the area of the frame that you want the camera to focus on. It's much like Canon's FlexiZone system (though slightly more restrictive), allowing you to choose from 49 different focus points.

To the right of those buttons is the zoom controller. You can go from wide-angle to telephoto in about 1.2 seconds -- fairly quick. I counted seven "steps" across the zoom range.

To the right of the LCD are three additional buttons plus the four-way controller. The buttons (playback mode, menu, and display) should be self-explanatory. The four-way controller is used for menu navigation, plus:

  • Up - Drive (self-timer [10 and 2 secs], continuous shooting [see below], remote control [instant and 3 secs]) {record mode} / DPOF print marking {playback mode}
  • Down - Mode (see below)

The S4i has a single continuous shooting mode. It's pretty slow, taking two photos in two seconds, then pausing to write the images to memory for four seconds before the camera could take another shot.

Pressing down on the four-way controller opens the mode menu, a sort of virtual mode dial. As you can see in the screenshot above, there are a ton of options. These include:

  • Program mode - automatic but with full menu access
  • Night scene - for long exposures
  • Moving picture mode - why they couldn't call this movie mode is beyond me; anyhow, more later
  • Panorama assist mode - helps you line up pictures for later stitching
  • 3D image mode - create 3D pictures; requires the optional 3D image viewer if you want to look at them
  • Landscape
  • Flower
  • Portrait
  • Self-portrait
  • Surf & snow
  • Autumn colors
  • Sunset
  • Museum
  • Text
  • Food
  • Soft focus
  • Posterization - I've reviewed some cameras that seem to do this with every picture!
  • Digital filter (Black and white, sepia, red, pink, violet, blue, green, yellow, slim)
  • User mode - quickly access your favorite camera settings
  • Marine mode - for use with the underwater case

That's a lot of options! I don't know if you caught it, but buried in the digital filter items is a "slim filter" option. You can make yourself thinner... or fatter, if you desire. I should add that this is fairly easy to do in photo editing software as well.

The top of the camera is where you can really get a feel for just how impressive that lens design is. It doesn't look like it can fit inside that body, but it does.

The only things on the top of the camera are the shutter release and power button. Pentax has improved the design of these two buttons since I tested the original Optio S -- it's harder to accidentally press the wrong one.

The power button is also used to enter voice recording mode (by holding it down for two seconds). You can record as much audio as your memory card can hold (16MB holds about an hour). The audio files are saved in WAV format.

Not much to see on this side of the camera, aside from the speaker.

On the other side of the camera are the I/O port, which are under plastic covers. The ports are USB + A/V (one port for both) and DC-in (for optional AC adapter). The USB port uses the old (slow) USB 1.1 standard.

On the bottom of the camera is the battery compartment, memory card slot, plastic tripod mount, and contacts for the battery charger. The battery and memory card slots are covered by a very flimsy plastic door (maybe they'll get it right on the Optio S4ii).

The included D-LI8 battery is shown at right.

Using the Pentax Optio S4i

Record Mode

It takes the S4i about 2.7 seconds to extend the lens and "warm up" before you can start shooting. I've seen faster on similar cameras.

I like all that info, but not how it blocks the subject

The camera focuses fairly quickly, taking about 1/3 second at wide-angle, and 1/2 second at telephoto. The image on the LCD pauses briefly while the camera is focusing. Low light focusing wasn't great, but better than expected from a camera without an AF-assist lamp.

Shutter lag was low, even at the slower shutter speeds at which it often is worse.

Shot-to-shot speed is also good, with a delay of under two seconds between shots, assuming that you've turned off the post-shot review feature. You can delete a photo you just took by pressing the flash/delete photo button.

Now, here's a look at the image size and quality choices available on the Optio S4i. Pentax uses a "star system" to represent image quality.

Resolution Compression # shots on 10MB on-board memory # shots on 16MB card
2304 x 1728 Best (***) 1 3
Better (**) 3 6
Good (*) 6 10

1600 x 1200

Best (***) 5 8
Better (**) 8 14
Good (*) 12 20
1024 x 768 Best (***) 11 18
Better (**) 20 33
Good (*) 26 43
640 x 480 Best (***) 25 40
Better (**) 38 62
Good (*) 51 83

See why I recommend a buying a memory card? To figure out how many photos you can fit on a larger card, just find multiply the numbers for the 16MB card by whatever the ratio is between the 16MB card and the larger card (e.g. 8 for a 128MB card).

There's no TIFF or RAW mode available on this camera. The camera names files as IMGP####.JPG, where # = 0001 - 9999. The camera maintains the numbering even if you erase the card.

The S4i has a fairly attractive and easy to navigate menu system. The options in the record menu are:

  • Recorded pixels (see chart)
  • Quality level (see chart)
  • White balance (Auto, daylight, shade, tungsten, fluorescent, manual)
  • Focusing area (Multiple, spot)
  • AE metering (Multi-segment, center-weighted, spot)
  • Sensitivity (Auto, 50, 100, 200)
  • Exposure compensation (-2EV to +2EV in 1/3EV increments)
  • 3D mode (Parallel, cross) - choose the recording method for 3D images
  • Time-lapse movie (Off, x2, x5, x10, x20, x50, x100) - see below
  • Digital zoom (on/off) - avoid using this whenever possible
  • Instant review (Off, 0.5, 1-5 sec) - post-shot review
  • Memory - the camera will store the selected settings in memory so they aren't lost when you turn off the camera. The available settings include:
    • Flash
    • Drive
    • Focus mode
    • Zoom position
    • Manual focus position
    • White balance
    • AE Metering
    • Sensitivity
    • Exposure compensation
    • Digital zoom
    • Display mode
    • File numbering
  • Sharpness (Soft, normal, hard)
  • Saturation (Low, normal, high)
  • Contrast (Low, normal, high)

The S4i has a manual (custom) white balance mode, which lets you use a white or gray card to get accurate color in any lighting. Aside from manual focus, this is the only manual control on the camera.

The time-lapse movie is a little strange. This lowers the recording frame rate in movie mode so when you play the movie back at normal speed, things appear to "move faster". Thus, a movie shot at the x5 setting will appear to be moving 5 times faster than normal.

In addition to the record menu, there's also a setup menu. The choices in that menu include:

  • Format
  • Sound - adjust the annoying beep sounds
    • Playback volume
    • Operation volume
    • Startup sound (Off, 1-3)
    • Shutter sound (Off, 1-3)
    • Key operation sound (Off, 1-3)
    • Focus sound (Off, 1-3)
    • Self-timer sound (Off, 1-3)
  • Date adjust
  • World time - view the time around the world
  • Language (English, French, German, Spanish, Italian, Russian, Korean, Chinese (x2), Japanese)
  • Start-up screen (on/off)
  • Video out (NTSC, PAL)
  • USB connection mode (PC, PictBridge)
  • Sleep timeout (Off, 30 sec, 1-2 min)
  • Auto power off (Off, 3, 5 min)
  • Custom function (Exposure compensation, recorded pixels, quality level, white balance, focusing area, AE metering, sensitivity, time-lapse movie, instant review, sharpness, saturation, contrast) - define what the left/right directions on the four-way controller do.
  • Quick button (Green mode, capture mode, white balance, memory, resize, trimming, copy image & sound, alarm, format, sound, world time, start-up screen) - another shortcut button
  • Reset

Well enough about menus, let's do photo tests now.

The S4i took a nice picture of our 3" tall macro subject, though perhaps I should've done a longer exposure. Colors are saturated and there camera captured plenty of detail.

There are two macro modes on the S4i: regular and super. In regular macro mode, the focal range is 18 - 50 cm, which isn't that great. To get closer, use super macro mode, which lowers the focal range down to 6 - 20 cm. Do note that the lens is fixed in the middle zoom position in super macro mode.

The night shot did not turn out as well as I would've liked, and for one reason: the camera couldn't take in enough light. The fully automatic S4i chooses the shutter speed for you, and 4 seconds (which was used here) is as slow as you can go. That's enough for some low light shots, but not for all. There was a bit of noise in this shot, as well.

Hopefully you're not surprised with the redeye test results -- tiny camera + flash close to lens = major redeye. You can try to remove this in software.

The distortion test shows a number of things: moderate barrel distortion (at wide-angle), vignetting (dark corners), and some blurry corners as well. While I did not see any vignetting in my real world photos, I did spot blurry corners in several photos.

A blurry corner


Noise destroys the details

Muddy detail

Life is full of compromises. In the case of the Optio S4i, you're trading photo quality for camera size. The photos aren't bad by any means, and will make nice smaller prints and web photos. But if you make big prints or like inspecting photos at 100%, then this camera may not be for you. Why? For one, there's the blurry corners that I mentioned. The camera also has a bit of a noise problem, overprocessing images to the point that they look like watercolors. The noise does all kinds of weird things, most notably eating away at details, as you can see in my samples above.

That's too bad, as color and exposure are quite good, and purple fringing levels are low.

As always, don't just take my word for it -- have a look at the photo gallery and judge the quality for yourself!

Movie Mode

The S4i has an average movie mode. You can record 320 x 240 video with sound at 15 frames/second until the memory card is full. The on-board memory holds a grand total of 53 seconds, so you'll want a memory card to record for longer. Files are saved in AVI format, using the M-JPEG codec.

You cannot use the zoom lens during filming. You can set the zoom before you start, however, assuming that you've installed the 1.01 firmware.

Movies are saved in AVI format.

Here's a sample movie for you. I apologize for the wind noise -- it's always windy here and these cameras with front-mounted mics love to pick up wind noise.

Click to play movie (1.5MB, AVI format)

Can't view it? Download QuickTime.

Playback Mode

The Optio S4i has a nice playback mode. The camera has the basic playback features nailed: slide shows, DPOF print marking, thumbnail mode, voice memos (30 secs), and image protection are all here. The camera is also PictBridge-enabled, for direct printing to compatible photo printers.


The zoom and scroll feature is here too, allow you to zoom in as much as 4X into your photo, and then scroll around. While it's a little slow to start, once you're zoomed in, the scrolling is fast.

Two of the more advanced features include resizing and trimming. You can resize an image to any of the smaller resolutions, and you can change the quality as well. The trimming feature allows you to crop a photo -- the resolution and quality settings are the same as the original image. In both cases, the original image is kept.

You can also copy images from internal memory to a memory card, and vice versa. There is no way to view photos in the internal memory while an SD card is inserted, though.

One more function is buried in the playback menu: an alarm clock. You can set up to three alarms. It's a camera! No, it's al alarm clock! It's both!

The Optio can show plenty of information about your photos -- just press the display button. The camera moves through images extremely quickly -- there's no delay between images.

How Does it Compare?

The Pentax Optio S4i is a camera that's most notable for its size and design rather than its image quality. In terms of design, cameras don't anymore compact and stylish than this one: it just looks cool. The lens design is amazing -- it almost doesn't seem like it can fit inside the body, but it does. The camera also fits in any pocket (or Altoids tin) with ease. The body is generally well built, except for the cheap door covering the memory card and battery compartment. In terms of performance, the camera is average in all respects, with perhaps the exception of image playback. The S4i has a lot of features, especially scene modes, but it's still just a point-and-shoot camera, with no manual control over shutter speed or aperture. I do appreciate the inclusion of manual focus and white balance, though.

Now the bad news: image quality is below average. Images have soft corners, muddy details, and an overall softness that makes things look overprocessed. Not a big deal for small prints, but for large prints and full-size viewing it's disappointing. You can also except some pretty nasty redeye on this tiny camera. The S4i's movie mode is nothing to write home about either. The camera lacks an AF-assist lamp, but it didn't focus as poorly as I expected in low light. Pentax includes a tiny 10MB of onboard RAM, so be prepared to buy an extra memory card.

The Optio S4i is a decent camera, but there are better choices out there, though they won't be as small as this.

What I liked:

  • Ultra-thin design still impressive in 2004
  • Quite a few controls for a point-and-shoot
  • Supports underwater case
  • Histograms in record and playback mode
  • Impressive playback mode
  • Lots of scene modes
  • Cool digital filters, 3D picture mode

What I didn't care for:

  • Photo quality -- noisy, soft, plus blurry corners too
  • Manual shutter speed/aperture controls would be nice
  • Movie mode not so hot in 2004
  • No AF illuminator
  • Redeye
  • No memory card included; paltry 10MB of built-in memory
  • Flimsy door over memory card/battery compartment

Some other ultra-compact cameras worth looking at include the Canon PowerShot S410, Casio Exilim EX-Z40 (quite similar to the S4i), Minolta DiMAGE Xg, Kyocera Finecam SL400R, Nikon Coolpix 4200, Olympus Stylus 410, and the Sony Cyber-shot DSC-T1.

As always, I recommend a trip down to your local reseller to try out the Optio S4i and its competitors before you buy!

Photo Gallery

See how the photo quality stacks up in our photo gallery!

Want another opinion?

Read a review of the Optio S4i over at Steve's Digicams.

Buy it now

Feedback & Discussion

If you have a question about this review, please send them to Jeff. Due to my limited resources, please do not e-mail me asking for a personal recommendation.

To discuss this review with other DCRP readers, please visit our forums.

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