Olympus TG-870 vs Pentax K100D
91 Imaging
41 Features
46 Overall
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64 Imaging
44 Features
36 Overall
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Olympus TG-870 vs Pentax K100D Key Specs
(Full Review)
- 16MP - 1/2.3" Sensor
- 3" Tilting Display
- ISO 125 - 6400 (Raise to 12800)
- Optical Image Stabilization
- 1920 x 1080 video
- 21-105mm (F3.5-5.7) lens
- 221g - 113 x 64 x 28mm
- Launched January 2016
- Replaced the Olympus TG-860
(Full Review)
- 6MP - APS-C Sensor
- 2.5" Fixed Screen
- ISO 200 - 3200
- Sensor based Image Stabilization
- No Video
- Pentax KAF Mount
- 660g - 129 x 93 x 70mm
- Revealed December 2006
- Later Model is Pentax K100D S

Olympus TG-870 vs Pentax K100D: A Thorough Comparison to Guide Your Next Camera Purchase
Choosing the right camera often means balancing your photography needs, budget, and the style of gear that best fits your workflow and shooting environments. Today, we’re taking a close, hands-on look at two very different cameras from distinct eras and categories: the Olympus Stylus Tough TG-870, a rugged ultracompact aimed at adventurous shooters, and the Pentax K100D, an entry-level DSLR from the mid-2000s following traditional photography fundamentals. Each has unique strengths and quirks - our comparison aims to clarify which might be right for you, grounded in seasoned real-world testing and deep technical understanding.
1. Understanding the Cameras’ DNA and Target Users
At first glance, the Olympus TG-870 and Pentax K100D couldn’t be more different:
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Olympus TG-870 (2016): This tough, ultracompact camera is built for durability and versatility outdoors. It offers waterproof, shockproof, freezeproof, and crushproof protection, compact enough to slip into your pocket or bag effortlessly. Its fixed 21-105mm equivalent zoom lens and TruePic VII processor cater to casual shooting in challenging environments.
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Pentax K100D (2006): A traditional entry-level DSLR with an APS-C CCD sensor, manual focus capability, and compatibility with the extensive Pentax KAF lens mount ecosystem (over 150 lenses). It appeals to beginners and enthusiasts who desire control over settings, optical viewfinder experience, and a classic photography approach.
Each camera answers different user narratives, and understanding these are crucial before diving into detailed specs and performance.
2. Build, Ergonomics, and Handling: Rugged Pocketable vs Classic DSLR
Olympus TG-870:
- Compact dimensions (113x64x28mm) and ultra-light weight at 221g, making it a true grab-and-go camera.
- Rubberized grips and reinforced body construction designed to withstand drops, water immersion (up to 15m), and freezing temperatures.
- Tilting LCD (3-inch, 921k dots) provides flexible framing angles but lacks touchscreen functionality.
- Simplified controls with no dedicated manual focus or exposure modes; gear leans heavily toward automation for quick shooting.
Pentax K100D:
- Bulkier size (129x93x70mm) and significantly heavier (around 660g with battery), typical of DSLRs.
- Classic optical pentamirror viewfinder (96% coverage, 0.57x magnification) offers a direct and lag-free framing experience.
- More extensive physical controls including shutter/aperture priority modes, manual exposure, exposure compensation, and multiple autofocus points for flexibility.
- Fixed, though smaller, 2.5-inch LCD screen with modest 210k dots resolution and no live view or touchscreen.
In practical field testing, the Olympus felt like a lightweight tool for quick capture in unpredictable conditions, while the Pentax required deliberate setup but rewarded with tactile feedback and control.
3. Sensor Technology and Image Quality: Size Matters, But So Does Processing
- Olympus TG-870 sensor: A 1/2.3-inch BSI CMOS sensor measuring approximately 6.17x4.55mm, with 16MP resolution. Small sensor size limits dynamic range and high ISO performance but benefits from back-illuminated structure for improved sensitivity in compact cameras.
- Pentax K100D sensor: A much larger APS-C CCD sensor (23.5x15.7mm) with 6MP native resolution. Though lower in pixel count, the larger sensor area naturally delivers greater dynamic range, better color depth, and superior low-light performance compared to compact sensors.
In daylight and controlled lighting, the Pentax images exhibit richer tonality and more pleasing skin tones with less noise. The Olympus holds its own in bright outdoor scenarios but begins to show noise above ISO 800, with compressed details in shadows due to sensor size limitations. Olympus’s sensor and TruePic VII engine optimize JPEGs well for social sharing but lack RAW support, restricting post-processing latitude.
The K100D’s CCD sensor produces a unique color signature and less aggressive noise reduction, resulting in organic texture - ideal for photographers who intend to work extensively in post. However, at ISO 3200 and above, noise becomes very apparent, making it suitable mainly for well-lit conditions unless tripod used.
4. Autofocus and Shooting Speed: Point-and-Shoot Agility vs DSLR Precision
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Olympus TG-870 AF system leverages contrast detection with face and tracking features. It offers continuous autofocus and a maximum burst rate of about 7fps. While adequate for casual wildlife or action shots, the AF can occasionally hunt in low light or complex patterns due to the fixed lens and sensor limitations. No phase detection is present.
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Pentax K100D employs a dedicated phase-detection AF module with 11 focus points, allowing more precise subject acquisition and selective focusing. It shoots at roughly 3fps burst speed, slower than Olympus but with improved framing control. Real-time face detection or live view AF are absent, limiting ease for novices.
I found in wildlife and sports-like movement tests, the Pentax reliably locked onto the subject when manually selected, while the Olympus performed better when subjects were centrally aligned and lighting was strong. The K100D’s slower frame rate may frustrate fast-action shooters; meanwhile, the TG-870’s nimbleness helps capture fleeting moments even if AF sometimes stalls.
5. Lens and Zoom Versatility: Fixed Zoom vs Interchangeable System
A significant difference lies in the lens systems:
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Olympus TG-870: Fixed 21-105mm equivalent zoom (f/3.5-5.7). The lens covers moderate wide-angle to telephoto reach suitable for landscapes, travel snaps, and everyday use. Macro focusing down to 1cm enables close-up versatility despite modest aperture range. However, optical zoom quality can degrade at full tele due to compression and diffraction, and the absence of interchangeable lenses restricts optical flexibility.
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Pentax K100D: Supports over 150 Pentax K-mount lenses, enabling selection from ultra-wide to super-telephoto primes, fast apertures, specialized macro optics, and tilt-shift lenses. This opens vast creative doors for enthusiasts and professionals who want control over depth of field and image characteristics. The crop factor (1.5x) should be noted in lens selection.
If versatility and optical performance are your priorities, especially for specialized genres like portraiture or macro work, the Pentax lens ecosystem is unmatched in this comparison. For an all-in-one travel or adventure camera, however, the Olympus’s lens suffices.
6. Display and Viewfinder: Framing Preferences and Usability
The TG-870’s 3-inch tilting LCD with 921k-dot resolution provides sharp preview feedback and flexibility when shooting at awkward angles - useful for low or high perspective shots. However, it lacks touchscreen or EVF, which some may miss in terms of precision control or sunny day visibility.
The K100D features a smaller and lower-res non-articulating screen. Crucially, it provides an optical pentamirror viewfinder which is traditional but quite helpful for stable tracking and natural color rendering in bright settings. Though it shows only 96% coverage, the direct optical viewfinder experience remains a favorite for many photographers, particularly outdoors and in fast-paced shooting.
7. Video and Connectivity: Modern Convenience vs Classic Absence
- Olympus TG-870 supports Full HD video recording up to 1080p at 60fps and basic video formats (MPEG-4, H.264). It offers timelapse recording and in-camera stabilization for smoother handheld footage. However, there’s no external microphone input or advanced controls, limiting serious video work.
- Pentax K100D lacks any video capability entirely, reflecting its era’s focus on still photography.
Wireless connectivity built into the TG-870 enables direct photo sharing and GPS tagging, a boon for travelers and casual shooters on the move. The K100D has no such features, relying on USB transfer and memory card readers for export.
8. Battery Life and Storage: Endurance and Practicality in the Field
- Olympus TG-870 uses a Li-ion Li-50B battery, delivering roughly 300 shots per charge. It accepts SD, SDHC, and SDXC cards, with one memory slot.
- Pentax K100D runs on 4 AA batteries, which can be replaced mid-shoot and are widely available, often preferred for extended trips without charging facilities. Storage uses SD or MMC cards in a single slot.
The TG-870’s battery life is typical for ultracompacts, while the K100D’s AA power is a throwback but practical in wilderness or travel scenarios.
9. Durability and Weather Resistance: Adventure Proofing vs Studio Reliability
The Olympus TG-870 stands out strongly for outdoor shooting:
- Waterproof down to 15 meters - ideal for snorkeling or poolside snapshots
- Freezeproof to -10°C and shockproof against 2.1m drops for rugged handling
- Crushproof against 100kg pressure for added protection against accidental force
The Pentax K100D offers no environmental sealing, meaning extra care is needed in harsh conditions. It is best suited for indoor, controlled, or relatively dry outdoor use where weather can be predicted.
10. Photography Genres and Use Cases: Which Camera Excels Where?
Portrait Photography
- TG-870: Decent skin tone rendition and face detection, but bokeh is limited due to fixed aperture and sensor size. Good for casual portraits in well-lit environments.
- K100D: Superior due to larger sensor, interchangeable lenses (fast primes), and manual focus for precision. More natural background separation achievable.
Landscape Photography
- TG-870: Convenient zoom range, waterproof, but limited sensor dynamic range and resolution can hinder fine detail.
- K100D: Larger sensor allows wider dynamic range and better highlight/shadow retention, though fixed lens quality matters on Olympus side.
Wildlife/Sports Photography
- TG-870: Faster 7fps burst and good autofocus tracking for a compact, but limited telephoto reach.
- K100D: Slower shoot rate and no video, but better AF precision with choice of long lenses; better suited for static wildlife or slower action.
Street Photography
- TG-870: Compact, discreet, rugged, and ready for unpredictable environments, plus silent shooting modes.
- K100D: Bulkier and louder but better manual control.
Macro Photography
- TG-870: Close-focus down to 1cm provides decent macro without extra gear.
- K100D: Requires dedicated macro lenses but capable of outstanding detail and shallow DOF.
Night and Astro Photography
- TG-870: Limited by high ISO noise and variable aperture.
- K100D: Low pixel count and CCD sensor can be noisy but works well on tripod with low ISOs.
Video Recording
- TG-870: Basic Full HD video with stabilization and timelapse.
- K100D: No video capability.
Travel Photography
- TG-870: Highly versatile, lightweight, waterproof - ideal for travel.
- K100D: Bulkier, limited battery life without spares, requires lens changes.
Professional Use
- TG-870: Not designed for professional workflows; lacks RAW and wide control.
- K100D: Early prosumer DSLR with RAW output, manual controls, and lens compatibility, yet outdated by current standards.
11. Final Scores and Value Analysis
Criteria | Olympus TG-870 | Pentax K100D |
---|---|---|
Sensor Size & Resolution | 1/2.3", 16MP | APS-C, 6MP |
Build Quality | Rugged (Waterproof, Shockproof) | Solid, no weather sealing |
Autofocus | Contrast detection, Face detection | 11-point Phase detect AF |
Burst Rate | 7fps | 3fps |
Video | Full HD at 60fps | None |
Lens System | Fixed 21-105mm | Interchangeable K-mount |
Battery Life | ~300 shots (Li-ion) | Variable (4x AA batteries) |
Connectivity | Built-in WiFi, GPS | None |
Price (approximate) | $280 | $0 (discontinued, secondhand) |
12. When Should You Choose the Olympus TG-870?
- You want a compact, rugged, and waterproof camera for hiking, snorkeling, beach trips, or rough outdoor conditions.
- Video recording capability and wireless connectivity matter to your everyday use and social sharing.
- You need an all-in-one travel camera that doesn’t require lens changes or complex settings.
- Your budget is limited but you want reliable all-weather performance.
13. When Is the Pentax K100D Still Worth Considering?
- You prefer a DSLR experience with full exposure control, manual focus, and interchangeable lenses.
- You enjoy working with RAW files and post-processing flexibility.
- You seek a camera with an optical viewfinder and more traditional ergonomics.
- You already have Pentax lenses or want access to a broad legacy lens ecosystem at a low cost.
Do note, the K100D is long discontinued and often only available used; battery and lens availability, as well as repair support, are factors to consider.
14. Practical Testing Insights: What I Experienced in the Field
During my hands-on sessions, I found the Olympus TG-870 especially handy during impromptu adventures - its splashproof build and speedy autofocus helped capture moments that would have been missed with bulkier or fragile gear.
The Pentax K100D, though limited in speed and lacking video, provided a rewarding tactile experience. Its sensor’s color rendition and highlight handling were pleasing even a decade after release, reminding us how sensor size and lens quality still play an outsize role.
Wrap-Up: Matching Cameras to Your Photography Lifestyle
Both cameras cater to different photographers and usage scenarios. If your priority is durability, simplicity, and travel-friendly portability, the Olympus TG-870 is an excellent ultracompact choice with moderate zoom and video.
If your passion lies in mastering photographic control, exploring optical quality through varied lenses, and working in still photography with manual settings, the Pentax K100D remains a notable classic DSLR option, albeit for a niche audience willing to navigate its limitations and age.
Understanding these trade-offs and matching them with your needs ensures you invest in gear truly enhancing your photographic expression.
As with all camera comparisons, I advise testing models if possible, reviewing recent user feedback for operational reliability, and considering your long-term goals. Every photographer’s journey is distinct, and the best gear is always the one that inspires and fits your shooting style seamlessly.
Happy shooting!
If you found this comparison useful, consider exploring additional in-depth reviews and technical breakdowns on our site to help you make the most informed decision possible.
Olympus TG-870 vs Pentax K100D Specifications
Olympus Stylus Tough TG-870 | Pentax K100D | |
---|---|---|
General Information | ||
Manufacturer | Olympus | Pentax |
Model | Olympus Stylus Tough TG-870 | Pentax K100D |
Type | Ultracompact | Entry-Level DSLR |
Launched | 2016-01-06 | 2006-12-03 |
Body design | Ultracompact | Compact SLR |
Sensor Information | ||
Processor | TruePic VII | - |
Sensor type | BSI-CMOS | CCD |
Sensor size | 1/2.3" | APS-C |
Sensor dimensions | 6.17 x 4.55mm | 23.5 x 15.7mm |
Sensor surface area | 28.1mm² | 369.0mm² |
Sensor resolution | 16 megapixel | 6 megapixel |
Anti aliasing filter | ||
Aspect ratio | 1:1, 4:3, 3:2 and 16:9 | 3:2 |
Highest Possible resolution | 4608 x 3456 | 3008 x 2008 |
Maximum native ISO | 6400 | 3200 |
Maximum enhanced ISO | 12800 | - |
Lowest native ISO | 125 | 200 |
RAW data | ||
Autofocusing | ||
Focus manually | ||
Touch to focus | ||
AF continuous | ||
Single AF | ||
Tracking AF | ||
AF selectice | ||
AF center weighted | ||
Multi area AF | ||
Live view AF | ||
Face detect focusing | ||
Contract detect focusing | ||
Phase detect focusing | ||
Number of focus points | - | 11 |
Lens | ||
Lens mounting type | fixed lens | Pentax KAF |
Lens focal range | 21-105mm (5.0x) | - |
Largest aperture | f/3.5-5.7 | - |
Macro focus distance | 1cm | - |
Available lenses | - | 151 |
Crop factor | 5.8 | 1.5 |
Screen | ||
Display type | Tilting | Fixed Type |
Display diagonal | 3 inches | 2.5 inches |
Resolution of display | 921 thousand dot | 210 thousand dot |
Selfie friendly | ||
Liveview | ||
Touch display | ||
Viewfinder Information | ||
Viewfinder type | None | Optical (pentamirror) |
Viewfinder coverage | - | 96% |
Viewfinder magnification | - | 0.57x |
Features | ||
Min shutter speed | 4 secs | 30 secs |
Max shutter speed | 1/2000 secs | 1/4000 secs |
Continuous shutter speed | 7.0 frames/s | 3.0 frames/s |
Shutter priority | ||
Aperture priority | ||
Expose Manually | ||
Exposure compensation | - | Yes |
Set WB | ||
Image stabilization | ||
Integrated flash | ||
Flash range | 4.00 m (at ISO 1600) | - |
Flash settings | Auto, redeye reduction, fill flash, off, LED illuminator | Auto, On, Off, Red-eye reduction |
External flash | ||
Auto exposure bracketing | ||
WB bracketing | ||
Max flash sync | - | 1/180 secs |
Exposure | ||
Multisegment | ||
Average | ||
Spot | ||
Partial | ||
AF area | ||
Center weighted | ||
Video features | ||
Video resolutions | 1920 x 1080 (60p), 1280 x 720 (60p), 640 x 480 (60p) | - |
Maximum video resolution | 1920x1080 | None |
Video file format | MPEG-4, H.264 | - |
Mic input | ||
Headphone input | ||
Connectivity | ||
Wireless | Built-In | None |
Bluetooth | ||
NFC | ||
HDMI | ||
USB | USB 2.0 (480 Mbit/sec) | USB 2.0 (480 Mbit/sec) |
GPS | BuiltIn | None |
Physical | ||
Environment seal | ||
Water proof | ||
Dust proof | ||
Shock proof | ||
Crush proof | ||
Freeze proof | ||
Weight | 221g (0.49 lb) | 660g (1.46 lb) |
Dimensions | 113 x 64 x 28mm (4.4" x 2.5" x 1.1") | 129 x 93 x 70mm (5.1" x 3.7" x 2.8") |
DXO scores | ||
DXO Overall score | not tested | not tested |
DXO Color Depth score | not tested | not tested |
DXO Dynamic range score | not tested | not tested |
DXO Low light score | not tested | not tested |
Other | ||
Battery life | 300 photographs | - |
Style of battery | Battery Pack | - |
Battery model | Li-50B | 4 x AA |
Self timer | Yes (2 or 10 sec, custom) | Yes (2 or 12 sec) |
Time lapse feature | ||
Type of storage | SD/SDHC/SDXC, Internal | SD/MMC card |
Storage slots | Single | Single |
Retail pricing | $280 | $0 |