Nikon D100 vs Sony A9
The Nikon D100 and the Sony Alpha A9 are two digital cameras that were officially introduced, respectively, in February 2002 and April 2017. The D100 is a DSLR, while the A9 is a mirrorless interchangeable lens camera. The cameras are based on an APS-C (D100) and a full frame (A9) sensor. The Nikon has a resolution of 6 megapixels, whereas the Sony provides 24 MP.
Below is an overview of the main specs of the two cameras as a starting point for the comparison.
Going beyond this snapshot of core features and characteristics, what are the differences between the Nikon D100 and the Sony Alpha A9? Which one should you buy? Read on to find out how these two cameras compare with respect to their body size, their imaging sensors, their shooting features, their input-output connections, and their reception by expert reviewers.
An illustration of the physical size and weight of the Nikon D100 and the Sony A9 is provided in the side-by-side display below. The two cameras are presented according to their relative size. Three consecutive perspectives from the front, the top, and the back are available. All size dimensions are rounded to the nearest millimeter.
If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Sony A9 is notably smaller (27 percent) than the Nikon D100. Moreover, the A9 is markedly lighter (14 percent) than the D100. It is noteworthy in this context that the A9 is splash and dust-proof, while the D100 does not feature any corresponding weather-sealing.
The above size and weight comparisons are to some extent incomplete since they do not consider the interchangeable lenses that both of these cameras require. A larger imaging sensor will tend to go along with bigger and heavier lenses, although exceptions exist. You can compare the optics available for the two cameras in the Nikon Lens Catalog (D100) and the Sony FE Lens Catalog (A9). Mirrorless cameras, such as the A9, have moreover the advantage that they can use many lenses from other systems via adapters, as they have a relatively short flange to focal plane distance.
Concerning battery life, the D100 gets 370 shots out of its EN-EL3 battery, while the A9 can take 650 images on a single charge of its NP-FZ100 power pack. The power pack in the A9 can be charged via the USB port, which can be very convenient when travelling.
The following table provides a synthesis of the main physical specifications of the two cameras and other similar ones. If you want to switch the focus of the display and review another camera pair, you can move across to the CAM-parator tool and choose from the broad selection of possible camera comparisons there.
|1.||Nikon D100||144 mm||116 mm||81 mm||780 g||370||n||Feb 2002||1,999|
|2.||Sony A9||127 mm||96 mm||63 mm||673 g||650||Y||Apr 2017||4,499|
|3.||Canon 10D||150 mm||107 mm||75 mm||850 g||500||n||Feb 2003||1,999|
|4.||Nikon D90||132 mm||103 mm||77 mm||703 g||850||n||Aug 2008||1,299|
|5.||Nikon D300||147 mm||114 mm||74 mm||925 g||1000||Y||Aug 2007||1,799|
|6.||Nikon D40||124 mm||94 mm||64 mm||522 g||470||n||Nov 2006||499|
|7.||Nikon D80||132 mm||103 mm||77 mm||668 g||600||n||Aug 2006||999|
|8.||Nikon D50||133 mm||102 mm||76 mm||620 g||400||n||Apr 2005||749|
|9.||Nikon D70s||140 mm||111 mm||78 mm||679 g||500||n||Apr 2005||899|
|10.||Nikon D200||147 mm||113 mm||74 mm||920 g||400||Y||Nov 2005||1,699|
|11.||Nikon D70||140 mm||111 mm||78 mm||679 g||400||n||Jan 2004||999|
|12.||Nikon D1X||157 mm||153 mm||85 mm||1100 g||1200||Y||Feb 2001||5,999|
|13.||Sony A9 II||129 mm||96 mm||76 mm||678 g||690||Y||Oct 2019||4,499|
|14.||Sony A7 III||127 mm||96 mm||74 mm||650 g||610||Y||Feb 2018||1,999|
|15.||Sony A7R II||127 mm||96 mm||60 mm||625 g||290||Y||Jun 2015||3,199|
|16.||Sony A7S II||127 mm||96 mm||60 mm||627 g||370||Y||Sep 2015||2,999|
|17.||Sony A7 II||127 mm||96 mm||60 mm||599 g||350||Y||Nov 2014||1,999|
|Notes: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.|
Any camera decision will naturally be influenced heavily by the price. The manufacturer’s suggested retail prices give an idea on the placement of the camera in the maker’s lineup and the broader market. The D100 was launched at a markedly lower price (by 56 percent) than the A9, which puts it into a different market segment. Usually, retail prices stay at first close to the launch price, but after several months, discounts become available. Later in the product cycle and, in particular, when the replacement model is about to appear, further discounting and stock clearance sales often push the camera price considerably down. Then, after the new model is out, very good deals can frequently be found on the pre-owned market.
The imaging sensor is at the core of digital cameras and its size is one of the main determining factors of image quality. All other things equal, a large sensor will have larger individual pixel-units that offer better low-light sensitivity, wider dynamic range, and richer color-depth than smaller pixels in a sensor of the same technological generation. Moreover, a large sensor camera will give the photographer more control over depth-of-field in the image and, thus, the ability to better isolate a subject from the background. On the downside, larger sensors tend to be associated with larger, more expensive camera bodies and lenses.
Of the two cameras under consideration, the Nikon D100 features an APS-C sensor and the Sony A9 a full frame sensor. The sensor area in the A9 is 129 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.5 and 1.0. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.
With 24MP, the A9 offers a higher resolution than the D100 (6MP), but the A9 has smaller individual pixels (pixel pitch of 5.94μm versus 7.85μm for the D100). Yet, the A9 is a much more recent model (by 15 years and 2 months) than the D100, and its sensor will have benefitted from technological advances during this time that enhance the light gathering capacity of its pixel-units.
The resolution advantage of the Sony A9 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A9 for good quality output (200 dots per inch) amounts to 30 x 20 inches or 76.2 x 50.8 cm, for very good quality (250 dpi) 24 x 16 inches or 61 x 40.6 cm, and for excellent quality (300 dpi) 20 x 13.3 inches or 50.8 x 33.9 cm. The corresponding values for the Nikon D100 are 15 x 10 inches or 38.2 x 25.4 cm for good quality, 12 x 8 inches or 30.6 x 20.3 cm for very good quality, and 10 x 6.7 inches or 25.5 x 16.9 cm for excellent quality prints.
The A9 has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.
The Nikon D100 has a native sensitivity range from ISO 200 to ISO 800, which can be extended to ISO 200-1600. The corresponding ISO settings for the Sony Alpha A9 are ISO 100 to ISO 51200, with the possibility to increase the ISO range to 50-204800.
For many cameras, data on sensor performance has been reported by DXO Mark. This service determines an overall sensor rating, as well as sub-scores for low-light sensitivity ("DXO Sports"), dynamic range ("DXO Landscape"), and color depth ("DXO Portrait"). The table below summarizes the physical sensor characteristics and sensor quality findings and compares them across a set of similar cameras.
| DXO |
|2.||Sony A9||Full Frame||24.0||6000||4000||4K/30p||24.9||13.3||3517||92|
|13.||Sony A9 II||Full Frame||24.0||6000||4000||4K/30p||25.0||14.0||3434||93|
|14.||Sony A7 III||Full Frame||24.0||6000||4000||4K/30p||25.0||14.7||3730||96|
|15.||Sony A7R II||Full Frame||42.2||7952||5304||4K/30p||26.0||13.9||3434||98|
|16.||Sony A7S II||Full Frame||12.0||4240||2832||4K/30p||23.6||13.3||2993||85|
|17.||Sony A7 II||Full Frame||24.0||6000||4000||1080/60p||24.9||13.6||2449||90|
Many modern cameras are not only capable of taking still images, but can also record movies. The A9 indeed provides for movie recording, while the D100 does not. The highest resolution format that the A9 can use is 4K/30p.
Apart from body and sensor, cameras can and do differ across a range of features. For example, the A9 has an electronic viewfinder (3686k dots), while the D100 has an optical one. Both systems have their advantages, with the electronic viewfinder making it possible to project supplementary shooting information into the framing view, whereas the optical viewfinder offers lag-free viewing and a very clear framing image. The viewfinder in the A9 offers a wider field of view (100%) than the one in the D100 (95%), so that a larger proportion of the captured image is visible in the finder. In addition, the viewfinder of the A9 has a higher magnification (0.78x vs 0.53x), so that the size of the image transmitted appears closer to the size seen with the naked human eye. The adjacent table lists some of the other core features of the Nikon D100 and Sony A9 along with similar information for a selection of comparators.
|13.||Sony A9 II||3686||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|14.||Sony A7 III||2359||n||3.0||922||tilting||Y||1/8000s||10.0||n||Y|
|15.||Sony A7R II||2400||n||3.0||1229||tilting||n||1/8000s||5.0||n||Y|
|16.||Sony A7S II||2400||n||3.0||1229||tilting||n||1/8000s||5.0||n||Y|
|17.||Sony A7 II||2400||n||3.0||1230||tilting||n||1/8000s||5.0||n||Y|
One difference between the cameras concerns the presence of an on-board flash. The D100 has one, while the A9 does not. While the built-in flash of the D100 is not very powerful, it can at times be useful as a fill-in light.
The reported shutter speed information refers to the use of the mechanical shutter. Yet, some cameras only have an electronic shutter, while others have an electronic shutter in addition to a mechanical one. In fact, the A9 is one of those camera that have an additional electronic shutter, which makes completely silent shooting possible. However, this mode is less suitable for photographing moving objects (risk of rolling shutter) or shooting under artificial light sources (risk of flickering).
The D100 writes its imaging data to Compact Flash cards, while the A9 uses SDXC or Memory Stick PRO Duo cards. The A9 features dual card slots, which can be very useful in case a memory card fails. In contrast, the D100 only has one slot.
For some imaging applications, the extent to which a camera can communicate with its environment can be an important aspect in the camera decision process. The table below provides an overview of the connectivity of the Nikon D100 and Sony Alpha A9 and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|13.||Sony A9 II||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|14.||Sony A7 III||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|15.||Sony A7R II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|16.||Sony A7S II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|17.||Sony A7 II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
It is notable that the A9 offers wifi support, which can be a very convenient means to transfer image data to an off-camera location. In contrast, the D100 does not provide wifi capability.
Studio photographers will appreciate that the Sony A9 (unlike the D100) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.
Both the D100 and the A9 have been discontinued, but can regularly be found used on eBay. The D100 was replaced by the Nikon D200, while the A9 was followed by the Sony A9 II. Further information on the two cameras (e.g. user guides, manuals), as well as related accessories, can be found on the official Nikon and Sony websites.
So what is the bottom line? Is the Nikon D100 better than the Sony A9 or vice versa? Below is a summary of the relative strengths of each of the two contestants.
Arguments in favor of the Nikon D100:
- Brighter framing: Features an optical viewfinder for clear, lag-free composition.
- Easier setting verification: Features an LCD display on top to control shooting parameters.
- Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
- More affordable: Was introduced into a lower priced category (56 percent cheaper at launch).
- More heavily discounted: Has been available for much longer (launched in February 2002).
Advantages of the Sony Alpha A9:
- More detail: Has more megapixels (24 vs 6MP), which boosts linear resolution by 100%.
- Better image quality: Is equipped with a larger and more technologically advanced sensor.
- Richer colors: The sensor size advantage translates into images with better, more accurate colors.
- More dynamic range: Larger sensor captures a wider spectrum of light and dark details.
- Better low-light sensitivity: Larger sensor produces good images even in poorly lit environments.
- Broader imaging potential: Can capture not only stills but also 4K/30p video.
- Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
- More framing info: Has an electronic viewfinder that displays shooting data.
- More complete view: Has a viewfinder with a larger field of view (100% vs 95%).
- Larger viewfinder image: Features a viewfinder with a higher magnification (0.78x vs 0.53x).
- Larger screen: Has a bigger rear LCD (3.0" vs 1.8") for image review and settings control.
- More detailed LCD: Has a higher resolution rear screen (1440k vs 118k dots).
- More flexible LCD: Has a tilting screen for odd-angle shots in landscape orientation.
- Fewer buttons to press: Has a touchscreen to facilitate handling and shooting adjustments.
- Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
- Faster burst: Shoots at higher frequency (20 vs 3 flaps/sec) to capture the decisive moment.
- Less disturbing: Has an electronic shutter option for completely silent shooting.
- More compact: Is smaller (127x96mm vs 144x116mm) and will fit more readily into a bag.
- Less heavy: Has a lower weight (by 107g or 14 percent) and is thus easier to take along.
- Longer lasting: Gets more shots (650 versus 370) out of a single battery charge.
- Easier travel charging: Can be conveniently charged via its USB port.
- Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
- Sharper images: Has stabilization technology built-in to reduce the impact of hand-shake.
- More legacy lens friendly: Can use many non-native lenses via adapters.
- Faster data transfer: Supports a more advanced USB protocol (2.0 vs 1.1).
- Easier file upload: Has wifi built in for automatic backup or image transfer to the web.
- Easier device pairing: Supports NFC for fast wireless image transfer over short distances.
- Easier wireless transfer: Supports Bluetooth for image sharing without cables.
- Better studio light control: Has a PC Sync socket to connect to professional strobe lights.
- Greater peace of mind: Features a second card slot as a backup in case of memory card failure.
- More modern: Reflects 15 years and 2 months of technical progress since the D100 launch.
If the number of relative strengths (bullet points above) is taken as a guide, the A9 is the clear winner of the contest (31 : 5 points). However, the relative importance of the various individual camera aspects will vary according to personal preferences and needs, so that you might like to apply corresponding weights to the particular features before making a decision on a new camera. A professional wildlife photographer will view the differences between cameras in a way that diverges from the perspective of a family photog, and a person interested in architecture has distinct needs from a sports shooter. Hence, the decision which camera is best and worth buying is often a very personal one.
How about other alternatives? Do the specifications of the Nikon D100 and the Sony A9 place the cameras among the top in their class? Find out in the latest Best DSLR Camera and Best Mirrorless Interchangeable Lens Camera listings whether the two cameras rank among the cream of the crop.
In any case, while the specs-based evaluation of cameras can be instructive in revealing their potential as photographic tools, it remains incomplete and does no justice, for example, to the way the D100 or the A9 perform in practice. User reviews, such as those found at amazon, can sometimes inform about these issues, but such feedback is often incomplete, inconsistent, and biased.
This is why expert reviews are important. The table below provides a synthesis of the camera assessments of some of the best known photo-gear review sites (amateurphotographer [AP], cameralabs [CL], dpreview [DPR], ephotozine [EPZ], photographyblog [PB]). As can be seen, the professional reviewers agree in many cases on the quality of different cameras, but sometimes their assessments diverge, reinforcing the earlier point that a camera decision is often a very personal choice.
|1.||Nikon D100||..||..||+ +||o||..||Feb 2002||1,999|
|2.||Sony A9||5/5||+ +||89/100||5/5||5/5||Apr 2017||4,499|
|3.||Canon 10D||..||..||+ +||..||..||Feb 2003||1,999|
|4.||Nikon D90||..||+ +||+ +||4/5||4.5/5||Aug 2008||1,299|
|5.||Nikon D300||..||+ +||+ +||5/5||4.5/5||Aug 2007||1,799|
|6.||Nikon D40||..||81/100||+ +||o||4.5/5||Nov 2006||499|
|7.||Nikon D80||..||+||+ +||o||4.5/5||Aug 2006||999|
|8.||Nikon D50||..||78/100||+ +||4/5||4.5/5||Apr 2005||749|
|9.||Nikon D70s||..||..||..||..||5/5||Apr 2005||899|
|10.||Nikon D200||..||+ +||+ +||o||..||Nov 2005||1,699|
|11.||Nikon D70||..||..||+ +||..||..||Jan 2004||999|
|12.||Nikon D1X||..||..||+ +||..||..||Feb 2001||5,999|
|13.||Sony A9 II||..||..||90/100||5/5||5/5||Oct 2019||4,499|
|14.||Sony A7 III||..||+ +||89/100||5/5||5/5||Feb 2018||1,999|
|15.||Sony A7R II||5/5||+ +||90/100||5/5||5/5||Jun 2015||3,199|
|16.||Sony A7S II||5/5||+||..||4.5/5||5/5||Sep 2015||2,999|
|17.||Sony A7 II||5/5||+||82/100||4.5/5||5/5||Nov 2014||1,999|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
The review scores listed above should be treated with care, though. The ratings were established in reference to similarly priced cameras that were available in the market at the time of the review. A score, therefore, has to be seen in close connection to the price and market introduction time of the camera, and comparing ratings of very distinct cameras or ones that are far apart in terms of their release date have little meaning. Also, please note that some of the review sites have changed their methodology and reporting over time.
Other camera comparisons
Did this review help to inform your camera decision process? If you would like to see a different side-by-side camera review, just make a corresponding selection in the search boxes below. As an alternative, you can also directly jump to any one of the listed comparisons that were previously generated by the CAM-parator tool.
Specifications: Nikon D100 vs Sony A9
Below is a side-by-side comparison of the specs of the two cameras to facilitate a quick review of their differences and common features.
|Camera Model||Nikon D100||Sony A9|
|Camera Type||Digital single lens reflex||Mirrorless system camera|
|Camera Lens||Nikon F mount lenses||Sony E mount lenses|
|Launch Date||February 2002||April 2017|
|Launch Price||USD 1,999||USD 4,499|
|Sensor Specs||Nikon D100||Sony A9|
|Sensor Format||APS-C Sensor||Full Frame Sensor|
|Sensor Size||23.7 x 15.6 mm||35.6 x 23.8 mm|
|Sensor Area||369.72 mm2||847.28 mm2|
|Sensor Diagonal||28.4 mm||42.8 mm|
|Sensor Resolution||6 Megapixels||24 Megapixels|
|Image Resolution||3008 x 2000 pixels||6000 x 4000 pixels|
|Pixel Pitch||7.85 μm||5.94 μm|
|Pixel Density||1.63 MP/cm2||2.83 MP/cm2|
|Moiré control||Anti-Alias filter||Anti-Alias filter|
|Movie Capability||no Video||4K/30p Video|
|ISO Setting||200 - 800 ISO||100 - 51,200 ISO|
|ISO Boost||200 - 1,600 ISO||50 - 204,800 ISO|
|DXO Sensor Quality (score)||..||92|
|DXO Color Depth (bits)||..||24.9|
|DXO Dynamic Range (EV)||..||13.3|
|DXO Low Light (ISO)||..||3517|
|Screen Specs||Nikon D100||Sony A9|
|Viewfinder Type||Optical viewfinder||Electronic viewfinder|
|Viewfinder Field of View||95%||100%|
|Viewfinder Resolution||3686k dots|
|Top-Level Screen||Control Panel||no Top Display|
|LCD Framing||Live View|
|Rear LCD Size||1.8inch||3.0inch|
|LCD Resolution||118k dots||1440k dots|
|LCD Attachment||Fixed screen||Tilting screen|
|Touch Input||no Touchscreen||Touchscreen|
|Shooting Specs||Nikon D100||Sony A9|
|Focus System||Phase-detect AF||On-Sensor Phase-detect|
|Manual Focusing Aid||no Peaking Feature||Focus Peaking|
|Max Shutter Speed (mechanical)||1/4000s||1/8000s|
|Continuous Shooting||3 shutter flaps/s||20 shutter flaps/s|
|Shutter Life Expectancy||50 000 actuations||500 000 actuations|
|Electronic Shutter||no E-Shutter||up to 1/32000s|
|Image Stabilization||Lens stabilization only||In-body stabilization|
|Fill Flash||Build-in Flash||no On-Board Flash|
|Storage Medium||CF cards||MS or SDXC cards|
|Second Storage Option||Single card slot||Dual card slots|
|Connectivity Specs||Nikon D100||Sony A9|
|Studio Flash||no PC Sync||PC Sync socket|
|USB Connector||USB 1.1||USB 2.0|
|HDMI Port||no HDMI||micro HDMI|
|Microphone Port||no MIC socket||External MIC port|
|Headphone Socket||no Headphone port||Headphone port|
|Wifi Support||no Wifi||Wifi built-in|
|Near-Field Communication||no NFC||NFC built-in|
|Bluetooth Support||no Bluetooth||Bluetooth built-in|
|Body Specs||Nikon D100||Sony A9|
|Environmental Sealing||not weather sealed||Weathersealed body|
|Battery Life (CIPA)||370 shots per charge||650 shots per charge|
|In-Camera Charging||no USB charging||USB charging|
144 x 116 x 81 mm
(5.7 x 4.6 x 3.2 in)
127 x 96 x 63 mm
(5.0 x 3.8 x 2.5 in)
|Camera Weight||780 g (27.5 oz)||673 g (23.7 oz)|
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