Canon 1D Mark II N vs 1D Mark III
The Canon EOS-1D Mark II N and the Canon EOS-1D Mark III are two professional cameras that were announced, respectively, in August 2005 and February 2007. Both are DSLR (Digital Single Lens Reflex) cameras that are equipped with an APS-H sensor. The 1D Mark II N has a resolution of 8.2 megapixels, whereas the 1D Mark III provides 10.1 MP.
Below is an overview of the main specs of the two cameras as a starting point for the comparison.
|Canon 1D Mark II N||Canon 1D Mark III|
|Digital single lens reflex||Digital single lens reflex|
|Canon EF mount lenses||Canon EF mount lenses|
|8.2 MP, APS-H Sensor||10.1 MP, APS-H Sensor|
|no Video||no Video|
|ISO 100-1600 (50-3200)||ISO 100-3200 (50-6400)|
|Optical viewfinder||Optical viewfinder|
|2.5" LCD, 230k dots||3.0" LCD, 230k dots|
|Fixed screen (not touch-sensitive)||Fixed screen (not touch-sensitive)|
|8.5 shutter flaps per second||10 shutter flaps per second|
|Weathersealed body||Weathersealed body|
|1200 shots per battery charge||2200 shots per battery charge|
|156 x 158 x 80 mm, 1565 g||156 x 157 x 80 mm, 1155 g|
Going beyond this snapshot of core features and characteristics, what are the differences between the Canon EOS-1D Mark II N and the Canon EOS-1D Mark III? 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.
Body comparison: Canon 1D Mark II N vs 1D Mark III
The side-by-side display below illustrates the physical size and weight of the Canon 1D Mark II N and the Canon 1D Mark III. The two cameras are presented according to their relative size. Three successive views from the front, the top, and the rear are shown. All width, height and depth measures 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 Canon 1D Mark II N and the Canon 1D Mark III are of equal size. However, the 1D Mark III is markedly lighter (26 percent) than the 1D Mark II N. In this context, it is worth noting that both cameras are splash and dust-proof and can, hence, be used in inclement weather conditions or harsh environments.
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. In this particular case, both cameras feature the same lens mount, so that they can use the same lenses. You can compare the optics available in the Canon EF Lens Catalog.
Concerning battery life, the 1D Mark II N gets 1200 shots out of its NP-E3 battery, while the 1D Mark III can take 2200 images on a single charge of its LP-E4 power pack. As can be seen in the images above, both cameras have a battery grip built in. This facilitates image-taking in portrait orientation and gives it additional battery power.
The adjacent table lists the principal physical characteristics of the two cameras alongside a wider set of alternatives. If you want to switch the focus of the display and review another camera pair, just select a new right or left comparator from among the camera models in the table. Alternatively, you can also move across to the CAM-parator tool and choose from the broad selection of possible camera comparisons there.
|Canon 1D Mark II N»||6.1 in||6.2 in||3.1 in||55.2 oz||1200||Y||Aug 2005||3,999||-||Canon 1D Mark II N|
|Canon 1D Mark III«||6.1 in||6.2 in||3.1 in||40.7 oz||2200||Y||Feb 2007||4,499||-||Canon 1D Mark III|
|Canon 5D Mark IV« »||5.9 in||4.6 in||3.0 in||31.4 oz||900||Y||Aug 2016||3,499||Canon 5D Mark IV|
|Canon 5DS« »||6.0 in||4.6 in||3.0 in||32.8 oz||700||Y||Feb 2015||3,699||Canon 5DS|
|Canon 1D Mark IV« »||6.1 in||6.2 in||3.1 in||43.4 oz||1500||Y||Oct 2009||4,999||-||Canon 1D Mark IV|
|Canon 5D Mark II« »||6.0 in||4.5 in||3.0 in||30.0 oz||850||Y||Sep 2008||3,499||-||Canon 5D Mark II|
|Canon 1Ds Mark III« »||5.9 in||6.3 in||3.1 in||48.9 oz||1800||Y||Aug 2007||7,999||-||Canon 1Ds Mark III|
|Canon 5D« »||6.0 in||4.4 in||3.0 in||31.6 oz||400||Y||Aug 2005||3,299||-||Canon 5D|
|Canon 1D Mark II« »||6.1 in||6.2 in||3.1 in||54.1 oz||1200||Y||Jan 2004||4,499||-||Canon 1D Mark II|
|Canon 1Ds Mark II« »||6.1 in||6.2 in||3.1 in||42.9 oz||1200||Y||Sep 2004||7,999||-||Canon 1Ds Mark II|
|Canon 1Ds« »||6.1 in||6.2 in||3.1 in||44.6 oz||600||Y||Sep 2002||8,999||-||Canon 1Ds|
|Canon 1D« »||6.1 in||6.2 in||3.1 in||55.9 oz||500||Y||Sep 2001||6,499||-||Canon 1D|
|Nikon D3« »||6.3 in||6.2 in||3.5 in||45.9 oz||4300||Y||Aug 2007||4,999||-||Nikon D3|
|Note: Measurements and pricing do not include easily detachable parts, such as interchangeable lenses or optional viewfinders.|
Any camera decision will naturally be influenced heavily by the price. The listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The 1D Mark II N was launched at a somewhat lower price (by 11 percent) than the 1D Mark III, which makes it more attractive for photographers on a tight budget. 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.
Sensor comparison: Canon 1D Mark II N vs 1D Mark III
The imaging sensor is at the core of digital cameras and its size is one of the main determining factors of image quality. A large sensor will tend to have larger individual pixels that provide better low-light sensitivity, wider dynamic range, and richer color-depth than smaller pixel-units 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.
Both cameras under consideration feature an APS-H sensor, but their sensors differ slightly in size. The sensor area in the 1D Mark III is 4 percent smaller. They nevertheless have the same format factor of 1.3. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.
Technology-wise, the 1D Mark III uses a more advanced image processing engine (DIGIC III) than the 1D Mark II N (DIGIC II), with benefits for noise reduction, color accuracy, and processing speed.
Despite having a slightly smaller sensor, the 1D Mark III offers a higher resolution of 10.1 megapixels, compared with 8.2 MP of the 1D Mark II N. This megapixels advantage comes at the cost of a higher pixel density and a smaller size of the individual pixel (with a pixel pitch of 7.21μm versus 8.17μm for the 1D Mark II N). However, it should be noted that the 1D Mark III is a somewhat more recent model (by 1 year and 6 months) than the 1D Mark II N, and its sensor might have benefitted from technological advances during this time that partly offset its pixel-size disadvantage.
The resolution advantage of the Canon 1D Mark III implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the 1D Mark III for good quality output (200 dots per inch) amounts to 19.4 x 13 inch or 49.4 x 32.9 cm, for very good quality (250 dpi) 15.6 x 10.4 inch or 39.5 x 26.3 cm, and for excellent quality (300 dpi) 13 x 8.6 inch or 32.9 x 21.9 cm. The corresponding values for the Canon 1D Mark II N are 17.5 x 11.7 inch or 44.5 x 29.7 cm for good quality, 14 x 9.3 inch or 35.6 x 23.7 cm for very good quality, and 11.7 x 7.8 inch or 29.7 x 19.8 cm for excellent quality prints.
The Canon EOS-1D Mark II N has a native sensitivity range from ISO 100 to ISO 1600, which can be extended to ISO 50-3200. The corresponding ISO settings for the Canon EOS-1D Mark III are ISO 100 to ISO 3200, with the possibility to increase the ISO range to 50-6400.
Since 2007, DXO Mark has published sensor performance measurements that have been derived using a consistent methodology. This service assesses and scores the color depth ("DXO Portrait"), dynamic range ("DXO Landscape"), and low-light sensitivity ("DXO Sports") of camera sensors, and also publishes an overall camera score. Of the two cameras under consideration, the 1D Mark III has a markedly higher DXO score than the 1D Mark II N (overall score 5 points higher), which will translate into better image quality. The advantage is based on 0.4 bits higher color depth, 0.5 EV in additional dynamic range, and 0.1 stops in additional low light sensitivity. The following table provides an overview of the physical sensor characteristics, as well as the sensor quality measurements for a selection of comparators.
|Canon 1D Mark II N»||APS-H||8.2||3504||2336||-||22.3||11.2||975||66||Canon 1D Mark II N|
|Canon 1D Mark III«||APS-H||10.1||3888||2592||-||22.7||11.7||1078||71||Canon 1D Mark III|
|Canon 5D Mark IV« »||Full Frame||30.1||6720||4480||4K/30p||24.8||13.6||2995||91||Canon 5D Mark IV|
|Canon 5DS« »||Full Frame||50.3||8688||5792||1080/30p||24.7||12.4||2381||87||Canon 5DS|
|Canon 1D Mark IV« »||APS-H||16.0||4896||3264||1080/30p||22.8||12.0||1320||74||Canon 1D Mark IV|
|Canon 5D Mark II« »||Full Frame||21.0||5616||3744||1080/30p||23.7||11.9||1815||79||Canon 5D Mark II|
|Canon 1Ds Mark III« »||Full Frame||21.0||5616||3744||-||24.0||12.0||1663||80||Canon 1Ds Mark III|
|Canon 5D« »||Full Frame||12.7||4368||2912||-||22.9||11.1||1368||71||Canon 5D|
|Canon 1D Mark II« »||APS-H||8.2||3504||2336||-||22.3||11.1||1003||66||Canon 1D Mark II|
|Canon 1Ds Mark II« »||Full Frame||16.6||4992||3328||-||23.3||11.3||1480||74||Canon 1Ds Mark II|
|Canon 1Ds« »||Full Frame||11.0||4064||2704||-||21.8||11.0||954||63||Canon 1Ds|
|Canon 1D« »||APS-H||4.1||2496||1662||-||-||-||-||-||Canon 1D|
|Nikon D3« »||Full Frame||12.1||4256||2832||-||23.5||12.2||2290||81||Nikon D3|
Feature comparison: Canon 1D Mark II N vs 1D Mark III
Apart from body and sensor, cameras can and do differ across a variety of features. The 1D Mark II N and the 1D Mark III are similar in the sense that both have an optical viewfinder. The latter is useful for getting a clear image for framing even in brightly lit environments. The viewfinders of both cameras offer the same field of view (100%), but the viewfinder of the 1D Mark III has a higher magnification than the one of the 1D Mark II N (0.58x vs 0.55x), so that the size of the image transmitted appears closer to the size seen with the naked human eye. The following table reports on some other key feature differences and similarities of the Canon 1D Mark II N, the Canon 1D Mark III, and comparable cameras.
|Canon 1D Mark II N»||optical||Y||2.5||230||fixed||n||1/8000s||8.5||n||n||Canon 1D Mark II N|
|Canon 1D Mark III«||optical||Y||3.0||230||fixed||n||1/8000s||10.0||n||n||Canon 1D Mark III|
|Canon 5D Mark IV« »||optical||Y||3.2||1620||fixed||Y||1/8000s||7.0||n||n||Canon 5D Mark IV|
|Canon 5DS« »||optical||Y||3.2||1040||fixed||n||1/8000s||5.0||n||n||Canon 5DS|
|Canon 1D Mark IV« »||optical||Y||3.0||920||fixed||n||1/8000s||10.0||n||n||Canon 1D Mark IV|
|Canon 5D Mark II« »||optical||Y||3.0||920||fixed||n||1/8000s||3.9||n||n||Canon 5D Mark II|
|Canon 1Ds Mark III« »||optical||Y||3.0||230||fixed||n||1/8000s||5.0||n||n||Canon 1Ds Mark III|
|Canon 5D« »||optical||Y||2.5||230||fixed||n||1/8000s||3.0||n||n||Canon 5D|
|Canon 1D Mark II« »||optical||Y||2.0||230||fixed||n||1/8000s||8.3||n||n||Canon 1D Mark II|
|Canon 1Ds Mark II« »||optical||Y||2.0||230||fixed||n||1/8000s||4.0||n||n||Canon 1Ds Mark II|
|Canon 1Ds« »||optical||Y||2.0||120||fixed||n||1/8000s||3.0||n||n||Canon 1Ds|
|Canon 1D« »||optical||Y||2.0||120||fixed||n||1/16000s||8.0||n||n||Canon 1D|
|Nikon D3« »||optical||Y||3.0||922||fixed||n||1/8000s||11.0||n||n||Nikon D3|
The 1D Mark II N writes its imaging data to Compact Flash or SD cards, while the 1D Mark III uses Compact Flash or SDHC cards. Both cameras feature dual card slots, which can be very useful in case a memory card fails.
Connectivity comparison: Canon 1D Mark II N vs 1D Mark III
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 Canon EOS-1D Mark II N and Canon EOS-1D Mark III and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
|Canon 1D Mark II N»||Y||-||-||-||-||-||1.1||-||-||-||Canon 1D Mark II N|
|Canon 1D Mark III«||Y||-||-||-||-||-||2.0||-||-||-||Canon 1D Mark III|
|Canon 5D Mark IV« »||Y||mono||mono||Y||Y||mini||3.0||Y||Y||-||Canon 5D Mark IV|
|Canon 5DS« »||Y||mono||mono||Y||-||mini||3.0||-||-||-||Canon 5DS|
|Canon 1D Mark IV« »||Y||stereo||-||Y||-||mini||2.0||-||-||-||Canon 1D Mark IV|
|Canon 5D Mark II« »||Y||mono||mono||Y||-||mini||2.0||-||-||-||Canon 5D Mark II|
|Canon 1Ds Mark III« »||Y||-||-||-||-||-||2.0||-||-||-||Canon 1Ds Mark III|
|Canon 5D« »||Y||-||-||-||-||-||2.0||-||-||-||Canon 5D|
|Canon 1D Mark II« »||Y||-||-||-||-||-||1.1||-||-||-||Canon 1D Mark II|
|Canon 1Ds Mark II« »||Y||-||-||-||-||-||2.0||-||-||-||Canon 1Ds Mark II|
|Canon 1Ds« »||Y||-||-||-||-||-||FW||-||-||-||Canon 1Ds|
|Canon 1D« »||Y||-||-||-||-||-||FW||-||-||-||Canon 1D|
|Nikon D3« »||Y||-||-||-||-||mini||2.0||-||-||-||Nikon D3|
Both cameras feature a PC Sync terminal to control professional strobe lights, which will be appreciated by studio photographers.
Both the 1D Mark II N and the 1D Mark III have been discontinued, but can regularly be found used on eBay. The 1D Mark II N was replaced by the Canon 1D Mark III, while the 1D Mark III was followed by the Canon 1D Mark IV. Further information on the two cameras (e.g. user guides, manuals), as well as related accessories, can be found on the official Canon website.
Review summary: Canon 1D Mark II N vs 1D Mark III
So what is the bottom line? Is the Canon 1D Mark II N better than the Canon 1D Mark III or vice versa? The listing below highlights the relative strengths of the two models.
Reasons to prefer the Canon EOS-1D Mark II N:
- More affordable: Was introduced into a lower priced segment (11 percent cheaper at launch).
- More heavily discounted: Has been on the market for longer (launched in August 2005).
Arguments in favor of the Canon EOS-1D Mark III:
- More detail: Has more megapixels (10.1 vs 8.2MP), which boosts linear resolution by 11%.
- Better image quality: Scores markedly higher (5 points) in the DXO overall evaluation.
- Better jpgs: Has a more modern image processing engine (DIGIC III vs DIGIC II).
- Larger viewfinder image: Features a viewfinder with a higher magnification (0.58x vs 0.55x).
- Larger screen: Has a bigger rear LCD (3.0" vs 2.5") for image review and settings control.
- Faster burst: Shoots at higher frequency (10 vs 8.5 flaps/sec) to capture the decisive moment.
- Less heavy: Has a lower weight (by 410g or 26 percent) and is thus easier to take along.
- Longer lasting: Gets more shots (2200 versus 1200) out of a single battery charge.
- Faster data transfer: Supports a more advanced USB protocol (2.0 vs 1.1).
- More modern: Was introduced somewhat (1 year and 6 months) more recently.
If the count of relative strengths (bullet points above) is taken as a measure, the 1D Mark III is the clear winner of the contest (10 : 2 points). However, the pertinence of the various camera strengths will differ across photographers, so that you might want to weigh individual camera traits according to their importance for your own imaging needs before making a camera decision. A professional wedding photographer will view the differences between cameras in a way that diverges from the perspective of a travel photog, and a person interested in cityscapes has distinct needs from a macro 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 Canon 1D Mark II N and the Canon 1D Mark III place the cameras among the top in their class? Find out in the latest Best DSLR Camera listing 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 partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the 1D Mark II N or the 1D Mark III. User reviews that are available, for instance, at amazon can sometimes shed light on these issues, but such feedback is all too often partial, inconsistent, and inaccurate.
Expert reviews: Canon 1D Mark II N vs 1D Mark III
This is why hands-on reviews by experts are important. The following table reports the overall ratings of the cameras as published by some of the major camera review sites (cameralabs, dpreview, ephotozine, imaging-resource, and photographyblog). 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.
|Canon 1D Mark II N»||-||-||-||-||-||Aug 2005||3,999||-||Canon 1D Mark II N|
|Canon 1D Mark III«||-||-||-||o||-||Feb 2007||4,499||-||Canon 1D Mark III|
|Canon 5D Mark IV« »||+ +||87/100||4.5/5||5/5||4.5/5||Aug 2016||3,499||Canon 5D Mark IV|
|Canon 5DS« »||+||83/100||4.5/5||5/5||4.5/5||Feb 2015||3,699||Canon 5DS|
|Canon 1D Mark IV« »||-||89/100||-||5/5||-||Oct 2009||4,999||-||Canon 1D Mark IV|
|Canon 5D Mark II« »||91/100||79/100||4/5||5/5||-||Sep 2008||3,499||-||Canon 5D Mark II|
|Canon 1Ds Mark III« »||-||+ +||4.5/5||-||-||Aug 2007||7,999||-||Canon 1Ds Mark III|
|Canon 5D« »||88/100||+ +||o||o||-||Aug 2005||3,299||-||Canon 5D|
|Canon 1D Mark II« »||-||+ +||-||o||-||Jan 2004||4,499||-||Canon 1D Mark II|
|Canon 1Ds Mark II« »||-||+ +||-||-||-||Sep 2004||7,999||-||Canon 1Ds Mark II|
|Canon 1Ds« »||-||+ +||-||-||-||Sep 2002||8,999||-||Canon 1Ds|
|Canon 1D« »||-||+ +||-||-||-||Sep 2001||6,499||-||Canon 1D|
|Nikon D3« »||-||+ +||5/5||o||4.5/5||Aug 2007||4,999||-||Nikon D3|
|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. Thus, a score needs to be put into the context of the launch date and the launch price of the camera, and comparisons of ratings among very different cameras or across long time periods have little meaning. It should also be noted that some of the review sites have over time altered the way they render their verdicts.
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 use the search menu below. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.
- Canon 100D vs Canon 1D Mark III
- Canon 1D Mark II N vs Canon 7D
- Canon 1D Mark II N vs Canon T7
- Canon 1D Mark II N vs Nikon D5000
- Canon 1D Mark II N vs Sony A850
- Canon 1D Mark III vs Fujifilm X-T100
- Canon 1D Mark III vs Nikon D2X
- Canon 1D Mark III vs Nikon D3X
- Canon 1D Mark III vs Panasonic FZ300
- Canon 1D Mark III vs Panasonic GX9
- Canon 1D Mark III vs Sony A7
- Canon 1D Mark III vs Sony A7S II
Specifications: Canon 1D Mark II N vs Canon 1D Mark III
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||Canon 1D Mark II N||Canon 1D Mark III|
|Camera Type||Digital single lens reflex||Digital single lens reflex|
|Camera Lens||Canon EF mount lenses||Canon EF mount lenses|
|Launch Date||August 2005||February 2007|
|Launch Price||USD 3999||USD 4499|
|Sensor Specs||Canon 1D Mark II N||Canon 1D Mark III|
|Sensor Format||APS-H Sensor||APS-H Sensor|
|Sensor Size||28.7 x 19.1 mm||28.1 x 18.7 mm|
|Sensor Area||548.17 mm2||525.47 mm2|
|Sensor Diagonal||34.5 mm||33.8 mm|
|Sensor Resolution||8.2 Megapixels||10.1 Megapixels|
|Image Resolution||3504 x 2336 pixels||3888 x 2592 pixels|
|Pixel Pitch||8.17 μm||7.21 μm|
|Pixel Density||1.49 MP/cm2||1.92 MP/cm2|
|Moiré control||Anti-Alias filter||Anti-Alias filter|
|Movie Capability||no Video||no Video|
|ISO Setting||100-1600 ISO||100-3200 ISO|
|ISO Boost||50-3200 ISO||50-6400 ISO|
|Image Processor||DIGIC II||DIGIC III|
|DXO Sensor Quality (score)||66||71|
|DXO Color Depth (bits)||22.3||22.7|
|DXO Dynamic Range (EV)||11.2||11.7|
|DXO Low Light (ISO)||975||1078|
|Screen Specs||Canon 1D Mark II N||Canon 1D Mark III|
|Viewfinder Type||Optical viewfinder||Optical viewfinder|
|Viewfinder Field of View||100%||100%|
|Top-Level Screen||Control Panel||Control Panel|
|LCD Framing||Live View|
|Rear LCD Size||2.5 inch||3.0 inch|
|LCD Resolution||230k dots||230k dots|
|LCD Attachment||Fixed screen||Fixed screen|
|Shooting Specs||Canon 1D Mark II N||Canon 1D Mark III|
|Autofocus System||Phase-detect AF||Phase-detect AF|
|Continuous Shooting||8.5 shutter flaps/s||10 shutter flaps/s|
|Shutter Life Expectancy||200 000 actuations||300 000 actuations|
|Fill Flash||no On-Board Flash||no On-Board Flash|
|Storage Medium||CF or SD cards||CF or SDHC cards|
|Second Storage Option||Dual card slots||Dual card slots|
|UHS card support||no||no|
|Connectivity Specs||Canon 1D Mark II N||Canon 1D Mark III|
|Studio Flash||PC Sync socket||PC Sync socket|
|USB Connector||USB 1.1||USB 2.0|
|HDMI Port||no HDMI||no HDMI|
|Wifi Support||no Wifi||no Wifi|
|Body Specs||Canon 1D Mark II N||Canon 1D Mark III|
|Environmental Sealing||Weathersealed body||Weathersealed body|
|Battery Type||NP-E3 power pack||LP-E4 power pack|
|Battery Life (CIPA)||1200 shots per charge||2200 shots per charge|
156 x 158 x 80 mm
(6.1 x 6.2 x 3.1 in)
156 x 157 x 80 mm
(6.1 x 6.2 x 3.1 in)
|Camera Weight||1565 g (55.2 oz)||1155 g (40.7 oz)|
Did you notice an error on this page? If so, please get in touch, so that we can correct the information.