Canon 1Ds Mark II vs Olympus E-P5
The Canon EOS-1Ds Mark II and the Olympus PEN E-P5 are two digital cameras that were announced, respectively, in September 2004 and May 2013. The 1Ds Mark II is a DSLR, while the E-P5 is a mirrorless interchangeable lens camera. The cameras are based on a full frame (1Ds Mark II) and a Four Thirds (E-P5) sensor. The Canon has a resolution of 16.6 megapixels, whereas the Olympus provides 15.9 MP.
Below is an overview of the main specs of the two cameras as a starting point for the comparison.
|Canon 1Ds Mark II||Olympus E-P5|
|Digital single lens reflex||Mirrorless system camera|
|Canon EF mount lenses||Micro Four Thirds lenses|
|16.6 MP, Full Frame Sensor||15.9 MP, Four Thirds Sensor|
|no Video||1080/30p Video|
|ISO 100-1,600 (50 - 3,200)||ISO 200-25,600|
|Optical viewfinder||Viewfinder optional|
|2.0 LCD, 230k dots||3.0 LCD, 1037k dots|
|Fixed screen (not touch-sensitive)||Tilting touchscreen|
|4 shutter flaps per second||9 shutter flaps per second|
|Lens stabilization only||In-body stabilization|
|Weathersealed body||not weather sealed|
|1200 shots per battery charge||330 shots per battery charge|
|156 x 158 x 80 mm, 1215 g||122 x 69 x 37 mm, 420 g|
Going beyond this snapshot of core features and characteristics, what are the differences between the Canon EOS-1Ds Mark II and the Olympus PEN E-P5? 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 Canon 1Ds Mark II and the Olympus E-P5 is provided in the side-by-side display below. The two cameras are presented according to their relative size. Three consecutive views from the front, the top, and the rear side are shown. All width, height and depth measures are rounded to the nearest millimeter.
The E-P5 can be obtained in three different colors (black, silver, white), while the 1Ds Mark II is only available in black.
If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Olympus E-P5 is considerably smaller (66 percent) than the Canon 1Ds Mark II. Moreover, the E-P5 is substantially lighter (65 percent) than the 1Ds Mark II. It is worth mentioning in this context that the 1Ds Mark II is splash and dust resistant, while the E-P5 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 Canon EF Lens Catalog (1Ds Mark II) and the Micro Four Thirds Lens Catalog (E-P5). Mirrorless cameras, such as the E-P5, 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 1Ds Mark II gets 1200 shots out of its NP-E3 battery, while the E-P5 can take 330 images on a single charge of its BLN-1 power pack. As can be seen in the images above, the 1Ds Mark II has 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 1Ds Mark II||156 mm||158 mm||80 mm||1215 g||1200||Y||Sep 2004||7,999|
|Olympus E-P5||122 mm||69 mm||37 mm||420 g||330||n||May 2013||999|
|Canon 1D X Mark III||158 mm||168 mm||83 mm||1440 g||2850||Y||Jan 2020||6,499|
|Canon 1D X Mark II||158 mm||168 mm||83 mm||1530 g||1210||Y||Feb 2016||5,999|
|Canon 6D||145 mm||111 mm||71 mm||770 g||1090||Y||Sep 2012||2,099|
|Canon 1D X||158 mm||168 mm||83 mm||1551 g||1120||Y||Oct 2011||6,799|
|Canon 1D Mark IV||156 mm||157 mm||80 mm||1230 g||1500||Y||Oct 2009||4,999|
|Canon 1D Mark III||156 mm||157 mm||80 mm||1155 g||2200||Y||Feb 2007||4,499|
|Canon 1Ds Mark III||150 mm||160 mm||80 mm||1385 g||1800||Y||Aug 2007||7,999|
|Canon 1D Mark II N||156 mm||158 mm||80 mm||1565 g||1200||Y||Aug 2005||3,999|
|Canon 5D||152 mm||113 mm||75 mm||895 g||400||Y||Aug 2005||3,299|
|Canon 1Ds||156 mm||158 mm||80 mm||1265 g||600||Y||Sep 2002||8,999|
|Olympus E-M5 II||124 mm||85 mm||45 mm||469 g||310||Y||Feb 2015||1,099|
|Olympus E-M10||119 mm||82 mm||46 mm||396 g||320||n||Jan 2014||699|
|Olympus E-PL7||115 mm||67 mm||38 mm||357 g||350||n||Aug 2014||599|
|Olympus E-M1||130 mm||94 mm||63 mm||497 g||350||Y||Sep 2013||1,399|
|Panasonic GX7||123 mm||71 mm||55 mm||402 g||350||n||Aug 2013||999|
Notes: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.
(1) Number of images that can be taken on a full battery charge according to the CIPA-standard; (2) Official announcement.
Any camera decision will obviously take relative prices into account. The retail prices at the time of the camera’s release place the model in the market relative to other models in the producer’s line-up and the competition. The E-P5 was launched at a markedly lower price (by 88 percent) than the 1Ds Mark II, 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.
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. Further, a large sensor camera will give the photographer additional creative options when using shallow depth-of-field to isolate a subject from its background. On the downside, larger sensors tend to be more expensive and lead to bigger and heavier cameras and lenses.
Of the two cameras under consideration, the Canon 1Ds Mark II features a full frame sensor and the Olympus E-P5 a Four Thirds sensor. The sensor area in the E-P5 is 74 percent smaller. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.0 and 2.0. The sensor in the 1Ds Mark II has a native 3:2 aspect ratio, while the one in the E-P5 offers a 4:3 aspect.
In terms of underlying technology, both cameras are build around CMOS sensors.
With 16.6MP, the 1Ds Mark II offers a slightly higher resolution than the E-P5 (15.9MP), but the 1Ds Mark II nevertheless has larger individual pixels (pixel pitch of 7.21μm versus 3.76μm for the E-P5) due to its larger sensor. However, the E-P5 is a much more recent model (by 8 years and 7 months) than the 1Ds Mark II, and its sensor will have benefitted from technological advances during this time that further enhance the light gathering capacity of its pixels.
The Canon EOS-1Ds Mark II 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 Olympus PEN E-P5 are ISO 200 to ISO 25600, with the possibility to increase the ISO range to 100-25600.
Consistent information on actual sensor performance is available from DXO Mark for many cameras. 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 Overall DXO ratings for the two cameras under consideration are close, suggesting that they provide similar imaging performance. The adjacent table reports on the physical sensor characteristics and the outcomes of the DXO sensor quality tests for a sample of comparator-cameras.
|Canon 1Ds Mark II||Full Frame||16.6||4992||3328||none||23.3||11.3||1480||74|
|Olympus E-P5||Four Thirds||15.9||4608||3456||1080/30p||22.8||12.4||895||72|
|Canon 1D X Mark III||Full Frame||20.0||5472||3648||4K/60p||24.2||14.5||3248||91|
|Canon 1D X Mark II||Full Frame||20.0||5472||3648||4K/60p||24.1||13.5||3207||88|
|Canon 6D||Full Frame||20.0||5472||3648||1080/30p||23.8||12.1||2340||82|
|Canon 1D X||Full Frame||17.9||5184||3456||1080/30p||23.8||11.8||2786||82|
|Canon 1D Mark IV||APS-H||16.0||4896||3264||1080/30p||22.8||12.0||1320||74|
|Canon 1D Mark III||APS-H||10.1||3888||2592||none||22.7||11.7||1078||71|
|Canon 1Ds Mark III||Full Frame||21.0||5616||3744||none||24.0||12.0||1663||80|
|Canon 1D Mark II N||APS-H||8.2||3504||2336||none||22.3||11.2||975||66|
|Canon 5D||Full Frame||12.7||4368||2912||none||22.9||11.1||1368||71|
|Canon 1Ds||Full Frame||11.0||4064||2704||none||21.8||11.0||954||63|
|Olympus E-M5 II||Four Thirds||15.9||4608||3456||1080/60p||23.0||12.5||842||73|
|Olympus E-M10||Four Thirds||15.9||4608||3456||1080/30p||22.8||12.3||884||72|
|Olympus E-PL7||Four Thirds||15.9||4608||3456||1080/30p||22.7||12.4||873||72|
|Olympus E-M1||Four Thirds||15.9||4608||3456||1080/30p||23.0||12.7||757||73|
|Panasonic GX7||Four Thirds||15.8||4592||3448||1080/60p||22.6||12.2||718||70|
Many modern cameras are not only capable of taking still images, but can also record movies. The E-P5 indeed provides for movie recording, while the 1Ds Mark II does not. The highest resolution format that the E-P5 can use is 1080/30p.
Beyond body and sensor, cameras can and do differ across a range of features. For example, the 1Ds Mark II has an optical viewfinder, which can be very useful when shooting in bright sunlight. In contrast, the E-P5 relies on live view and the rear LCD for framing. That said, the E-P5 can be equipped with an optional viewfinder – the VF-4. The following table reports on some other key feature differences and similarities of the Canon 1Ds Mark II, the Olympus E-P5, and comparable cameras.
|Canon 1Ds Mark II||optical||Y||2.0||230||fixed||n||1/8000s||4.0||n||n|
|Canon 1D X Mark III||optical||Y||3.2||2100||fixed||Y||1/8000s||20.0||n||n|
|Canon 1D X Mark II||optical||Y||3.2||1620||fixed||Y||1/8000s||16.0||n||n|
|Canon 1D X||optical||Y||3.2||1040||fixed||n||1/8000s||14.0||n||n|
|Canon 1D Mark IV||optical||Y||3.0||920||fixed||n||1/8000s||10.0||n||n|
|Canon 1D Mark III||optical||Y||3.0||230||fixed||n||1/8000s||10.0||n||n|
|Canon 1Ds Mark III||optical||Y||3.0||230||fixed||n||1/8000s||5.0||n||n|
|Canon 1D Mark II N||optical||Y||2.5||230||fixed||n||1/8000s||8.5||n||n|
|Olympus E-M5 II||2360||n||3.0||1037||swivel||Y||1/8000s||10.0||n||Y|
One feature that is present on the 1Ds Mark II, but is missing on the E-P5 is a top-level LCD. While being, of course, smaller than the rear screen, the control panel conveys some of the essential shooting information and can be convenient for quick and easy settings verification.
The Olympus E-P5 has an intervalometer built-in. This enables the photographer to capture time lapse sequences, such as flower blooming, a sunset or moon rise, without purchasing an external camera trigger and related software.
The 1Ds Mark II writes its imaging data to Compact Flash or SDHC cards, while the E-P5 uses SDXC cards. The 1Ds Mark II features dual card slots, which can be very useful in case a memory card fails. In contrast, the E-P5 only has one slot. The E-P5 supports UHS-I cards (Ultra High Speed data transfer of up to 104 MB/s), while the 1Ds Mark II cannot take advantage of Ultra High Speed SD cards.
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-1Ds Mark II and Olympus PEN E-P5 and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
|Canon 1Ds Mark II||Y||-||-||-||-||-||2.0||-||-||-|
|Canon 1D X Mark III||Y||mono||mono||Y||Y||mini||3.1||Y||-||Y|
|Canon 1D X Mark II||Y||mono||mono||Y||Y||mini||3.0||-||-||-|
|Canon 1D X||Y||mono||-||Y||-||mini||2.0||-||-||-|
|Canon 1D Mark IV||Y||stereo||-||Y||-||mini||2.0||-||-||-|
|Canon 1D Mark III||Y||-||-||-||-||-||2.0||-||-||-|
|Canon 1Ds Mark III||Y||-||-||-||-||-||2.0||-||-||-|
|Canon 1D Mark II N||Y||-||-||-||-||-||1.1||-||-||-|
|Olympus E-M5 II||Y||stereo||mono||Y||-||micro||2.0||Y||-||-|
It is notable that the E-P5 offers wifi support, which can be a very convenient means to transfer image data to an off-camera location. In contrast, the 1Ds Mark II does not provide wifi capability.
Studio photographers will appreciate that the Canon 1Ds Mark II (unlike the E-P5) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.
Both the 1Ds Mark II and the E-P5 have been discontinued, but can regularly be found used on eBay. The 1Ds Mark II was replaced by the Canon 1Ds Mark III, while the E-P5 does not have a direct successor. Further information on the two cameras (e.g. user guides, manuals), as well as related accessories, can be found on the official Canon and Olympus websites.
So how do things add up? Which of the two cameras – the Canon 1Ds Mark II or the Olympus E-P5 – has the upper hand? Is one clearly better than the other? A synthesis of the relative strong points of each of the models is listed below.
Arguments in favor of the Canon EOS-1Ds Mark II:
- Better low-light sensitivity: Requires less light for good images (0.7 stops ISO advantage).
- Easier framing: Has an optical viewfinder for image composition and settings control.
- Easier setting verification: Features an LCD display on top to control shooting parameters.
- More portrait friendly: Features an integrated vertical grip for easier portrait shooting.
- Longer lasting: Can take more shots (1200 versus 330) on a single battery charge.
- Better sealing: Is weather sealed to enable shooting in dusty or wet environments.
- 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 heavily discounted: Has been available for much longer (launched in September 2004).
Advantages of the Olympus PEN E-P5:
- More dynamic range: Captures a broader range of light and dark details (1.1 EV of extra DR).
- Broader imaging potential: Can capture not only stills but also 1080/30p video.
- Larger screen: Has a bigger rear LCD (3.0" vs 2.0") for image review and settings control.
- More detailed LCD: Has a higher resolution rear screen (1037k vs 230k 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 burst: Shoots at higher frequency (9 vs 4 flaps/sec) to capture the decisive moment.
- Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
- More compact: Is smaller (122x69mm vs 156x158mm) and will fit more readily into a bag.
- Less heavy: Has a lower weight (by 795g or 65 percent) and is thus easier to take along.
- 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.
- Easier fill-in: Has a small integrated flash to brighten shadows of backlit subjects.
- Easier file upload: Has wifi built in for automatic backup or image transfer to the web.
- Faster buffer clearing: Has an SD card interface that supports the UHS-I standard.
- More affordable: Was introduced into a lower priced category (88 percent cheaper at launch).
- More modern: Reflects 8 years and 7 months of technical progress since the 1Ds Mark II launch.
If the count of individual advantages (bullet points above) is taken as a guide, the E-P5 is the clear winner of the contest (17 : 9 points). However, the relevance of individual strengths will vary across photographers, so that you might want to apply your own weighing scheme to the summary points when reflecting and deciding on a new camera. 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 1Ds Mark II and the Olympus E-P5 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 partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the 1Ds Mark II or the E-P5. 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.
This is where reviews by experts come in. The adjacent summary-table relays the overall verdicts of several of the most popular 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 1Ds Mark II||..||+ +||..||..||..||Sep 2004||7,999|
|Olympus E-P5||+ +||78/100||4.5/5||4.5/5||5/5||May 2013||999|
|Canon 1D X Mark III||+ +||..||..||..||..||Jan 2020||6,499|
|Canon 1D X Mark II||..||89/100||4.5/5||5/5||4.5/5||Feb 2016||5,999|
|Canon 6D||+ +||83/100||4.5/5||4.5/5||4.5/5||Sep 2012||2,099|
|Canon 1D X||..||..||4.5/5||4.5/5||4.5/5||Oct 2011||6,799|
|Canon 1D Mark IV||..||89/100||..||5/5||..||Oct 2009||4,999|
|Canon 1D Mark III||..||..||..||o||..||Feb 2007||4,499|
|Canon 1Ds Mark III||..||+ +||4.5/5||..||..||Aug 2007||7,999|
|Canon 1D Mark II N||..||..||..||..||..||Aug 2005||3,999|
|Canon 5D||88/100||+ +||o||o||..||Aug 2005||3,299|
|Canon 1Ds||..||+ +||..||..||..||Sep 2002||8,999|
|Olympus E-M5 II||+ +||81/100||5/5||4.5/5||5/5||Feb 2015||1,099|
|Olympus E-M10||..||80/100||5/5||4.5/5||5/5||Jan 2014||699|
|Olympus E-PL7||+||..||5/5||4.5/5||4/5||Aug 2014||599|
|Olympus E-M1||+ +||84/100||4.5/5||4.5/5||4.5/5||Sep 2013||1,399|
|Panasonic GX7||+||79/100||5/5||4.5/5||5/5||Aug 2013||999|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
The review scores listed above should be treated with care, though. The assessments were made in relation to similar cameras of the same technological generation. Hence, a score should always be seen in the context of the camera's market launch date and its price, and comparing ratings of very distinct cameras or ones that are far apart in terms of their release date have little meaning. Also, kindly note that some of the listed sites have over time developped their review approaches and their reporting style.
Other camera comparisons
Did this review help to inform your camera decision process? In case you are interested in seeing how other cameras pair up, just make your choice using the following search menu. As an alternative, you can also directly jump to any one of the listed comparisons that were previously generated by the CAM-parator tool.
- Canon 1Ds Mark II vs Canon 50D
- Canon 1Ds Mark II vs Fujifilm GFX 50R
- Canon 1Ds Mark II vs Leica S Typ 007
- Canon 1Ds Mark II vs Nikon D1X
- Canon 1Ds Mark II vs Nikon D5000
- Canon 1Ds Mark II vs Panasonic TS7
- Canon 600D vs Olympus E-P5
- Canon G12 vs Olympus E-P5
- Canon G5 X Mark II vs Olympus E-P5
- Canon T6i vs Olympus E-P5
- Leica V-LUX 1 vs Olympus E-P5
- Olympus E-P5 vs Olympus TG-6
Specifications: Canon 1Ds Mark II vs Olympus E-P5
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 1Ds Mark II||Olympus E-P5|
|Camera Type||Digital single lens reflex||Mirrorless system camera|
|Camera Lens||Canon EF mount lenses||Micro Four Thirds lenses|
|Launch Date||September 2004||May 2013|
|Launch Price||USD 7,999||USD 999|
|Sensor Specs||Canon 1Ds Mark II||Olympus E-P5|
|Sensor Format||Full Frame Sensor||Four Thirds Sensor|
|Sensor Size||36.0 x 24.0 mm||17.3 x 13.0 mm|
|Sensor Area||864 mm2||224.9 mm2|
|Sensor Diagonal||43.3 mm||21.6 mm|
|Sensor Resolution||16.6 Megapixels||15.9 Megapixels|
|Image Resolution||4992 x 3328 pixels||4608 x 3456 pixels|
|Pixel Pitch||7.21 μm||3.76 μm|
|Pixel Density||1.92 MP/cm2||7.08 MP/cm2|
|Moiré control||Anti-Alias filter||Anti-Alias filter|
|Movie Capability||no Video||1080/30p Video|
|ISO Setting||100 - 1,600 ISO||200 - 25,600 ISO|
|ISO Boost||50 - 3,200 ISO||100 - 25,600 ISO|
|Image Processor||DIGIC II||TruePic VI|
|DXO Sensor Quality (score)||74||72|
|DXO Color Depth (bits)||23.3||22.8|
|DXO Dynamic Range (EV)||11.3||12.4|
|DXO Low Light (ISO)||1480||895|
|Screen Specs||Canon 1Ds Mark II||Olympus E-P5|
|Viewfinder Type||Optical viewfinder||Viewfinder optional|
|Viewfinder Field of View||100%|
|Top-Level Screen||Control Panel||no Top Display|
|LCD Framing||Live View|
|Rear LCD Size||2.0inch||3.0inch|
|LCD Resolution||230k dots||1037k dots|
|LCD Attachment||Fixed screen||Tilting screen|
|Touch Input||no Touchscreen||Touchscreen|
|Shooting Specs||Canon 1Ds Mark II||Olympus E-P5|
|Focus System||Phase-detect AF||Contrast-detect AF|
|Manual Focusing Aid||no Peaking Feature||Focus Peaking|
|Max Shutter Speed (mechanical)||1/8000s||1/8000s|
|Continuous Shooting||4 shutter flaps/s||9 shutter flaps/s|
|Time-Lapse Photography||no Intervalometer||Intervalometer built-in|
|Image Stabilization||Lens stabilization only||In-body stabilization|
|Fill Flash||no On-Board Flash||Build-in Flash|
|Storage Medium||CF or SDHC cards||SDXC cards|
|Second Storage Option||Dual card slots||Single card slot|
|UHS card support||no||UHS-I|
|Connectivity Specs||Canon 1Ds Mark II||Olympus E-P5|
|Studio Flash||PC Sync socket||no PC Sync|
|USB Connector||USB 2.0||USB 2.0|
|HDMI Port||no HDMI||micro HDMI|
|Wifi Support||no Wifi||Wifi built-in|
|Body Specs||Canon 1Ds Mark II||Olympus E-P5|
|Environmental Sealing||Weathersealed body||not weather sealed|
|Battery Life (CIPA)||1200 shots per charge||330 shots per charge|
156 x 158 x 80 mm
(6.1 x 6.2 x 3.1 in)
122 x 69 x 37 mm
(4.8 x 2.7 x 1.5 in)
|Camera Weight||1215 g (42.9 oz)||420 g (14.8 oz)|
Did you notice an error on this page? If so, please get in touch, so that we can correct the information.