Canon 40D versus Canon 70D

The Canon EOS 40D and the Canon EOS 70D are two enthusiast cameras that were officially introduced, respectively, in August 2007 and July 2013. Both are DSLR (Digital Single Lens Reflex) cameras that are equipped with an APS-C sensor. The 40D has a resolution of 10.1 megapixel, whereas the 70D provides 20 MP.

Body comparison

The physical size and weight of the Canon 40D and the Canon 70D are illustrated in the side-by-side display below. Three consecutive perspectives from the front, the top, and the back are presented. All size dimensions are rounded to the nearest millimeter. You can also toggle the display to switch to a percentage comparison if you prefer that the measures are being expressed in relative terms (in this case, the camera on the left – the 40D – represents the basis or 100 percent across all the size and weight measures).

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Canon 70D is notably smaller (8 percent) than the Canon 40D. Moreover, the 70D is markedly lighter (8 percent) than the 40D. It is noteworthy in this context that the 70D is splash and dust-proof, while the 40D 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. In this particular case, both cameras feature the same lens mount, so that they can use the same lenses. You can find an overview of suitable optics in the Canon EF Lens Catalog.

Concerning battery life, the 40D gets 750 shots out of its BP-511A battery, while the 70D can take 920 images on a single charge of its LP-E6 power pack.

The table below summarizes the key physical specs of the two cameras alongside a broader set of comparators. 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 comparisons there.

The listed prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The 70D was somewhat cheaper (by 8 percent) than the 40D at launch, but both cameras fall into the same price category. 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.

Sensor comparison

The size of the sensor inside a digital camera is one of the key determinants 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 are more costly to manufacture and tent to lead to bigger and heavier cameras and lenses.

Both cameras under consideration feature an APS-C sensor, but their sensors differ slightly in size. The sensor area in the 70D is 2 percent bigger. They nevertheless have the same format factor of 1.6. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

With 20MP, the 70D offers a higher resolution than the 40D (10.1MP), but the 70D has smaller individual pixels (pixel pitch of 4.11μm versus 5.73μm for the 40D). Yet, the 70D is a much more recent model (by 5 years and 10 months) than the 40D, and its sensor will have benefitted from technological advances during this time that enhance the light gathering capacity of its pixel-units.

For most cameras, data on sensor performance has been reported by DXO Mark. 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 70D has a markedly higher DXO score than the 40D (overall score 4 points higher), which will translate into better image quality. The advantage is based on 0.4 bits higher color depth, 0.3 EV in additional dynamic range, and 0.4 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.

Many modern cameras are not only capable of taking still images, but also of capturing video footage. The 70D indeed provides for movie recording, while the 40D does not. The highest resolution format that the 70D can use is 1080/30p.

Feature comparison

Beyond body and sensor, cameras can and do differ across a range of features. The 40D and the 70D 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 table below summarizes some of the other core capabilities of the Canon 40D and Canon 70D in connection with corresponding information for a sample of similar cameras. If you need more detail on the specs, you can find comprehensive listings, for example, in the dpreview camera hub.

Both the 40D and the 70D have been discontinued, but can regularly be found used on ebay. The 40D was replaced by the Canon 50D, while the 70D was followed by the Canon 80D.

Summary

So what is the bottom line? Is there a clear favorite between the Canon 40D and the Canon 40D? Below is a summary of the relative strengths of each of the two contestants.

Reasons to prefer the Canon EOS 40D:

• More heavily discounted: Has been available for much longer (launched in August 2007).

Arguments in favor of the Canon EOS 70D:

• More detail: Has more megapixels (20 vs 10.1MP), which boosts linear resolution by 41%.
• Better image quality: Scores markedly higher (4 points) in the DXO overall evaluation.
• Better low-light sensitivity: Can shoot in dim conditions (0.4 stops ISO advantage).
• Broader imaging potential: Can capture not only stills but also 1080/30p video.
• More detailed LCD: Has a higher resolution rear screen (1040k vs 230k dots).
• More flexible LCD: Has swivel screen for odd-angle shots in portrait or landscape orientation.
• Fewer buttons to press: Has a touchscreen to facilitate handling and shooting adjustments.
• Longer lasting: Gets more shots (920 versus 750) out of a single battery charge.
• Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
• More modern: Reflects 5 years and 10 months of technical progress since the 40D launch.

If the count of relative strengths (bullet points above) is taken as a measure, the 70D is the clear winner of the contest (10 : 1 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.

In any case, while the specs-based evaluation of cameras is instructive in revealing their potential as photographic tools, it remains partial and cannot reveal, for example, the handling experience and imaging performance when actually working with the 40D or the 70D. At times, user reviews, such as those published at amazon, address these issues in a useful manner, but such feedback is on many occasions incomplete, inconsistent, and unreliable. This is where reviews by experts come in. The adjacent table relays the overall verdicts of several of the most popular camera review sites. You can find the full text of the reviews, respectively, at cameralabs.com, dpreview.com, ephotozine.com, imaging-resource.com, and photographyblog.com.

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 comparisons

If you would like to see a different side-by-side camera review, just use the search menu below. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored. If you do not see the camera that you are looking for, kindly get in touch, and I will try to update the database with the necessary infos.