Image Quality Comparison Canon 5Dmk2 and Canon 7D

Canon currently offer two mid-range camera bodies in the form of the 7D and the 5Dmk2.  Both cameras have been on the market for a while, with the 5Dmk2 being the older camera.  The 5Dmk3 is about to arrive on the market as I am writing this post, but it comes in at a substantially higher price than its predecessor and is positioned a little higher in the product line, so at this point in time it is not a direct replacement for the 5Dmk2, which will for now continue to be sold alongside the 5Dmk3.

Although the Canon 5Dmk2 and the Canon 7D look quite similar, the two bodies are quite different in many ways, and none more so than in their sensor characteristics.

The 7D is an APS-C sensor camera, with 18mp of resolution.  The 5Dmk2 has a full-frame sensor, which is larger than that of the 7D, with 21mp resolution.  There is more to understanding sensor characteristics than just megapixels though, as these two cameras are only 3mp apart when it comes to resolution.

The actual physical size of the APS-C sensor in the 7D is 22.3mm long and 14.9mm high.

In comparison the sensor in the 5Dmk2 is 36mm long and 24mm high.  The sensor in the 5Dmk2 is approximately 1.6x larger than that of the 7D sensor.

Pixels, or photosites, are not all the same, and they have an individual size too, sometimes referred to as pixel pitch.  The 5Dmk2 has fairly large pixels, at 6.4 microns.  The large sensor in the 5Dmk2 is divided up into these photosites, each one around 6.4 microns across, and there are 21 million photosites in all.

The much smaller sensor in the 7D is divided up into photosites, each one around 4.3 microns across.  There are 18 million photosites/pixels in all.

It should be clear from following this explanation that the photosites or pixels on the 7D sensor are much smaller than those of the 5D sensor.

Looked at another way, if you took the larger pixels of the 5Dmk2, and divided up a 7D-sized sensor using these pixels, you would only get 8 million of them to fit on it (which would equate to the 30D sensor of a few years ago). 

When comparing the full frame 5Dmk2 image with that of the APS-C sensor of the 7D, bear in mind that the sensor cannot change the focal length of the lens.

Those in the market for a mid-range Canon dslr body often end up having to choose between these two camera bodies, and as such it is useful to be able to see and compare images taken with the two cameras, side by side.

With the help of Chris Frylink and his 7D, we set up the two cameras to shoot some comparative images.

We used a Canon EF 70-200 f/2.8L IS II lens, mounted on a tripod.  Only the camera body was changed each time.  No sharpening was applied other than a default setting of 25 in Adobe Camera Raw.  Raw images opened in Photoshop CS5, downsized and saved using File Save For Web and Devices at 190kb file size. Images were taken with the lens set at 115mm focal length, and from the exact same position and lens angle.

Canon 5Dmk2, 21mpixels, full frame, pixel pitch 6.4microns.  Resized to 800x533.  1/100s at f/4.0, Iso 400.

Canon 7D, 18mp, APS-C, pixel pitch 4.3microns.  Resized to 800x533. 1/60s at f/4.0, Iso 400.

The lens projects the image that it captures onto the camera sensor.

The larger sensor of the 5Dmk2 captures 36mm x 24mm of what the lens projects which is pretty much corner to corner of the image circle.  The smaller 7D sensor captures the middle portion of that, with its 22.3mm x 14.9mm sensor.  So a portion of what the lens projects does not get recorded on the 7D sensor, that being the outside edges of the frame.

The difference in how much of the image the two different cameras record can be clearly seen above.  There is no cropping with the above images.  There is a great difference between the size of the subject in the two images.  As these images are taken at iso 400, and downsized to 800x533 for web use, it is difficult to be able to evaluate any quality differences at this point.

For the next pair of images, we decided to make the subject about the same size.  In other words, if you were not able to move closer with the 5Dmk2 in order to get the baboon the same size as in the 7D frame, or were limited to 115mm focal length, then your option would be crop until the subject size was the same.

Canon 5Dmk2, Cropped to 8.2mp, pixel pitch 6.4microns. Resized to 800x533. 1/100s at f/4.0, Iso 400.

Canon 7D, No cropping, 18mp, pixel pitch 4.3microns. Resized to 800x533. 1/60s at f/4.0, Iso 400.

We cropped the 5Dmk2 image until the baboon was roughly the same size as in the 7D image.  This left the 5Dmk2 image with resolution of 8.2mp, compared to the 7D image at 18mp.  When viewing the two original images on my screen there is still not a whole lot of quality difference between the two at these display sizes.  If 8mp is enough for your requirements, then it is feasible to crop the 5dmk2 file heavily to get the subject to a bigger size.  In case you noticed, we did have a slight wind problem with our furry baboon model subject, and had to reposition between the two camera body shoots.  This also explains the baboons angry expression in the second image.  It did not affect the background or noise levels at all.

To really compare quality with the subject size equalized, we needed to crop in heavily on the files from both cameras.  

As the 5Dmk2 has more pixels, it can be cropped more heavily in order to get the subject the same size.  For the next pair of images we did just that.  We cropped so that there would be both high-contrast detail areas in the frame, (around the baboons eye, and fur) as well as distant, out-of-focus low contrast background areas to check for noise.

Canon 5Dmk2, Cropped to 1mp.  Pixel pitch 6.4microns. Iso 400.

Canon 7D, Cropped to 2.3mp.  Pixel pitch 4.3microns. Iso 400.

Surprizingly, the 5Dmk2 image shows about the same noise level, even though it is cropped to 1mp.  It is still sharper visibly than the 7D image, and were one to sharpen the 7D image, it should be borne in mind that doing so would increase the visibility of the noise in the 7D file.
The 5Dmk2 image shows superior fine detail contrast in these two comparisons.  
According to some sources the 7D has a strong anti-aliasing filter, which is likely one reason why it does not produce raw images that appear quite as sharp or fine-detail contrasted as the 5Dmk2.
It is very easy to sharpen the 7D file in processing but it would need to be done with care to avoid sharpening background areas were noise would be made more prominent by sharpening.  This fits in with my own experience with the 7D files, in that they needed a little more careful processing to show at their best.
I was surprized at just how well the 5Dmk2 image held up in this crop.  At the same time, the cropped 7D file has twice the resolution so if necessary, could be printed at twice the size of the 5Dmk2 file.

What follows are similar crops, from the same cameras, lens and subject, but new images taken at iso 800.

Canon 5Dmk2, Cropped to 1mp.  Pixel pitch 6.4microns. Iso 800

Canon 7D, Cropped to 2.4mp.  Pixel pitch 4.3microns. Iso 800.

At iso 800, the 5Dmk2 noise becomes slightly more visible, specially at that very heavy crop.  Again, there is not that much difference although the noise in the 7D image has a smoother look to it with less blotching visible.

This comparison shows that in good light, and at ISO 400, it is possible to crop the 5Dmk2 image until it matches the "subject size" of the same image taken on the 7D, and that there is not a great deal of difference in the image quality of the two cameras using this method.  The 5Dmk2 image appears sharper out of the camera.

At extreme crop sizes, the higher resolution of the subject-size equalized frame of the 7D gives it an advantage.

A different method of testing sensor characteristics between the two cameras would be to compare image quality between the two bodies when longer focal length lenses were used on the 5Dmk2's bigger sensor, to 'equalize' the sensor characteristics, for example shooting the 7D at 100mm focal length and the 5dmk2 at 160mm, approximately.

After extensive use of both of these camera bodies, my own findings in actual shooting conditions pretty much supported what comparing these images show.  Importantly, when one does not crop the 5Dmk2 image as heavily as we have here, it produced even better results.

I will be posting a second image quality comparison between these two camera bodies shortly, where focal length was changed in order to equalize subject size.  In other words, comparing 5Dmk2 images taken at 160mm with 7D image taken at 100mm.

We did not calibrate the two camera bodies to the camera lens.  Whilst there were no clouds in the sky, and we shot as quickly as possible between changing bodies, there might be slight changes in available light.  

For my purposes, in raw format, I felt completely happy that the pictures were sharp enough and that both lens and camera combinations were working properly.

With proper sharpening applied, there would be lots more detail showing on the subject.

To read a full review of the 7D, click here: EOS 7D Review

To read a full review of the EF 70-200 f/2.8L IS II click here:  EF 70-200 f2.8 IS II Review

Look through the archives of the blog in order to locate other such comparison posts between different Canon camera models.

Male Lion Coalitions - More Power Than One

Male lions in Southern Africa typically live in coalitions.  In the southern African region, south of the Zambezi River, the average coalition size is around two males.  Actual coalition sizes can vary from two males to seven males.
These coalitions are normally made up of lions that are brothers, and often half-brothers, and cousins.  They usually have their beginnings when these males are all still cubs, living in their natal pride.  It has been recorded though that unrelated males may join up and form coalitions later in their lives.

The Western Boys, Mombo, a coalition of two.  Canon 40D, Canon 70-200 f2.8 IS.  1/50s at f2.8, iso 800

These young male lions start showing signs of the bonding behaviour that will ultimately be a critical component of their coalition lifestyle.  They will typically spend more and more time in each others company as they grow older within the pride, and less time with their sisters.  Such behaviour can be witnessed in the way that sub-adult males in a pride will often sleep alongside one another.  They also show their developing independence in the way that start lagging behind the pride when they are on the move.  Sometime between the ages of two and four they may end up leaving the pride.  Their departure may be hastened by the arrival of new adult males, or they may begin to elicit aggression from their own fathers.  They usually leave as a group, made up of brothers, cousins and half-brothers.

Attaining independence can be extremely stressful on the young males, as they have to learn how to hunt for themselves.  They also scavenge whenever the opportunity arises during this period.
They sometimes move big distances during this period, looking for females and food, and either trying to avoid or confront resident male lions.

A coalition of three, the Border Boys, Linyanti, Botswana.  Formerly six, this coalition split into two groups of three each.  Canon 30D, Canon 70-200 f2.8 IS.  1/400s at f/10.  Iso 200

Successful coalitions find females, and gain access to them by chasing away the resident male/s.  These fights can be fatal, and adult males and younger males are often killed in this way.  In several such instances that I witnessed in Botswana where one male of a coalition pair was killed, the remaining male stayed alone and did not accept a new coalition partner.

Once a coalition has gained access to females, they typically become more settled for a while, and spend much time mating and siring cubs.  After a few years, and often when most of the pride females already have cubs, the males tend to become more relaxed in how much together time they spend with each other.  Coalitions may also start to spend more time away from their original pride females after a while.  They leave the females for short periods to patrol their territories, but also to seek other females in neighbouring territories.  Some coalitions can end up holding two or even three different prides of females.  In such instances the males may move between the different groups of females, sharing their time between them.
Another thing that happens is that males within a coalition may also begin to move on their own. Almost invariably these solitary ranging movements by the males are temporary, and are driven by the desire to find new females.  Wandering males typically return, after a day or perhaps a week, to their coalition partners.  This kind of behaviour also places them at great risk, as moving alone often beyond the boundaries of their territories means that they are without the support of their coalition partners should they encounter another male or males.  Wandering males in Botswana would sometimes return to their coalition showing signs of serious fights, and sometimes they don't come back at all.  In this way a strong coalition can become weakened sooner than one would expect, due to the lack of cohesion amongst the original members.

A male lion in the Savuti concession, one half of a coalition pair.  This male was injured whilst on his own, without the support of his coalition partner, and sustained these scars in a fight with a neighbouring rival male.  Two months later he got killed deep inside another males territory.  Canon 1DMk4, Canon 300f2.8L IS.  1/125s at f/4.0.  Iso 800.

If a coalition is overthrown, and the males driven away, any cubs younger than two years old are at risk of being killed.  When new males encounter females strange to them, they will very often try to kill the cubs.  They do not see the cubs as competition, but rather act instinctively to rid the female of her biological investment in another lions cubs, and create conditions that will lead to females mating with the new pride males as quickly as possible.

Strong coalitions of male lions can lead to stable lion populations as the males are able to hold on to their territories for long enough to ensure the survival of their cubs.

From a photographers point of view, male coalitions open up a range of opportunities.  There is always interaction, usually affectionate, between the coalition members to photograph.  Such bonding moments create a contrast between large and imposing alpha predators and the affectionate side of their nature.  Being able to photograph more than one male lion in a frame also adds much.
Male lion coalitions are an impressive and powerful phenomenon of the natural world, and I try to take photographs that show something of that.

Comparing Pixels, 2009 to 2007, The Canon 1Dmk4 and 40D

In this post I have taken two Canon camera bodies that are quite different in many aspects and compared the images that each one produces.  The 1Dmk4 is currently Canon’s high-end sport and wildlife camera body (about to be replaced by the 1DX).  It is a fast, high-specification camera that sells for around the USD5000 mark.

The other camera in this comparison is the Canon 40D, which is a mid-level camera body that is no longer manufactured, having been superseded by two newer bodies in its price range, which was around USD1300 .

The 40D was announced in August 2007, while the 1Dmk4 was announced in October 2009. 

At first glance, it may make no sense at all to compare any aspect of these two camera’s performance with one another.  

However, if you dig a little deeper, the two camera’s share one important thing and that is their pixel pitch.  Both cameras have pixels of 5.7 microns in size.  They are also just over two years apart in age.  With this in mind, comparing image quality should provide a reasonable idea of how pixel efficiency has improved over time for Canon users.

Canon have tended to change pixel pitches often over the years, following a trend that saw each new model making use of smaller and smaller individual pixels.  This trend can make comparing advances in sensor and pixel efficiency a bit confusing when comparing different cameras, as sensor size, pixel pitch and efficiency can all be variables.

By making use of two cameras that have the same pixel pitch, the variables can mostly be eliminated.

The 1Dmk4 has an APS-H (27.9mm x 18.6mm) sensor which has 16 million pixels on it.

The 40D has an APS-C (22.2 x 14.8mm) sensor which has 10 million pixels on it.

The Mk4 has a larger sensor, but the size of the individual pixels is exactly the same as those on the 40D sensor at 5.7 microns.

Canon 1Dmk4, Cropped from 16 to 10mp, Iso 400.  Focal length 115mm.

Canon 40D, As shot at 10mp, Iso 400.  Focal length 115mm.

The image from the 1Dmk4 above was cropped from 16mp to 10mp, to exactly match the 10mp resolution of the 40D.  As the two cameras have identically-sized pixels, the resulting cropped image renders the subject at exactly the same size.  In other words, you can crop a 40D-sized image exactly out of a 1Dmk4 image by removing 6 megapixels.

I had to overexpose the 40D by just about a third of a stop in processing to get it to the same brightness level as the Mk4 image, but that should have little effect on noise and quality.

At this small size for web, the downsized images don't look at all that different to my eye.  That is of course one drawback of having to work with web size constraints when viewing.

This also shows that it can be quite difficult to really evaluate an image that has been downsized to a small web preview.  To state this in another way, if your primary output for your images is going to be at small sizes on the internet, you might not need what the high-end cameras deliver.

Canon 1Dmk4, Cropped from 16 to 0.4mp, Iso 400.  Focal length 115mm. 

Canon 40D, Cropped from 10 to 0.4mp, Iso 400.  Focal length 115mm. 

In the next two images, I have cropped very heavily in order to show what is really going on with noise.  It is quite clear that the 1Dmk4 is showing a lot less noise in the image than the 40D image.  The difference is equivalent to about one-stop.  In other words the amount of noise on a 1Dmk4 image at iso 800 is similar to the amount showing on the 40D image at iso 400.

The 40D was not regarded as a particularly noisy camera in its time, and many of my published images were taken with the camera.  I usually tried to keep the Iso at 400 or below when possible.

The 1Dmk4 pixels benefit from just over two years of development, and it shows quite clearly in the solid improvement (I would estimate just less than one stop) when comparing raw image output with the older sensor..at low to moderate iso settings.

Canon 1Dmk4, Cropped from 16 to 0.4mp, Iso 3200.  Focal length 115mm.

Canon 40D, Cropped from 10 to 0.4mp, Iso 3200.  Focal length 115mm. 

With the next two images I kept the crop the same, to show detail, and shot both cameras at iso 3200.

Things change a little bit at high iso settings, with the difference between the two sensors becoming more pronounced.

The 1Dmk4 images are showing a fair amount of noise at this very heavy crop, but not nearly as much as the 40D.  The noise levels in the 40D image are very high, and are affecting the image quality.

At iso 3200 the difference between the two sensors is greater than when they are at iso 400.  This is revealing, in that it clearly shows how the newer sensor in the Mk4 is losing less quality with each higher iso setting than the older sensor.  In other words, the new sensor is falling off less steeply at higher iso settings.  At iso 3200 the 1Dmk4 is showing less noise than the 40D at iso 1600.  The difference is more than one stop, at these higher iso settings.

This comparison was conducted in very low light.  Shutter speeds when shooting at iso 400 were in the region of 1/10 second.  Unfortunately I did not have my toy zebra to photograph but made use of the furry baboon.  I purposefully positioned the subject so that the background would hold dark, unfocused areas to check for noise.  Noise is easiest to see when viewed parts of the frame that are uniformly low in contrast.

No noise reduction has been applied to these images.  I shot in raw, and converted the images in Adobe Camera Raw.  The only sharpening was the default capture sharpening setting of 25, applied evenly to both images.  I resized the images to 800x533 pixels in Photoshop and saved them at 190Kb.

In summary, the comparison shows that in just over two years, and using the same size pixel, technology advances between the 40D sensor and the 1Dmk4 sensor resulted in an improvement at low to mid-range iso settings in noise of just less than one stop, and at higher iso settings the difference was closer to two stops.

It is worth noting that the 1Dmk4 sensor benefitted from Canon's gapless microlens technology in its design as well as processor advances.

Camera makers routinely claim massive improvements in low-light performance between successive models, but it is always important to note whether they are referring to heavily processed jpg images or raw output.  Usually the jpg images used as examples are so heavily processed by strong noise reduction applications that most fine detail is removed from them, and these claims may not stand up to real-world situations.

It is more realistic to compare noise on raw images such as those above.  There is of course much more to image quality than just noise.  On the other hand, noise is something that anyone who has photographed in low light will need to be aware of, and reducing noise is one of the most important aspects of improving overall quality.

There are significant improvements to be seen in the efficiency of the 5.7 micron pixels from the 2009-era sensor when compared to the 2007-era sensor.

Low Light Image Quality Comparison Canon 1Dmk4 and 7D

Canon currently produce two camera bodies that have quite a high degree of similarity, based on their general specifications.  The two bodies are the Canon 7D, which is an APS-C sensor camera, that has 18mp of resolution, 8 fps drive and the Canon 1Dmk4, which has a larger APS-H sensor inside, with 16mp and 10 fps drive speed.

I often am asked as to what some of the main differences are in image quality between these two cameras.  With this in mind I set up the two cameras to shoot some comparative images from both in order to compare some of their characteristics.  In two earlier comparisons I shot the two cameras at ISO 400 and at ISO1600, in good light.  I used the same lens and focal length for both of those comparisons and I cropped the 1Dmk4 file until the subject size matched that of the 7D.  Those two posts make interesting reading in case you have not read them and a good basis for comparison with the results of this post.

For this comparison I took a completely different approach to comparing image quality.  In order to equalize the difference in subject size resulting from the different sensor sizes in the two cameras, I used a longer focal length on the 1Dmk4.

I used a Canon EF 70-200 f/2.8L IS II lens, mounted on a tripod.  Only the camera body was changed each time.  No sharpening was applied other than a default setting of 25 in Adobe Camera Raw.  Raw images opened in Photoshop CS5, downsized and saved using File Save For Web and Devices at 190kb file size. 

Canon 1Dmk4, 70-200f2.8.  1/40 at f5.0, Iso 3200.  Focal length 130mm.  As framed 16mp.

Canon7D, 70-200f2.8.  1/50 at f5.0, Iso 3200.  Focal length 102mm.  As framed 18mp.

The images were taken in very low light, as can be seen from the exposure details.  For the first two images I shot at iso 3200 on both cameras.  The frame includes some darker areas where noise tends to be seen more easily as well as a detailed subject in the silver can.

The first image is that of the Mk4, with its 1.3x crop effect, taken with the lens focal length at 130mm.  The image directly beneath it, and above this text, is that taken with the 7D, with its 1.6x crop effect, taken at 102mm.  The size of the subjects in the frame are pretty similar, which is a result of shooting the Mk4 at 130mm and the 7D at 102mm ( I was aiming at 100mm).  

I had to add just a little (0.3) positive exposure adjustment to the 7D image in LR to get it to a similar brightness level.

Viewing at the small size that I am able to post at on the blog doesn't really reveal too much difference in visible image quality between the two cameras.  At this point the two images above represent downsized versions of a 16mp capture on the larger sensor (27.9 x 18.6) of the 1Dmk4 and an 18mp capture on the 7D's (22.3 x 14.9 ) smaller sensor.

Canon 1Dmk4, 70-200f2.8.  1/40 at f5.0, Iso 3200.  Focal length 130mm.  Cropped to less than 2mp. 

Canon 7D, 70-200f2.8.  1/50 at f5.0, Iso 3200.  Focal length 102mm.  Cropped to less than 2mp. 

I then cropped the same two images.

In order to make it a bit easier to compare the image quality more easily,  I made heavy crops.  I tried to keep the subject size the same.  Megapixel size of each image is roughly 1.5 to 1.7mp before downsizing.

This crop allows the detail in the image to be more accurately observed, even after downsizing for the blog image parameters.  

Comparing the quality of the two iso 3200 images side by side shows that the Mk4 image has a lot less visible noise than the 7D image.  It shows less visible colour noise in the khaki background, and it shows far less noise in the dark wood below the can.  Looking at the silver tones on the can itself, it can be seen that noise in the 7D image is giving it a slightly grainy look.  

The Mk4 image is showing less colour noise throughout the image, and is also retaining detail and fine contrast far better, easily visible in the printed letters on the can.

Canon 1Dmk4, 70-200f2.8.  1/20 at f5.0, Iso 1600.  Focal length 130mm.  Cropped to less than 2mp. 

Canon 7D, 70-200f2.8.  1/13 at f5.0, Iso 800.  Focal length 102mm.  Cropped to less than 2mp. 

I took more images for comparison, from the same position and with the same lens settings, but this time with the 1Dmk4 set at iso 1600 and the 7D at iso 800.  

Compared in this way the 1Dmk4 and the 7D images appear quite similar in quality and noise, with the 1Dmk4 perhaps showing a very slightly superior image.

These numbers translate into a raw noise advantage of roughly one stop for the 1Dmk4 over the 7D.

Discussion

The roughly one stop advantage of the 1Dmk4 when compared to the 7D using the method outlined above, of using longer focal length to reach a similar subject size, is not unexpected.

The technology applied to these sensors is from the same era, and both use Canon's gapless microlens technology to maximize light gathering.

The differences mainly come about from the larger individual megapixels that are found on the 1Dmk4 sensor.  Each pixel is 5.7 microns whereas the pixels found on the 7D are 4.3 microns.

The larger pixels seem to better at gathering light, at the expense of subject size.  If you are able to make up the difference in subject size, either by moving closer to the subject, or using longer focal length then the camera with the bigger pixels will deliver higher-quality images, all other things being equal. 

After extensive use of both of these camera bodies, my own findings in actual shooting conditions pretty much supported what comparing these images shows in this post.  It is also important to remember that the images above are converted directly from raw captures with no processing done.  They would benefit from noise reduction and sharpening processing steps.

I did not calibrate the two camera bodies to the camera lens.  I shot indoors in very low light.

No sharpening applied to these images, but for my purposes, in raw format, I felt that both lens and camera combinations were working well enough for me to have confidence in the results.

To read a full review of the 7D, click here: EOS 7D Review

To read a full review of the 1Dmk4, click here:  EOS-1DMk4 Review

To read a full review of the EF 70-200 f/2.8L IS II , click here: EF 70-200 f/2.8L IS II Review

The Cheetah of Mountain Zebra National Park

The latest issue of Wild magazine, features an article on the Mountain Zebra National Park, which, if you have not been there, is in the Eastern Cape province, South Africa.  I was fortunate to have a couple of my cheetah images that I took in the park last winter, used in the magazine in support of the article.

Canon 1Dmk4, Canon EF 300 f/.28 IS.  Handheld, 1/250s at f/4.0, Iso 800.  Cheetah.

Helena and I were in the park in June last year, and our timing coincided with that of a very powerful cold front.  We only had two nights in the park.

Mountain Zebra National Park is a super location for wildlife photography, with an incredibly scenic mixture of habitats within its boundaries.  These range from elevated grasslands to rugged hills and distant mountain backgrounds.

We found lots of black wildebeest, springbok, mountain zebra, ostrich and hartebeest to keep our cameras clicking on our first two game drives.

By the middle of our last afternoon in the park it had clouded over, and a strong, icy wind was blowing.  Two stationery vehicles led us to a sighting of a large male cheetah with a collar, fast asleep.  After a while, the other vehicles left, and we were alone with the sleeping cheetah.  The cloud cover was heavy though, and conditions for photography were not great.  We did not mind at all though, and were happy to just be sitting close to the cat.

There was, however, a very thin, opening of clear sky just above the horizon.    It was almost too much to hope that the cheetah was going to be awake, and that the sun would shine through, at the same time.  For once, that is exactly how it happened.

First the cheetah woke up, rolled over, and looked around.  Next thing he noticed some kudu walking in the distance, and went into a focused crouch.  The sun now began to gradually illuminate the scene.  For a few moments, the rich, warm light brushed over the cheetahs face, and into his eyes.

Just moments later, the light was gone, but not before I had managed to take the accompanying shot. 

Although the image is only of a cat lying down, I was more than happy with the wonderful light, the cheetah’s pose, and the far-off mountains in the background.  Luckily the road that we were on was below the level of the ground that the cheetah was lying on.  That meant I was able to shoot from a relatively low angle, which helped me include the mountain backdrop.

I shot with the Canon 1Dmk4, which at the time of writing is my preferred Canon camera for use in low light.  I used the EF 300 f/2.8L IS lens, and handheld it.  I chose an aperture of f/4.0, to make sure I got all of the cheetah in focus, and set the iso to 800, which translated into a shutter speed of 1/250s, which was fast enough to capture a sharp frame of the motionless cat.

Cheetah were reintroduced to the national park in 2007, and they are doing well.  There are six collared cats.  The collars allow researchers to locate the cheetah, not only for research but also for the cheetah’s own safety.  The national park borders on some farming areas where cheetah are not welcome, and the collars allow the park authorities to quickly locate and capture the cats before.

Collars on wild animals are not ideal for photography but they do serve an important purpose in this case.

To find out more about Wild magazine, which is the official magazine of South African National Parks, click here:  Wild magazine website

ISO 1600 Image Quality Comparison - Canon 1Dmk4 and Canon 7D

Canon currently produce two camera bodies that have quite a high degree of similarity, based on their general specifications.  The two bodies are the Canon 7D, which is an APS-C sensor camera, that has 18mp of resolution, 8 fps drive and the Canon 1Dmk4, which has a larger APS-H sensor inside, with 16mp and 10 fps drive speed.

I often am asked as to what some of the main differences are in image quality between these two cameras.  With this in mind I set up the two cameras to shoot some comparative images from both in order to compare some of their characteristics.  In an earlier post I carried out this exercise with both cameras set at ISO 400.  You can find that post by looking in the Blog Archive on the right side of this page under the February tab.

For this comparison I set them to ISO 1600.

I used a Canon EF 70-200 f/2.8L IS II lens, mounted on a tripod.  Only the camera body was changed each time.  No sharpening was applied other than a default setting of 25 in Adobe Camera Raw.  Raw images opened in Photoshop CS5, downsized and saved using File Save For Web and Devices at 90kb file size.  

The images were taken in good light, as can be seen from the exposure details.  The black and white zebra made a good target for comparing detail in blacks, whites and fur, especially around the edges of the ears.  I also included the dark green and shadow patches in the background for comparing noise levels.

Canon 1Dmk4. ISO 1600.  1/500s at f/5.0, as taken.  16mp, no cropping.

Canon 7D. ISO 1600.  1/5000s at f/5.0, as taken.  18mp, no cropping.

The first image is that of the Mk4, with its 1.3x crop effect.  The image directly beneath it, and above this text, is that taken with the 7D, with its 1.6x crop effect.

Another way to better understand the size difference between the images is to relate them to the sensors in each camera.

The APS-H sensor in the 1Dmk4 is 27.9mm long and 18.6mm high.  When the image circle is projected from the rear of the lens, more of it falls onto this sensor then the smaller sensor in the 7D, hence the wider field of view, with more background visible.

The APS-C sensor in the 7D is 22.3mm long and 14.9mm high.  When the image is projected from the rear of the lens, this smaller sensor can only record over its smaller surface and you lose more of the captured image around the edges of the image circle.

These two pictures serve to show the difference in subject size between the image obtained by the 1DMk4 and the 7D then, out of the camera.

The Mk 4 image is made up of 16 megapixels, and each pixel is 5.7 microns in size.

The 7D image is made up of 18 megapixels, and each pixel is 4.3 microns in size.

None of that is apparent whilst looking at them now, only the fact that the 7D is giving you a bigger zebra.

In the next step I have cropped the same two images.

Canon 1Dmk4. ISO 1600.  Cropped from 16mp to 6.8mp.

Canon 7D. ISO 1600.  Cropped from 18mp to 12mp.

In order to make it a bit easier to see differences at what might be considered a normal crop size, I cropped the bottom image, from the 7D, to 12 megapixels, thus discarding 6 megapixels. 

Then, I 'equalized' the two cameras by cropping the Mk4 image, until the zebra was the same size, approximately, as the zebra in the 7D image.  This left me with a cropped 1Dmk4 image of close to7 megapixels, still pretty much usable for most requirements in resolution.

Comparing the quality of the two images on my 23" screen side by side, I cannot see any massive quality differences between them.  To my eye the blacks look a little better on the Mk4 image, and the background may be showing very slightly more noise on the 7D image.

For the last example, I again cropped the two images further, keeping the zebra pretty much the same size.

Canon 1Dmk4. ISO 1600.  Cropped from 16mp to 2mp, downsized to 800x533.

Canon 7D.  ISO 1600.  Cropped from 18mp to 3.5mp, downsized to 800x533.

This time I cropped in heavily, to try and make it easier to judge image quality almost at pixel level.

The cropped 1Dmk4 image comes in at 2.0 megapixels, from a 16mp original, and downsized to 800x533 for the test.

The cropped 7D image comes in at 3.5 megapixels, from an 18mp original, and downsized to 800x533 for the test.

In this post I cropped a little less aggressively than on the last pair of images in the ISO 400 post.  I chose here to crop the Mk4 image to 2mp which is really for illustrative purposes only.

For my own workflow for web I prefer not to go under about 4mp in resolution with any image.

To my eye the Mk4 file is still slightly superior in terms of noise, the blacks, and the general tone of the whites in the image.  On the other hand the 7D file is retaining more detail in most areas, due to the Mk4 file running out of pixels.

Discussion

This comparison shows that in good light, and at ISO 1600, it is possible to crop the 1Dmk4 image until it matches the "subject size" of the same image taken on the 7D, and that there is not a great deal of difference in the image quality of the two cameras when this cropping is carried out.  The Mk4 image shows a slight contrast advantage at moderate cropping levels.  At extreme crop sizes, the higher resolution of the 7D gives it a definite advantage.  

If you are surprized at how close the two sensors are in these comparison images, it needs to be remembered that they come from the same era, with similar levels of technology applied, and we have taken away the advantage that the larger Mk4 pixels may have by cropping it to equalize subject size.

The comparison images were also shot in bright light, which also narrowed the low-light advantage that the Mk4 holds.  

A different method of testing sensor characteristics and image quality between the two cameras would be to compare image quality between the two bodies when longer focal length lenses were used on the Mk4's bigger sensor, to 'equalize' the sensor characteristics, for example shooting the 7D at 100mm focal length and the Mk4 at 130mm, approximately.

I have taken a set of images for this purpose, in very low light and will be posting that comparison soon. 

After extensive use of both of these camera bodies, my own findings in actual shooting conditions pretty much supported what comparing these images shows but I would of course not usually be shooting at ISO1600 in such bright light to begin with, though from the results you can see that you could if you wanted to.

Where focal length is a limiting factor, in other words if the subject is so far away that only very heavy cropping will get enough subject in the frame for the final output, and in good light, the 7D has a resolution advantage and its smaller pixel pitch are hard to beat.  The comparison test carried out here simulates a situation where focal length was limited, in other words we cropped the subject much closer, in stages, with heavier cropping being applied to the Mk4.

I did not calibrate the two camera bodies to the camera lens.  Whilst there were no clouds in the sky, and I shot as quickly as possible between changing bodies, there might be slight changes in available light, though not enough for the camera metering to pick up. I may have also not gotten absolutely sharp focus on the Mk4 iso 1600 shot as the nose of the zebra is not as sharp as in some of the other test frames at different settings with the same camera and body but this will not affect the noise comparison much.  I do not have a 7D with me at the moment to repeat this image.

No sharpening applied to these images, but for my purposes, in raw format, I felt that both lens and camera combinations were working well enough.

With proper sharpening applied, there would be lots more detail showing on the subject, even the slightly softer (user-error generated)  Mk4 image.

To read a full review of the 7D, click here: EOS 7D Review

To read a full review of the 1Dmk4, click here:  EOS-1DMk4 Review

To read a full review of the EF 70-200 f/2.8L IS II , click here: EF 70-200 f/2.8L IS II Review