canon 7d vs 1d mark iii - iwishicouldfly.com 7d vs 1d... · canon 7d vs. 1d mark iii a bird...

Canon 7D vs. 1D Mark III

A bird photographer’s comparison of the Canon 7D and the Canon 1D Mark III cameras.

By Alan Stankevitz

Before getting into the nuts and bolts of this article, please note that this comparison is designed for those who shoot

birds/wildlife in a focal-length-limited scenario. In other words, the photographer can’t move closer to the subject and

must photograph the subject from a set distance. Post-processing in this scenario requires the image to be cropped in

most cases.

In almost all of the reviews and comparisons found on the Internet and elsewhere, camera images are compared in a

studio environment and the photographer frames the subject by moving closer or further away in order to frame the

subject identically when using different cropped or uncropped sensor cameras.

As a bird photographer, I find these tests rather frustrating because they do not cover focal-length-limited scenarios in

which I encounter on almost a daily basis. In the field, I must photograph from a set distance unable to walk up to the

bird and take its picture. Doing so would spook the bird.

1.3x vs 1.6x Sensors

The Canon 7D camera has a 1.6x sensor. This means that the images taken with the 7D when compared with a full-frame

camera such as the 5D Mark II, appear to be 60% larger. “Appear” is the key word here. The camera sensor is not

magnifying the image, it’s “pre-cropping” the image. The end result is that the images taken with the Canon 7D are

already pre-cropped by 60%. With that stated, the 7D is also an 18 megapixel camera. That’s a lot of photo sensors

crammed onto one chip. If that chip was manufactured as a full 35mm sensor, it would be 46 megapixels!

The downside to having photo sensors densely packed is noise. A common analogy used regarding sensors refers to the

sensors as being buckets collecting photons. The smaller the bucket, the less photons there are to be collected. This

increases the signal-to-noise ratio making for noise that can be distracting in an image.

The Canon 1D Mark III has a 1.3x sensor. Images are “pre-cropped” as in the case of the 7D, but to a lesser extent.

It is important to note the differences in the size of the 7D and 1D Mark III sensors because it does play a role when

post-processing images of birds in the wild. Since the 7D is pre-cropped to a greater degree than the 1D Mark III, the 1D

Mark III images will require greater post-process cropping.

Post-Process Cropping

No matter what software you may use to process images, in almost all cases you will do some form of cropping. We crop

to put images on the Internet. We crop to send images to publishers. We crop before printing images to hang on our

walls. You get the picture. (No pun intended.)

In my particular case, I crop my images using Photoshop CS4. Publishers require that my images be processed to 300 ppi

(pixels per inch). I also do the same when sending images to the lab to be printed. It is such a common way to crop,

Photoshop has default settings for this form of cropping. For this reason, all images in this comparison were cropped to

300 ppi, 8 x 10 format.

As stated earlier, the 1D Mark III’s images will require a greater degree of cropping than those from the 7D due to the

sensor sizes used in each camera. The goal of the following comparisons is to end up with cropped images depicting the

subject identically in each set.

How the image comparisons were taken The following image comparisons were done in the field with rather cooperative wild birds/animals. Every attempt has

been made to compare “apples to apples”. The exact same settings were used in all cases between both cameras: ISO, f-

stop, and shutter speed. Images were recorded in RAW format and then processed into 16-bit TIF images with Canon’s

Digital Photo Professional (DPP) version 3.7.1.1. No sharpening was applied and no noise reduction other than color

noise removal. Removing color noise does not affect the image resolution, so it was applied equally to both camera’s

images. Luminance noise reduction does affect the resolution and therefore was not applied.

Once the images were converted to TIF, they were post-processed using Adobe Photoshop CS4, version 11.0.1.

Example 1: Downy Woodpecker, ISO 3200

Canon 7D, f/8, 1/1000 sec, ISO-3200, 840mm

Original Image

Canon 1D Mark III, f/8, 1/1000 sec, ISO-3200, 840mm

Original Image

Canon 7D, 100% zoom, original image Canon 1D Mark III, 100% zoom, original image

The images above show a 100% zoom of both images. The 7D’s image appears magnified compared to the 1D Mark III

due to the 1.6x sensor vs. 1.3x sensor. Noise appears in both images, but not too bad for ISO 3200. When images are

properly exposed, noise is usually tolerable with both of these cameras up to and including ISO 3200.

The next step is to crop each image so that they are framed identically (8” x 10” , 300 ppi format):

Canon 7D, cropped 8” x 10”, 300 ppi Canon 1D Mark III, cropped 8” x 10”, 300 ppi

Now, let’s again look at a 100% crop with both images cropped identically:

Canon 7D, 100% zoom, 8” x 10” cropped image Canon 1D Mark III, 100% zoom, 8” x 10” cropped image

When cropping images to 8” x 10”, 300 ppi format, Adobe Photoshop will resample the images and either add pixels or

remove pixels to create an image that is 2,400 pixels by 3,000 pixels in size. The native format for these two cameras are

as follows:

7D: 3,456 x 5,184 pixels

1D Mark III: 2,592 x 3,888 pixels

In more cases than not, the 1D Mark III’s image when cropped will be resampled upwards in size for an 8 x 10 inch, 300

ppi format. This means that Photoshop will add pixels to bring the cropped image up to the desired size. When

Photoshop resamples upwards, this indicates that no further resolution is available for the crop.

In the case of the 7D, there’s more room available to crop an image before upward resampling occurs. Considering that

the 7D’s image is already pre-cropped by the sensor by a factor of 1.6x and there’s 18 megapixels to play with, there’s a

lot more resolution available when post-processing the image when compared to the 1D Mark III.

As the above comparison shows, the 7D’s image has better feather detail with similar noise levels.

Example 2: Eastern Gray Squirrel, ISO 800

Canon 7D, f/8, 1/800 sec, ISO-800, 600mm

Original Image

Canon 1D Mark III, f/8, 1/800 sec, ISO-800, 600mm

Original Image

In this instance, our squirrel was sunbathing on the trunk of a tree. This gave me plenty of time to take its picture with

both cameras. I very easily could have shot these images with lower ISO settings, but I wanted to show how ISO 800

looks in a bright setting with proper exposure.

Let’s take a look at a 100% zoom of both images:


Now let’s crop the images to frame the squirrel identically with both cameras (8” x 10”, 300 ppi):




I purposely centered this crop to highlight any background noise. Noise appears most prevelantly in areas of images that

either have blurred backgrounds or dark shadows. Both images have very similar noise levels with the 7D being slightly

more noisy, but sharper. The hairs on the squirrel’s tail and around its ear are sharper compared to that of the 1D Mark

III.

Example 3: Herring Gull, ISO 400, pushed 1 stop

Canon 7D, f/7.1, 1/2000 sec, ISO-400 +1, 840mm

Original Image

Canon 1D Mark III, f/7.1, 1/2000 sec, ISO-400 +1, 840mm

Original Image

In this instance, I purposely framed the gull against a brown, blurred background and underexposed the image by one

full stop. Blurry backgrounds (bokeh) is a good place to look at noise and this brown background has a fair amount of it.

This plus the fact that the original images were underexposed, will bring out the worst for this ISO level.

Let’s take a look at a 100% zoom of both images:


The 7D’s image clearly shows more noise at 100% zoom, but remember it is a 1.6x sensor. Our gull is already pre-

cropped. Now let’s frame the bird identically as in the first two examples:




Here we have a nice shot of the gull’s head and eye. This image required the greatest amount of cropping out of all the

examples. The 1D Mark III suffers more in this instance due to extensive upsampling. The 1D Mark III image may have

about the same level of noise as the 7D, but it is not as fine-grained as the 7D. The sharpness of the 7D is quite a bit

more noticeable as well.

Conclusion

Both cameras are fine cameras for bird/wildlife photography. The differences that are apparent in these examples can

only be seen while “pixel peeping”. The 7D exhibits greater resolution than the 1D Mark III and that should not be a

surprise. An 18 megapixel sensor with a crop factor of 1.6x should outresolve a 10 megapixel, 1.3x crop factor camera.

What may be a surprise is that the 7D only exhibits slightly higher noise levels in focal-length-limited situations in which

the photographer cannot move closer to frame the subject identically with both cameras. Framing the subject identically

can only be done afterwards through cropping, with the 1D Mark III requiring greater cropping than the 7D due to the

1.3x sensor. The greater cropping required by a 1.3x sensor or even more cropping required by a full-frame sensor tends

to equalize the noise in all three types of Canon DSLR sensors. At least, I have found this to be true when adding the

Canon 5D Mark II to the comparison.

As an added footnote to this comparison, I have recently acquired images from the 1D Mark IV and have compared it to

the 7D. The Mark IV has lower noise than the 7D but still a tad less resolution. By reducing the noise slightly in a 7D

image, the Mark IV images look identical from both a noise and resolution standpoint. Again, these comparisons were in

a focal-length-limited scenario.

I cannot stress enough how this conclusion applies ONLY in situations where a wildlife photographer cannot walk up to

its subject. Results would be different otherwise.

Thanks for reading,

Alan Stankevitz

website: www.iwishicouldfly.com

email: [email protected]

canon 7d vs 1d mark iii - iwishicouldfly.com 7d vs 1d... · canon 7d vs. 1d mark iii a bird...

Documents