Atlanta portrait and wedding photographers Craig & Cathy Willis

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File Size and DPI: Confusion Between Nikon and Canon Digital


When you open up a file in Photoshop or Nikon Capture, you will see a difference between how they display the size or "resolution" why this happens I am sure is due to how each camera maker has programmed it to do just that.

If you look close, as much as they try to out do each other, each does many things just the opposite. You will see this in how functions are set up with their respective cameras.

My personal feeling about that is once you get used to how one of the brands works, your going to be less likely to switch, because when you pick the other brand up to play with it, the camera will not feel familiar at all, and the person will quickly say to themselves, I don't like this, everything is backward, or works so much differently, yet both do the same job, and that is capture images beautifully.

If you took the time to get familiar you will see that both are very much alike, and you would find your way around these differences in a very short time.

Your decision really needs to be about lenses in the first place when buying a camera.

If you already own a nice set of lenses of one brand or another, then it really does not make a lot of sense to go for the other brand, unless you have money to burn, and don't mind spending money each time the wind changes direction.

However there are many valid reasons to pick one compared to the other, and that is something you have to find is right for you. Having owned and used both brands, as well as a few others, I have found my match, but that same pick would be the wrong choice for the next photographer, it's good that we have so many to pick from.

No matter what camera body you own right now, will most likely not be the same model of camera body you will own in the next two or three years, but the lenses are going to be the same ones, and perhaps a couple additions.

Back to the topic of this page, and that is the confusion about how Canon opens up in your photo editing software showing it at 72 ppi and that alarms some people when they first see that, but you have nothing to worry about, it does not mean your camera took the image at only a resolution of 72 ppi at all. But the physical size in inches looks impressive. I suppose that is why Canon picked it to open up that way.

Nikon digital cameras open up showing a smaller physical size, but open up showing 300 ppi. If you take each on and change the PPI but keep the same output ratio, you will see that the file size in inches will change accordingly.

Click image for a fullsized image in a new window.

Perhaps this image will help make it easier to see.

I used these two file also to show another point of interest that I will touch on later.

Actual file size is what is important and if you use the numbers and do the math you will see how they get the "MP" size of your camera.

The Canon 1D Mark II is an 8 MP camera.

3504 X 2336 is the file size of this camera, which = 8,185,344 or 8 Mega Pixels.

The Nikon D2H is a 4.1 MP camera.

2464 X 1632 is it's file size which in turn equals 4,021,048 or 4 Mega Pixels.

Now 8 is twice as much as 4 right? But then why at the same resolution, either the 72 or 300, is the files physical size not the same ratio, and that is why is the one not twice as big as the other. See the blue lines on the image above.

I will leave you to ponder on that one at this time.

Part of this discussion that prompted this page, further developed about what some cameras shoot as far as DPI if shooting JPEG and Vs RAW capture.

Some saying that with Canon you get 180 DPI when shooting JPEG, which I have found to be true, and 240 DPI when shooting RAW with Canon digital, which I have not done, so I cannot verify that at this time with no Canon camera in my camera bag.

With my Nikon D2H, I get the same if I shoot JPEG or RAW NEF file format.

I don't have the answers, and I am not sure that it matters that much anyhow, but when I ask the question myself to the Experts using Canon cameras, they don't have an explanation either.

Click image for a fullsized image in a new window.

Top one is JPEG the bottom one is RAW NEF.

Notice any difference in color? Notice that both have the same file name. This was taken with one exposure, but having the camera write a RAW file and a Large Fine JPEG at the same time.

I exposed for the white, as if it was gray, and therefore it is two stops underexposed.

But the RAW file can handle that problem, and take the adjustments just fine, where you can easily see that they JPEG file cannot render even close with such under exposure.

There are many other fine points that I could show to prove that RAW capture beats JPEG capture hands down.




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