Full Framed or Cropped
Now, here’s a discussion item. For most of the digital single lens reflex (DSLR) world, they use 35mm film as the benchmark for everything digital. Even though the media is completely different the comparisons are always made back to shooting with film. I guess there’s good and bad for that. For our purposes, the subject of sensor size comes back to referencing the size of a camera’s sensor to that of a full framed 35mm piece of film. I’ll even add, this comparison is applied for large format as well. I’ll attribute this to the huge familiarity folks have with 35mm film. Any reference to 35mm tends to apply a bit of reality to hypothetical discussions.
The point of today’s article is the merits of full-framed or cropped sensors. Referencing back to 35mm film, full framed is a sensor that’s equal in size to a 35mm film while cropped is something less then that. Today’s article is about comparing the merits between the two formats.
First of all, I’m not so sure folks understand why 35mm is the benchmark. Here’s a little history. The 35mm is the standard because the first successful “compact” camera was introduced and built by Ernst Leitz. Now his cameras are called Leica’s. Back in the late 20’s and early 30’s they used a film intended for the motion picture industry for use in their cameras. From that came the standard we all take for granted today. Who would’ve thought we’d be basing our size standards on something from the motion picture industry?
So, the standard is the standard. Still, it’s a measure or a benchmark but it doesn’t necessarily mean that its size is better than anything else. That’s what I want to explore. Will a “full-framed” sensor be better than a “cropped” sensor? I’ll reserve my judgement for later.
Assuming full-framed is full-framed, what are the differences when you go with a cropped sensor? The most obvious is the field of view (FOV) is less. Without getting into the quality of the image, does a cropped sensor make a difference? It sure does. For comparative purposes, I’ll use Nikon’s APS-C sensor as the size of our cropped sensor. It is 2/3rd’s the size of 35mm--long side is 1 inch instead of 1.5 inches. These sensors will appear to have more apparent magnification. Is it really magnification? It’s only magnification in the same way you might squint through your fingers held into a really small circle. Somehow you might think you can see further, with more magnification. From the image point of view it really looks like you’re seeing things closer. From the same physical point, your 200mm lens now looks like a 300mm lens. The APS-C fov is 2/3’s the size of a full-framed 35mm sensor. It sounds like you’re getting something for nothing. But, are you?
What’s the drawback? Once again presuming image quality isn’t a factor you lose the wide range with cropped sensors. As much magnification you get on the long end of lenses, you get less wide on the wide end of wide-angles. That’s a problem for many people including landscape shooters.
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