Everyone loves their full frame camera. By default they’re better all-around cameras than crop sensor cameras for a variety of reasons. The biggest being, of course, that they don’t cut off (or crop) the image when it’s captured. For this and other reasons, it’s a bit counterintuitive why–when it comes to taking panoramas–a crop sensor camera is going to yield higher resolution (what I’m calling “better quality”) photos than a full frame sensor.
8mm Images on a Full Frame Sensor
When you shoot panoramic imagery, it’s going to be pieced or stitched together from a number of images. You need some overlap between the images so that they’ll stitch properly. Typically, taking the pictures at 90° stops works well if you’re intending on spherical panoramas. I shoot with an 8mm Sigma lens that has a 180° field of vision both horizontally and vertically.
This is particularly noticeable in the image that is produced with the lens. The image is circular! On a full frame sensor, the visible image will extend to the short side of the frame. On this 20 megapixel, Canon EOS 6D, that’s about 3600 pixels.
8mm Images on a Crop Sensor
Using the same 8mm lens, here’s an image taken on a Canon t3i – a crop sensor camera. The most noticeable difference should be that the image fills nearly the entire frame. Instead of the 3600 pixel-round image from the full frame sensor, you now get a full 5200 pixels on the long edge of the crop sensor frame. Remember–you need some overlap between images (along the horizontal field of vision) to stitch a proper spherical panorama.
In both the full frame and crop sensor, you have enough along the horizontal axis to stitch. In the crop-sensor image (at left) you can see there is a lot more frame usage along the vertical axis. In fact, the long edge of the sensor produces about 5200 pixels. Since you’re getting the full 180° in one frame, the height (in pixels) of that image ends up being the height of the finished panorama.
Resulting Panorama from Full Frame Sensor Imagery
As you can see below the panorama that is created when all four full frame images are stitched together is roughly 7000px by 3500px. That’s a 2:1 ratio because we have a full 360° x 180° field of vision. While this image looks great and will render well in a spherical projection, take note that the overall pixel count is about 24.5 megapixels. This isn’t a whole lot more than your full frame image to begin with – which is about 20 megapixels.
Resulting Panorama from Crop Sensor Imagery
After seeing the imagery above, you might not have too much concern with how your full frame panos are turning out. To be honest, I don’t think the end product is that bad! There was a little post-processing done in Lightroom, but the overall clarity and resolution is pretty good. However, take a look at the pano created from the crop-sensor imagery. Your immediate focus should be on that 11,000 pixel width. The total pixel count for this pano is a whopping 60 megapixels, nearly two-and-a-half times the full frame panorama. On the surface, or at the default zoom level, you may not be able to tell the difference between the two panos.
The difference lies when you zoom in. Your end goal for this could be a beautiful vista or a detailed before and after image of a bathroom remodel. There’s probably not much point in having a deep zoom on an image that has mountains and tress in the distance. On the other hand, seeing the detail on a retail display and being able to distinguish between product types or even see prices would be invaluable in certain situations.
Wrapping up the discussion of Full Frame vs. Crop Sensor for Panoramas
As you’ve read and seen, and contrary to popular belief, crop sensor cameras will actually produce a higher resolution panorama. If that’s what you’re concerned about, stick with that Canon t5i even when your 5D Mark 3 is begging to be used.
Obviously, we’ve used a single variable – resolution – to declare which camera type is better for panoramas. But what about other factors? Some folks are aware that the nature of full frame cameras allow much a higher ISO without the inevitable noise and grain in the image. Maybe you’re shooting in a pretty dark area and don’t want to take 10 minutes to shoot each pano.
What are some reasons you like to use your full frame instead of a crop sensor for panoramic images? Is it a particular feature of your camera? An inherent benefit to the full frame sensor that I didn’t bring up?