Lightweight Backpacking Camera Selection 101 – Why Sensor Size Matters
If you don’t want to go into all the gory details at this point you can just jump to a discussion of the lightweight backpacking cameras I use.
While some point and shoot lightweight backpacking cameras may produce quite serviceable photos, don’t expect professional quality images from a camera with a sensor* the size of your little fingernail and a lens the size of a snap pea. It would be great if a 5 oz Point and Shoot (P/S) compact camera produced images close to the quality of images from a 3 ½ pound digital SLR (DSLR) camera and lens combination like a Canon 5D and 24-105mm f/4L IS lens. But camera sensor and lens size has significant impact on image quality. In summary: better image quality requires a larger sensor, which in turn requires a larger camera body and a larger lens, and ultimately a heavier camera.
Since we can’t bypass laws of physics (sensor* and lens size), each backcountry photographer will need to find a satisfactory compromise between camera size/weight and image quality.
* Sensor is the device in a digital camera that electronically captures the image. It performs the same function as film in old style film cameras.
Major factors to consider for image/photo quality
- Larger sensors produce better image quality: (see Table of Sensor Sizes and Pixel Densities below)
A P/S camera has a sensor 5% the size of the full-frame sensor of a camera like the Canon 5D. If each camera has the same number of pixels, then the pixels on the P/S camera will need to be 5% the size of the full-frame camera’s pixels in order to fit on the smaller sensor. So each P/S pixel can only gather 5% of the light of a full-frame sensor pixel—sometimes only a few photons per pixel (yes literally down to the photon level!). Without going into gritty detail, the close pixel spacing and limited light gathering ability of smaller sensors leads to less resolution/sharpness (for the same pixel count), less dynamic range (especially problems with clipped highlights, i.e. entirely white areas without detail), less color saturation, more noise, decreased ISO performance, and ultimately lower image quality.
- Lens size matters: A larger sensor requires a larger lens to cover the larger sensor area. In addition, there is a limit to how precisely one can shape a small lens (e.g. a P/S camera lens). Due to the immense popularity P/S cameras and digital video recorders, there have been astonishing advancements in the optical quality of small molded plastic lenses. Nonetheless, the best optical quality is still from precisely ground glass lenses. These are the lenses used for for mid-size-semi-pro-sensors (approx. 30-40% of 35mm coverage) to full frame sensors (100% of 35mm coverage). Larger lenses do cost a lot more. A top quality lens might cost between $800 to several thousand dollars. But there are bargains to be had with some gems in the $200 to $500 range (e.g.Sigma’s Art Series prime lenses). And even some quite good zoom kit lenses.
- Intended print size or use of images: If you intend to use the camera to produce 800 pixel snaps for your webpage, a good P/S camera should to the trick (although you will still a reduction in dynamic range, and color accuracy). But if you intend to frame large prints, you will be disappointed with the results from a P/S camera. To get sharp 16×20 or larger prints, with good color and tonality you’ll need at least a mid-size-semi-pro-sensor camera (approx. 30-40% of 35mm coverage) with a high quality lens—something like the Sony a6000.
Finally, there are no takeovers for backpacking photography. A small sensor P/S camera is extremely unlikely to produce a high quality enlargement no matter how fabulous the shot. Photoshopping is unlikely to make significant improvements. Think hard before you commit to a smaller sensor camera.
Killer Point and Shoot Cameras for backpacking
Some great, almost pocketable, 11 ounce “point and shoot” cameras produce superb images. The major disadvantage is high cost.
- Sony Cyber-shot DSC-RX100 IV 20.2 MP with its large 1″ technology-leading sensor, excellent optics and image stabilization
- Panasonic LUMIX DMC-LX100K 13MP with a huge 4/3 sensor (only uses a portion of the sensor, so gets about 1.5x more sensor area than the Sony) but is only 13 megapixels.
Mirrorless crop format cameras are probably your best option for serious photography
You best option for serious backpacking photography is probably one of the inexpensive mirrorless crop format camera (APS, APC, μ4/3) like current Sony a6000. The best of these cameras approach full-format SLR picture quality in a light, compact camera with interchangeable lenses. By doing away with a SLR mirror and viewfinder, but retaining the larger sensor and lenses of an SLR, you significantly reduce weight and bulk but retain picture quality. The 16 ounce Sony a6000 with the right $200 prime lens (Sigma 30mm f2.8 DN), can produce image quality challenging the Canon 5D.
And I admit, even I am tempted from time to time to carry a Canon 5D into the backcountry for its superb resolution and image quality! Note: The full-format mirrorless Sony a7 is starting to make inroads into the serious professional photo market. Even here photographers are finally getting tired of the weight and bulk DSLRs.
Cameras and Their Sensor Sizes
The following is a list of some cameras and their sensor sizes.
As a rough estimate, the lower the pixel density (mp/cm2) the higher the image quality of the camera.
Pixel density counts, but there may still be significant image quality differences between cameras with sensors of similar pixel densities (although probably not enough to jump camera classes). These differences in image quality are usually due to improved sensor technology and improved camera image processing. E.g.:
- Even though it has a higher pixel density, the new Olympus E-620 has almost 1.0 EV more highlight range than the older E-520. But it still doesn’t have the RAW headroom (dynamic range) or high ISO performance of the best, mid-sized sensor APC/APC cameras (e.g. Nikon D300 or Canon Rebel XSi), let alone a full 35mm sized sensor camera (e.g Canon 5D mk2 or Nikon D700).
- The Canon PowerShot G10 performs considerably better against compact cameras than its extremely high 34 mp/cm2 pixel density might indicate. But its 10x higher pixel density cannot match the image quality of the mid-sized APC/APS and 4/3 sensor cameras like the Canon Rebel XSi or Olympus E-620.
- The improved technology of the Canon 5D Mk II (sensor and image processing) has better image quality (but not by a lot) over the older and lower pixel density 5D. And at 21 vs. 12.7 mega pixel the Mk II has more resolution. But the 2.4 mp/cm2 Canon 5D Mk II does not have near the RAW headroom (dynamic range) of the 1.5 mp/cm2 Nikon D700.
Available Lenses: Their Quality and Their Weight
Larger sensors require larger lenses. Larger lenses are heavier, and significantly more expensive to make. In particular it is quite difficult to make an inexpensive, high quality full frame (35mm) lens for cameras like the Canon 5D. This is where the smaller, high quality midsized sensor lenses like the Olympus Zuiko μ4/3 format lenses really shine. For the Sony a6000 there are some incredible deals with Sigma’s Art Series prime lenses. So make sure you check out the availability of high quality lightweight lenses before committing to a particular camera line. Sometimes, the lenses are significantly more important for weight and image quality than the camera body. And it is likely that you will own and use the lenses far longer than a given camera body.