CITY ESCAPES

Nature Photography, LLC

Newsletter

January, 2013

Full-Frame vs. Cropped Digital Camera Sensors

Digital camera sensor sizes can be confusing.  Like many things technical, they are often given names consisting of a combination of letters and numbers that tell the uninitiated absolutely nothing.  Many of us wonder why we should even care; after all, the only easily discernible difference -- for those who aren’t fluent in geekspeak, anyway -- is the price tag.  There are significant differences between the characteristics of various sensor sizes, though, and even if you aren’t looking to buy a new camera soon, understanding those differences may help you get the most out of the camera you currently have.

Most sensor size names are based upon their relation to the size of a 35mm film negative.  Thus, a full-frame sensor is roughly the same size as a 35mm film negative, while almost everything else is smaller.  (Medium- and large-format digital sensors do exist, but they are such a completely different animal, and so prohibitively expensive, that we will not discuss them here.)  Just as the size of cameras themselves vary widely from camera phones through point-and-shoots up to professional-grade behemoths, so do the sensor sizes.  Each has particular traits that make it more or less useful for any given situation and photographer. 

Given that full-frame sensors are only available for DSLRs, we will focus here only on that line of cameras.  Therein lie two main choices: full-frame sensors and crop-frame sensors.  Here are some of the differences.

* Zoom factor: a full-frame sensor will give you the same field of view as a 35mm film camera, given an equivalent lens.  In other words, looking through a full-frame camera with a 100mm lens attached, you will see the same field of view as looking through a 35mm film camera with a 100mm lens attached.  The smaller crop-frame sensors, however, will “zoom in” on your subject.  Thus, looking at that same subject through a camera with a crop factor of 1.5 is like looking at it through a 150mm lens on a 35mm film camera.  Whatever is in the center of your frame will fill up more of the frame, and whatever is on the edges will be cropped out.  This is great for subjects where getting closer is desirable, such as wildlife or sports photography, but not necessarily helpful for subjects where a wider expanse is wanted, such as landscape photography.

* Depth of Field: Because full-frame sensors “see” more, in order to fill the frame to the same degree as a crop-frame sensor with any given subject, either a longer focal length must be used, or the photographer must get closer to the subject.  This makes the depth of field shallower, as both techniques help to isolate the subject from its background.  If you’ve ever been frustrated by your point-and-shoot camera’s inability to blur backgrounds, this is why: you can neither get close enough to your subject (and still maintain focus), nor do you have a long enough focal length at your disposal.  On the other hand, large-format cameras can have trouble achieving a deep enough depth of field for landscapes.  Apertures must be closed down anywhere from a stop to a stop and a half to get an equivalent depth of field to a crop-frame sensor.  

* Noise: In general, the bigger the sensor, the larger the photosites (the actual instruments that record light at a specific point on the sensor).  This means that even though a full-frame sensor and a crop-frame sensor may each create 12 mp images, images from the full-frame sensor will be cleaner, with less noise, and with a greater dynamic range (more shades from light to dark are successfully captured).  This is especially evident in low-light photography, where full-frame sensors can significantly increase the maximum usable ISO. 

* Detail: Those larger photosites allow for much greater detail in the image, as well.  To maintain detail in a deep depth of field image, however, requires longer exposure times or increased ISO settings.  Due to the full-frame sensor’s lower noise content, this may not present any real problem, requiring only a few tweaks to settings and, of course, a tripod.

* Lenses: One thing to note is that the lenses for the two different types of sensors are quite different.  Full-frame lenses can be used to full effect with either type of sensor, while crop-frame lenses are limited in their abilities on a full-frame camera.  Namely, the camera will automatically crop the area to be used on the full-frame sensor to equal the size of the crop-frame sensor, effectively negating many of the benefits of the full-frame sensor.  You will still get the advantages of the larger photosites, but the number of those photosites utilized will be drastically reduced. Also, lenses for full-frame cameras tend to be much larger, heavier, and significantly more expensive than their crop-frame counterparts. Using full-frame lenses on crop-frame cameras can have a peculiar advantage, though.  Most lenses produce images that are sharpest at the center and that blur toward the edges.  Since crop-frame sensors will not register the edges of the full-frame lens, the blurriest parts of the image are automatically removed. 

Hopefully this information will help you understand how to use your current camera to a fuller capacity.  And if you’re in the market to upgrade, you now have a little more information to ponder.

Good luck, and good shooting!

January’s Monthly Specials

Get 10% off of unframed, 8x12 prints of “Calling Darwin – Galapagos Mockingbird” and / or “Nature’s Paintbrushes” when you order from our specials page. As with all of our unframed prints, these prints are eligible for our No Hassle Returns. 

January’s Fun Facts

January’s birthstone is the garnet.  We are familiar with the deep burgundy color that makes garnets so extraordinary, but did you know that this gemstone occurs in a wide range of colors?  Natural garnets come in all colors – even colorless --except shades of blue, and larger garnets can be multi-colored.  Some garnets that are particularly hard do not find their way to a jeweler’s, where we are accustomed to finding them, but rather to an industrialist’s: they are made into sandpaper, appropriately called garnet paper.

If you have any questions, or suggestions for future newsletters, please email us at: [email protected]

Become a fan on Facebook at

http://www.facebook.com/NaturePhotographs

CITY ESCAPES Nature Photography, LLC

www.cityescapesphotography.com

774-277-9682