How-To Geek

Photography with HTG: What Is A Full Frame Camera? Do I Need One?

Ever heard of a “full frame” camera? Today we’ll learn just what this means by taking a look at camera formats, racking up some serious photo geek cred, and finally deciding if the expensive cameras are worth the heavy pricetag.

Be warned, this is a particularly geeky article! While it’s not too technical, some readers may be intimidated by all of the photography lingo within, unless you’ve been keeping up with all of our series of photography articles, or are just really photo savvy. Check it out!

Full Frame and Cropped Sensor: What Does This Mean?


Digital cameras render images based on information captured from image sensors, like the one shown above inside this Nikon D70. (Edit: Reader Fred says “All you can see is the mirror and the eyepiece prism reflected in in, the sensor is behind both the mirror and the shutter on that DSLR you have pictured.” Regardless, this is where the sensor lives, when it is not covered by these things!)

Light, much like it does anywhere else, harmlessly passes through the lens, refracts, bounces around, and exits again. Without the presence of a photosensitive material (in this case, a sensor, in some others, photo films) that light doesn’t end up doing much of anything. Indeed, even in the presence of photosensitive materials, the light that doesn’t strike the sensor doesn’t really end up doing anything useful to the photographer.

This active imaging area is what gives you your photo when you open and close the shutter—your lens captures more light than you can use on your limited size sensor, and throws away the rest. Note the rectangular shape of your photograph, and compare it to the shape of the sensor in the image above, and you can quickly piece together what’s going on inside your camera.


Most common DSLRs use a sensor that’s smaller than the potential image area of a 35mm strip of film—the size of this image area is called the “format” of the camera. 35mm was a standard format for film, and this size is roughly what we mean when we call a camera “full frame.” The format for your “ordinary” DLSR is called APS-C, or “Advanced Photo System, Type-C.” A Nikon D40 or the D70 we showed above are both typical APS-C cameras and have sensors smaller than a full frame—some call this a “cropped frame.” So what can we expect when using one versus another, and how do they stack up?

What’s The Difference In The Two Formats?


You may have a knee jerk reaction of “a bigger sensor has GOT to be better!” This is not necessarily the case—at least, the truth is very nuanced.

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All things equal, full frame cameras at the same distance have a larger image area. This means that if you attempt to take the same picture at the same distance, your cropped frame camera will crop your picture. That’s bad, right? You’re automatically getting less image in your shot.

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Here’s where things start to get murky. A larger sensor does not translate to higher pixel density—in other words, you can have a 12MP cropped frame sensor or a 12MP Full frame sensor. In this image, with the photographer shooting at the same distance, the full frame is able to resolve less detail than the cropped frame because the lens is interpreting it as if it was farther away. Does this mean that the full sensor is worse at resolving detail? Kind of, but not really. It does mean that an identical shot with all other things equal on a full frame will mean you’ll be squeezing more detail into a smaller slice of your image area. Can you just get closer? Yes, of course you can.


Here’s a related side note. If you’ve ever had a hard time taking a picture with a cellphone camera, and find that you have to back up a long, long distance—chances are it’s because of the camera’s limited sensor size cropping out so much of the detail.


So what do full frame format cameras do well? Without a doubt, they have to be good for something to justify the expense. (Just wait until we take a look at that!) Because full frame sensors are larger, they can gather more light, and can be made more sensitive, allowing higher ISO numbers to create better images in low light environments. In addition to this, the individual cells (called photosites) on the sensor are broader and deeper (so to speak) and allow a more nuanced, richer image to be captured, and not just at night. (Note that this doesn’t increase the image size or the number of colors in an image—it only makes the sensor more accurately read the colors in the frame.)


As we’ve discussed in previous entries of Photography with How-To Geek, higher ISO exposures usually create more noise in an image—and larger sensors only allow for the creation of more noise. Look at it this way—in a light critical situation, the smallest variance in light can be detected and recorded. With extremely high ISOs, the light is recorded practically at the individual photon level, so the slightest change in light can create image noise. Cropped sensors receive somewhere around full stop of light less light than a full frame sensor—more light hitting your sensor means a less grainy image. This is achieved by having a larger photosite—larger individual cells for gathering light on the sensor. A full frame sensor with a lower megapixel rating will have less noise than a full frame with a higher megapixel image. This also means that a full frame with 12MP will have considerably less noise than a cropped frame with 12MP. A greater pixel density will always mean greater noise at high ISO settings, and cropped sensors tend to have greater pixel density.


Because nothing in photography is simple, there is one more advantage to the full frame format, and it can be sort of confusing. Because the sensor is larger, the focal length changes compared to a cropped frame sensor. This allows photographers to take shots of far tighter, closer shots than possible with smaller frame images. If you can imagine a full frame format camera oscura with reflected rays focused from a small object, it begins to make sense. Smaller formats mean that they have a smaller area to focus on, and therefore require more distance to properly cross and meet again in focus.

Why Are Full Frames So Expensive?


The sensor shown above is the largest format in the image depicting the various format sizes, and perfectly illustrates the exponential cost increase for larger sensors. You may ask yourself why, if there are so many trade-offs, would full frames be prices so much higher than cropped frames?

The answer lies in the manufacturing process of the sensors themselves. The larger the frame, the greater the probability of it having a manufacturing defect, based on total surface area alone. It’s more difficult to produce a larger sensor defect free, because one tiny defect ruins the entire sensor. Smaller sensors have a smaller area of continuous space to be defect free. In addition to this problem of greater chances of manufacturing defects over surface area, the process itself can be considerably more labor intensive. For this very reason, the cropped frame has de facto ousted 35mm as the new standard mostly as a function of the affordability.

So, Do I Actually Need a Full Frame Camera?


That’s a tough question to answer. If you’re a hobbyist photographer, you probably can’t justify the expense of a $3,000-$5,000 camera just for taking pictures of sunsets, birds and neat looking trees. If you’re very serious about your photography and hoping to become a professional, the additional benefits of richer color, lights and darks could be a boon. But simply buying more and more expensive equipment will not make you a better photographer, but taking lots of pictures and learning about the camera you have most likely will. So, even very serious amateur photographers should spend a long time pondering if a full frame camera is right for them.

Professionals will get the most mileage out of a full frame camera, not because they’re going to need to use the full frame camera more often or they’re going to always need the increased capacity for light, etc. Simply because a full frame takes a different image than a cropped frame format camera, many choose to include full and cropped frame sensor cameras into their toolkit. A true professional will use the right tool for the right job, and sometimes that tool is a full frame camera, and sometimes it isn’t.

There are professionals and talented amateurs alike that swear by one format over another—it can prove to be a very personal decision depending on the kind of photos you want to take, and the habits you have. If you have your own reasons for loving the full frame format or hating it, feel free to tell us about it in the comments!

Image Credits: Sensor Klear Loupe by Micheal Toyama, available under Creative Commons. Nikon D70 by Rama, available under CeCILL license. Sensor Sizes Overlaid by Moxyfyre, available under Creative Commons. Belomo MC 17mm f2.8 Ojo de Pez para Full Frames by Mauro Fuentes, available under Creative Commons. Full Frame Sensor vs 1.6 crop by Steve Koukoulas, available under Creative Commons. Me and Shana by Jeff Wright, available under Creative Commons. Nikon D3S review by Mukul Soman, available under Creative Commons. Macro Full Frame by Gustavo Duran, available under Creative Commons. Project 366 – 358/366 March of the Cameras HBW by TheSussman (Mike), available under Creative Commons.


Eric Z Goodnight is an Illustrator and Stetson-wearing wild man. During the day, he manages IT and product development for screenprinted apparel manufacturing; by night he creates geek art posters, writes JavaScript, and records weekly podcasts about comics.

  • Published 09/21/11

Comments (13)

  1. Usman

    Very well explained, and I agree with what you mentioned regarding noise. As far as my experience goes, a hobbyist photographer is okay with a cropped sensor. But not a SUPER-CROPPED sensor. If you’re buying a DSLR, don’t get anything with a sensor smaller than an APS-C sensor (Canon/Nikon, doesn’t matter). Trust me, don’t get a four thirds or micro-four thirds sensor camera. The smaller the sensor, the more noise you wil get in your pictures (obviously, smaller sensor=less light, and you bump the ISO to get a brighter picture, but unfortunately, with a lot of noise)

    I made the mistake of getting an Olympus four-thirds sensor camera (as my first DSLR). I got to know the basics, but it isn’t fun at all when you get noise in your images.

  2. bkj

    APS-C is fine for those venturing into the world DSLR photography.

    The next debate HTG should take on….Canon vs. Nikon

  3. Eric Z Goodnight

    @bkj: That sounds like it’ll start a fight!

  4. Aashish

    I’d like HTG to do a fair review of other DSLR camera models veersus Canon & Nikon for the amateur hoobyist. I am a Pentax loyalist and I’d like to see an honest compare to see if Canon and Nikon really are the best thing for an amateur or if it makes any difference at all. Basically, some tips on avoiding marketing gimmicks & hype.

  5. Jeff t

    There is no real debate between Canon and Nikon. At any point in time, either of the two may have an edge on technology, but that doesn’t make one better than the other. The only way for a consumer to make a decision is to go to your local camera shop and try each one out.

  6. Fred

    In the photo above of the D70, and the subsequent text underneath;

    “Digital cameras render images based on information captured from image sensors, like the one shown above inside this Nikon D70. ”

    It says you can ‘see’ the sensor iside the D70, which is simply untrue, all you can see is the mirror and the eyepiece prism reflected in in, the sensor is behind both the mirror and the shutter on that DSLR you have pictured.

    As for which is better, Canon or Nikon, or indeed any other manufacturer, if you have lots of kit lenses from your film days, then stick with what you already own as lenses are not cheap, (Nikon is better at being able to use old lenses on their newer cameras than Canon in this regard)

    If you have not yet bought an DSLR, then there really is very little to choose in many ways today, I have had Nikon, Canon and Fuji cameras over the years, both film and digital in most cases, and if I was buying a ‘new’ camera, I think I might be tempted by the Fuji, mainly for its increased dynamic range and it’s ‘dual sensor’ arrangement, after all why do in software what you can catch in the camera ‘1st time’

    It is also worth getting a camera with the new ‘ultrasonic’ self cleaning sensors, to have a sensor cleaned will cost around £100 as part of a service cost, and that gets expensive real fast.

  7. Tim K.

    The decision for some is what lenses do they already have. If you are invested in one brand with lenses it is doubtful you are going to switch to another brand. I had a Minolta Maxxum 7 with quite an extensive lens collection and was pleased when Sony bought out the brand. I now have a Sony DSLR (A700) and all my lenses wotk with it. I like that the Minolta / Sony camera bodies have stabilations built right into the body and all of my lenses benefit from this.

    Sony just introduced the replacement for my camera (A77) which does away with the mirror. I am considering this as a replacement and really was holding out for a “Full Frame” replacement. After reading this article I don’t even see the need for it.

    Thanks HTG

  8. Kerensky97

    Perfect timing for this article!

    I was just reading DPReview’s review of the Leica 4/3’s Macro lens for the Lumix G series when I came across this sentence that made me call “Bullsh!t!”:
    “However it’s perhaps worth pointing out that if you’re trying to capture the finest possible detail at 1:1 magnification, the G1’s finer pixel-pitch sensor means it will handily out-resolve the 5D Mark II (although not the APS-C EOS 7D).”

    The idea of a $500 Micro 4/3’s camera beating out Canon’s $2500 High end camera seems laughable, but looking at it now and knowing how sensor density and cropping work it makes alot more sense.

  9. Ed.Mu

    The sensor i think HTG tried to point out was the one in the article title image with the writing below that says “Photography with How-To Geek”

    That there is the sensor.

  10. David

    It would have been nice if you had mentioned the impact that the sensor size has on the effective focal length of the lenses used with aps-c cameras.

  11. Eric Z Goodnight

    @David: That is one of the topics I want to cover, it’s just very complicated. I want to get a lot more reading and research done before I try to bring that to HTG readers.

  12. chris barrett

    I don’t think you mentioned that the smaller sensor cameras, having a smaller imaging area, can use smaller and lighter lenses than the equivalent larger frame models. The smaller size and weight may be a advantage for those who wish to carry a lighter camera with them

  13. Satanta

    I’ve been a photographer for over 20 years. I really like Digital for ease of editing and number of images I can shoot in a session but I honestly miss the simplicity of film. Been researching cameras for *months* and still not sure what to go with.

    Something you said about ‘Buying more expensive gear’ reminds me of a joke any photographer can appreciate:

    A photographer goes tp have dinner at a friends house. The friends wife has done a large, impressive spread of foods and, as happens with most photographers the friends wife inquires about his work.

    After looking at some of the photographers work the friends wife says “You must own some really expensive equipment to take such great photos.”

    A few hours later as the photographers is leaving he shakes hand and bids farewell then turns to the friends wife and says “That was a wonderful meal-you must own some expensive cooking utensils to cook so well.” ;)

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