Field of View in Full frame vs. Crop Sensor Cameras [Includes photo comparison]

When photographers are interested in buying a full frame camera for the first time as an upgrade from their crop frame DSLR, they often have a nagging question.  Most photographers have heard there is a difference in the field of view (how much of the scene you can see) when using the same focal length of camera on either a crop frame or full frame camera.  So, they want to know how much of a difference it will make.

If you’re brand new to this concept, you can check out this article, where I discuss the difference between crop and full frame sensors.  This is also something that I discuss in my beginning online photography class.

They usually aren’t sure how to phrase this question, so they ask something like these questions:

  1. Do you have any comparison photos of the mm difference between crop frame and full frame cameras?
  2. I know my crop sensor camera is cutting off some of the picture, but how much?
  3. What does a picture look like at 18mm on a crop frame camera, compared to 18mm on a full frame camera?

Field of View, and How it is Impacted by the Crop Factor

Field of view simply means the amount of the scene that you can capture in one frame.  A full frame sensor is physically larger than a smaller crop frame APS-C sized sensor.  This physical difference in the size of the sensor changes the physics of how the lens focuses the image on the sensor.  The larger sensor captures more field of view than the crop frame camera if all else is equal.

The sample picture below shows a picture taken at 18mm on a crop sensor camera, and the same picture at 18mm on a full-frame camera.  The difference is quite surprising.

full frame vs. crop sensor comparison photo

The inner rectangle is the photo taken with a Nikon crop sensor DSLR, the full outer picture is taken at 18mm as well, but with a full frame camera.

Focal Length Equivalents

Please keep in mind that not all crop sensor DSLRs have the same size sensor.  The crop factor on APS-C crop sensor DSLRs from Pentax, Olympus, Sony, and Nikon is 1.5.  The crop factor for most Canon DSLRs is 1.6x.  That means that if you take an 18mm lens and put it on a Canon and Nikon, the Canon picture will be slightly more zoomed in.

On the table below showing the equivalent focal lengths of a full frame and crop sensor camera, I have used the more common 1.5x crop factor.  Canon cameras will be ever so slightly more zoomed in than even what the table shows.

Crop sensor and full frame equivalent mm focal lengths comparison chart.

This chart is based upon a 1.5x crop factor, which is the most common crop factor for “crop sensor” aps-c size sensors in DSLRs.

According to the table above, for example, you would have to use a 75mm lens on a full frame camera in order to get a photo with the exact same field of view as a photo from a crop sensor camera shooting at 50mm.

WHY Does the Sensor Size Change the Field of View?

Physics, that’s why!  Remember that the job of the lens is to take a scene and focus it to a small area.  The lens creates the reflected scene and puts it on the image sensor, which records the light focused by the lens.  Naturally, the larger the sensor is, the more of the focused image it can see.  If you’re more of a visual learner, check out the picture below that explains the concept.

 

Why larger full-frame DSLR sensors see more view than smaller aps-c crop frame sensors.

See how the larger sensor is able to capture the entire reflected image, but the smaller sensor can’t? That’s why! Also, notice the reflected image is upside-down. Your DSLR flips the picture around automatically.

If you’d like to learn more about how your camera works and the basics of photography, you might consider taking my 30-Day Beginning Online Photography Class.

So is Full Frame Worth the Extra Cost?

It depends on what type of photography you’re doing.  It’s easy to say that full frame is better, but that’s not necessarily true.  For example, if you don’t have the money to plunk down on extremely expensive super telephoto lenses, then you may want the crop factor of a crop sensor camera to help you shoot wildlife or sports.  If you’re a landscape photographer, then you may want to spend the extra money on a full frame camera to help you go wider.

If you are in the market for a full frame camera, however, you should really take a long hard look at the Canon 6D or the Nikon D600.  These cameras are only a few months old and are MUCH less expensive than full frame cameras have traditionally been.

Comments from the I.P. Community

  1. Kristen P says

    Jim, is it a true statement to say that if I move to a full frame camera and shoot landscape that I’ll spend a great deal of time in post-processing working to stitch foreground and background images together just to get a composition with full depth of field? If so, is the payoff then good enough to move to full-frame if there’s that much more work to do just to get a decent landscape photo? Thanks in advance.

  2. Rich H says

    The Image is not cropped at all… how silly would it be to just crop the image and lose half the available light… what actually happens is the image is focused so that all the light is falling on the sensor. Just think of the X drawn over the lens as a pair of scissors with a hinge at the cross point. Now you will understand that when you close the image (scissors) down (bring the lines closer to parallel to one another) until the left side lines fit just over the entire image (causing all the light to fall perfectly on the smaller sensor) that at the same time on the other side of the lens (Toward the subject) it narrows giving a narrower (and more magnified view). This is exactly how it really works.

    • Jim Harmer says

      @Rich H – You are of course correct. I think most of us understand it isn’t CROPPED like in the sense you are saying. But it certainly is effectively cropped.

  3. Rich H says

    Great Jim! Glad we agree… in Photography no one wants feel they are wasting light… and in this sense, the APS-C and smaller sensors… do the best they can with all the light from the lens…it’s just placed over a smaller area. I never liked the term Cropped Sensor for the exact reason that it implies you lose light as well as field of view.

  4. Doug Thompson says

    I would suggest there is an additional aspect to this discussion that photographers should be knowledgable of and that is lense angle of view and how IT is affected by crop frame sensors. This decides what gets to your sensor, large or small. Knowing this allows one to select lenses that complement ones photographic style, especially with the DX cameras so many of us use. I tend to lean towards it is the glass , not the camera. Composition is still a manual process, and bigger does not overrule that.

  5. CHRISTIAN says

    i think it is correct to say cropped sensor because in relation to the full frame (35mm) sensor it is really cropped. What it is not cropped is the light. That’s why there are lenses for cropped and full sensors since they optimize the light through the onto the sensor.

    cool post Jim!

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