Getting Composition as Right as You Can in the Camera v. Cropping

Gateway Arch, St. Louis, Missouri, USA

My images are online at Dennis Mook Photography

So why does it matter whether or not you strive to get your image's composition as close to ideal in the camera versus cropping as needed later in your editing software?

There are some important pros and cons to getting it right versus being a bit lazy and cropping later in your imaging software.  Here are some of the things you should think about. 

Cons

Just quickly thinking about this topic you should be able to deduce that by being "loose" with your composition or being lazy or sloppy or inattentive (whatever you want to call it) and not trying to get your composition as right as you can in your camera, you lose:

a) Quality.  By cropping you no longer use your entire sensor but only a part of it. Depending how much you crop will dictate how much of your sensor surface you are now not using.  In effect, you are now using a smaller sensor camera.  If you wish to make enlargements, you may artificially restrict yourself or, if there is a specific large size you desire, you may no longer have the quality to enlarge that big.

b) Pixels.  Say you bought a 16mp camera.  Hmmm.  Didn't you buy that camera because you wanted a camera with about that many pixels?  If you crop, you are losing pixels.  Your 16mp camera may end up being a 9mp camera.  Why would you want to do that?  Wouldn't a valid analogy be making images with the jpeg file format and throwing out lots of pixels?  If you are okay with throwing away pixels I bet you would buy a corvette and drive around in nothing higher than second gear.  Same thing.

c) Perceived depth of Field.  A cropped image has to be enlarged more to achieve any given size.  As you know, depth of field is dependent upon several things.  Focal length of the lens, aperture, distance of subject and viewing distance.  Something in your image that looks in focus on your camera's LCD may not look in focus on your computer screen.  Additionally, something that looks in focus on your computer screen may not look in focus in a 16X24" print.  As you enlarge the image, the perceived depth of field is reduced.  It has to do with the circle of confusion.  If you don't know what that is, you really need to research and understand it.

Look at these two images.  The first, composed sloppily, is a handheld grab shot from my 16mp Olympus E-M5.  I don't like the composition as there is too much extraneous stuff in there that distracts me as a viewer from the subject, the red rose blossom.  The first image is just about full frame (4608 pixels X 3456 pixels) and comes out to be 15.9mp.  The second, cropped image, is 2117 pixels X 1587 pixels, or 3.35mp.  I'm only using 21% of my image and also 21% of my sensor. 

 

 

 

Why would I want to lose that many pixels, that much quality and artificially reduce my options for enlargements or viewing later.  On your computer screen you won't be able to detect much difference in quality, but I bet if you wanted to make a 13' X 19" print of the second image, you may find you just don't have the quality with which you are satisfied to make that desired print size.  You might as well not bought that expensive, high pixel camera.

 

Pros

There are some benefits to cropping in cropping after the fact.  Only you can decide if they are worthwhile on a case by case basis.

a) Edge Sharpness. Typically, lenses are sharpest in the center, then are less sharp toward the edges.  By cropping, you can eliminate the less sharp region of your lens to have an overall technically better image.  That being said, instead of cropping, I suggest you buy a cropped frame (APS-C or DX) camera and use all full frame (FX) lenses on it.  By doing so, you are making an image, correctly composed in camera, and the camera's sensor format is cropping off the less sharp edges and corners.  Then you can retain all the pixels and all the quality your sensor is capable of producing.

b) Vignetting (shading). Typically, due to physics, most lenses have partially correct light falloff at the four corners of you image.  By cropping, you can eliminate that issue. That being said, software, both in the camera and in editing software, can rectify that issue pretty much automatically now.  If the software cannot do it automatically, then you can do it manually.  No need to crop the image to eliminate vignetting.

c) Straighten Verticals. When making images with vertical lines, such as when photographing buildings, you may lose important image elements if you tightly compose.  This is because if you straighten the vertical lines in your image editing software, you will lose some of the image, which could result in ruining your image.  If I determine at the time I am composing the image that I will need to straighten verticals, I will purposely (not out of sloppiness or laziness) compose loosely  so I have room about the edges of the image, that can be cropped out when straightening verticals, which will not ruin the image.

Now, there is one caveat to all this.  I own and use the Nikon D800E.  It has 36.3 whopping mega pixels!  Way more than one really needs.  If you own a camera with a huge amount of mega pixels, you can crop and not lose quality for your purpose.  I can afford to crop 1/3 of my image area, even possibly 1/2 of my image area and still have 24 or 18 mega pixel images.  But, again, by cropping the image, your technique must be extra perfect as any mistakes, shakiness, miscalculated depth of field, etc., will be magnified as you now have to magnify the image more to get the same size final product.

 

Trade-off?  Image edge quality versus Loss of pixels and quality.  Careful technique versus sloppiness.  You decide.  Its your money and your gear and your images.

Thanks for looking.  Enjoy!

Dennis Mook



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