The Crop Factor…

First off, my apologies for the absenteeism yesterday.  After a really fun photo shoot with some friends in downtown Denver (more on that next week), I got home super late (by working standards – my shift is 7-4 and I need to take a bus an hour to get there…so I leave at 6, which means I am up at 5!), and went almost straight to bed!  Hopefully the content today will make up for this, because it’s time to talk about (cue fanfare music)…the crop factor!

Now, before anyone gets all uppity because sensor crop factors have been discussed ad infinitum, just relax, because this isn’t about sensors (well, a little, but indirectly).  I am talking about cropping your pictures in camera.  We all do it, often to improve composition, or to focus in on one area of an image – but what about those undesired crops?  What am I talking about?  I am talking about images where it looks really great “in camera” but when you go to print it, the native aspect ratio won’t work for the size you want to print to.  See, most SLR cameras (non-full frame anyway) have roughly an aspect ratio of 2:3.  This means that you can print at this ratio without losing anything in your image.  But, if you want to print at a different aspect ratio, then something has to be cropped out.

So, what aspect ratio will work with the 2:3 proportions? Who all remembers their grade school math?  All you have to do is multiply each side of the ratio by the same number.  So, prints that work are …

  • 2×3″ prints (2:3 x 1:1 = 2×3)
  • 4×6″ prints (2:3 x 2:2 = 4:6)
  • 6×9″ prints (2:3 x 3:3 = 6:9)
  • 8×12″ prints (2:3 x 4:4 = 8:12)

You get the gist…but here’s the thing – the only “standard” print size that really fits our native camera aspect ratio is the 4×6″ print.  What if we want an 8×10″ print?  Well, cropping is required then.  This means losing some of your image.  So, this also means that you need to think about this during image composition in camera – if you like it – and want to print it – remember to frame things so that the crop won’t lose key elements of the picture.  Here’s a perfect example:

isla_original

I took the above shot on a trip down in Isla Mujeres.  I absolutely love this shot.  The problem is that my proportions are lost when I crop to print an 8×10.  Take a look at the 8×10 crop:

isla_crop

It still looks pretty good, and I love the colors still, but some of the impact has been lost by cropping out the frame on both the left and the right.  See how the brown “framing element” has been lost?  I could have cropped less on that side and more on the orange side (even though the orange side is still cropped to a degree), but hopefully you’ll see the difference easily enough because it’s really the orange, yellow and blue that I think are the fundamental colors that hold my eye for this shot.  Suffice to say, I still loved it enough to print and frame an 8×10…but that’s not the point here.

The point is to try and remember to frame your composition in camera with “the crop factor” in mind.   By taking these measures into consideration, you can really have many more printable memories.  So, when you go out shooting this weekend, keep the crop factor in mind.  Happy shooting, enjoy the weekend, and we’ll see you back here on Monday!

Aspect Ratio adjustments explained

I can’t tell you the number of times I’ve gone to print pictures I’ve taken only to find that I had composed it in a way that a portion of the image was lost when printed because it had to be cropped out to fit on the paper.  Today I am going to share a technique in Photoshop that will help you get around that pesky limitation.

First a little background – the reason why we are losing part of the picture is because we are changing the aspect ratio.  What is aspect ratio?  Simply enough, it’s the relative size of the long side of the picture to the short side.  Aspect ratios are often referred to by their lowest common factor.  So, a 4×6 print uses a 3:2 aspect ratio.  (Aspect ratios usually are stated with the larger of the numbers coming first…)  An 8×10 has an aspect ratio of 5:4.  Want to print a 16×20?  Guess what – it’s got an aspect ratio of 5:4 too!  Here are some of the most common aspect ratios that you see in photography:

4:3 – Point and Shoot Cameras
3:2 – 35mm Film cameras and most APS-C sensor cameras (SLR’s)
1.81:1 – APS-H Mode (High Def)
3:1 – APS-P (Panoramic)

So, with an SLR camera, since your sensor approximates an aspect ratio of 3:2, getting an 8×10 print means you need to keep your subject matter in from the edges because when you crop to the new ratio, at least one of those edges (and a little of the other) will be lost from the crop.  So, having now explained  “why”, let’s now look at the “how” (as in how to fix it!) in the delayed tutorial for the week:

Web Version (Flash):  Re-framing your pictures