Cropping

From Antalya
(Redirected from Crop)
Jump to: navigation, search

What is important in your picture

Cropping is a very interesting processing skill to learn. Normally you try to frame your pictures right. But if you are aware of how you might crop the picture, you may stop obsessing about framing (or zooming).

Just the Basics

The first thing to realize is that you will not need all the pixels that you acquire in your image. Just take a look at Images for Print and Posters to get an idea. While there is nothing wrong with taking properly framed shots, sometimes you can realize that if you can not get close or you do not have the right focal length with you, just mentally being able to accept that you will crop the image later is a key skill that will help you.

In this way, you will be able to frame the picture so that it can be later cropped rather than actually trying to get it right at the time.

Of course people also crop pictures to get rid of things they did not want in their shots, there is nothing wrong with that, but once you realize that a 20 Megapixel camera takes shots that are if not 5 times at least 2 times larger than most needs, you will be more free. Once you experiment with this, you will realize that a zoom while practical is not that necessary.

One example

This is with a Nikon 85 in a museum in Manchester, UK. Robot orig.jpg I liked the robot, and I was not too much bothered by things that were around it. I concentrated on the robot, knowing that this could easily be cropped, so I am not bothered by the fact that the writing on the right is not complete, or there is something on the left.

Robot mark.jpg

Once you start cropping there is no need to stay at a specific aspect ratio. I ended up with a more square crop. It does not look spectacular maybe, but being able to disregard things that are not right in the picture or being free of the aspect ratio of the camera is very liberating.

Robot crop.jpg

There is a lot of resolution in your pictures

In the following table, I compare the resolution of a crop from a Nikon D700 with 12 Megapixels using a Nikon 35 that would correspond to the same field of view of different focal lengths.

Focal length X pixels Y pixels Megapixels
50mm 3098 2061 6.3
70mm 2253 1499 3.3
85mm 1869 1244 2.3
105mm 1525 1015 1.5
200mm 805 536 0.4

This means that I can crop a picture out of the one taken with a 35mm lens using a relatively old digital camera that corresponds to what I would see with a 105mm lens and still have a larger resolution than I use on these webpages (1280x850) and I would have to resize, who needs a zoom, when you can crop. Of course this requires that your 35mm shot is quite sharp if we need to make every pixel count.

This should give you a scale of what is possible with cropping.


Second example

This is maybe a forced example. I sometimes try to challenge myself, and take interesting combination of body and lens for a day trip. This time I had a manual focus Nikon 180 on a Nikon D850 which has over 40 Megapixel resolution. On a hike I ended up with this picture Nikon180 flower.jpg

It does not really look that interesting at first sight. The Nikon 180 is an excellent lens, but with a minimum focus distance of about 2 meters it is the furthest thing from a macro. But if you have a calm hand, good light, a bit of luck and maybe some experience, you know that you can get a pretty usable picture of the blue flower when you crop this. Question is how good can a tiny piece of the image be Nikon180 flower crop.jpg

Now this crop is 1280x1280 from the center which is pixel for pixel from the camera, no enhancement nothing. This is as good as I could get if I was using a macro as well. Now the question is, where will I use the picture. For a 2m poster probably the macro would be better, but for everything on social media, the web even reports and presentations, this is more than enough.




These pages are for Amateur Photographers and not really for seasoned photographers and professionals. I have no affiliation or commercial interest with any brand/make. I write from my own experience. I ended up using mainly Nikon, so I am more familiar with this brand than others. See price for notes on pricing as well as photography related links.