Video resolution, file size and image quality.
A while ago I thought I’d take my camera out for an afternoon’s videoing and so headed off to Linlithgow Palace. Once I’d got some editing done I found I had a video of just under 10 minutes in length. Usually I render out at 720p for a YouTube or Vimeo upload, but this time I thought I’d render at 1080p just to see how things went. At the end of the processing I found myself with a file of just over 2 gigabyte. This I thought a little bit large for uploading from home so went up to Uni did my upload (to Vimeo) from there. That went nice and fast, in fact it uploaded faster than the length of time it took me to type out title, description and all that sort of stuff. Once back home thought I would re-render it but this time in my more usual 720p (other settings the same) just to do a compare and contrast. My just under 10 minute came down at just over 400 megabyte.
So we’re talking about one fifth the size of the 1080p video. Playing the two videos side by side it was hard to notice any difference in quality, it was there but you really had to pick around the edges to see it. Now and again I’d pause at a suitable moment where perhaps a a sign was in view or maybe a car number plate or something similar and try and read it, and it was more readable in the 1080p version. However as a flowing video it was quite difficult to tell the difference between the two, yet the 720 giving me so much more free hard drive space compared to 1080.
I also rendered it out in standard definition quality at 360p size (looking towards uploads for mobile devices or older smart phones). Here we had a file size of just under 60 megabyte, or a little under 3% of the 1080p file size. Comparing the video here to the others there was a very definite reduction in quality. It still wasn’t too bad to watch, however when you had this 360 next to either the 720 or 1080 the difference really jumped out at you. On the other hand it was still more than good enough for a portable device if you were on the train.
Something to think about. Take the 1080 HD video size, which is a 1920 by 1080 rectangle. Multiply that out and it comes to just over 2 million pixels. Or to put it another way, if you’re in a shop talking about video and cameras and the sales staff are busy trying to sell you this camera rather than that camera because this camera has more mega pixels on the sensor… well, if you’re going to actually film at the native HD resolution then all you really need is this just over 2 mega-pixel size sensor. Bigger does not always mean better.