Definition, Resolution? I still realise after the fact that I sometimes use one of the words with the wrong meaning. At the end of the day, in context, it may still make sense to the people I’m talking with. But the correct logical approach would be to use the right word with the right meaning, right? So, let’s define these expressions…
Definition (of a digital image)
It is the expressed value of the ‘total number of pixels’, or in other words, the ‘horizontal and vertical number of pixels’.
E.g. 1920 x 1080 (HD) or 2,073,600 pixels, 4096 x 2160 (4K) or 8,847,360 pixels.
It refers to the pixel density of an image, which can be expressed in the number of Pixels Per Inches (PPI).
|Type||Definition||Megapixels||Image Ratio||Native Pixel Aspect Ratio (PAR)||Image Scan|
|Video||HD 1080 (Rec. 709)||1920 x 1080||2,07||16/9||1.77||Square pixels||Interlaced/ Progressive|
|Ultra HD 4K (Rec. 2020)||3840 x 2160||8,3||16/9||1.77||Square pixels||Progressive|
|Ultra HD 8K (Rec. 2020)||7680 x 4320||33,2||16/9||1.77||Square pixels||Progressive|
|Film||2K DCI (Digital Cinema Initiatives)||2048 x 1080||2,2||17/9||1.89||Square pixels||Progressive|
|4K DCI||4096 x 2160||8,8||17/9||1.89||Square pixels||Progressive|
For a given Definition, the Resolution will vary depending on the size of a screen: at a constant Definition, the larger your screen, the lower the Resolution and vice versa. E.g. an HD TV monitor and a tablet have the ability to project the same Definition, but it is their Resolution that differs.
(Source: Sony PXW-FS7)
The number of pixels is a component of a sensor’s quality1. It determines how much potential detail a camera is going to capture, but the amount of visible detail (and accuracy of detail) can also depend on the lens, bit rate, various camera settings, etc.
Whether the number of megapixels is going to matter to you will depend on your intended use and workflow. In fact, the megapixel resolution becomes a pertinent factor when enlarging or performing crops; it can be relevant to photographers for which productions are destined for print (e.g. large advertising boards) as will remain a great level of detail. But it can also be relevant in many other cases – e.g. when stabilising video footage, re-framing a crooked shot, etc. For the vast majority of video camera operators, 7MP to 16MP seems like the standard range.
Let us know in comments what camera you’re using and how you apply this principle to your workflow. Perhaps, I or other operators can learn a thing or two.
E.g. which camera are you using? photography or video? how do you benefit from your camera’s resolution and on which application (portraits, landscapes, sports, etc…)?