For many photographers, the primary concept of ISO is fairly straightforward to understand as a part of the three factors of correct publicity. However when you begin to dig a bit deeper into totally different elements of ISO, that understanding will get shakey. On this 10.5-minute video, Dave McKeegan makes an attempt to demystify the subject.
McKeegan begins by explaining what ISO is, so in the event you’re solely involved with understanding what is supposed by Native, Base, and Expanded ISO, you possibly can skip to about the three-minute mark.
In brief, Keegan says that Base ISO varies by digital camera and producer and whereas generally it’s ISO 100, it will also be as little as ISO 64. Native ISO is separate and refers to a spread of sensitivities provided by a digital camera from the base ISO by way of the most default sensitivity quite than a selected level.
Expanded ISO is the time period used to explain pushing a digital camera’s software program to push sensitivity limits even additional past at each the excessive and low ends.
For most individuals, the complicated level isn’t essentially with understanding what Expanded ISO is, however listening to each Native and Base ISO used seemingly interchangeably. To raised perceive the distinction, this definition might be the easiest to know: A local ISO is an precise utility setting in the digital camera that doesn’t require interpolation in processing. The Base ISO is the lowest of the Native ISO choices.
The place this could change into particularly complicated is whenever you hear the phrases Twin Base ISO and Twin Native ISO, and firms appear to make use of these phrases interchangeably.
Panasonic describes its “distinctive expertise” as Twin Native ISO:
Twin Native ISO is a singular expertise from Panasonic that may be present in the cameras which are a part of the cinema digital camera lineup. The sensor of the VariCam digital camera has two native ISO settings, 800 and 5000. Which means that, merely put, you possibly can make the most of having two movie shares in a single digital camera. This lets you shoot ISO 800 for regular lighting conditions, or to achieve nearly three stops with ISO 5000 to seize magic hour or candle-lit scenes; all with none lack of dynamic vary, decision, or colour.
Based on McKeegan, Twin Base ISO — generally additionally known as Twin-Band ISO — refers to the identical concept:
Twin-Band ISO the place the digital camera has two base ISOs. Lots of the Alpha 7 cameras, for instance, have a base ISO of 100 in addition to a second base ISO at 640. And the purpose for that is that there are two a number of circuitry on the sensor: a low achieve circuit, and a excessive achieve circuit that’s optimized for working with a weaker sign.
It may be complicated to listen to similar-sounding phrases that refer to 2 totally different concepts (resembling Base and Native) however including two extra totally different phrases that consult with the identical basic idea provides one other layer of potential confusion that makes the complete idea exhausting to understand. Hopefully, by the finish of McKeegan’s video, you’ve got a greater sense of what all these phrases imply.
Picture credit: Header picture licensed through Deposit Photos.