Jerry R

Lives in United States CO, United States
Works as a Physicist
Joined on Jan 22, 2006


Total: 2, showing: 1 – 2
On article What is equivalence and why should I care? (2341 comments in total)
In reply to:

wwick: Because the information on this site is always so excellent – and I assume my grasp of “equivalence” is pretty good – I was surprised to find myself confused. I don’t get how “total amount of light” on large versus small sensors is supposed to figure into the topic at hand. My guess is that it’s meant to be a non-technical way of introducing the concept of the inverse square law. If so, the graphic accompanying that discussion does not fully meet the criteria. It seems to me the relevant concept could be stated like this:

A Full Frame camera with an Equivalent FL set to an Equivalent DOF of a Micro Four Thirds camera would need 4 times more light than the smaller sensor. This would necessitate an increase in shutter speed, ISO, or the light level of the subject itself.

As to the consequences of increasing shutter speed or ISO with large versus small sensors, I’ll defer to you guys, but in terms of the basic optics, I think the article got a little more entangled than was necessary.

The S/N of the sensor is a function of the the individual pixel size not the sensor size. A FF sensor with the same size pixels as a 1" sensor will have the same S/N as a the 1" sensor.
Averaging pixels when printing will yield an advantage in S/N of the larger sensor.

Total light reaching the larger sensor vs the smaller sensor is nonsense when discussing S/N of the sensor. DPreview should know better.

Link | Posted on Nov 21, 2016 at 02:00 UTC

Why is there no "my threads" button next to "New Thread" and "Ask a Question"

Link | Posted on Oct 4, 2012 at 14:17 UTC as 42nd comment
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