"Spot metering" with marker, and impact of zoom

[VideoMaker]

I want to "spot meter" a specific object. Am I correctly understanding that I can zoom in on a specific object until it fills the marker rectangle, and I will then be metering just that object?

 

[Barry_Green]

Yes.* The marker measures the luminance within that rectangle.

*But, it depends on what your iris is. If you have the lens set at wide-open f/1.6, and then you zoom all the way in, the iris at full telephoto will be no more than f/3.0. So whatever you meter there, will be darker than it would be when you zoomed back out. If your iris is f/3.0 or deeper to begin with, then it should stay the same regardless of what your zoom setting is.

 

[VideoMaker]

Good point Barry. I'll be sure to move in closer rather than zoom when taking a reading which goes more than f/3.0.

Yes.* The marker measures the luminance within that rectangle.

*But, it depends on what your iris is. If you have the lens set at wide-open f/1.6, and then you zoom all the way in, the iris at full telephoto will be no more than f/3.0. So whatever you meter there, will be darker than it would be when you zoomed back out. If your iris is f/3.0 or deeper to begin with, then it should stay the same regardless of what your zoom setting is.