FF Commentary by Thom

Started Nov 4, 2013 | Discussions thread
Ontario Gone
Ontario Gone Veteran Member • Posts: 4,183
Re: FF Commentary by Thom

Bmoon wrote:

The F stop is only regulates the light intensity striking the sensor and its the Ap dia that determines the total amount of light striking the sensor and is really that what determines the shutter speed.

Let me back up here. What exactly do you mean by regulate? Everything I have ever read and heard suggests F stop is simply a way to gauge the exposure of a sensor. The lens determines how much light is let through, but the sensor size is what determines how much of that light gets absorbed. Does the entire industry have it wrong?

Many will argue that they can shoot DX at iso 100 F2.8 1/100sec and on ff iso100 2.8 1/100sec so that 2.8 lens n dx is as fast as the FF lens but they fail to see that the FF image captured 2.25 times more light so that image would contain lmore than half the noise so to equalize the total light striking the sensor one could shoot that FF at iso 225 and increase the shutter speed by 1 stop and still capture the same noise ( total light) as its DX brother but at a faster shutter speed.

Hmm. This is odd bc I have FF and crop lenses, and when I set them at the same apertures/FL/iso, the SS is identical.

F stop is really meaningless when comparing between formats as it only gauges the light intensity striking the sensor with 2 vastly different sensors dimensions.

Again, i disagree. F stop is not meaningless, it tells you how to find comparative SS between systems. What it doesn't tell you is how much noise you will get. Of course you get less noise with larger sensors, you are gathering more light. But putting a FF lens on a smaller sensor is wasting light. So no, it's not Ap dia that determines the total amount of light striking the sensor as your fist sentence above states, bc you don't mention sensor size. If i am wrong, please enlighten us all, explain why F stop even exists?

 Ontario Gone's gear list:Ontario Gone's gear list
Nikon D7000 Canon EOS 70D Nikon AF-S DX Nikkor 35mm F1.8G Nikon AF-S Nikkor 50mm f/1.8G Canon EF 40mm f/2.8 STM
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