danrhiggins wrote:
Regarding noise and the light/image capture pipeline, in Sony cameras I found this YouTube video by a guy named Dan Fox to be extremely helpful. He uses simplifying analogies and diagrams to point out how noise both occurs during the light gathering process in the sensor and how it is introduced through the image processing pipeline/process. He addresses topics like dual-gain ISO and ISO invariance.
I am not a hardware engineer (I was a software engineer ;-)) so I can't judge what Dan has to say. It is a bit nerdy but he walks through all this in a way that made a lot of sense to me. And for the electrical engineers out there it may seem overly simplistic. It is only about a year old and the original A1 had been out for a while when he put this together.
All in all it's a nice video but he absolutely butchered the definition of dual conversion gain, claiming there are two wells. I assume it was an attempt to dumb it down for the average viewer but it made no sense whatsoever.
danrhiggins wrote:
Regarding noise and the light/image capture pipeline, in Sony cameras I found this YouTube video by a guy named Dan Fox to be extremely helpful. He uses simplifying analogies and diagrams to point out how noise both occurs during the light gathering process in the sensor and how it is introduced through the image processing pipeline/process. He addresses topics like dual-gain ISO and ISO invariance.
I am not a hardware engineer (I was a software engineer ;-)) so I can't judge what Dan has to say. It is a bit nerdy but he walks through all this in a way that made a lot of sense to me. And for the electrical engineers out there it may seem overly simplistic. It is only about a year old and the original A1 had been out for a while when he put this together.
from an engineering perspective, the transistor switches to turn on the extra capacitor doesn't make sense to me at all, the design is counterproductive as there is a voltage loss over the transistor. and from other circuits ive seen that have 3 gain sensors that is not the method they use.
The problem is that the measurements differ depending on whether the camera has a lens attached or not. The instructions for the measurements for photontophotos were to use a cap for the body when making dark measurements, which leads to a different result if you cap a lens for the dark measurements. Claff has clarified this in some of his posts, but I don't believe that info is on the photonstophotos web site. I probably should have clarified that in this thread too, but I will now.
With a lens attached the transition is at 640 for both electronic and mechanical shutter.