this what happen when u had 2 different people with different system with different shooting style.
theory versus hand-on experience
First, let me be clear. MontoyaSG did
NOT at any point in his post specify his comments as unique to the Alpha system. It was a sweeping comment not restricted to the Alpha system and not restricted to "certain circumstances" that in order to reduce noise, you should overexpose by 1 to 2 steps.
That statement is simply not true in the majoirty of situations. In the majority of situations you are best served by exposing correctly.
And please don't suggest that it is my theory against his or your experience.
I might have no direct experience with Alpha DSLRs but I have a reasonable amount of knowledge about the Canon system and a tonne of information about the Nikon system. I have for the last nine years pushed camera systems to the limit of their ISO performance routinely both indoors and out and I have seen first hand the evolution of sensor technology each step from the D1 through to the D3 and everything in between, as well as the 1D series. My work means that I need the best possible performance from a sensor at high ISOs. The D3 and 1D series are designed for photographers that work in my industry, and their raison d'etre is to deliver the best high ISO performance possible.
Maybe what I have been doing wrong for the last seven years is that I should have been overexposing by 0.7 stops.
And I know the theory as well - if you overexpose enough then for example your shadows become midtones, reducing the noise in that area of the image. The problem is frequently you *can't* overexpose by 0.7 stops. The whole reason most users hit that high an ISO that noise becomes a problem in the first place is because they have insufficient available light. And as I've pointed out, if you have that much available light in the first place, then you should *probably* be using a lower ISO in the first place.
Probably is highlighted because yes, in certain circumstances and with some DSLRs you might achieve a better result if not better overall quality.