How sensor size affect performance...

Ok, this may be a long post, i have so much things in my head!

One thing i am doing is try to take control of the DOF+Aperture+Subject Distance+Background distance.

The compromise may be between having eough subject in focus, the background as blurred as i can but without having a huge background, keep the distance from the subject low since i may be shooting in places where i have not much room to step back.

I often use a 30mm, i already stopped it down at 2.8 with the idea that the head of the cat should always be completely in focus. But afeter all i like better when the whole cat is in focus: the texture of the fur should be defined and well contrasted in the whole body!

So i started reading about aperture and the jureny has begun...

I ended up reading this:

http://www.dpreview.com/articles/2666934640/what-is-equivalence-and-why-should-i-care/

i already readed this when it was published but i was missing something... I start reading the comments this time and it opened up my mind...

If you look to some ISO test around you will see that FF is being a whole stop better than apsc (being sensor similar in technology...). I always tought that it was due to the sensor size but now i understand that there is a bigger factor!

I assumed that iso 100 was "no signal amplification" to make it easy. iso 200 = 2x singnal amplification and so on... Totally wrong. If we assume that iso 100 is "no signal amplification" on a fullframe sensor, the same iso on a apsc sensor needs (and gets) a 2x signal amplification, 4x on a mft sized sensor, 8x on a point and shot camera. If you look at it from this perspective the P&S sensor is doing a really good job: getting an almost noisless image at iso 100 on a P&S camera is light getting an almost noisless image with a FF.

On the other side, it makes hard to go with the quality of a point and shot.

Where does this takes me?

No surprise that if the actual Iso/DOF performance (apsc samsung nx) is nearly fitting my needs there is no chance that actual mft sensor will do the same. On the other hand if one day i will choose to go for a FF i really will not need a stoped down lenses because DOF I need is simpliy provided by a standard lens (classic f3.5-f5.6 standard zoom).