GH2 2 questions for GH2 distance+lens? and lens vs ISO?

[raatid]

Good day to you all,

I have two questions:

1- If I use a 80mm and shot a subject, then put a 50mm going closer to the subject,
then put a 35mm and going closer to the subject, all making the subject appearing the same size. What is the real difference?

2- the ISO on the hacked GH2 can go up to 12800 (watch work of EOSHD at night time almost in the dark ! "Shot entirely at ISO 12,800 on the GH2 with Vitaliy's hack version 3.63"), so why a slow lens cannot be balanced with the ISO, what are the factors involved?

 

[mcbob]

1) http://en.wikipedia.org/wiki/Angle_of_view

2) http://www.cambridgeincolour.com/tutorials/camera-exposure.htm

 

[raatid]

thank you very much mcbob

 

[stoneinapond]

1- If I use a 80mm and shot a subject, then put a 50mm going closer to the subject,
then put a 35mm and going closer to the subject, all making the subject appearing the same size. What is the real difference?

Foreground to background relationship. As the lens gets longer, the level of compression between the two increases.

2- the ISO on the hacked GH2 can go up to 12800 (watch work of EOSHD at night time almost in the dark ! "Shot entirely at ISO 12,800 on the GH2 with Vitaliy's hack version 3.63"), so why a slow lens cannot be balanced with the ISO, what are the factors involved?

Increase in noise.