Color of central circle in Newton's rings

[justawebuser]

Hello guys ,
Can someone explain me why color of central circle in transmission case is bright whereas it is dark for the reflection case?
Thanks a lot,

 

[Simon Bridge]

Because you get a lot of light coming from there in one case and not the other.

 

[CWatters]

Do you understand why rings are produced?

 

[Philip Wood]

Have a look at the circumstances when sharp phase reversals do or don't take place.

 

[Simon Bridge]

@justawebuser: in order to best answer your question, we need to know how you are thinking about Newton's rings in the first place.
It is not obvious how the issue is a problem for you.
i.e.
why would you expect matters to be otherwise?
how do you think the rings are made in the first place?

Without some idea of how you think, we are unlikely to be able to help you.