Michelson interfermetory point source types of fringes? When we illuminate a Michelson interferometer with a point source with the mirrors at $0$ separation and with an angle between them, I have read we get linear fringes at infinity. Is it also true (like with an extended source) that we get linear fringes at the mirrors and what can we say about the shape of the fringes between these points? Does any of this depend on how large or small the angle between the mirrors is?
EDIT
Just to  clarify things, the main question I am asking is:
Given the 'wedge' configuration of mirrors in a Michelson interferometer do we get linear fringes both at infinity and at the mirrors or just at infinity?  
EDIT 2
I have found this source (link to google books), which explains why we need an extended source to see Newton rings and why we can't use just a point source. Would I be correct in saying that this reasoning is also true for the Michelson interferometer?
 A: Interferometers rely on division of amplitude, when most other interference devices (Young double slit, Fresnel mirrors, Fresnel double prism, Billet double lens, Lloyd mirror...) rely on division of wavefront. Apart from this difference, the way they work is the same: from a single primary source, make two secondary coherent sources. As a consequence, the fringes you obtain with a Michelson interferometer are the same as those obtained with Fresnel mirrors.
Two coherent monochromatic, point sources give fringes in all space with hyperboloid geometry, as a result of constant optical path difference $AM-BM=pλ$. The $p=0$ fringe is a plane in space (which intersects the screen along a straight line) for any $λ$; it is the only fringe independent of $λ$.
If the source is polychromatic, the resulting fringes are the sum of the fringes made by each monochromatic radiation in its spectrum. Fringes will blur each other, except the $p=0$ one. Hence, with a polychromatic (e.g. "continuous" white) source, you typically get a white, straight, $p=0$ fringe surrounded by a few nearly straight, coloured fringes, where "nearly" is theoretical, because practically the screen is too small to observe any curvature.
Always think of an interference pattern as the intersection of 3D fringes with the screen plane. With extended sources, the fringes are localized in space, so you can see a pattern only if the screen is in the appropriate region. With monochromatic point sources, the fringes are not localized, you can see a pattern wherever the screen is. With polychromatic point sources, the $p=0$ fringe is an infinite plane, you can see a straight pattern if and wherever the screen plane intersects it.
Side note: the circular fringes of equal inclination are simply the intersection of the hyperboloids with a screen perpendicular to their axis of symmetry.
A: There are two types of interference fringes:  


*

*fringes of equal thickness which you obtain with an extended source
and the mirrors inclined to one other.  These are the type of fringes you get with wedges and Newton's rings.  These fringes are localised in the wedge so you need to focus in the region of the wedge to see them.  These are like contour lines.

*fringes of equal inclination which you obtain by having a point
source of light and the mirrors "parallel" to one another and this is the type you are referring to.  These fringes are localised at infinity so you need to focus the light coming from the interferometer with a lens (could be your eye) to be able to see them.
More here 
