Viewfinder specs...

[denizenx]

Was looking at some DSLRs...
The olympus e410 SLR has 95% FOV and 0.95x mag and the Sony a200 has 95% and 0.86x mag on paper but the latter is quite obviously bigger (side by side comparison).

so my question is -- the 0.86x value is a multiplier of the subject or the sensor?

[LittleWolf]

Originally Posted by denizenx Was looking at some DSLRs... The olympus e410 SLR has 95% FOV and 0.95x mag and the Sony a200 has 95% and 0.86x mag on paper but the latter is quite obviously bigger (side by side comparison). so my question is -- the 0.86x value is a multiplier of the subject or the sensor?

The SLR viewfinder forms a simple telescope. The magnification of a telescope is determined by both the objective lens and the eyepiece.

Viewfinder magnification specs are always referenced to a given lens (typically 50mm lens, focused at infinity). You cannot compare viewfinder (eyepiece) magnifications unless you use similar objective lenses (i.e. identical focal lengths).