Mirror in Auto RB Graflex 4x5 camera - back-silvered?!

Hi,

I have an older Auto RB Graflex 4x5 SLR camera (with longer bellows, interchangeable lens board, drop bed, and front rise) whose mirror seems to be "back-silvered" with a dimension of height 127mm, long end 118mm, short end 90mm. I have not taken out the mirror so I do not know the thickness.

Is it normal or factory original to have a back-silvered mirror instead of front-silvered mirror for this older version of Auto RB Graflex 4x5? The mirror is in very good condition, is it could be a later replacement that might be installed the wrong way?

Thanks!

Yes, originally rear surface mirrors were used in the Graflex SLR cameras. This was done because mirror coating technology had not yet advanced enough to make a durable front surface coating.

To the best of my recollection, the change to front surface occurred in the mid-1930s.

You can change to a front surface mirror if you need to replace it, but you will need to re-shim the ground glass further away from the mirror to ensure the plane of focus stays the same.

Hunter_Compton said:

Yes, originally rear surface mirrors were used in the Graflex SLR cameras. This was done because mirror coating technology had not yet advanced enough to make a durable front surface coating.

To the best of my recollection, the change to front surface occurred in the mid-1930s.

You can change to a front surface mirror if you need to replace it, but you will need to re-shim the ground glass further away from the mirror to ensure the plane of focus stays the same.

Click to expand...

Thanks for the information. Since the mirror is in good condition, I will just leave it as is and get focus calibrated on the ground glass.

some repairpeople stick dollhouse mirror ontopof the old mirror to "replace" it.

ezphotolessons said:

some repairpeople stick dollhouse mirror ontopof the old mirror to "replace" it.

Click to expand...

Yes I need to look into it, since the current viewfinder focus screen does not agree with the film plane focus panel.

A clean modern front surface mirror will of course look clearer and brighter than the older one but really for the most part the difference is that you only kind of get a little bit of ghosting or flare in the bright areas when viewing with the older mirror.