cutting a viewfinder screen to size

[johan_de_groote]

I want to put a glass in my Pentacon 6 with a split prism focussing aid. I

really need it to use the camera because with glasses I don't see enough of the

screen and without I don't see if I have focussed correctly.

 

I have a screen around butit is too large. I also understand the priciples

behind cutting glass. But do I score it at the ground side or at the smooth

side? I would like not to mess this up as I only have one...

[bob_sunley]

Are you sure the screen is glass? Most split prism screens are plastic.

[joseph_wisniewski]

I usually take a plastic focusing screen, cut two pieces of wood slightly larger, drill a hole in one piece so that if the center split screen were placed in that hole, one edge of the screen would protrude from between the wood blocks by the amount of material I wish to remove, sandwich the screen in pec-pads, clamp it between the blocks, and wet sand (did you catch the word "wet"?) the screen down to the block. Repeat this procedure for each of the four edges. Have fun.

 

And let me repeat, wet sand the screen, with emphasis on "wet".

[ronald_moravec1]

Wet sand is emery cloth on a piece of heavy glass dripping with water.

 

Wash off all the grit and get everything clean befor moving to a new edge.

 

I would work with 400 grit for small amounts, 100 for faster removal.

[johan_de_groote]

I took it out of its paper because you made me doubt. And indeed it is plastic. I assumed it would be glass as the Pentacon 6 split screen I bought and mounted last weekend was a serious piece of solid glass.

 

The block of wood idea is a very good one, I'll go that way.

 

Thanks guys.