Fixing scratches on a focusing screen

[ParkerSmithPhoto]

Is there any way to freshen up a scratched focusing screen? Both my Bronicas have a variety of scratches which are not terrible, but kind of irritating.

Thanks!

 

[jochen]

Hello,
if the scratches are on the glossy upper side, maybe with a special polishing paste for transparent plastic. If they are on the fresnel side: no chance!

 

[2bits]

Hi Jochen,
I have used "Fitz" on plastic display cases with great success. A lot of plastic modelers use it to buff out plastic windshields. It is a liquid buffing compound, comes in a squeeze tube. Look up Fitz in modeling magazines and websites. I have never tried it on a focusing screen. It's very fine stuff though. Another remedy is old fashion toothpaste, it's also a mild abrasive. I'd follow the advise above on where to use it.
Good luck,
2bits

 

[Newt_on_Swings]

Plastic screens can be resurfaced with plastic polish, again like jochen says only on the transparent side. If its a scratch on the other side the only solution is a replacement. You can surely shoot with it and it wont affect the image, after awhile you wont really notice it, as your brain reconfigures (well mine does atleast).

 

[ic-racer]

Buy a new one.

 

[PentaxBronica]

Not always possible. I don't think you can still get brand new screens for the Bronica system, and most used ones seem to have at least a few marks.

You might want to try the plastic polish or toothpaste on one of the less obtrusive scratches first (say if you have one at the top of the viewfinder), that way if it doesn't help matters you won't make the screen unusable. If it works perfectly then you can attack the rest.

 

[lxdude]

Hello,
if the scratches are on the glossy upper side, maybe with a special polishing paste for transparent plastic. If they are on the fresnel side: no chance!

True, except the glossy side is the lower side-the fresnel side is the upper side.

 

[PentaxBronica]

Eh?

My ETR and ETRSi have the ground glass on the underside, it must be right as focus is spot on. Always assumed that Bronica did this so that the more robust smooth side was revealed when you changed viewfinders.

 

[lxdude]

True, except the glossy side is the lower side-the fresnel side is the upper side.

DOH! I misspoke. The glossy upper side IS the fresnel side. Drag a fingernail or the edge of a piece of paper across it lightly, and you will hear the sound made by the ridges. Or look with a loupe.

 

[ic-racer]

Not always possible. I don't think you can still get brand new screens for the Bronica system,

18 different new Bronica screens show up on a B&H site search.