Need Split image focusing screen

[Berk Sirman]

I put this on classifieds forum a few days ago but got no replies. Before I give up I'll try my luck here.

I need a focusing screen to judge the focus on the film plane while setting the backfocus on my FSU lenses (a J8 and a J3) I tried it with one that have microprisms in the middle and it just did not work. I cannot get consistent results as how the crystals appear depends on the angle you look at the focusing screen. So I need a pure matte (has to be very bright) or better a split image focusing screen.

Needless to say the focusing screen does not have to be in good shape, it can have all the scratches, dirt and dust as long as the split image is clear.

I use a 15x loupe while doing this. Any tips on how to adjust backfocus easier also welcome.

So, does anyone here have any (non-new) split image focusing screens that they want to sell/give away?

Thanks, Berk

 

[Andy K]

When I did this with my old Agfa Isolette folder I used greaseproof paper (the type used in cooking) taped to a stiff card frame. You may be able to do the same.

 

[normclarke]

Hi Berk,
Have you access to 3M's magic tape this I have judged to be better than a proprietry screen. Just tape it across the film track. About $5.00 a reel.

Cheers,
normclarke.

 

[Berk Sirman]

Thanks, I'll look into those options.

I live in Sweden and I do not know whether we have that 3M tape here.

Berk

 

[Jerevan]

Just about any store has this Magic Scotch tape which works fine.

If you want a real ground glass, get some plain glass from a whatchacallit (window repair store?) and use a cutter or get it cut to size at the store. Use the kind of automotive paste used for grinding engine valves. Put the paste on another piece of glass, lay it on top of the first one and with circular motion grind your own customised ground glass!

Etched glass might work fine too. It should also be possible to find in glass repair store.

A 15x loupe sounds like too much, it will probably get you problems, focussing on a lot of grain, rather than a clear picture. A loupe with 4x is well enough. A linen tester works dandy for me.

 

[pshinkaw]

I recently made a focusing screen for this purpose out of a piece of clear plastic packaging, (the kind that products are displayed in on hangar racks at stores). I think it may be PET plastic. I cut a flat piece out and roughed it up with a piece of 150 grit sandpaper. It worked fine for calibration purposes.

-Paul

 

[Buze]

Even better the "cristal" case of a discarded CD is really ideal. Bonus is it's very rigid and break easily. So mark a strong ouline with a blade and snap it to dimensions. Then sand it carefully with the smallest grain you can find.

Then use a powerful loupe to check the focus...

Here is that setup used to calibrate my Moskva 5:

 

[bmattock]

This is not easy to find, but when they come up on eBoy, nobody knows what they are, so they go for cheap:

Zeiss "Matsch-Rahmen" 540/11 - that's what it says on the box. It really means "Mattscheiben-Rahmen" which means 'ground glass frame'.

This is a real ground-glass focusing aid designed to be put into the open area between the film frame rails - held in with spring tension. You can't close the camera back while the thing is in there, but you can easily adjust focus, rangefinder, etc. Works great. Worth picking up if you come across one.

Best Regards,

Bill Mattocks