Schneider listed all their lenses as covering 9x12 rather than 5x4 at one time, they are a German company after all, and that's the equivalent Continental European format of the era the lenses were made. Look at the
data for Xenars etc.
You won't see any mention of 5x4, 10x8 etc in 1960's Schneider literature, I have a 1970 Schneider Professional Lenses Review leaflet(in English) in front of me and all sizes for coverage are metric. So don't read too much into the 90mm angulon being listed as 9x12, the difference between the formats is quite small, almost exactly the same lengngth, 5x4 is a touch wider.
Kerry Thalman and Chris Peres tested quite a few LF lenses some years ago, they tested quite a few 90mm f6.8 Angulons because of the quality issue, the best were excellent the poor once dire. There's plenty of photographers getting excellent results from their Angulons.
Ian
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