Kinoliker hey don’t know where you got this info from but it is not legit. It’s very hard to design an anamorphic lens with big coverage. All taking lenses from the ultrascopes can cover s35, including the 40mm cooke speed panchro, and i would not use the panchro for anything else than s35. In the case pf ultrascopes there is another bottleneck regarding coverage and this is the scope itself.
There is another thing you have to keep in mind. About any s35 lens longer than 75mm can cover large format. But I find this confusing theorem because coverage doesn’t necessarily mean that the optical quality is preserved. Corner illumination and mtf are greatly reduced. Now back to the ultrascopes and the very confusing term “full frame”. When talking about coverage of anamorphic lenses we have to know the vertical height of a sensor and the aspect ratio to finish in. Let’s say we want to finish in 2.39 (2.40) , in that case we shoot 1.2 aspect ratio of the sensor. Let’s say our sensor is 18mm in vertical height that means we will shoot 21.6mm horizontally. We can now observe the vignetting. Obviously anamorphic shooting is about distortion and its subjective to what degree we find coverage still usable. I would’t shoot the 40mm ultrascope with more vertical height than 16mm when finishing in 2.39. But 18mm is possible, but there will be quite some vignetting and at infinity focus you might see some hard edges coming i; knowing you reached the outer limits. Now back to the very confusing and wrong term “full frame”, full frame as a photography term depriving from half frame olympus pen format and full frame is then 36× 24mm. Meaning that the vertical height is 24mm. Most so called large format cameras are 1.78 or 1.89 aspect sensors and mostly Dont go beyond 20mm in sensor height which is close to the s35 full frame format which is 18mm height, and cameras like alexa 4:3 (alexa mini etc) have this resolution. So technically when shooting anamorphic the alexa open gate has about the same image size as most full frame 1.89 aspect sensors. So I advice when speaking about anamorphic lenses and their coverage to state the vertical height of the sensor and the aspect ratio you want to finish in after a desqueeze. Otherwise it becomes “lockerroom talk ”.
40mm ultrascope has a coverage of 16mm height, 50mm can do 18mm and 85 I like not to go beyond 22, otherwise the edge blur etc and pincushion becomes ugly. These lenses where designed for academy 16mm. Even if you can use them on bigger frames it doesn’t mean you should do so, they were designed for academy film , and sometimes you might find out that some lenses can cover beyond but in most cases that leads to mediocre results.
Hope this helps!