Using the calculator, I'm getting the following values:

- 34 fL zoom method
- 57 fL for 16x9 anamorphic image at my screen height before lens expansion

Now, if I take that 57 fL number and multiply it by 61% (6% light loss through the lens, 33% light "loss" due to expansion), I get a result of 34.7 fL. This tells me that in my situation the lens is essentially pointless.

The calculator has a checkbox for if you're using a lens but it seems to just be doing a basic 1.33x multiple of the light output when using the zoom method. This gives me 45 fL, which obviously doesn't align with my math.

Am I doing this math correctly? Is the discrepancy due to the fact that the calculator isn't take the different zoom levels of the two options when checking the anamorphic lens box?