Henry,
Thanks for the extra detail. Doesn't seem like you found a simple explaination for the reduced fov. I can't say I've had a look at radial magnification. Something to add to the list.
I recently learned that the official ISO method for measuring ER specifies that the instrument should be stopped down to a 2mm EP, but it seems listing available ER is also permissible . Other companies list the ER for full the full EP. The ERs across the BDII XD range vary from 15mm to 17.5mm. They were all fine with my glasses so I'd guess that is the ISO method. However, the difference in effective ER can alter the AFoV.
David
Thanks for the extra detail. Doesn't seem like you found a simple explaination for the reduced fov. I can't say I've had a look at radial magnification. Something to add to the list.
I recently learned that the official ISO method for measuring ER specifies that the instrument should be stopped down to a 2mm EP, but it seems listing available ER is also permissible . Other companies list the ER for full the full EP. The ERs across the BDII XD range vary from 15mm to 17.5mm. They were all fine with my glasses so I'd guess that is the ISO method. However, the difference in effective ER can alter the AFoV.
David
