Hi,
The Angle Of View of Sinar Sinaron W 90mm f/4.5(according to http://www.sinar.ch/file_uploads/bib...a_objekt_e.pdf , Page 5), is 105°. The other 90mm(Sinar Sinaron W 90mm f/6.8), has an AOV of 102°.
One of my lenses is Sinar Sinaron W 90mm f/4.5, but with 102°(rather than 105°) engraved on the front cell of the lens. Other specifications of the lens like filter size & slip-on cap sizes(except No of elements, which I do not know), are similar to the 105°/4.5 lens. The 102° AOV lens, has different filter size, slip-on cap sizes& No of elements. The difference in price is big(700 USD in B&H). I own it as a 2nd hand lens.
Could anyone explain?
Thanks.