Determine lens design

Hi Everyone,

Can a lens design (such as Sonnar, Planar, etc.) be determined by the formula used in a lens, i.e. number of elements and grouping ?

Cheers

Up to a point. The clasic designs have a basic outline and it can be seen even where modern lens designers have moved it along and developed things further. Also, new glass types, aspherical lenses and complex zooms add further complication to the simple basic start.

For example, take three elements and you have a Triotar design, common on inexpensive cameras for many decades. Add a cemented element to the rear one and you have a better corrected Tessar design, capable of good quality.

Add another element and we have a Sonnar or Planar. To see how these things relate you really need a book about lenses. I'd recommend as a start "The Lens Book" by Roger Hicks. Then you can go on from there if you need to.

Best regards

John

Thanks John. I'll try to chase down that book.