Andre Oldani , Sep 01, 2003; 02:25 p.m.
The Schneider ALPA APO-Helvetar 5.6/48mm is a new lens for the ALPA 12 system. The construction is unique and based on the no longer produced Schneider Super Angulon 47 (non XL and in this version and barrel construction exclusively available for ALPA at the moment). In fact the image circle is smaller - 123mm at f2 - than the actual SA 47XL. It covers 6x9 easily with the big advantage of producing good results even fully open. The classical medium/large format lenses of that type normally perform best at f11 and up and full aperture is only for focussing purpose.
As said the Helvetar doesn't need to stop down for good results. XL lenses are optimised for a very large image circle so that you can use them also on y 4x5". The price you have to pay for this is a very soft image at full aperture. That's why the Helvetar has also in this respect a special status.
Nevertheless, the Helvetar offers for the 6x9 format still some shift reserves: 16mm landscape and 12mm in portrait (a center filter is recommended). It is a very compact lens. To make it easier for the customer it's construction is done for the same filter diameter as other Schneider lenses (filters, hoods in 67mm thread) and the front tube acts even as a small lens hood.
This lens calculation should also deliver a very good quality with digital backs. Here it should not be used over an image circle of some 80mm.
Actually I am testing on of the first batch/pre series lenses and I am very pleased with the results. The angle of view one gets from it at 6x9 is the same as the Carl Zeiss Biogon T* 4.5/38mm on the special ALPA format 44x66mm (both with 2:3 ratio). I hope to come up with results on
www.alpavision.ch in some weeks. For the moment one can find product pictures of the Helvetar at
www.alpavision.ch/press.