|
Modern
CCD chips are as large as or even larger than small film. Of course a
high quality instrument like the Helix 250 must have a constant optical
quality across the field of 43 mm. Only then can we say that we have a
very high quality rich-field camera.
As can be seen in the diagrams, our optical designer has once again
succeeded. In practice there will be no quality difference between the
corners and the optical axis. Beside that, the focus is perfectly flat.
The maximum deviation is only 0.06 mm from 400 nm to 700 nm.
The flat field makes the Helix 250 also very suitable for film. With a modified 6x6
roll film cassette, images with a 52 mm diameter can be taken! Of course, a SLR camera can also be used.
|