I just bought my first wide angle lens (Caltar II-N 90mm 4.5 ) for my 4x5 and have been taking some test shots. Is it normal for these wide angle lenses to be soft at the edges? (I checked the negative and it looks soft also.)
Thanks.
I just bought my first wide angle lens (Caltar II-N 90mm 4.5 ) for my 4x5 and have been taking some test shots. Is it normal for these wide angle lenses to be soft at the edges? (I checked the negative and it looks soft also.)
Thanks.
At the "standard" photographing aperture of f:22 it should be almost as contrasty as the center, unless you have not the propper distance between the front and back elements.
In that case the lens has to be shimmed for propper spacing.
Peter
Wide open, some softness at the outer edge of the image circle is normal. However, closed down, the image should be razor sharp from edge-to-edge.
As you know, CaltarII-N's are re-badged Rodenstock Grandagons. They are outstanding wide angle lenses (no charge for the plug, Bob).
Check for fungus. Perhaps it was dropped and an element has been slightly displaced.
Also, is the thin brass shim missing? Un-screw the front lens element and check.
It doesn't sound like a do it yourself project.
This type of damage requires the attention of a factory trained repair person.
Perhaps Bob Solomon will chime in here and advise you.
If its only soft on one side, it might be that the swing is set wrong. Wide lenses are more sensitive to tilt and swing, as the light hits the film at a large angle. Also the image is dim at the edges, so its more difficult to see that the tilt and swing are correct.
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