View Full Version : Converted Symmar sample

Ole Tjugen
28-Mar-2007, 23:18
Since the question comes up every once in a while, I've dug out an old picture shot with a convertible Symmar 150mm in the 256mm setting. Since it has to be big to show the aberrations, I've put it on flickr:


Ole Tjugen
28-Mar-2007, 23:20
Addendum: If anyone really wants it, I've got a 2780x2050 pixel version, too. :)

29-Mar-2007, 00:57
Just curious, Ole - where is this northernmost beech forest in Norway?

Ole Tjugen
29-Mar-2007, 01:17
It's in Seim, Lindås kommune, about 50km north of Bergen.

29-Mar-2007, 01:28
Correct, that's what I thought. These northernmost things are sometime false, see e.g. the world's northernmost forest (birch forest, Betula pubescens) claimed in Norway near Hammerfest (called Johannes (sp?)forest) which it is not.

JW Dewdney
29-Mar-2007, 01:41
I can't see any aberrations at THAT size...! I CAN, however, see some reflections (I assume it was shot through a window!) Is there a link to the bigger one? It's funny how everyone assumes that the convertibles were somehow compromised and inferior to modern lenses - they were actually QUITE good, IMO - but only some perhaps. I think Schneider were designing them for the prime focal length and noticed, incidentally, that they COULD be used with rear group only, nearly acceptably. I BELIEVE that it was a marketing mistake more than an optical one.

Ole Tjugen
29-Mar-2007, 02:19
No reflections, but a little bit of flare at the top there. It was one of those days with a light cloud cover which makes the light flat but the sky brilliantly white - and it's almost impossible to shade the lens well enough. Even when all the glass is behind the aperture.

I've snipped out a bit from the top left corner. There is a hint of chromatic aberration which could be helped with a coloured filter when shooting B&W, but the astigmatism is greater by far. After taking this picture I dropped all thoughts of using coloured filters with converted lenses - unless I have a better reason than sharpness to do so.

BTW - the sharpness isn't that great. That's not a problem with the lens, but with my Agfa Duoscan T1200 scanner - and my scanning skills!