09-07-2011, 08:00 AM
[quote name='Klaus' timestamp='1315381462' post='11364']
Again - I do not advise this method for (ultra-)wide lenses which have a (negative) field curvature issue. You will end with soft corners in the foreground.
This was very obvious during the tests with the Sigma 12-24mm II. Initially I used AF (which suggested infinity focus) - resulting in exactly those soft corners. After switching to manual focusing and choosing ~1m the soft corners were gone (within the capabilities of the lens).
The method is probably fine for lenses with a very flat focus field.
[/quote]
Thank you for your advice, Klaus. I admit that I did not understand well what you wrote since I am lack of the knowlege of the "field curvature issue". Now I understand it better. A side question: is this the reason why the Merklinger method did not become polular?
Frank
Again - I do not advise this method for (ultra-)wide lenses which have a (negative) field curvature issue. You will end with soft corners in the foreground.
This was very obvious during the tests with the Sigma 12-24mm II. Initially I used AF (which suggested infinity focus) - resulting in exactly those soft corners. After switching to manual focusing and choosing ~1m the soft corners were gone (within the capabilities of the lens).
The method is probably fine for lenses with a very flat focus field.
[/quote]
Thank you for your advice, Klaus. I admit that I did not understand well what you wrote since I am lack of the knowlege of the "field curvature issue". Now I understand it better. A side question: is this the reason why the Merklinger method did not become polular?
Frank