ICA aplanat Helios 260 mm F8 Vergrossenung

[nadoske]

Hello.

Just found this lens for sale, want to know something about it. Why ICA made repro or enlarger aplanat? There was much more corrected lens designs like anastigmats. What is this? And how it will be for shooting like 13x18?

[Dan Fromm]

Hmm. CZJ sold Tessars in barrel with mounting threads at each end. They were marked Vergrosserung (enlarging) on one end and nothing or Verkleinerung (reductions) on the other. Dual purpose lenses. They were used for taking with, if I recall correctly, "nothing" or Verkleinerung facing the subject and for enlarging with Vergrosserung facing the print. Their diaphragm control rings were marked on both sides so that they could be read with the lens in either orientation.

When aplanats were made no lenses made were specially for enlarging. If you believe their propaganda, Boyer's plasmat type Saphir <<B>> was the first lens computed specifically for enlarging.

[nadoske]

So its kind of special made lens? but why somebody need enlarging aplanat? Will that have any effect on photo?

[Dan Fromm]

No, it is an ordinary normal run-of-the-mill general purpose lens. Use it for taking, use it for enlarging. I have no idea whether it is better for taking than for enlarging or vice versa. It can't be optimized for both.

[Vaidotas]

Aplanat as symmetrical design lens is free of distortion and relativelly cheap to produce so it might be the reason to use them as affordable enlarging / reducing lens? Aplanat is much superior against petzval in this application.

[Michael E]

IIRC, it was recommended to use your taking lens as your enlarging lens, because it would "correct" the light fall off towards the edges better than a different lens with different characteristics.

[nadoske]

Thank you)