using an aero ektar

[pruts]

Hello

Is it interesting to use an Aero ektar for wet plate ? I am not sure that the emulsion of wetplate , that has a limited sensitivity for a part of the spectrum of light, can be used with an Aero ektar lens.
Yhx , I hope my ENGLISH wad good enough to explainmyself
Marc / Belgium

[ScottPhotoCo]

The AE works fine for 4x5 wet plate.


Tim
www.ScottPhoto.co

[Mark Sawyer]

It works, but you lose some speed due to the yellowish cast of the glass absorbing the UV/blue light. My experience was that the f/2.5 Aero Ektar had about the same speed as an f/4.5 Tessar. So they're good for wet plate if you want an extremely shallow depth of field, but not for faster exposures.

[Dan Fromm]

The yellowish cast can be removed by exposing the lens to UV-B light. There are lamps ...

[Neil Purling]

I have heard the Aero-Ektar were corrected for working wide open or nearly so and the correction focuses on the red end of the spectrum. I don't know if any of that is true. One of those on a 4x5 Speed-Graphic looks like a chunk of sewer pipe. It sounds like a good lens for reportage where flash is not an option.
I can't understand how the elements of a lens can turn yellow, or if just the front element affected? Does the Aero-Ektar use Lanthanum glass, because I was wondering if that was radioactive. I think that is another urban legend around the lens, just like the cures for the yellowing lens elements.

[Jason Greenberg Motamedi]

The yellowish cast can be removed by exposing the lens to UV-B light. There are lamps ...

True, but this doesn't seem to have a huge impact wetplate/colorblind exposure with these lenses.

Years ago I tried exactly what Mark suggests, comparing a AeroEktar to a Tessar. I found that the AeroEktar was effectively f4.5 (with daguerreotypes) before removing the yellow stain and about f3.5 after removing the stain. Maybe I didn't remove it enough? Anyhow, my conclusion was that there was something about the glass that didn't work well with blue light.

[Mark Sawyer]

The yellowish cast can be removed by exposing the lens to UV-B light. There are lamps ...

Alas, it doesn't remove all of the yellowing. My two (7- and 12-inch) Aero Ektars live in a sunny west-facing window in southern Arizona, and always have a little yellow to them.


I have heard the Aero-Ektar were corrected for working wide open or nearly so and the correction focuses on the red end of the spectrum. I don't know if any of that is true. One of those on a 4x5 Speed-Graphic looks like a chunk of sewer pipe. It sounds like a good lens for reportage where flash is not an option.
I can't understand how the elements of a lens can turn yellow, or if just the front element affected? Does the Aero-Ektar use Lanthanum glass, because I was wondering if that was radioactive. I think that is another urban legend around the lens, just like the cures for the yellowing lens elements.

Most aero films are panchromatic and pretty closely match the visual range, so most aero lenses will be optimized for they visual range. The AE does use Lanthanum glass, which is radioactive not from the Lanthanum, but from the Thorium, which is included in the Lanthanum glass formula.