Apochromatic - any difference?

[Bob Salomon]

Arne,

That 90 is out of production today. As I said, some discontinued N versions are still available. For instance we still have the 45mm in stock. The 45, 75 and 90 were introduced together and came after the 50, 80, 105 and 150 versions.

This early in the morning I forgot to list the 90 N.

[Oren Grad]

It is a duplicating lens not an enlarging lens.

Bob, I understand the difference in mechanical features. But from an optical perspective, what would be the difference between a "duplicating" lens and an "enlarging" lens, other than the magnification for which it's optimized?

If you wanted to make projection prints at a magnification of, say, 1.5x, woudn't a lens optimized for projection at scales of 0.5x-3x be a better choice than a lens optimized for projection at scales of 2x and larger, regardless of whether the label says "duplicating" or "enlarging"?

[Bob Salomon]

Oren,

It won't cover the negative format. For instance the 75mm ones will not cover 645 in an enlarger.

Then the quality sucks when used as an enlarging lens.

[Oren Grad]

Oren,

It won't cover the negative format. For instance the 75mm ones will not cover 645 in an enlarger.

Then the quality sucks when used as an enlarging lens.

Indeed, because they have recommended scale ranges of 0.8x-1.2x and 1.2x-2.5x, respectively, which don't approach the range you'd typically want for enlargements from such a small negative.

But let's take a different example: the 120 Apo-Rodagon-D, which per the Linos catalog has a recommended scale range of 0.5x-3x for projection applications from a maximum film format of 4x5. Now suppose the intended application is a 2x enlargement from 4x5. What is it about the optical design that would result in optimal quality for projecting from film to film ("duplicating"), but not from film to paper ("enlarging")?

[Bob Salomon]

Oren,

It is made to make dupes from 4x5 not print from 4x5. You should just go ahead and buy one and report on the problems as an enlarging lens for 4x5.

[Rob_5419]

Thanks Bob.

I think I'm understanding now. Although I don't have the original boxes, I've just gone back to the darkroom to check. The 50mm Apo-Rodagon I use doesn't have an -N suffix on the box. The multi-coating is purple in hue.

The 80mm Apo-Rodagon does have an -N suffix on the box (how could I never notice?). The multi-coating is also purple and green.

I guess I've learnt that I haven't been using the 50mm f2.8 Apo-Rodagon(-N) lens that I thought I had been all this time. I don't want to think about the cost error I made when I originally acquired this non -N lens.

I think I'll take David's advice and sell up for a 150mm Apo-componon S. At least the terminology is less bewildering.

Thanks for your help guys - I've learnt how little I actually know about Rodenstock lenses despite using them regularly.

[Bob Salomon]

"The multi-coating is purple in hue. "

Rob,

That is the coating color. That lens does is not multi-coated. Only the Apo Rodagon-N series is.

[Dr Klaus Schmitt]

Try a Nikon Apo EL Nikkor once and you feel the difference - goosebumps running up and down your spine....

[patfahey]

"Try a Nikon Apo EL Nikkor once and you feel the difference - goosebumps running up and down your spine...."

Ten years ago, I would have agreed with this statement. I own both a Nikkor Apo El 105, and a Rodenstock 105mm APO N. Ten years ago the Apo El was heads above everything else out there. Today -- no. Little if any difference at all when compared to the current top of the line lenses. Remember, the Nikkor lens is a very old design. It's been around for decades, I believe.

-Pat

[Rob_5419]

Thanks for the thoughts again.

Klaus - I like the Nikkor Apos, although there's something about the Rodenstock which is more satisfying in the image for me although I'm not quite sure what. Possibly warmer in colour (when I was doing colour printing) than the Nikkors.

Can I ask you Pat: what differences do you discern between the Nikkor 105mm & the Rodenstock? I own neither focal length btw...