Do I really need an APO lens?

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I am now the proud owner of an Omega D2V XL (I wanted a D2 for about 30 years). I'd like to get a really good lens. I was planning on getting an 80mm Schneider Componon-S lens. A salesman told me that I will get noticeably better results from an APO lens. Is this true? Since I am only doing B&W I thought the Componon-S would be fine.

Thanks!

-- Craig Brown (csbrown@tastybuzz.com), September 23, 1999

Answers

It will do just fine. He wanted more commission. James

-- James (James_mickelson@hotmail.com), September 24, 1999.

I second the motion; I have that lens & it is superb for B&W and is no slouch on color. The APO lens would probably only buy you improvements on color and then only under some conditions. Everything in the chain such as the film, the negative quality and how solidly the enlarger is set up will have at least as great a bearing on the ultimate results.

Cheers,

-- Duane Kucheran (dkucheran@creo.com), September 24, 1999.


I wanted to respond that an APO enlarger lens is non-sense for B&W printing but actually I don't know. APO is a correction for the breaking of light into separate waves of colored light, the spectrum, when it passes through glass. APO corrects mainly for the green light falling not on the same focal plane as the other colors of the spectrum. I don't think it's right to say that it only counts in color-photography then.

-- Lot (lotw@wxs.nl), September 25, 1999.

What size negative are we talking about? With an 80mm I assume it is a 35mm neg., it will give you everything you want in b/w, save the extra money and get another lens (150mm) for 45 negs, I have a D2V which I converted to a Zone VI cold light head, have never regreted it in 8 years. Pat

-- pat j. krentz (krentz@cci-29palms.com), September 25, 1999.

Since the light in your enlarger puts out a continuous spectrum, apochromatic lens performance would have an effect. It has nothing to do with whether or not you're printing color.

The rest of the story....

Apo lenses are apochromatic at only one specific repro ratio or a narrow range; outside that, it's not apo no matter what the label says.

And now to the marketing issue.

While the technical standard for apo performance is that the lens focuses the spectrum in use to the same plane, many manufacturers now fudge that, using "close enough to be called apo" etc. Note that many lenses that weren't marked apo a few years ago are now marked apo without any changes other than lens-barrel markings.

After all, who's going to enforce any sort of standard on them?

Now...you can only see maybe up to 10 lp/mm, and you get some visual response out to around 30 lp/mm although you can't directly see that. Any decent modern enlarging lens will do that.

Of _MUCH_ more importance is precise enlarger alignment, the use of glass neg carriers, careful focusing, printing at the optimum lens aperture etc.

I'd bet that not more than one percent of enlargers in use are aligned remotely close to proper, and for that 99 percent of users of mis-aligned enlargers it doesn't matter much because the lenses are being used at apertures too large or too small.

So rather than spend extra money for an apo lens, I strongly recommend you spend the money for a good alignment tool such as the Zig-Align or the Versalab Parallel. Cheapo tools that use a bubble level etc are pretty useless.

-- John Hicks / John's Camera Shop (jbh@magicnet.net), September 25, 1999.



Hi. It's true that as long as your print in a white light APO will show its advantages, however if you use MG B&W papers you would filter this white light to a rather narrow wawelenght distribution and APO don't work. I haven't really seen any distribution curves for MG filters, and I don't know how narrow, but the fact that they are collored means that some part of the spectra are cut out. So, it depends on what are you planning to do. E.

-- Evgeni Poptoshev (evgeni.poptoshev@surfchem.kth.se), October 04, 1999.

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