Re: Emotive lenses

[dmorton@cix.compulink.co.uk (David Morton)]

In-Reply-To: <32559DAC.21B5@ecentral.com>
> George,
> 
> There is more, much more to lens design then just bending light.  There 
> are so many different designs allieds,triplets,symmetrical and so on. 
> The main difference is the attitude of the company itself.  The 
> Japanese (at least in 35mm) tend to build there lenses to the market 
> and spend very little in Yen on there raw material (glass).  Zeiss and 
> Leitz tend to build there lenses to a certain high criteria. They  pay 
> a large amount of  Marks for there raw material (high refractive index 
> glass). After spending all this money they then decide what the price 
> will be.

This just isn't true, you can count the number of manufacturers of high 
refractive index and other specialist glasses on the fingers of one 
mitten, and the German lens manufacturers use the same sources as 
everyone else. Nikon in particular have been innovative in their use of 
such materials in their 'serious' lens designs (though I accept that 
these days they make a lot of price-driven crap).

>  The optical engineers are trying to acheive something that is almost 
> more important then mere resolution.  The color and contrast that a 
> lens can see gives it the "character" you were talking about.  This is  
> done with glass makeup (chemical additives) not the phisical shape.  
> The coating may indirectly help this ability by absorbing stray light, 
> but the refractive index and material makeup of the glass gives it 
> character.

I'm afraid this smacks of the same pseudo science which one finds at the 
'snake oil' end of the audiophile market, where claims are made for the 
performance of specialist cables (for example) which are not justified by 
the evidence (I had a client who was a specialist cable manufacturer, and 
I could tell you stories which would horrify you).

Optical design is a fiercely complex field - I've done quite a bit of it 
myself - but it's not magic. An experienced designer can tune an optical 
design to produce a range of different 'looks' in the images it produces. 
However, like any engineer producing what are, after all, consumer 
products, the designer of 35mm camera lenses is under the thumb of the 
marketing department, and in a world where the quality of a lens is 
measured by the kind of limited (*desperately* limited) 'resolution' 
results one sees in photographic magazines, it's not surprising that less 
satisfactory designs become the norm.

A good analogy is the gear ratios chosen for manual shift motor cars. At 
least one manufacturer (Alfa Romeo) was forced away from an exquisitely 
chosen set of ratios to one which produced better fuel consumption 
figures at the 'spot' speeds used in the standard MPG tests prescribed by 
government legislation.

Of course, in the real world, the original ratios worked better, and gave 
greater fuel economy.

dmorton@cix.compulink.co.uk      |
david@cassandra.compulink.co.uk  |  "The loss of an old man
(+44) 181 450 5459               |  is like the destruction
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