Archived posting to the Leica Users Group, 2008/11/24

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Subject: [Leica] Are Leica lenses muliticoated?
From: kididdoc at (Steve Barbour)
Date: Mon Nov 24 07:41:16 2008
References: <> <><4AE8990C-C0EA-4C66-B><> <> <9B4C173E1A764301A715211C9ED9D6B6@dadquad> <p06230900c54fd464d250@[]>

On Nov 23, 2008, at 9:14 PM, Henning Wulff wrote:

> You need good contrast along with good resolution to achieve  
> 'sharpness', ie, a perception of 'good resolution'.


but even contrast without resolution can give an impression of  
sharpness...especially with small web jpeg files...
> You don't need a lot of contrast to achieve outstanding resolution,  
> nor do you need much resolution to achieve outstanding contrast.

so it seems the math would show two really independent parameters....

with sharpness being a "perception"   yet this often can be  

thanks Henning,  Steve

> The 'softness' or 'glow' or 'glamour' that is ascribed to older  
> lenses is a combination of low contrast and flare, both things that  
> can be controlled by using correct coatings, multi-coatings or  
> whatever for the glass types and curvatures of lenses. The latter  
> also plays a part.
> You can have low contrast without a lot of flare, but it's not easy.  
> It's often proposed that to achieve a very high effective dynamic  
> range a low contrast lens is desirable, but that often leads to  
> flare, which tends to be localized and cannot be dealt with easily.  
> Therefore, a lens that is chosen for its low contrast  
> characteristics like the DR Summicron often causes problems due to  
> flare. Of course, when the stars align the results can be  
> outstanding, but a low contrast lens is not a panacea for dealing  
> with large dynamic ranges.
> As I mentioned earlier in this thread, the earliest multi-layer  
> coated lens I know of is the 35/1.4 Summilux introduced around 1960;  
> I'm sure there were ealier examples but this lens was one of the  
> very first commercially produced lenses using this technology. Once  
> designers were able to take advantage of reducing the reflectance  
> and therefore scatter of specific spectral bands, it opened up a  
> huge range of possibilities, especially in marketing :-). Whether  
> one uses 3, 7 or 20 layers is a bit like whether your razor has 2,  
> 3, or 5 cutting blades. Past a certain point it's mostly marketing,  
> especially if your lens is for general photographic use under  
> uncontrolled conditions.
> Coatings for controlled conditions can be optimized to a much  
> greater degree; lenses for reproduction, especially three colour or  
> even more so monospectral reproduction could have highly optimized  
> coatings that required only a few layers, with slightly different  
> thicknesses varying from the center to the edges.
> If you know a lens well, you can use it's flare characteristics to  
> your advantage, in particular to achieve an 'older' look, but if  
> what you're mainly concerned with is reducing contrast, there are  
> usually other ways of achieving that that are more controllable.
> I've had a lot of different lenses over the last 50 years, and still  
> have quite a few. Among the latter are still a few low contrast  
> lenses and a couple that have very specific flare characteristics,  
> but on the whole I prefer lenses that medium to medium-high in  
> contrast with as little flare as possible. Those are the easiest to  
> work with. If I wish, I can create most types of flare after I take  
> the picture. I can't remove it easily if it's in the negative or  
> digital file if at all.
>> Steve you really need good contrast to achieve good resolution, the  
>> two go
>> hand in hand. The well recognised smooth look that you are  
>> describing may be
>> partly from moderate contrast, but also from the degree of correction
>> present. With more aberration present, the out of focus blurs can  
>> retain
>> their general shape and be smoother by being more blurred! That is  
>> not meant
>> to be a criticism of valid personal preference. Of course my taste  
>> there is
>> probably well established.
>> Has anyone else noticed that this evolving thread is almost a  
>> digest of
>> perennial LUG topics?
>> Lens coatings,
>> Lens cleaning,
>> Artistic vs. technical,
>> Favourite lenses
>> What great master photographers used etc etc
>> Now I suppose I have introduced the B word.
>> Cheers
>> Geoff
>> Pick up your camera and make the best photo you can.
>> -----Original Message-----
>> Subject: Re: [Leica] Are Leica lenses muliticoated?
>> this same argument applies to some of the greatest and highest  
>> resolution
>> lenses of the past...for example  the Summicron 50/2 DR...low  
>> contrast
>> combined with very high resolution allows a unique smooth  
>> look...and you can
>> always increase the contrast if desired...
>> I am not sure how the coating impacts, or what the coating is for  
>> the DR...
>> this look and behavior likely accounts for this lens being the  
>> desert island
>> favorite of so many individuals...
>> Steve
>> _______________________________________________
>> Leica Users Group.
>> See for more information
> -- 
>   *            Henning J. Wulff
>  /|\      Wulff Photography & Design
> /###\
> |[ ]|
> _______________________________________________
> Leica Users Group.
> See for more information

In reply to: Message from freakscene at (Marty Deveney) ([Leica] Are Leica lenses muliticoated?)
Message from ricc at (Ric Carter) ([Leica] Are Leica lenses muliticoated?)
Message from jls at (Jeffery Smith) ([Leica] Are Leica lenses muliticoated?)
Message from kididdoc at (Steve Barbour) ([Leica] Are Leica lenses muliticoated?)
Message from hoppyman at (Geoff Hopkinson) ([Leica] Are Leica lenses muliticoated?)
Message from henningw at (Henning Wulff) ([Leica] Are Leica lenses muliticoated?)