ASPH Lens

[wwulfsohn]

What is the advatage of an ASPH lens? Is it worth the extra money?

Thank you.

Bill

[adan]

The Leica designation ASPH simply means that somewhere in the lens there are one or more glass elements with apherical (non-spherical) surfaces.

The particular advantage that such a surface delivers varies from one lens design to another depending on how the lens designer chooses to use it.

In some designs it allows for a smaller lens with the same performance as a non-ASPH; in other cases it allows for better performance and/or speed in the same volume.

But in general, Leica's ASPH lenses tend to be more compact for their aperture than non-ASPHs - or sharp further into the corners at full aperture than their non-ASPH predecessors - or tend to have a bit more overall contrast (which makes pictures look snappier) - or some combination of the above.

BTW many other manufacturers use aspherical elements these days - once they were very hard to manufacture, but blank-molding techniques (pioneered by Leica and Hoya) mean they are turning up in even the simplest consumer-zoom lenses.

Leica ASPH lenses cost more more because of the "Leica" part of their name than the "ASPH" part, per se.

Personally - I prefer the look of the non-ASPH but otherwise recent lenses myself, for the most part. So I - agian personally - do NOT find the ASPH designation worth extra money per se.

But I did spring for a 75 Summicron ASPH because I wanted that focal length, size and speed and there was no alternative. And the same may eventually be true for the 28 Summicron ASPH. And for those lenses, the ASPH construction likely is one of the reasons they are so compact for their speed.

[masjah]

Originally Posted by wwulfsohn

What is the advatage of an ASPH lens? Is it worth the extra money?

Thank you.

Bill

Bill

The possibility of an aspherical lens surface is just one tool in the armoury of the lens designer. Others include high refractive index glass, low dispersion glass, glass with highly nonlinear dispersion characteristics ("anomolous partial dispersion") computer aided design tools, years of experience, high manufacturing accuracy (avoiding the need for designs which are tolerent of manufacuturing tolerances) to list but a few. Leica will use aspherical technology in a current design if it is needed. The lens will be priced bearing in mind all these factors, and more! So please don't attach too much significance to the use of aspherical surfaces per se.

[robsteve]

Originally Posted by wwulfsohn

What is the advatage of an ASPH lens? Is it worth the extra money?

Thank you.

Bill

Yes, it is worth the extra money. Any Leica lens with ASPH or APO in the designation will be of the latest design and best performance.

Which ASPH lens are you interested in? There are not as many in the R line as in the M line.

[Digitom]

Originally Posted by masjah

Bill

The possibility of an aspherical lens surface is just one tool in the armoury of the lens designer. Others include high refractive index glass, low dispersion glass, glass with highly nonlinear dispersion characteristics ("anomolous partial dispersion") computer aided design tools, years of experience, high manufacturing accuracy (avoiding the need for designs which are tolerent of manufacuturing tolerances) to list but a few. Leica will use aspherical technology in a current design if it is needed. The lens will be priced bearing in mind all these factors, and more! So please don't attach too much significance to the use of aspherical surfaces per se.

I have been in Solms a few weeks ago on a guided tour and we saw some general parts of the manufacturing of ASPH lenses. The grinding is sure made not by hand anymore, but the process for one first single lens grinding needs about 20 Minutes, compared to "normal" lenses which need only 6 Minutes (that is only the 1st step of the long process the lens run through). And there is only 1 lens in process of one machine at the same time. This is a result of the accuracy Leica is performing in the manufactory process. They do not use multigrinding several lenses at same time. The accuracy of the surface is checked by interferometry and is less then 1/10 000mm. Sure also Leica only use that complex efforts for the lenses if it is necessary. So the price is well I think! But nevertheless, depending on the use and the requirements YOU have, you must decide. All lenses are very well, and these days Leica brings out a new serial of 4 non asperical lenses for the M System which is also high performance: summarit M. Sure I would be happy with that kind of lenses if I would be a user of M.

[endustry]

Originally Posted by robsteve

Yes, it is worth the extra money. Any Leica lens with ASPH or APO in the designation will be of the latest design and best performance.

I agree with the first part but the second is subjective. I like the look of the 50mm Summilux Asph with film but it is way too sharp for my tastes on the M8.