Uncoated lenses

[msbarnes]

I've always believed that coated lenses were better; atleast from a technical standpoint. I've shyed away from uncoated lenses and went for coated and/or multi-coated lenses whenever possible for any camera/lens/format.

After doing some investigation it seems that coating improves contrast and reduces flare and its effects really depend on the lens design.

Jurgen from Certo6 believes that it doesn't really matter and I've seen some impressive shots from uncoated folders, so now I'm thinking of trying some uncoated-lensed folders because they are cheaper.

With a lens shade, is the difference night and day? Anyone actually prefer uncoated lenses for these folders?

 

[DamenS]

I haven't tried an uncoated lens before, but Voigtlander do Single-Coat versions of a couple of their M Lenses (which are mullti-coated in standard version), which is meant to lessen contrast (which should give better shadow detailing and maybe a smoother tonality in B/W). I would imagine the same should hold true for an uncoated lens - just watch out for flare (I would definitely use a lens hood) !

 

[Livesteamer]

Uncoated lenses can do well if you use a lens hood and be careful about flare. I recently ran a roll of Ektar thru my 1929 uncoated Leica Elmar and got some very nice results. If the lens has some haze it will flare more. Good Luck. Joe

 

[Lflex]

I am not into folders, but I have an uncoated Tessar on my Rolleiflex Automat from (1937)

Rolleiflex Automat v. 1 by mandoflex, on Flickr

And a coated Xenar (tessar design) on my Rolleiflex T (1974)

Rolleiflex T by mandoflex, on Flickr

The results are like night and day but it may not all be attributed entirely to the lack of coating. The prewar lens may also have developed a little fogging/haze with time that softens the results a little more that they would have been in 1937. Completely unaffected prewar lenses are almost impossible to find.

For the past 2 years I have been living in a country where the sun shines a lot and the contrast is difficult to manage. This inspired me to buy the uncoated Rolleiflex and a modern Voigtlander single-coated 35mm for my Leica.

My home country in northern europe is clouded and dull most of the year, and I would probably never have thought of spending money on a low contrast lens while living there.

Uncoated lenses flare like crazy and will benefit from a hood (and a yellow filter if you shoot black and white)

 

[sevo]

Uncoated lenses have about 4% light loss per glass-air surface where coated ones have about 1% and multicoated ones have 0.2%-0.5%. For low element counts, less than half of that scattered light will end on film.

Now a Tessar or triplet have merely three groups, that is six lens/air surfaces - that amounts to 24% light loss and maybe 8-10% haze. A 12 group zoom, multicoated, has roughly half the reflection caused light loss, and the same haze (as backscatter increases with the element count). That is, for these simple three group designs uncoated worked out well enough to deliver qualities that are still within range of current industry standards, and (when stopped down well enough to diminish their residual errors) single coated Tessars can still deliver spectacular clarity compared to modern lenses.

 

[graywolf]

Actually, there are no uncoated lenses.

Read on before you argue.

Coating came about because it was discovered that older lenses had a "bloom" that new lenses did not. That bloom increased contrast and reduced reflections a bit. It was caused by contaminants in the air setting up on the glass in the lens. They then set out to do the same thing artificially. They figured it out, and factory coated lenses started coming out in the late 1930's, that was a soft coating, so was usually only applied to the the internal surfaces. The need for better aerial photos during WWII, resulted in the development of hard coatings that could be applied to the outer surfaces of the lens that would not be damaged by normal cleaning, that became the norm after the war. Then in the 1970's multi layer coatings were developed.

But the point is any lens more than about 20 years old has that "bloom" coating that was so desired prior to factory coatings. So, in fact there are no uncoated lenses today, unless you use some serious chemical cleaning to remove the bloom.

 

[Lflex]

Actually, there are no uncoated lenses.

Read on before you argue.

Coating came about because it was discovered that older lenses had a "bloom" that new lenses did not. That bloom increased contrast and reduced reflections a bit. It was caused by contaminants in the air setting up on the glass in the lens. They then set out to do the same thing artificially. They figured it out, and factory coated lenses started coming out in the late 1930's, that was a soft coating, so was usually only applied to the the internal surfaces. The need for better aerial photos during WWII, resulted in the development of hard coatings that could be applied to the outer surfaces of the lens that would not be damaged by normal cleaning, that became the norm after the war. Then in the 1970's multi layer coatings were developed.

But the point is any lens more than about 20 years old has that "bloom" coating that was so desired prior to factory coatings. So, in fact there are no uncoated lenses today, unless you use some serious chemical cleaning to remove the bloom.

Never heard about it. A reference would be nice.

 

[john341]

Uncoated lens

Uncoated lens

My experience is with a Nettar 515 uncoated lens. When I put my first roll of Ektacolour through it I thought I would have faded looking pix but the results were as good as other lenses! I love this little folder now. Gosh they made some good stuff earlier...

 

[uhoh7]

Actually, there are no uncoated lenses.

Read on before you argue.

Coating came about because it was discovered that older lenses had a "bloom" that new lenses did not. That bloom increased contrast and reduced reflections a bit. It was caused by contaminants in the air setting up on the glass in the lens. They then set out to do the same thing artificially. They figured it out, and factory coated lenses started coming out in the late 1930's, that was a soft coating, so was usually only applied to the the internal surfaces. The need for better aerial photos during WWII, resulted in the development of hard coatings that could be applied to the outer surfaces of the lens that would not be damaged by normal cleaning, that became the norm after the war. Then in the 1970's multi layer coatings were developed.

But the point is any lens more than about 20 years old has that "bloom" coating that was so desired prior to factory coatings. So, in fact there are no uncoated lenses today, unless you use some serious chemical cleaning to remove the bloom.

My 1937 sonnar has been diagnosed with exactly this fine oxidation, and I have been sworn to never clean it

that's basically untouched....and it is no slouch at infinity either:

full size

Dusk with partial overcast...with sun it has pretty decent contrast

same lens @f/1.5 on 35mm ektachrome 400

 

[sevo]

Coating came about because it was discovered that older lenses had a "bloom" that new lenses did not. That bloom increased contrast and reduced reflections a bit. It was caused by contaminants in the air setting up on the glass in the lens. They then set out to do the same thing artificially. They figured it out, and factory coated lenses started coming out in the late 1930's, that was a soft coating,

Well, no, that would be rather a odd history of lens coating. The phenomenon is self-evident (soap bubbles) and the physical mechanism behind it had been already explained early in the 19th century by Fresnel.

"Blooming" was a polishing artefact some makers attempted to control and market before WWI, but it proved to be a dead end on the way to lens coatings - a few British makers continued to sell "bloomed" lenses at a extra charge, but it did not really take over. The phrase reappeared more loudly in British lens marketing after Zeiss had started to market their coated lenses - but at that time it must either have been a very short lived soft coating or mere marketing speak, as the "bloomed" lenses from that period I have seen so far show no trace of blooming or coating.

The first working coatings that appeared on the market were Smakula's hard vacuum deposited MgFl coatings - essentially the same thing we still have to day. Soft (wet deposit) coatings had been known for quite some time before that, but they were too short lived and useless on the most critical lens front. They were only marketed in the first two decades of coating - probably as a stop-gap measure as competitors were forced to offer some coating that did not infringe on the Zeiss patents.

 

[graywolf]

Never heard about it. A reference would be nice.

Well, that would be hard. When I got into photography in the early 1950's the local library had a lot of books from the 1930's & 40's, but now, I can not even get any of them on interlibrary loan. And, of course, I do not remember exactly what books I read back then. Remember, hard coating was brand new back then, and even the pre-war soft coating was fairly new, so it was stuff the was written about in detail.

How many here realize that that red "Special" on Kodak's top of the line lenses meant that it had the old soft coating? And that all lenses labeled "Ektar" had the hard coating, and that was the difference between an Anastigmat Special and an Ektar lens of the same formula.

I read a lot of things today that appear to be something someone made up and everyone quoted it. Although, I will admit that sometimes I get a bit confused by all the useless info in my head, I do not believe that is happening here (GRIN).

 

[sevo]

How many here realize that that red "Special" on Kodak's top of the line lenses meant that it had the old soft coating? And that all lenses labeled "Ektar" had the hard coating, and that was the difference between an Anastigmat Special and an Ektar lens of the same formula.

Weell... The Kodak 35 had a choice of the uncoated Anastigmat Special or a (hard) coated version of the same marketed as Anastar - no Ektar there.