Karl Piers
Forum Enthusiast
Do Canon have any Tessar lenses in their EF/EF-S line-up, and if not, why not?
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Canon EF Tessar lenses
- Thread starter Karl Piers
- Start date
Tessar are Zeiss lenses, why would Canon have them in their line up ??? (if you asking if Zeiss makes them for Canon EF mount then yes. Do a google search for Zeiss ZE mount lenses).
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Take any advice given on a forum with a grain a salt. (that includes mine). Nobody is
perfect, though many claim to be.
Chez Wimpy
Veteran Member
Karl Piers
Forum Enthusiast
The question concerns Tessar-type lenses. Plenty of manufacturers other than Zeiss have made them. Check out the link from Chez Wimpy.
genotypewriter
Senior Member
Karl Piers
Forum Enthusiast
no need, I already have an Industar 50-2, which I mount on my various EOS cameras via an M42 adapter.
My question, to expand a little, is whether any of the Canon EF lenses are Tessars (I don't think any are ...), and if not, why not, since the design has a long tradition of employment by quality lens manufacturers such as Leica, Zeiss, Rolleiflex, etc. Is there any technical reason why Canon couldn't make an EF Tessar? Does the inclusion of AF motors, for instance, preclude the Tessar design being used?
Paul Boothroyd
Senior Member
I hate to presume but I think that the OP means, "Do Canon have any classic Tessar type design lenses in their line-up" - which is a completely different question to the one he asked.
A 'classic' Tessar design comprises four lens elements in three groups and the only modern |Canon lens which has that configuration is the Lifesize convertor for the 50/2.5 Macro lens - and that really doesn't count as it's not a stand-alone lens.
Most modern SLR lenses need to be a rather more complicated design than the classic Tessar one.
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Paul
A 'classic' Tessar design comprises four lens elements in three groups and the only modern |Canon lens which has that configuration is the Lifesize convertor for the 50/2.5 Macro lens - and that really doesn't count as it's not a stand-alone lens.
Most modern SLR lenses need to be a rather more complicated design than the classic Tessar one.
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Paul
Karl Piers
Forum Enthusiast
Why?
genotypewriter
Senior Member
Look at it like this... according to your wikipedia article, the fastest tessar is a f/2.8... that doesn't sound anything like what Canon likes to do with their high end primes (except the isolated 14L)
GTW
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Paul Boothroyd
Senior Member
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Because with a simple 4 elements/3 groups design it is very difficult to design anything for 35mm cameras but a lens with modest aperture, and around about 50mm focal length.
In fact the earliest 35mm camera Tessars were all 50mm and with f3.5 maximum aperture - going to a f2.8 Tessar had to wait for the invention of effective lens coatings, and the aeraliest of these weren't exactly stellar performers even at the time.
Paul
Karl Piers
Forum Enthusiast
I don't really buy that explanation. An f/2.8 Tessar was available in 1932. And maximum aperture isn't always the be-all and end-all of lens design - many other factors may come into play - e.g. sharpness, CA, and w.r.t Tessars weight/portability.
Paul Boothroyd
Senior Member
Have you by any chance bought the patent for the classic Tessar design?
Just kidding...........
You seem to be carrying a torch for this design, despite been given a rundown on the limitations you seem to think that the classic Tessar would be useful today. Why? How? What would it do better than modern lenses - for example: would a 4 element in 3 groups design of 50/2.8 perform better than say the EF 50/1.8? Would it be sharper, smaller, cheaper?
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Paul
Just kidding...........
You seem to be carrying a torch for this design, despite been given a rundown on the limitations you seem to think that the classic Tessar would be useful today. Why? How? What would it do better than modern lenses - for example: would a 4 element in 3 groups design of 50/2.8 perform better than say the EF 50/1.8? Would it be sharper, smaller, cheaper?
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Paul
Karl Piers
Forum Enthusiast
No, you're well wide of the mark on that. I don't happen to find your reasons convincing. Don't take it too hard. Unless you think your reasons are Canon's reasons, none of what you suggest actually follows at all. Macro lenses start at f/2.8, many zoom lenses are even slower, the well-respected F/4 70-200 is slower still. We all accept these limitations, due to the advantages that accrue to these lenses in other respects. My questions as to why Canon hasn't chosen to use the Tessar are based on curiosity - since it would appear to offer a very compact form.
What is the benefit of the Tessar design? Just small size?
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Whoever said 'a picture is worth a thousand words' was a cheapskate.
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You should ask Canon then.
PS
Maybe you should do your own homework too - the next Zeiss related Wikipedia page gives you the plain answer from the very source: http://en.wikipedia.org/wiki/Zeiss_Planar .
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Paul Boothroyd
Senior Member
Karl Piers wrote:
No, you're well wide of the mark on that. I don't happen to find your reasons convincing.
Not 'my' reasoning - it's a fact that the classic Tessar design was actually seen as limited back in the 1930's. Cheap to make and very good when well made and used within its' limitations, which were accepted back then. Don't forget that this design actually dates to 1902 when the original had a maximum aperture of f6.3.
Macro lenses start at f/2.8,
OK. I think a 1970's (?) Nikkor Macro was based on a Tessar type.
many zoom lenses are
even slower, the well-respected F/4 70-200 is slower still.
You can't physically make a classic Tessar design (just 4 elements in 3 groups remember) into a zoom though!
My questions as to why Canon hasn't chosen to use the Tessar are based on curiosity - since it would appear to offer a very compact form.
Pancake style standard 50mm at f2.8? - and get an AF motor into it, have to be USM; and then the cost starts to outweigh everything else. Where's the market? No point saving a few mm of size on a 1 series and too expensive for the xxxD market.
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Paul
No, you're well wide of the mark on that. I don't happen to find your reasons convincing.
Not 'my' reasoning - it's a fact that the classic Tessar design was actually seen as limited back in the 1930's. Cheap to make and very good when well made and used within its' limitations, which were accepted back then. Don't forget that this design actually dates to 1902 when the original had a maximum aperture of f6.3.
Macro lenses start at f/2.8,
OK. I think a 1970's (?) Nikkor Macro was based on a Tessar type.
many zoom lenses are
even slower, the well-respected F/4 70-200 is slower still.
You can't physically make a classic Tessar design (just 4 elements in 3 groups remember) into a zoom though!
My questions as to why Canon hasn't chosen to use the Tessar are based on curiosity - since it would appear to offer a very compact form.
Pancake style standard 50mm at f2.8? - and get an AF motor into it, have to be USM; and then the cost starts to outweigh everything else. Where's the market? No point saving a few mm of size on a 1 series and too expensive for the xxxD market.
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Paul
Paul Boothroyd
Senior Member
More to the point: would people buy it with the restricted aperture over the f1.8? How much cheaper would it need to be to be attractive - see my other post please.
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Paul
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Paul
Malcolm_Stewart
Leading Member
My first SLR was a Contaflex 1 with a Zeiss 45mm f2.8 Tessar, which I bought in 1958. I'd read so much about Zeiss and Tessars etc. that I really expected super results. Not so - as soon as I used it on architecture, the edges were very soft. So I bought lens test charts and a microscope, and did a series of checks and plotted the results. My Tessar suffered horribly from curvature of field, but at least it was sharp in the centre. Very sharp at f8 where in the centre, it easily out-resolved the film. (My Tessar's faults were easily visible in relatively small enlargements, say around 6" x 8" or smaller, from full frame. At the time I used a TTH Ental or Ental II as the enlarging lens.)
A short time later I bought a Vito II with the 50 f3.5 Color Skopar. This exhibited quite a different performance. Nowhere was it as sharp as the Tessar in the centre of the field, but its field was flat, and far better suited to shooting street scenes where hard edged detail often got to the edges.
Only when I bought my Minolta SRT101 in 1969 did I get a standard lens (55 f1.7 Rokkor) which struck me as really sharp, but that's more like a Gauss design.
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Malcolm Stewart
Milton Keynes, UK
zenit_b
Well-known member
Well ok its actually a Nikon lens - but it is a 21st century lens and it is a tessar...
"..As I predicted in 2001, sharpness is optimized for collectors, not for photographers.
It's very sharp in the center at all settings.
As expected for an f/2.8 Tessar, it's blurry in the corners at f/2.8, if you look on-screen at 100%. It's fine for normal photos.
The corners are optimum by f/8, but still a little bit softer even at f/5.6 if you're looking for it..."
http://www.kenrockwell.com/nikon/45.htm
"..As I predicted in 2001, sharpness is optimized for collectors, not for photographers.
It's very sharp in the center at all settings.
As expected for an f/2.8 Tessar, it's blurry in the corners at f/2.8, if you look on-screen at 100%. It's fine for normal photos.
The corners are optimum by f/8, but still a little bit softer even at f/5.6 if you're looking for it..."
http://www.kenrockwell.com/nikon/45.htm
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