1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

So, Planar, or Tessar?

Discussion in 'Lens Matters' started by Still_Togging_Along, Jul 26, 2009.

  1. Still_Togging_Along

    Still_Togging_Along In the Stop Bath

    I am rather intrigued about Zeiss's Tessar and Planar lenses, mainy because these designs are so (if you pardon the pun) Iconic. The one thing that puzzles me is that whilst the Tessar was advertised as 'The Eagle eye of your camera' and Zeiss's logo is derived from the Tessar's optical layout, the Planar, is considered by many people to be the 'better' of the two lenses. However, whilst ruminating over this subject, I discovered that the Planar, prior to and for some time after multi-coatings started being used, (yet another Zeiss '1st'!) suffered from flare which also reduced it's contrast. On the other hand, the Tessar, had a reputation for it's extremely satisfying levels of contrast.

    I think I am right in saying that the Planar delivers higher levels of resolution than the Tessar and is considered the more desirable because it also f1.8 rather than f2.8 optic. However, I wonder which of these lenses produces the 'better' image, when used at say, f8?
     
  2. Roger_Provins

    Roger_Provins Well-Known Member

    The Tessar has 4 air to glass surfaces whereas the Planar has 12 hence, before coatings were available, the Tessar delivered better contrast. The Tessar is only at it best when f3.5 is the maximum aperture but it was stretched to f2.8 - mainly for marketing reasons - folk wanted fast glass then as now.

    I would expect a modern Planar to out-perform a modern Tessar in any test although the difference could be small.
     
  3. Malcolm_Stewart

    Malcolm_Stewart Well-Known Member

    I have a Contaflex 1 fitted with a 45mm f2.8 Tessar, bought back in 1958. It suffers from serious curvature of field, but in the centre at f8 it's very sharp. I also have a Vito II fitted with the 50mm f3.5 Color Skopar from the same era. This never reaches the high central resolution of the Tessar at f8, but does have a flat field, and is much better in practice for street photography. i.e. The tops of church spires remain adequately sharp which simply doesn't happen with this Tessar, which was a great disappointment. OK for bitingly sharp portraits in the centre of the field! (Both lenses were carefully tested using the original AP lens testing charts, and negatives examined under a microscope for the resolution figures.)

    More recently, I've bought both a CZ 50mm f1.7MM T* and a 50 f1.4AE Planar T* in Contax/Yashica fitting. The f1.4 delivers, and fitted to my EOS 5D shows usable contrast at f1.4, and excellent overall sharpness f4 on. If only it was available in an AF form!
     
  4. parisian

    parisian Well-Known Member

    This Planar has never let me down;
    [​IMG]
     
  5. beejaybee

    beejaybee Marvin

    Certainly at f/8 or faster. I'd expect the Tessar to hold its own, maybe just a tad crisper at small apertures - even with modern coatings the extra glass in the Planar doesn't help contrast.

    Many Tessars of focal length around 75mm were also installed in 6x6 format cameras, which gives a capture angle a bit too wide for the design ... hence soft corners, expecially at large apertures.
     

Share This Page