Lens #2: Pentax 67 135mm f/4 Macro

Initially, I had no plans to buy this lens but could not resist the temptation when I saw it at a bargain price in a very good condition at a used camera gear online marketplace. I actually looked for a 165mm f/2.8 lens, which could be a good supplement to my 90mm f/2.8, but decided to first try 135mm f/4 Macro.

Unfortunately, and, oddly enough, very few technical details can be found about this lens, except for the well-known facts which you can read on the relevant page of PentaxForums.com. Nevertheless, some information regarding its optical implementation can be traced.

Pentax 67 135mm f/4  - helicoid extension at infinity and closest distances

Pentax 67 135mm f/4 Macro – helicoid extension

It is an implementation of Voigtländer semi-symmetrical Dynar lens formula – a modification of Heliar lens which is also a variant of the Cooke triplet design. The Pentax lens is very close to the f/3.5 Dynar that was previously renamed Heliar. The Dynar is an ancestor to all modern Heliars.

Close focusing and macro capabilities

This lens was developed specifically for close focusing. At the maximum lens extension of 42mm it gives only 0.31× magnification ratio with exposure factor about ×1.72. To achieve 1× magnification the lens should be extended by additional 93mm with full set of extension tubes #1+2+3. As a result, you get a very long lens with exposure factor ×4 which is equal to the actual lens speed f/8. This results in focusing screen becoming very dark and makes the actual focusing very difficult.

Field of view

The focal length of a 135mm lens with the field of view 36.5° is close to that of the old 150mm f/2.8 lens with field of view 33°. Well, I like to use it for close portraits, as for such image scale there is no need in extension tubes.

Size and weight

Pentax 67 135mm f/4 Macro compared with 90mm, 105mm and 165mm

Pentax 67 135mm f/4 Macro compared with other lenses

It is a portable, lightweight and very handy lens despite its size comparable to 165mm f/2.8 lens but 200g lighter.

Hood

The lens has a deeply recessed front element, so it doesn’t actually need a hood. But in certain situations it still may be required. Original clip-on plastic hood PH-SA 67mm costs around $50. A cheap compact metal round hood for $3 can be a good substitute.

Filters

It has a 67mm filter thread which works fine with both screw-in and special bayonet mount filters.

Aperture

Pentax 67 135mm f/4 Macro - aperture opening

Pentax 67 135mm f/4 Macro – aperture opening

The lens has 8 aperture blades, which is typical for most of the Pentax 67 lenses. I rarely stop it down below f/16, so I will show several photographs of aperture opening up to this value.

Image quality and bokeh effect

The lens is very sharp throughout the entire aperture range. The key reason for this has to do with its nearly symmetrical design, thanks to the Heliar optical formula. It helps to almost completely eliminate lateral colour, coma and distortion. And there is one more bonus – it has a very pleasant “Heliar-style” bokeh effect and is sharp even when wide open. I like to use it for closeup portraits.

Pentax 67 135mm f/4 Macro - Example #1 (wide open). © Sasha Krasnov - Portrait Photographer
Pentax 67 135mm f/4 Macro - Example #2 (wide open). © Sasha Krasnov - Portrait Photographer
Pentax 67 135mm f/4 Macro - Example #3 (wide open). © Sasha Krasnov - Portrait Photographer
Pentax 67 135mm f/4 Macro - Example #4 (wide open). © Sasha Krasnov - Portrait Photographer

Summary

Well, it is a close focusing lens designed to focus closer than normal lenses, sharp and lightweight with the focal length between standard and portrait lenses. So, it is more convenient for me than a classic portrait focal length, as I do not like to stand too far away from a model when shooting close-ups and use extension tubes. In my opinion, it is an underrated lens in the Pentax 67 lineup of lenses.

Lens data

Pentax 67 135mm f/4 Macro - optical formula

Pentax 67 135mm f/4 Macro – optical formula

  • Focal length: 135mm
  • 35mm equivalent: 70mm
  • Optical formula: 5 elements, 3 groups
  • Field of view: 36.5°/29° (Diagonal/Horizontal)
  • Aperture: 4 ~ 32 (8 blades)
  • Close distance: 75cm
    • Magnification: 0.31×
    • Picture area: 23×18cm
    • Exposure factor: ×1.72 (+0.78EV)
    • Effective lens speed: 5.2 ~ 42
  • Filter: 67mm, screw-in and bayonet
  • Hood: Built-in, PH-SA 67mm
  • Case: S90-140
  • Dimensions: 91.5×95mm
  • Weight: 0.65kg
// Sasha Krasnov
SMC PENTAX 67 1:28 90mm

← Lens #1: Pentax 67 90mm f/2.8

Lens #3: Pentax 67 165mm f/2.8 →

SMC PENTAX 67 1:28 165mm

7 Comments

  1. Roberto

    Great lens with incredible sharpness even at non macro distances!

  2. tobias

    Are you still using the lens? I’m considering to add it to my 45 and 105 at the moment. The 105 at times feels a bit to short so I was looking for either the 135 or 165. The 135 is tempting as it lets me get closer, the 165 however I suppose feels more like a classical 85mm KB portrait lens. Both tempting – which one do you prefer to shoot?

    • Hello Tobias!

      Yes, I still have and use 135mm instead of 165mm by these reasons:
      a) weight;
      b) close focusing;
      c) focal length — I prefer “shorter” lenses for portraits because I like to be in touch with the model. As the lens “longer” the focusing distance is greater for the same magnification ratio;
      d) the hood is better for 135mm.

      As for me 165mm is too oversized for everyday usage. I’ve described the reasons in article about 165mm — http://skrasnov.com/pentax-67/165mm-f28/

      As for standard lenses — I’ve both, 90mm and 105mm. The first is very versatile lens. So, having 45mm it is better to keep 90mm instead 105mm. Also you will have gap about 17 deg between 90mm and 135mm instead of 9.5 deg for 105mm to 135mm jump. It is more convenent configuration 45mm — 90mm — 135mm.

      But you are right about classic 85mm lens on 35mm format. But you should use the lens that features your style of photography rather than to comply with the tenets.

  3. Ken Smith

    Sasha,
    Thanks for the info about your lenses. I sold my Pentax 6×7, but am acquiring 6×7 lenses to use in macro and telephotography of bees and birds. Your insight and technical info convinced me to take advantage of these great lenses and great deals to use with my Sony A7r2. I have already been using the Pentax 6×7 300mm f4 and 2x telextender to photograph Spotted Towhees in the birdbath as well as Quail and finches. I am even considering re-acquiring a 6×7 for a b&w portrait series. Cheers, Ken

  4. Dear Sasha,

    First I want to thank you for the very complete information about everything pentax 67. It really helped me a lot choosing my set-up. But my question is if you know what the red and white markings on the barrel mean? Thanks in advance.

    Kind Regards,

    Jan

    • Thank you Jan! I’m really like to help you. White markings on the top of the lens means magnification scale, because it’s still a macro lens. So, if you focused on something and get number 15 by this scale it means that the subject will be 1/15 = 0.667× of original size. As you may note the maximum maginfication is 1/3.2 = 0.313×. To get the life-size enlargement this lens requires whole set of extension tubes (#1+2+3).

      Which red markings did you mean? I’ve used red colour to point attention to the certain characteristics.

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