• Ultraviolet Photography

Kyoei 135mm f/3.5 Acall

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#1 UlfW

    Ulf W

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Posted 27 March 2021 - 14:19

Last Update: 03 April 2021 agb/label/title
Finalized: Work in progress.

Kyoei 135mm f/3.5 Acall

Manufacturer: Kyoei Optical Co. Ltd.
Manufacturer's lens designation: Kyoei Optical Co. Ltd. Acall 135mm 1:3.5 No.<serial number>
Currently manufactured: No

Lens type: Manual focus, Prime, Short Tele Lens
Design: TBD
Focal length: 135mm
Aperture range: f/3.5 – f/22, Preset Manual, 12 blades
Focus Range: 4.5 feet to infinity
Sensor format/coverage: up to 24 mm x 36 mm
Mount: M42 x 1 thread
Helicoid: Yes
Flange Focus distance: M42/45.46 mm,
Front filter: 46 mm x 0.75 mm
Introduction year: between 1965 and 1970???
S/N of test object: 80050

Image of test object:

Attached Image: IMG_2714.jpg Attached Image: IMG_2715.jpg Attached Image: IMG_2716.jpg

Transmittance Summary

Definitions of the parameters below
  • Range: This Soligor 1:3,5 f=135mm transmits from 1-80% in an increasing slope from 330nm to 400nm.
  • TVISmax (%) = 90%
  • T400nm (%) = 86%
  • T365nm (%) = 66%
    This high percentage is an indicator for relatively short exposure time under typical UV-pass filtration peaking around 360 nm or when using 365 nm UV-LED illumination.
  • λUV HMvis(nm) = 352nm
  • λUV HM400(nm) = 351nm
  • λUV Zero(nm) = 330nm
  • These three values indicate that the lens is marginally working even for some shorter wavelength UV-A photography with some filters and the few for this, suitable cameras.

Spectral Transmission Graphs

UV-NIR, Kyoei 135mm f/3.5
Attached Image: Screen Shot 2021-03-19 at 09.31.19.png
The transmission measurement accuracy into the end of NIR range is less good due to limitations in the light source.

UV, Kyoei 135mm f/3.5
Attached Image: Screen Shot 2021-03-19 at 09.30.35.png
UV-Log, Kyoei 135mm f/3.5
Attached Image: Screen Shot 2021-03-19 at 09.30.09.png
Numerical Spectra Data available: Pending

General comments about the UV-reach:

Filters and how to use them on this lens:
The front filter thread is a 46mm standard filter thread.

It is also possible to use rear mounted filters, either in lens mount adapters for mirrorless cameras like Sony A-series etc, or placed directly in the camera.

Handling and focussing:

Flare and sun-stars:


Lens distortion:

Chromatic Aberration in UV:
Ulf Wilhelmson
Curious and trying to see the invisible.