3 replies to this topic

[UlfW]

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

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Kuribayashi 105mm f/3.5 K.C. Petri Orrikkor

Manufacturer: Kyoei Kogaku
Lens front ring label: Kuribayashi K.C. Petri Orrikkor 1:3.5 f=105mm No.<serial number>
Introduction year: 1959
Currently manufactured: No

Lens type: manual focus, prime, short telephoto
Design: 3 elements in 3 groups
Focal length: 105mm
Aperture range: f/3.5 – f/22, 16 blades, manual preset
Magnification range: tbd. Closest focus 1.2m.
Sensor format/coverage: up to 24 mm x 36 mm

Mount: M42 x 1
Flange Focus distance: M42: 45.46 mm
Front filter: 46 mm x 0.75 mm

S/N of test object: 35888

https://w.atwiki.jp/...i/pages/75.html

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Image of test object:

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Transmittance Summary
Definitions of the parameters below

• Range: The Kuribayashi 105mm f/3.5 K.C. Petri Orrikkor - lens transmits 1-89% in an increasing slope from 330nm to 400nm.
  
• T_VISmax (%) = 90%
  
• T_400nm (%) = 89%
  
• T_365nm (%) = 75%

• λ_{UV HMvis}(nm) = 346 nm
  
• λ_{UV HM400}(nm) = 345 nm
  
• λ_{UV Zero}(nm) = 318 nm
  These three values indicate that the lens is working for UV-A and some UV-B photography.
  The rather high transmission at 365nm gives comparably short exposure times for a typical UV-pass filter-stack or a Baader U.

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Spectral Transmission Graphs
UV-NIR, Kuribayashi 105mm f/3.5 K.C. Petri Orrikkor

The transmission measurement accuracy into the end of NIR range is less good due to limitations in the light source.

UV, Kuribayashi 105mm f/3.5 K.C. Petri Orrikkor


UV-Log, Kuribayashi 105mm f/3.5 K.C. Petri Orrikkor


General comments about the UV-reach:
The lens do reach quite deep into UV for a 105mm lens.
This reach will be enough for most UV-photography, with sun or UV-converted flash as light source, together with a typical UV-pass filter-stack or a Baader U.

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

It is also possible to use rear mounted filters, in lens mount adapters, or placed directly in the camera.

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Handling and focussing:
Due to the long 45.46mm flange focus distance this lens will be possible to mount with lens mount adapters and focus at infinity with most DSLRs.

Sharpness:
TBD

Lens distortion:
TBD

Chromatic Aberration in UV:
TBD

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Image samples:

Edited by UlfW, 08 April 2021 - 07:22.

[Stefano]

I was randomly reading this topic, and just noticed that the λ_{UV Zero} value is off.

[Andrea B.]

Stefano, thank you. We will fix that.
Looks like another statement is not quite right: "this lens is working only for UVA photography".
Also mention of the Petri 135 mm lens. Looks like a cut & paste error.

[UlfW]

Andrea B., on 08 April 2021 - 05:27, said:

Stefano, thank you. We will fix that.
Looks like another statement is not quite right: "this lens is working only for UVA photography".
Also mention of the Petri 135 mm lens. Looks like a cut & paste error.

Fixed.

I am sure that there are more of them lurking in some of the other lens topics.
Please let me know when you find the next error.

Most of them are cut & paste errors, as I am using old topics to clone from, when writing new ones.
Then I edit the clones to fit the new test object. Sometimes I miss changing some details like in this post.

I am also slightly dyslectic and cannot see my typos.
Then it is very valuable with help from sharp eyes and brains from others.

Than you both for proofreading my posts and finding errors.

Edited by UlfW, 08 April 2021 - 07:35.