Pentax 67: Bayonet-mount filters

Bayonet-mount filters are another useful and interesting accessory for Pentax 67 lenses. While doing mostly black-and-white photography, it is almost impossible to go without special color filters helping to convert colors to black and white in line with your idea, allowing you to control the way they appear in the final image and ensuring that objects are well-separated and clearly defined.

In this article, we will not focus on what bayonet-mount filters to use in certain situations. The sheer number of filters used is quite limited, it is a standard set, and their use largely depends on your personal preferences. I, for instance, mostly use 1A (Skylight), Y2, O2, which are bayonet-type mounts, and sometimes YG, which is a screw mount, with my lenses.

Pentax filter with 6X7 bayonet mount closeup © Sasha Krasnov Photography

Pentax filter with 6X7 bayonet mount closeup

In black-and-white photography you have to alternate filters quite often, sometimes very often — yellow to orange, then orange to yellow, and the other way round. And this triggers a question about their usability.

A majority of Pentax 67 lenses have a bayonet filter option, which allows you to mount both bayonet and threaded filters, as well as to combine them together. That is a really great feature!

Bayonet mount

Let’s look at the bayonet mount closeup. Top image: female mount with two recesses in the thread. It permits another bayonet or screw-in filter. The lenses have the same female mount which also accepts both filter types. Bottom image: male mount with two tabs. It has a very convenient design that allows changing filters quickly and also to stack them together and removing them just as quickly.

Sometimes I use a combination of threaded and bayonet filters. I have a threaded YG which I screw onto the bayonet 1A and as a result get a filter that is almost identical to the bayonet one, as the impact of the 1A filter on black-and-white film can be neglected. What can be easier and more convenient?

Bayonet-mount filters

Some of these data are taken from the Asahi’s original filters manual.

UV 1A Y2 O2 R2 YG 81A 82A Lenses
67mm M
S
M
S
M
S
M
S
M
S
S M
S
S 90mm F2.8 LS, 90mm F2.8, 105mm F2.4, 135mm F4 Macro, 150mm F2.8, 165mm F2.8, 200mm F4, M* 400mm F4 (rear), M* 800mm F6.7 (rear)
77mm M
S
M
S
M
S
M
S
M
S
S M
S
S 55mm F4, 400mm F4 (rear), 600mm F4 (rear), 800mm F4 (rear), 1000mm F8 Reflex (rear)
82mm M
S
M
S
M
S
M
S
M
S
S M
S
S 45mm F4, 75mm F4.5, 75mm F4.5 Shift, 300mm F4
95mm M M M M M M 500mm F5.6
100mm M
S
M
S
M
S
M
S
M
S
S M
S
S 55mm F3.5
Exposure
factor
1.5× 1.5× The shutter speed should be multiplyed by this value to get the film properly exposed.
F-stop
compensation
0 0 1 1.5 2.5 1 0.5 0.5 The aperture should be opened by this extra f-stop to get the film properly exposed.
“M” for multi coated filters. “S” for single coated filters

All this is also true for color photography, but in general the use of filters there is more infrequent than in black-and-white photography. Of course, I have 80A and 85 filters but use them sporadically, that is why when I required them I just bought ordinary threaded filters.

P.S.

Thanks for reading! I would be very grateful if you point out my possible mistakes, add extra information, or just share your experience. Scroll down to the Leave a reply section and share your thoughts about it. Your opinion is important for me. I enjoy answering your questions as the answers may often benefit many other readers and the process of answering allows me to better piece together my existing knowledge and find ideas to improve my articles.

© Sasha Krasnov

11 Comments

  1. Cukierman Peter

    Hi,
    Your website about Pentax 67 and the 105/2.4 lens made me buying this camera.
    I just ordered one from Japan.
    I shall let you know my impressions when the camera arrives.
    I am sickly in love with the lens bokeh for potraits.

    Thanks , greetings from cold and grey Sweden/ in Scandinavia

    • Hi Peter

      Thanks very much for visiting my site and for this message! It’s so important to me. Do not hesitate to share your impression, it’s interesting and important to other users and just visitors. I hope you’ll get a lot of great images, and a lot of pleasure during the process. As for me, the last one is probably even more important 😉

    • Benoit

      I agree, a really good source of information which pushed me too to get one

  2. Joona

    I don’t understand why all bayonet mount filters aren’t compatible with all lenses. This is going to get expensive :’)

    • Because Pentax made lenses with various filter threads. It’s more strange why they didn’t make lenses with the same filter thread as Mamiya did. Most of Pentax 67 lenses were possible to design accepting 77mm filter thread.

  3. You have a great website. It’s been a handy resource for me thanks!

  4. Johhny Q

    Hi, you forget to mention that the change to shutter speeds or aperture settings only relate to cameras that are not using the TTL light meter.

    • Hi,

      even with the TTL prism, you need to adjust the f-stop or shutter speed to get the negative properly exposed. Only Pentax 67II has the aperture-priority auto exposure mode and it doesn’t need manual exposure adjusting in this mode.

  5. Thank you for your excellent web-site and this good article. I have recently acquired a variety of these filters. Something that no one has mentioned (but is kind of obvious) is that if you are using one of the old bayonet hoods and want to use a filter as well, then you have no choice but to go with the bayonet filter. Another thing I have not seen mentioned is that they are made with really thick glass. The 100mm filter, for example, weighs 147g because of this. Another feature to these, if you come across a filter in bad condition, is that you can carefully remove the glass with a spanner wrench to attempt to clean (more modern filters do not have this option).

    • Thank you Glen for this valuable addition. You are right about the bayonet-mount hood and filters. I use quite often simultaneously these filters and the hood with Pentax 67 75mm F4.5. But for Pentax 67 45mm F4 I bought a slim yellow-green screw-in filter and the hood to avoid vignetting.

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