Horseman 970 filters size

[Paulo Carvalho]

To initiate me in the large format photography, I bought a Horseman 970 with the 105 and 65mm Tokyo Kogaku lens.
Now it is time to buy filters...
Somebody can inform me which the size of the filters for these lenses?
My excuses for bothering with "small" questions.

[Will Strain]

my recollection is that there were some odd sizes on the Kogaku/Topcon lenses. Some were 34mm, some were 40.5mm, etc. I could not find the specifics for the two you named.

My suggestion would be to wait, see which of your lenses has the largest size, and get a step up ring for the others, so you can share filters.

[Hiro]

Although I don't know the answer to your question, I've read Topcon (Tokyo Kogaku) produced at least two versions each for the focal lengths mentioned.
65mm - f7 and f5.6 (f7 is more common and covers 4x5.)
105mm - f3.5 and f4.5 (f3.5 is more common and covers 6x9. f4.5 covers 4x5.)

Easiest and surest way would be to take the lenses to a store and see what fits. I also second Will's suggestion to standardize the filter size(s) using step-up rings.

[Robert A. Zeichner]

According to catalog #2, the 65mm f7 takes a 40.5mm .50mm pitch filter and the 105mm f5.6 takes a 43mm .50mm pitch filter.