Mineral photography - lens threads

An extremely valuable reference is an FAQ on photomacrography.net describing various threads used by different lenses and microscope objectives. It is so valuable that I have extracted and summarized (preserved) the information here.
0.8" x 36tpi         RMS microscope objectives               
25mm x 1mm           Schneider enlarging lenses
25mm x 0.75mm        Nikon CFI60 infinity microscope objectives,
1" x 32tpi           C mount (32 tpi = 0.794mm)
1.035" x 40tpi        ??  (40 tpi = 0.635 mm)
26mm x 36tpi         Mitutoyo infinity microscope objectives (36 tpi = 0.706mm)
26mm x 0.75mm        Nikon BD 210mm finite objectives,  Nikon CFI60 Infinites, Nikon LU Infinites, and others
27mm x 0.75mm        Nikon BD infinity objectives
32mm x 0.75mm        Nikon LU BD Plan series of large industrial objectives
32.5mm (?)           Schneider 135mm f/5.6 enlarger lens mount
39mm x 26tpi         Leica lens mount. The Enlarger lens standard. Often quoted as 1mm (26 tpi = 0.977mm)
40mm x 0.75mm        Leitz Photars, some, eg 50mm f/2.8
42mm x 0.75mm        T2 standard mount
42mm x 1mm           "M42" Pentax/Praktika lens mount, a common standard
50mm x 0.75mm        Schneider and other enlarging lenses

Filter threads: These are generally 0.75mm pitch at 43mm diameter and larger, 0.5mm pitch at 40.5mm diameter and smaller. Exceptions occur in the smaller diameters and some diameters are available in both. See eg Hoya Catalogue P17

Enlarging lens filter threads, used eg for reversing: Pitch 0.5mm or 0.75mm, shown where known. Code:

        Rodagon  28mm, 35mm,
        Rogonar-S  28mm, 35mm
	Old Style Componon *, 28mm, 35mm, 50mm, 60mm, 80mm, 105mm
        Xenon 40mm f/2.8

	El-Nikkor 50mm F/4.

	Comparon 105mm
	Componar C105mm
	Componon WA60mm

40.5mm x 0.5mm
	El-Nikkor 50mm f2.8&N, 63mm f2.8&N, 75mm f5.6&N, 105mm f5.6&N
	Rodagon 35mm, 50mm, 75mm, 80mm, 105mm,
	Comparon 135mm f/5.6

43mm  x 0.75mm   
	El-Nikkor 135mm f/5.6 and others
	Rogonar-S, 50mm, 60mm, 75mm, 90mm, 105mm,
	Rodagon 50mm, 60mm, 80mm, 105mm, 135mm
	Rodagon-WA, 40mm, 60mm, 80mm,
	Rodagon-G, 50mm, 105mm,
	Apo Rodagon-N, 50mm, 80mm, 90mm, 105mm,
	Apo Rodagon-D, 1:1 75mm f/4, 2:1 75mm f/4.5
	Comparon 50mm, 75mm
	Componon New Style 50mm, 60mm, 75mm, 105mm
	Componon-S 50mm, 80mm, 100mm*
	Componon WA 40mm
	HM Apo Componon 40mm f/2.8, 45mm f/4, 50mm f/2.8

	Rodagon-G 150mm
	Componon-S 135mm, 150mm

    "Old" and "New" style Schneider lenes are known to occur with different
    threads.  Rodenstock Rodagon 28mm and 35mm lenses have no filter threads
    on some (later?) versions


	25mm f/3.5 tba
	30mm MC f/2.8 No filter thread
	50mm MC f/2.8 ?
	50mm f/4 ?
	75mm f/4.5 ?

Copal Shutter mounts:

COPAL spec.         #0            #1            #3            #3s

front thread        M29.5-0.5    M40-0.75    M58-0.75    M56-0.75
back thread         M29.5-0.5    M36-0.75    M58-0.75    M56-0.75
overall thickness   20 mm        20 mm       32 mm       28.6 mm
front to iris       10.2 mm      10.75 mm    17.7 mm     16.25 mm
mount thread        M32.5-0.5    M39-0.75    M62-0.75    M61-0.75
lensboard hole      34.6 mm      41.6 mm     65 mm       64.1 mm
iris dia            24 mm        30 mm       45 mm       45 mm

Some other resources:

Lens register distances, and some thread sizes: http://www.graphics.cornell.edu/~westin/misc/mounts-by-register.html

An important macro lens listing: http://www.macrolenses.de/objektive.php

A forum discussion of Nikon and Mitutoyo M26 objective mounting threads: http://photomacrography.net/forum/viewtopic.php?t=12404

Feedback? Questions? Drop me a line!

Tom's Mineralogy Info / tom@mmto.org