Pentacon 300mm screw hole? What size is it?!

[greenbeens]

I have got a Pentacon 300mm f4. It have a screwhole under the lens that is made to put the lens on the tripod. But I cant figure it out what size is it: it's not 1/4, and it's sure not a 3/8.
What screw do I need to buy? Thx!

[Mr G]

Hi, have you got a photo of the lens, sounds to me like the tripod collar is missing.

[DConvert]

I was somewhat confused by the title - I assume that meant to say 300mm.
If it's nearly 1/4" but not quite it could be 6mm (M6). I seem to remember some tripod bits being sold in that size.
It's relatively simple to rethread M6 to take the standard 1/4" bolts.

If not M6 then some photos & measurements should help us to home in on the right size.

[marcusBMG]

The tripod mount point IS the normal 3/8"ths UNC standard. I have just checked the adapter in mine, it is the same as another cheap ebay 1/4" to 3/8" adapter, just a bit shorter.