bgate wrote:
I am in need of a tripod collar, I have looked at hundreds online in all price ranges. None of these advertised show the ring diameter, the one I need has a diameter of 56mm or 2.205",
this would fit a Pentax SMC Takumar, 300mm f4 lens. Can you offer suggestions?
Thank you.
Billy
Hi Billy,
Contact KEH.com and ask about it. They do a lot of repair and sometimes have spare parts.
If you haven't already done so, you also might look or post a request at pentaxforums.com
Most tripod mounting rings are VERY lens-specific. There simply aren't generics. Even third party rings are sized and shaped to fit specific lenses.
If you search eBay and other placed for tripod rings, you are going to find A LOT of rings for Canon lenses, so I'm providing some info about those, in particular.
I just measured a Canon Tripod Ring A, the smallest they make, and its inside diameter is over 2.5". All the other Canon tripod rings are larger inside diameter (I'm assuming your measurement is an inside diameter). So even though four different Canon Rings (A, B, C and D) are fairly widely available to buy new, second hand and from third party manufacturers, they simply won't work on your lens. They will all be way too large diameter. (Canon has various other tripod rings on lenses, but they're not removable.) Note: There are variants of the Canon tripod rings such as A (W) and A (B) and A II (W).... those are all the same size. The "W" just indicates it's the off-white color to match lenses of the same color, while "B" indicates a black ring. The "II" is a second version using a newer off-white color found on some of the more recent lenses.
There appear to be fewer Nikon tripod rings sold separately. All I could find were for 70-200mm f/2.8 lenses (which will be roughly the same diameter as Canon Ring B, used on their 70-200mm f//2.8 lenses).
The closest I could find on eBay is this iShoot brand from China. It says it's 61.5mm inside diameter.
https://www.ebay.com/itm/194210311759?hash=item2d37d62e4f:g:~q4AAOSwaZFgz-U1 Perhaps you could get a shim made to reduce the diameter to the 56mm you need. I have had things made from Delrin and would recommend that. It's a hard plastic that won't scratch the lens when it's rotated inside the ring. A machine shop should be able to make a shim from Delrin pretty easily, though a custom job like that might end up costing more than the tripod ring or the even more than the lens itself!
With a little further online searching, I found a site that sells all of iShoot's tripod rings. While their rings are listed as lens-specific, they do provide specifications including the inside diameter:
https://www.photoloving.com/Professional-Canon-Nikon-Sigma-Replacement-Tripod-Mount-Ring-iShoot-c40657/?pagenum=1. On that list I found another that might be possible to shim to fit your lens... a replacement ring made to fit the Nikon AF-S 300mm f/4 "PF" lens.
https://www.photoloving.com/tripod-mount-ring-for-nikkor-nikon-af-s-300mm-f4e-pf-ed-vr-p1537559.html This ring has an inside diameter of 68mm... so would need a thicker shim to fit your lens, compared to the 61.5mm ring in the eBay listing.
Back over at eBay I found a lot of rings listed to fit the Nikon 300mm "PF", many offered at a lower cost than at the iShoot website. It appears this ring also fits the Nikon 70-200mm f/4.