Home

Please support mflenses.com if you need any graphic related work order it from us, click on above banner to order!
SearchSearch MemberlistMemberlist RegisterRegister ProfileProfile Log in to check your private messagesLog in to check your private messages Log inLog in

just a few questions about holes and grease!
Post new topic   Reply to topic
Home   Manual Focus Lenses
View previous topic :: View next topic  


PostPosted: Wed Jul 19, 2017 10:47 am    Post subject: just a few questions about holes and grease! Reply with quote
no double meaning indeed here! XD I bought the pentacon 300mm f4, it have a hole to screw it on the tripod but I do not understand which size is it bacause the 3/8 bolt doesn't fit (it's too big), and the 1/4 is too small. which hole is it?

another question is: I'm looking for some lubricant some good economic grease to fix the focus ring of my pentacon (the actual grease is old and sticky and give bad fluidity to the focusing movement), may you suggest to me somethig to buy from ebay please? is possible shipped from Europe zone because I can't wait too long shipping time.

thx!


PostPosted: Wed Jul 19, 2017 11:24 am    Post subject: Reply with quote
I can't help with the tripod thread. But concerning lubricants, I think the most common for helicoids is "#10" from Japan:
http://www.micro-tools.de/Fette-OEle/Grease-Helical-10-Light-8ml.html

I personally use Robbe 5532, a silicon-based grease with added teflon. In my experience, the results are excellent:
http://www.ebay.com/itm/Robbe-Teflonfett-Prazissionsfett-Universalfett-Robbe-5532-X-/171547649047

Besides selecting the right grease, it's equally important that you clean up the old thouroughly and apply the exactly right amount of fresh grease. You only need very little to get the helicoid moving smoothly and if you apply too much, it's not getting any smoother but the resistance increases quickly.


PostPosted: Wed Jul 19, 2017 12:56 pm    Post subject: Re: just a few questions about holes and grease! Reply with quote
greenbeens wrote:
I bought the pentacon 300mm f4, it have a hole to screw it on the tripod but I do not understand which size is it bacause the 3/8 bolt doesn't fit (it's too big), and the 1/4 is too small. which hole is it?
thx!


Those (UNC/Witworth) are the only two standard threads for camera tripods. The number of possibilities is very extensive. If you have a vernier/dial/digital caliper that can measure the ID of the hole the range can be narrowed down considerably.

It could be a metric thread such as M8 (which is roughly half way between the two).
If it's on the foot of a lens it would probably be a fairly trivial task to drill/tap it to 3/8-16. With an older second hand lens it's possible someone has already altered the tripod mounting (perhaps due to cross-threading the original).


PostPosted: Wed Jul 19, 2017 2:04 pm    Post subject: Reply with quote
I've just had a look at my 300mm. It has a silver adapter to 1/4" UNC, similar to the ones sold on eg ebay but quite short. I tried one of my other 3/8" to 1/4" adapters, it screwed in stiffly most of the way, would probably work cut a bit shorter like the one the lens came with.


PostPosted: Wed Jul 19, 2017 2:17 pm    Post subject: Re: just a few questions about holes and grease! Reply with quote
greenbeens wrote:
no double meaning indeed here! XD I bought the pentacon 300mm f4, it have a hole to screw it on the tripod but I do not understand which size is it bacause the 3/8 bolt doesn't fit (it's too big), and the 1/4 is too small. which hole is it?

another question is: I'm looking for some lubricant some good economic grease to fix the focus ring of my pentacon (the actual grease is old and sticky and give bad fluidity to the focusing movement), may you suggest to me somethig to buy from ebay please? is possible shipped from Europe zone because I can't wait too long shipping time.

thx!


There isn't one grease to fit all lenses - it depends on the helicoid design. For example, grease that use with great results on Takumars makes Nikkors stop in their tracks. Basically, the larger the contact surface (longer helicoids/finer threads/more starts) the lighter the grease.


PostPosted: Thu Jul 20, 2017 10:13 am    Post subject: Reply with quote
you can see which kind of helicoids my lens have in the pictures posted in this topic: http://forum.mflenses.com/pentacon-300mm-f-4-disassembly-repair-t59496.html

considering the pictures which grease would fit the best in your opinion?

thx a lot!


PostPosted: Thu Jul 20, 2017 9:45 pm    Post subject: Reply with quote
VLR wrote:
I can't help with the tripod thread. But concerning lubricants, I think the most common for helicoids is "#10" from Japan:
http://www.micro-tools.de/Fette-OEle/Grease-Helical-10-Light-8ml.html
I've used #10 quite a lot, it's very light, search eBay for #10 helicoid grease, also #30, it's a little thicker, it's better for simple abrasive reduction for simple helicoids and alignment bars, it's from Japan hobby tools.
There is also Helimax XP, it's Lithium based, but it kicks normal lithium greases butt, it's designed specifically for optical helicoids.
Quote:

I personally use Robbe 5532, a silicon-based grease with added teflon. In my experience, the results are excellent:
http://www.ebay.com/itm/Robbe-Teflonfett-Prazissionsfett-Universalfett-Robbe-5532-X-/171547649047

Besides selecting the right grease, it's equally important that you clean up the old thouroughly and apply the exactly right amount of fresh grease. You only need very little to get the helicoid moving smoothly and if you apply too much, it's not getting any smoother but the resistance increases quickly.

This is important, you need very little grease, I use a small artist paint brush to apply a super thin layer, too much and you risk getting it somewhere you don't want it, like the aperture or optics. As you join the helicoid together, the excess gets pushed away anyways.
Post new topic   Reply to topic
Home   Manual Focus Lenses
Page 1 of 1