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

Pentacon 4/200 disassembled (mostly).
Post new topic   Reply to topic
Home   Equipment Care and Repairs
View previous topic :: View next topic  


PostPosted: Tue Apr 11, 2017 11:15 pm    Post subject: Pentacon 4/200 disassembled (mostly). Reply with quote
I disassembled in order to fix a popped iris leaf, so there was no need to remove the front elements from their housing, or split the focusing helical. But other than that this is the lens in its constituent parts, so I thought it might be helpful to someone in the future. This is what it takes to get to the diaphragm. You start at the mount and work your way to the other end until there's nothing left to strip down. The iris is the last thing to be revealed when stripping this lens down. On a plus note, it was as straightforward a process as was indicated by a 'how to' I found on the net, posted by another owner.





The culprit -



I cupped my hand in order to catch the shower of leaves I expected when I tipped the diaphragm holder over... and three lumps of five leaves thudded into my hand. So it looks like it's been longer than I remember since I last used it. I found the individual leaves to be pretty much pristine, but they did require a fingernail to ping them all apart. The internet seems to agree on washing them in soapy water, I'm guessing hand soap, as dishwashing soap usually contains salts. If anyone has any other ideas on cleaning I'd appreciate it. It's the first time I've tried to clean and reassemble an iris diaphragm.


PostPosted: Wed Apr 12, 2017 5:25 am    Post subject: Reply with quote
I would use alcohol and not water to clean it, acetone if it is too sticky.


PostPosted: Wed Apr 12, 2017 5:32 pm    Post subject: Reply with quote
kds315* wrote:
I would use alcohol and not water to clean it, acetone if it is too sticky.


Thanks kds.


PostPosted: Thu Apr 13, 2017 4:40 pm    Post subject: Reply with quote
kds315* wrote:
I would use alcohol and not water to clean it, acetone if it is too sticky.


Not acetone IMO - too agressive, liable to dissolve surface finish.
If oily, naphtha/coleman fuel/similar is the choice.


PostPosted: Thu Apr 13, 2017 5:01 pm    Post subject: Reply with quote
marcusBMG wrote:
kds315* wrote:
I would use alcohol and not water to clean it, acetone if it is too sticky.


Not acetone IMO - too agressive, liable to dissolve surface finish.
If oily, naphtha/coleman fuel/similar is the choice.


Yes, there's definitely a uniform 'blueing' to the blades, which I remember from days gone by is a method of protection. I've not actually cleaned them yet as it's on hold until I can work out how to put the focussing assembly (incl helical) back together. I'd left it alone, then in a fit of madness decided what could go wrong! *sigh*. I'll never learn.

I'd plumped for using white spirit, which is a naptha I think. I didn't think hand soap would guarantee removing the oil (grease I suspect) and I don't like the idea of using dishwashing soap.
Post new topic   Reply to topic
Home   Equipment Care and Repairs
Page 1 of 1