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

Blocked focus on a Biometar 80mm 2.8 for pentacon six
Post new topic   Reply to topic
Home   Equipment Care and Repairs
View previous topic :: View next topic  


PostPosted: Sat Sep 24, 2011 3:44 pm    Post subject: Blocked focus on a Biometar 80mm 2.8 for pentacon six Reply with quote
Dear all,
it happend to me to have a Biometar 80mm with a beautiful glass (no scratches, no fungus no cleaning marks) but unfortunately the focus ring moves only for 20- 25 degrees from infinty and than it becames hard and does not move any further. The lens was not very expensive so I decided to open it. A clue on a possible cause of the defect is the strong blow that bend the outer zebrated alluminium barrel

The other side of the body looks like this

If i try to unscrew moving the inner ring with the two "ears" it moves just a bit and then it stucks. I tried to remove the two brakets which hold the two "ears" and doing so the outer ring ( the one with the numbers of meters ) moves but the internal part does not. Maybe there is some retaining screw hidden somewhere? Or the blow coud have deformed the helicoid (I hope not!). Coud somebody be so kind to explain me how to unsrew the helicoid?And/or have an idea on what is that is preventing the focus ring to do its job? Thanks a lot!


PostPosted: Sat Sep 24, 2011 4:46 pm    Post subject: Re: Blocked focus on a Biometar 80mm 2.8 for pentacon six Reply with quote
Welcome to the forum! Please let me quote your message; a new user's first post can never contain pictures.

tak_61 wrote:
Dear all,
it happend to me to have a Biometar 80mm with a beautiful glass (no scratches, no fungus no cleaning marks) but unfortunately the focus ring moves only for 20- 25 degrees from infinty and than it becames hard and does not move any further. The lens was not very expensive so I decided to open it. A clue on a possible cause of the defect is the strong blow that bend the outer zebrated alluminium barrel

The other side of the body looks like this

If i try to unscrew moving the inner ring with the two "ears" it moves just a bit and then it stucks. I tried to remove the two brakets which hold the two "ears" and doing so the outer ring ( the one with the numbers of meters ) moves but the internal part does not. Maybe there is some retaining screw hidden somewhere? Or the blow coud have deformed the helicoid (I hope not!). Coud somebody be so kind to explain me how to unsrew the helicoid?And/or have an idea on what is that is preventing the focus ring to do its job? Thanks a lot!


PostPosted: Sat Sep 24, 2011 6:05 pm    Post subject: Reply with quote
here is the thread on how to dismantle the biometar lens
http://forum.mflenses.com/how-to-dismantle-an-atomic-bomb-biometar-80mm-p6-t30679.html


PostPosted: Sat Sep 24, 2011 7:43 pm    Post subject: Reply with quote
WolverineX wrote:
here is the thread on how to dismantle the biometar lens
http://forum.mflenses.com/how-to-dismantle-an-atomic-bomb-biometar-80mm-p6-t30679.html


First of all thanks for the kind wellcome in this exciting forum!
Thank for the interesting link. Following your clear procedure I thing I get to the point where I need to dismantle the "inner core" of the "bomb"! But I would like not to cause more damage than good. So I need some help from more "senior" people. Thanks again


PostPosted: Sat Sep 24, 2011 9:11 pm    Post subject: Reply with quote
Could you post a larger version of your first picture(the one with the zebra markings) in the inset .


PostPosted: Sun Sep 25, 2011 8:07 am    Post subject: Reply with quote
Kathmandu wrote:
Could you post a larger version of your first picture(the one with the zebra markings) in the inset .

sory for the low quality, but they have been taken with an Autofocus lens(....)
The bent alluminium does not touch the moving inner part, at least at the external edge, I have somne doubt on the internal hidden parts.

Post new topic   Reply to topic
Home   Equipment Care and Repairs
Page 1 of 1