View Full Version : please help me open this lens (dynar 18cm)

3-Oct-2017, 08:21
i have bought this lens, and it is in ok condition. rear lens is very nice, front group needs cleaning.
its a heliar design .
do i approach it by unscrewing the ring in the front (pic 1)
or by unscrewing the whole front part (seems like somebody has tried this before)
seller said that it would profit from a thorough cleaning in the front group but that he wasnt able to open it.

any advice?
thank you,

3-Oct-2017, 08:27

4-Oct-2017, 06:54
THe whole front section will unscrew, not the name ring. once the front group comes out, the center element should unscrew from the back of the front group. There may be a tangential grub screw holding the front group from unscrewing from the barrel. Dallmeyer pentacs were built similarly, (also a heliar derivative) and disassemble the same way. Use of a heat gun may help in loosening things up. Also, a strap wrench or two may be essential.

4-Oct-2017, 10:15
tx. thats helpful.
so its just a matter of force and controlled movement. the name ring can stay on. got it.

i will give it a try tomorrow.

6-Oct-2017, 14:29
it worked out perfectly.
this lens is now a gem! hard to believe its over 100 years old.
i am very much looking forward to mount it on my toyo 5x7.
i cleaned the fungus with isopropylic alcohol and cotton wipes. gently, then polished with fresh microfibre and breath...
it was like edsawyer suggested.
the front group came off and the elements unscrewed nicely.


7-Oct-2017, 15:40
Nice, good to hear it!