Congratulatons. There are instructions in various places on
re-cementing. I correspondent of mine, who does this, said I
could not possibly get the elements centered without a centering
machine. However, since the elements were very precisely centered
and ground parallel at the factory it seem that by edge clamping
one can get centering as good as original. The trouble is with
lenses where the edges are not parallel because they are of
different sizes.
You can buy optical cement via the internet. Its cured with
UV light. While they told me an ordinary UV lamp would not work I
was able to cement a couple of lenses with one of the tubular
ones used for growing plants.
I have to remind myself of what I learned about separating
lenses. Balsam can be separated by warming or soaking in solvent.
Synthetic cement is mostly done by shocking apart but it seems to
me I found a good solvent. I don't like the shocking method
because it can fracture the elements.
The black coating on the edges serves two purposes: one is to
prevent internal reflection from the edge but it also serves to
seal the edge. This is important for Canada Balsam which is
vulnerable to moisture. I think one reason few very old Zeiss
lenses show separation is that the edge coating was especially
effective. This coating must be very thin. Bausch & Lomb made a
special paint years ago for this purpose but I don't even
remember what it was called.
The photos you attached indicate you did a very good job.
Since you have had a Planar apart you can tell they must have
been very difficult lenses to make considering the very tight
spacing with the second component almost touching the front
element. I was always of the opinion that Schneider was more
concerned with efficiency of manufacture than Zeiss, who seemed
to do things the hard way if they thought it was better. OTOH, I
can see no difference in overall performance between the five
element Planar and five element Xenotar, both exceptionally good
lenses.
Harry overhauled my 2.8E many years ago, its still perfect. A
very nice man. I think he began to fall on hard times a few years
ago and am not certain he is still working.
On 10/31/2018 5:40 PM, José Manoel Pavoski Neto wrote:
Richard, what I'll say might sound heretic, but I've re-cemented it myself.
