(Sorry for the preamble) I grabbed my old AF20mm F2.8 lens with the D750 and went over the other side of the river to take a few shots of the cutting down of more dying"platanes" trees, which unfortunately are infected by a disease called "le chancre coloré" a sort of mushroom infection. Unfortunately this will kill 42,000 platanes which were planted 200 years ago both for reinforcing the canal du midi's canal banks as well as providing some shade for the horses which pulled the barges before the motorization of canal traffic, this is not counting the millions of other platanes which are everywhere in France.
Briefly, by the end of next week there will practically no trees left near me and in the next two years all will be denuded along the canal du midi from the med to Bordeaux.....very sad indeed!
Strangely the infection was brought into Europe in 1944 when invading Italy, from the US wooden munition cases and slowly the disease has worked it's way across Europe and has taken this long to get here 73 years no less, there is talk of a treatment for the disease but it's too late for the canals platanes.
Excuse me guys, I digressed! Anyway I took a couple of shots and was immediately surprised at the lack of contrast, on arriving home I shone a torch through the lens to find haze, last time I shot things looked OK.
I jumped in and removed the rear element group to find the haze within, the rest of the lens looks reasonably alright. I had to make a tool to open the rear element assembly hoping to give the group of four a quick clean up, but it was the lens cement that was the culprit.
Now I need to separate the couplet with a view to re-cementing, have any of you guys ever done such a thing, what method is used, is it done by warming or some sort of solvent? The rear group is only maybe 14mm in diameter so we are not talking about a large surface, some lens cement will also have to be found.
I know many will say that it's a job for a professional, but I have little to lose as although the lens still functions in it's current state I don't envisage myself shooting with it, other than that I would have to find some a replacement rear group, not easy to find no doubt.
Tips from you guys would be welcome, BC, Klaus, Markus or any other experienced or knowledgeable folk!
Thanks in advance!