Hi,
Many of you will probably still remember that my 300/4.5, which I obtained
for little money thanks to Brian Huber, was sick. In fact, it previously
only suffered from two tiny fungus specks, but in a caring attempt by yours
truly to cure the patient, I actually made the situation worse. Indeed, I
managed to damage the second element when counted from the front, and I also
found that even in a bathroom, it's virtually impossible to prevent dust
from entering the lens. To make matters worse, I could not reach the fungus,
and the two halves of the lens have been glued together (probably the lens
has been cleaned before by a previous owner, who then dumped the lens after
seeing the fungus re-appear?!?). Anyway, I inquired about the possibilities
for dissolving the glue that holds the two halves together and aceton was
mentioned. In the end, I decided that I'd probably better not try this
myself (to not further damage the lens), and I decided to leave the lens
as-is. I took several pictures with the lens and neither the fungus, nor the
damage on the inner element seems to visibly deteriorate the image quality.
Nonetheless, it kept bugging me that the element was damaged, and when I
obtained the "NC" (= No Coating :) ) 28/2, I decided that when looking for a
replacement element for this lens, I was also going to look for a
replacement element for the 300/4.5.
So, the quest for elements was on, and enter Patrick Johnson. Patrick very
kindly helped me in obtaining these elements from Oly America. A second 28/2
element has been back-ordered for some 8 months now, so we finally decided
to have the available elements shipped to Jaap Korten, so he could repair my
lenses already. Happy news: I just learned from Jaap that the 300/4.5 has
been repaired and is alive and well! I still have to send the 28/2 (which
I'll probably do tomorrow), and then that one can be repaired too. I'm
excited already to see the return of the 300/4.5 and the 28/2.
Good, so far for the update on my sick lenses, but now a few small
questions. I'm a bit worried about the still present fungus inside the
300/4.5. At present it doesn't seem to grow (at least not visibly) and no
image degradation seems to occur because of it. Nonetheless I wonder if
there are ways to stop its further growth. I checked with Jaap and in his
opinion it may be better to leave the lens as-is, rather than attempting a
risky aceton-manouvre. I tend to agree on this, but I wonder if there are
*completely safe* ways to kill the fungus without doing any damage to the
rest of the lens. From previous threads on the subject, I've gathered that
exposing the lens to strong UV light kills off the fungus, hence preventing
further growth. Now, for the questions:
1) Can anyone tell me whether exposing the lens to (strong) UV light will
absolutely not damage any other parts (such as coating) of the lens?
2) Will a regular "blacklight TL" bar provide the correct type of UV light
(I'm aware of the fact that there is both UV-A and UV-B radiation in sun
light, but I'm not certain which type(s) the blacklight emits, nor which
type I should use to kill the fungus)?
3) If a regular blacklight will do the trick: how long should I more or less
expose the lens to it?
Good, I hope someone can help me out here, and Brian: "our" 300/4.5 is
apparently doing much better already! :)
Finally, I'd like to take the opportunity to give a big "thank you" to three
people:
1) Brian Huber: for his help in getting the 300/4.5 for an excellent price
for me, instead of keeping it himself.
2) Patrick Johnson: for all his help in getting the elements from Oly
America, as well as for the excellent packaging and shipping of the
elements.
3) Jaap Korten: for numerous things, but particularly in this case for
curing my sick lenses.
I just wanted to share this good news with you guys. Now, from the
Zuiko-sick-bay, this was Olaf Greve, over and out. :)
Cheers!
Olafo
_________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.
< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >
|