PDA

View Full Version : major 'spots' in my 70-300 IS

rbbblues
25th of June 2005 (Sat), 03:28
when looking thru the unattached subject lens, i see a lot of black spots.....not on the exterior pieces of glass...seems to be on the insode elements.......how they got there, i don't know.....only shows up in images on longer time exposures.......someone try to explain, please.....also...what is the fix???
weemannie
25th of June 2005 (Sat), 11:39
It could be a fungus. If so, I think it needs to be serviced :(
Simon Spiers
25th of June 2005 (Sat), 13:12
If it is fungus you need to get it off asap:mad:
rbbblues
25th of June 2005 (Sat), 14:47
a 'fungus'???? ....i don't know if you guys are kidding or if you are serious.....for rel, i never heard of such a thing.........someone please reply.....i seriously need to keep this lens in use.......
thanks
ron chappel
25th of June 2005 (Sat), 20:01
Fungus is a common problem.
It tends to look like miniature spider webs or (less common) white fluffy blobs and other shapes.When there are tiny amounts in a lens it has zero effect on the images and can be cleaned out quite easily ,allthough it might not be inexpensive to clean.
When/if it grows thicker it can effect contrast,colour ballance and resolution .more serious deposits will also permamnantly damage the glass (allthough the lens may still be usable,depending on how bad it is)

Here are some images i found online.
http://www.chem.helsinki.fi/~toomas/photo/fungus/
Not great photo's-the top image shows the wrong colours.Fungus usually has a brown/neutral colour ,though not as strong as his second pic

Take your lens to a repair shop and see what they say
rbbblues
26th of June 2005 (Sun), 03:26
ron, thanks so much for your reply......will check it all out......
richard

ps: check out : www.richardbluesteinphotos.com if you get a chance
lancea
26th of June 2005 (Sun), 13:33
Here are some images i found online.
http://www.chem.helsinki.fi/~toomas/photo/fungus/
I have some fine fungus in my Pentax binoculars :) What amused me about that link was that they say a safe humidity to store my lenses is 30 to 50%. I won't even mention the recommended temperature of 20C. Looks like me and my camera gear will be moving to Alice Springs (although I see it's a bit cool at the moment) :mrgreen: