Raynox CM-3500 with Fungus

magom · Post by **magom** » Fri Mar 26, 2010 5:24 am

Hey guys!

Yesterday I received a Raynox CM 3500 lens Set from Asia for about 80€.

I'm pretty unhappy with the result because one of the lenses is full of fungus. And the second, the 12x has a beginning fungus inside.

The 6x lens is nearly perfect and in mint condition.

What do you think, is there a possibility to open them? I can't see any screws or something. It seems as if the lenses has been glued or burned into the plastic.

Do you think, that the 12x is still useble? Should I put it into the oven to kill the fungus or treat it a different way to avoid the icrease of the very little fungus spores?

Thanks a lot!

enricosavazzi · Post by **enricosavazzi** » Fri Mar 26, 2010 7:53 am

Hello,

lenses in the condition you illustrate are of course not acceptable, unless they have been clearly advertised as fungus-infested and sold at a substantial discount.

The problem with eBay and similar purchases is that it may cost more to return the defective items than to buy new ones. Returning the item in a way that guarantees your coverage by PayPal or similar agencies is also likely to cost several times more than the original purchase, and there is no refund for your shipment costs. There are also unscrupulous sellers who never acknowledge problems nor refund the buyer. My own policy in these cases is to be careful and never miss the deadline to leave negative feedback - this is what hurts these sellers most.

I guess you have already made sure that the fungus is on internal surfaces, not external ones. External fungus is easily cleaned away with e.g. alcohol and a lens tissue (never dry-wipe a lens). Usually, these relatively cheap lenses are permanently moulded into plastic frames and disassembly is not possible. After careful consideration (

), I would not recommend baking a plastic-mounted lens in an oven (it would simply melt the plastic long before killing the spores). Probably there are millions of fungus spores in every lens, but as long as the lens is kept in reasonable conditions (especially w.r.t. humidity) they do not have a chance to germinate. After they germinate, it depends on the type of fungus. Some hardy types can synthesize their own water from air oxygen and hydrogen extracted from organic compounds, so they may continue to grow without any water as long as they have a source of chemicals and chemical energy (usually, a contaminant film on lens surfaces or the cement between lens elements).

UV does kill spores as well as fungus, and a prolonged exposure to sunlight (as long as it does not overheat the plastic and its UV is not already filtered away by e.g. solar film) or artificial shortwave UV should effectively sterilize the lens and stop the growth of the fungus. Thymol is also an effective antifungal, but thymol vapours may take time to penetrate a cast-plastic mount. In any case, the lens will stay as dirty as it is now, unless the surfaces are cleaned.

No doubt you will hear some advice to get rid of a fungus-infested lens before it transmits the infestation to your other lenses. In my opinion, this is extremely unlikely to happen if the lenses are stored in proper conditions, and plenty of fungus/mold spores, in any case, are already in your "clean" lenses for sure.

magom · Post by **magom** » Fri Mar 26, 2010 8:36 am

Thank you for your great reply.

So do you think, that I can still use the 12x lens anyway?

Regards,
Ver

Charles Krebs · Post by **Charles Krebs** » Fri Mar 26, 2010 9:06 am

It's a frustrating and unfortunate thing, but if you can't return them, give them a try!

Anecdotal story....
Zeiss made some great microscope objectives (70's vintage) that suffered inordinately from internal element separation or "delamination" (apparently due to the optical adhesive used to join elements). I've used some that looked pretty bad when the optic was examined closely, but in use, they still provided excellent viewing and photographic images.

ChrisR · Post by **ChrisR** » Fri Mar 26, 2010 12:25 pm

never miss the deadline to leave negative feedback - this is what hurts these sellers most

You'll often find you can't. Ebay protect their big customers. If the seller offers to take it back, and you don't send it, he'll probably be successful in getting any bad feedback deleted. Sellers can also act against neutral or good feedback which carries a bad message.

gmazza · Post by **gmazza** » Sat Mar 27, 2010 11:31 am

Very unfortunate as the Raynox discontinued the CM-3500 in Jan/2008 the last ones at vendors have a increasing chance of being the most defective ones.

I really miss a 12 diopter adapter, with a 12 diopter in front of a 100mm macro lens (wich is a very popular format) moving the barrel of the lens is possible to get from 1:1 to 1:3 wich is a very important compositive range.

Just comparing, using the 8 diopter DCR-250 I go from 2:1 to 1:2 nd the next one the MSN -202 (25 diopter) I start in 1:3 to 1:5. So the no longer in production 12 diopter have a nice midrange spot.

Unfortunately our group is too small to justify continuing the production of the kit above

magom · Post by **magom** » Sat Mar 27, 2010 6:05 pm

Hey guys,

thank you so much for your answers. I think I will try to use and try the 12 diopter and the full of fungus 24 diopter directly as I receive the step Down ring to use them in front of a Milar 100mm, Apo Rodagon N 50mm and a Componon S 80/4. I hope I can get some nice results.

I haven't already tried a lot my equipment, but this season I will begin to present you some tests ans results

Thanks again,

Ver

Tesselator · Post by **Tesselator** » Tue Mar 30, 2010 9:48 am

Any progress to report or image samples to post?

On the topic of you're original question fungal damage should of course always be in the seller's description assuming they know about such things. Many times fungus will have almost no impact on the images and other times it's dramatically detrimental. It depends on quite a few things. The lighting, the aperture, the subject distance, which lens/surface the fungus is on, and etc. One of my copies of the EL-NIKKOR 63mm 2.8 has fungus pretty bad and it only shows up as very minor uneven looking "lighting" at f/16 when used at 1:2. At around f/5.6 and more towards 1:1 it's completely invisible and not humanly detectable. Yet another lens in about the same condition or a little worse:

isn't really detectable at all unless you know how it looked prior to the fungal invasion. I happen to know so I know it's just ever so slightly more soft than it was before. And I really mean just a tiny tiny bit - even though there is a lot of fungus - as you can see. I've seen images from others that were very soft and/or very blotchy due to fungus though so I guess it just depends.