Fungus in 18-55 kit lens

35mmfilmfan · 02-20-2017, 08:28 AM

I recently tried to p/ex an 18-55 kit lens at a well-known UK retailer. However, they examined it and rejected it as there was fungus in it. Contacted the Ebay seller from whom it was bought,
who gave an immediate no quibble 100% refund, including postage.

However, I have had a look at the lens, shining a light through it, using an 10x loupe etc, and I could see no evidence. So today I went and took some comparison shots with both the 'reject'
and my other 18-55 kit lens. Looking at the images (all on tripod, SR off, cable release, same subject) shot at all apertures and all marked focal lengths, and comparing those from each lens
using Irfanview, set up to load RAW, even at a magnification of over 200% I can see no difference in the quality of the shots.

Can anyone please tell me how the existence of fungus in a lens is likely to manifest itself in the image, please ?

Many thanks.

Tony

JohnX · 02-20-2017, 09:02 AM - **1 Like**

Can't help with the specific question regarding impact on image, but afaik fungus will be visible on the glass when a light is shone through the lens, so interesting how you're not seeing it but 'they' are.

Most of what I've read suggests little if any impact on image quality.

35mmfilmfan · 02-20-2017, 09:16 AM

Thanks, John, that's pretty much what I thought about seeing the fungus - as for impact on image quality, again what my testing confirms, but nice to have another opinion.
I suppose being a commercial concern, they have to cover themselves against any possible comeback.

Cheers

**sergysergy** · 02-20-2017, 09:18 AM

You could consider fungus, dust or scratches the same thing (i.e. something that should not be there). The impact on the quality of the image will depend on where they are (the closer to the sensor the worse) and how big the are (the bigger the worse...duh).

In this article you can see that having some of these will not affect the quality of your pictures that much:
Dirty lens article

A completely different story is whether your lens actually does have fungus or not.

35mmfilmfan · 02-20-2017, 09:29 AM

Again, thanks, Sergysergy - the major problem with my photos anyway is the photographer, not the camera or the lens !

Not a Number · 02-20-2017, 09:42 AM

If there is any noticeable effect it will primarily be in loss of contrast and some sharpness.

Na Horuk · 02-20-2017, 10:26 AM

Originally posted by 35mmfilmfan

Can anyone please tell me how the existence of fungus in a lens is likely to manifest itself in the image, please ?

Originally posted by JohnX

Most of what I've read suggests little if any impact on image quality.

Yep.
But shouldn't the shop tell you what their evidence of fungus is?
Anyway, a little fungus is not a big problem for image quality (usually), but most photographers get rid of infected lenses because they fear their other gear will get infected. Considering its a cheap lens and you got your money back, you should probably get rid of it, or de-fungus it if you know how. You can put it on ebay with a big notice "fungus!" for $2+shipping, and then buy a nice, clean Tamron 17-50mm f2.8 (which is a much better lens than the DA L18-55mm)

35mmfilmfan · 02-20-2017, 10:57 AM

Thanks for the comments and advice.

**lithedreamer** · 02-20-2017, 12:46 PM

Originally posted by Na Horuk

Yep.
But shouldn't the shop tell you what their evidence of fungus is?
Anyway, a little fungus is not a big problem for image quality (usually), but most photographers get rid of infected lenses because they fear their other gear will get infected. Considering its a cheap lens and you got your money back, you should probably get rid of it, or de-fungus it if you know how. You can put it on ebay with a big notice "fungus!" for $2+shipping, and then buy a nice, clean Tamron 17-50mm f2.8 (which is a much better lens than the DA L18-55mm)

It's of course worth noting that this isn't true. Any lens subject to the wrong conditions will develop fungus, cross-contamination isn't a thing.

Na Horuk · 02-21-2017, 04:31 AM - **1 Like**

Originally posted by lithedreamer

It's of course worth noting that this isn't true. Any lens subject to the wrong conditions will develop fungus, cross-contamination isn't a thing.

That's why I formulated things like that

I have read that cross-contamination doesn't happen, but I completely understand the fear of it, and I do not wish to take responsibility for someone else's gear. And when its just a kit lens, I would personally err on the side of caution and replace it, or defungus it (there are some blogs out there that talk about this btw, OP)

35mmfilmfan · 02-21-2017, 02:38 PM

Again, my thanks to one and all for the comments and help - the lens is currently in quarantine inside a zip bag while I consider my next move. Fortunately, I also have the WR version of the kit lens, so its loss is not a major issue.

**lithedreamer** · 02-21-2017, 02:52 PM

Originally posted by Na Horuk

That's why I formulated things like that

I have read that cross-contamination doesn't happen, but I completely understand the fear of it, and I do not wish to take responsibility for someone else's gear. And when its just a kit lens, I would personally err on the side of caution and replace it, or defungus it (there are some blogs out there that talk about this btw, OP)

Well that's the misconception. Cross-contamination can't happen becauses the spores are in all lenses, it's unavoidable. Any lens subjected to damp conditions for long enough will grow fungus. At least, that's how @dcshooter explained it to me.

02-20-2017, 08:28 AM	#1
35mmfilmfan Pentaxian Join Date: Oct 2016 Location: Norfolk, UK Posts: 4,341	Fungus in 18-55 kit lens I recently tried to p/ex an 18-55 kit lens at a well-known UK retailer. However, they examined it and rejected it as there was fungus in it. Contacted the Ebay seller from whom it was bought, who gave an immediate no quibble 100% refund, including postage. However, I have had a look at the lens, shining a light through it, using an 10x loupe etc, and I could see no evidence. So today I went and took some comparison shots with both the 'reject' and my other 18-55 kit lens. Looking at the images (all on tripod, SR off, cable release, same subject) shot at all apertures and all marked focal lengths, and comparing those from each lens using Irfanview, set up to load RAW, even at a magnification of over 200% I can see no difference in the quality of the shots. Can anyone please tell me how the existence of fungus in a lens is likely to manifest itself in the image, please ? Many thanks. Tony

02-21-2017, 02:38 PM	#11
35mmfilmfan Pentaxian Join Date: Oct 2016 Location: Norfolk, UK Posts: 4,341 Original Poster	Again, my thanks to one and all for the comments and help - the lens is currently in quarantine inside a zip bag while I consider my next move. Fortunately, I also have the WR version of the kit lens, so its loss is not a major issue. Last edited by 35mmfilmfan; 02-21-2017 at 02:49 PM. Reason: Missed out a word !

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
For Sale - Sold: Selling K50 + 18-55 WR kit lens + 18-135 WR lens	Moropo	Sold Items	7	02-10-2016 03:23 PM
Buying a K5 - but with 18-135mm lens kit? Or an 18-55 + 50-200mm lens kit?	robinfaz	Pentax K-5 & K-5 II	12	06-04-2012 01:44 PM
For Sale - Sold: WTT Pentax 18-55 AL II kit lens for 18-55 AL kit lens + money	wallyb	Sold Items	2	11-11-2009 02:26 PM
In Praise Of The 18-55 Kit Lens	Mike Bokeh	Pentax SLR Lens Discussion	21	10-12-2007 07:48 AM

02-20-2017, 09:02 AM - 1 Like	#2
JohnX Pentaxian Join Date: Jul 2009 Location: London Posts: 1,116	Can't help with the specific question regarding impact on image, but afaik fungus will be visible on the glass when a light is shone through the lens, so interesting how you're not seeing it but 'they' are. Most of what I've read suggests little if any impact on image quality.

02-20-2017, 09:16 AM	#3
35mmfilmfan Pentaxian Join Date: Oct 2016 Location: Norfolk, UK Posts: 4,341 Original Poster	Thanks, John, that's pretty much what I thought about seeing the fungus - as for impact on image quality, again what my testing confirms, but nice to have another opinion. I suppose being a commercial concern, they have to cover themselves against any possible comeback. Cheers

02-20-2017, 09:18 AM	#4
sergysergy Site Supporter Join Date: Jan 2011 Photos: Gallery Posts: 5,175	You could consider fungus, dust or scratches the same thing (i.e. something that should not be there). The impact on the quality of the image will depend on where they are (the closer to the sensor the worse) and how big the are (the bigger the worse...duh). In this article you can see that having some of these will not affect the quality of your pictures that much: Dirty lens article A completely different story is whether your lens actually does have fungus or not.

02-20-2017, 09:29 AM	#5
35mmfilmfan Pentaxian Join Date: Oct 2016 Location: Norfolk, UK Posts: 4,341 Original Poster	Again, thanks, Sergysergy - the major problem with my photos anyway is the photographer, not the camera or the lens !

02-20-2017, 09:42 AM	#6
Not a Number Moderator Join Date: Mar 2012 Location: Venice, CA Posts: 10,526	If there is any noticeable effect it will primarily be in loss of contrast and some sharpness.

02-20-2017, 10:26 AM	#7
Na Horuk Veteran Member Join Date: Feb 2012 Location: Slovenia, probably Photos: Gallery \| Albums Posts: 11,186	Originally posted by 35mmfilmfan Can anyone please tell me how the existence of fungus in a lens is likely to manifest itself in the image, please ? Originally posted by JohnX Most of what I've read suggests little if any impact on image quality. Yep. But shouldn't the shop tell you what their evidence of fungus is? Anyway, a little fungus is not a big problem for image quality (usually), but most photographers get rid of infected lenses because they fear their other gear will get infected. Considering its a cheap lens and you got your money back, you should probably get rid of it, or de-fungus it if you know how. You can put it on ebay with a big notice "fungus!" for $2+shipping, and then buy a nice, clean Tamron 17-50mm f2.8 (which is a much better lens than the DA L18-55mm)

02-20-2017, 10:57 AM	#8
35mmfilmfan Pentaxian Join Date: Oct 2016 Location: Norfolk, UK Posts: 4,341 Original Poster	Thanks for the comments and advice.

02-20-2017, 12:46 PM	#9
lithedreamer Site Supporter Join Date: Sep 2013 Photos: Gallery \| Albums Posts: 1,799	Originally posted by Na Horuk Yep. But shouldn't the shop tell you what their evidence of fungus is? Anyway, a little fungus is not a big problem for image quality (usually), but most photographers get rid of infected lenses because they fear their other gear will get infected. Considering its a cheap lens and you got your money back, you should probably get rid of it, or de-fungus it if you know how. You can put it on ebay with a big notice "fungus!" for $2+shipping, and then buy a nice, clean Tamron 17-50mm f2.8 (which is a much better lens than the DA L18-55mm) It's of course worth noting that this isn't true. Any lens subject to the wrong conditions will develop fungus, cross-contamination isn't a thing.

02-21-2017, 04:31 AM - 1 Like	#10
Na Horuk Veteran Member Join Date: Feb 2012 Location: Slovenia, probably Photos: Gallery \| Albums Posts: 11,186	Originally posted by lithedreamer It's of course worth noting that this isn't true. Any lens subject to the wrong conditions will develop fungus, cross-contamination isn't a thing. That's why I formulated things like that I have read that cross-contamination doesn't happen, but I completely understand the fear of it, and I do not wish to take responsibility for someone else's gear. And when its just a kit lens, I would personally err on the side of caution and replace it, or defungus it (there are some blogs out there that talk about this btw, OP)

02-21-2017, 02:52 PM	#12
lithedreamer Site Supporter Join Date: Sep 2013 Photos: Gallery \| Albums Posts: 1,799	Originally posted by Na Horuk That's why I formulated things like that I have read that cross-contamination doesn't happen, but I completely understand the fear of it, and I do not wish to take responsibility for someone else's gear. And when its just a kit lens, I would personally err on the side of caution and replace it, or defungus it (there are some blogs out there that talk about this btw, OP) Well that's the misconception. Cross-contamination can't happen becauses the spores are in all lenses, it's unavoidable. Any lens subjected to damp conditions for long enough will grow fungus. At least, that's how @dcshooter explained it to me.