Is it better to lose the biggest aperture or to leave some dead mold in the lens?

phidias81 · 12-04-2014, 10:24 AM

This is a follow up of this thread but I opened a new topic, since now it's a more general question. After noticing some mold on the back of my front lens, I first tried to disassemble it myself, and then I went to a local business (Indonesia) specialized on fixing lenses, it was the one that everybody suggested me. The owner told me that to remove the front lens he has to un-glue it basically and then put it back. But by doing so I would lose the possibility to use the aperture f/4, I don't know why (if somebody knows it It would be nice to have a short explanation). Checking the statistics of usage of this lens, it looks like out of about 5000 photos, only 15 use f/4. This is probably because I mostly use the 200mm focal lens of this zoom objective. So this means that it wouldn't be a big loss, but at the same time, I don't like the idea of downgrading its capabilities and the technician didn't seem too careful when handling my lens. And I still have the options to just kill the mold with UV lamp, and leave the dead mold there, that shouldn't bother too much since it's still small and peripheral. What would you suggest me to do?

SpecialK · 12-04-2014, 10:40 AM

I would likely replace it.

phidias81 · 12-04-2014, 10:44 AM

That's not an option for me, since I have no money to invest on a lens now. I could "fix it" at local price, that means 4$

**sergysergy** · 12-04-2014, 11:00 AM

I would live with the dead mold until you have the money to clean it properly.

LensBeginner · 12-04-2014, 11:59 AM

Originally posted by sergysergy

I would live with the dead mold until you have the money to clean it properly.

This.
No whack jobs and the quality loss is probably gonna be minimal anyway...

VisualDarkness · 12-04-2014, 12:43 PM

That sounds too weird for me to put my trust in that "repair man".

6BQ5 · 12-04-2014, 01:18 PM

The mold you describe on your front lens element will have very little actual impact on your images. It's too close to be focused on so you'll never see it. All you might see, depending on how bad it is, is a loss of contrast. The front element can take a lot of abuse before there is significant reduction in image quality. Elements further in have a larger impact on quality. The biggest impact here is on you knowing that there is mold present. It would bother me too. I would use the lens as-is until you can replace it with a different one.

LensBeginner · 12-04-2014, 01:52 PM

...and if you want to have a good laugh, just read this one:
Dirty lens article
WARNING: not for the faint of heart!!!

phidias81 · 12-04-2014, 06:34 PM

Originally posted by sergysergy

I would live with the dead mold until you have the money to clean it properly.

It doesn't exist to clean it properly apparently since the front element can't be disassembled further.

I think I will do as you all are saying and just leave the dead mold inside. Thank you for the suggestions

---------- Post added 12-05-14 at 10:47 AM ----------

Originally posted by LensBeginner

...and if you want to have a good laugh, just read this one:
Dirty lens article
WARNING: not for the faint of heart!!!

Definitely an educative article, now I have no more doubts

TaoMaas · 12-05-2014, 06:37 AM

I think I'd leave it. Being on the front element, it shouldn't have too great of an effect on most pics as long as you use a good hood and avoid shooting directly into light sources. Do what you can to kill it...then ignore it. I have an A200 f2.8 that I was able to pick up for cheap because it had a touch of mold on the front element. I've had it for about 20 years, the mold hasn't spread, and it's a non-factor in 99% of the pics I take with it.

12-04-2014, 10:24 AM	#1
phidias81 New Member Join Date: Dec 2014 Posts: 14	Is it better to lose the biggest aperture or to leave some dead mold in the lens? This is a follow up of this thread but I opened a new topic, since now it's a more general question. After noticing some mold on the back of my front lens, I first tried to disassemble it myself, and then I went to a local business (Indonesia) specialized on fixing lenses, it was the one that everybody suggested me. The owner told me that to remove the front lens he has to un-glue it basically and then put it back. But by doing so I would lose the possibility to use the aperture f/4, I don't know why (if somebody knows it It would be nice to have a short explanation). Checking the statistics of usage of this lens, it looks like out of about 5000 photos, only 15 use f/4. This is probably because I mostly use the 200mm focal lens of this zoom objective. So this means that it wouldn't be a big loss, but at the same time, I don't like the idea of downgrading its capabilities and the technician didn't seem too careful when handling my lens. And I still have the options to just kill the mold with UV lamp, and leave the dead mold there, that shouldn't bother too much since it's still small and peripheral. What would you suggest me to do?

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12-04-2014, 10:40 AM	#2
SpecialK Pentaxian Join Date: Dec 2006 Location: So California Photos: Gallery Posts: 16,481	I would likely replace it.

12-04-2014, 10:44 AM	#3
phidias81 New Member Join Date: Dec 2014 Posts: 14 Original Poster	That's not an option for me, since I have no money to invest on a lens now. I could "fix it" at local price, that means 4$

12-04-2014, 11:00 AM	#4
sergysergy Site Supporter Join Date: Jan 2011 Photos: Gallery Posts: 5,170	I would live with the dead mold until you have the money to clean it properly.

12-04-2014, 11:59 AM	#5
LensBeginner Veteran Member Join Date: Sep 2014 Photos: Albums Posts: 4,696	Originally posted by sergysergy I would live with the dead mold until you have the money to clean it properly. This. No whack jobs and the quality loss is probably gonna be minimal anyway...

12-04-2014, 12:43 PM	#6
VisualDarkness Veteran Member Join Date: Nov 2011 Location: Uppsala, Sweden Photos: Gallery Posts: 4,439	That sounds too weird for me to put my trust in that "repair man".

12-04-2014, 01:18 PM	#7
6BQ5 Veteran Member Join Date: Jun 2013 Location: Nevada, USA Photos: Albums Posts: 3,348	The mold you describe on your front lens element will have very little actual impact on your images. It's too close to be focused on so you'll never see it. All you might see, depending on how bad it is, is a loss of contrast. The front element can take a lot of abuse before there is significant reduction in image quality. Elements further in have a larger impact on quality. The biggest impact here is on you knowing that there is mold present. It would bother me too. I would use the lens as-is until you can replace it with a different one.

12-04-2014, 01:52 PM	#8
LensBeginner Veteran Member Join Date: Sep 2014 Photos: Albums Posts: 4,696	...and if you want to have a good laugh, just read this one: Dirty lens article WARNING: not for the faint of heart!!!

12-04-2014, 06:34 PM	#9
phidias81 New Member Join Date: Dec 2014 Posts: 14 Original Poster	Originally posted by sergysergy I would live with the dead mold until you have the money to clean it properly. It doesn't exist to clean it properly apparently since the front element can't be disassembled further. I think I will do as you all are saying and just leave the dead mold inside. Thank you for the suggestions ---------- Post added 12-05-14 at 10:47 AM ---------- Originally posted by LensBeginner ...and if you want to have a good laugh, just read this one: Dirty lens article WARNING: not for the faint of heart!!! Definitely an educative article, now I have no more doubts

12-05-2014, 06:37 AM	#10
TaoMaas Pentaxian Join Date: May 2007 Location: Oklahoma City Photos: Gallery \| Albums Posts: 3,574	I think I'd leave it. Being on the front element, it shouldn't have too great of an effect on most pics as long as you use a good hood and avoid shooting directly into light sources. Do what you can to kill it...then ignore it. I have an A200 f2.8 that I was able to pick up for cheap because it had a touch of mold on the front element. I've had it for about 20 years, the mold hasn't spread, and it's a non-factor in 99% of the pics I take with it.