How do I get internals of lens clean?

claskowski · 05-05-2019, 05:11 PM

I have had a Pentax 16-85mm lens for three years now... Somehow - a white microfibre is inside the lens. I have double-checked it and sure enough - it is there. Of all places - near the center of the lens. I also noticed that there are other specs of dust/crud inside the lens at various levels throughout the lens itself. I have also noticed this little spec for the past few months. I have had the sensor of my K-3ii professionally cleaned, cleaned the lens as well and the little bugger would keep showing in my photos - slowly creeping from somewhere to nest in the middle of the glass....

What steps would one recommend? If this is a sealed lens - how did the crud get inside? Photo is a crop - the fiber is near center of the pic.

The second pic shows the best I could do with an iphone and a flashlight - but one can see the little white specs of crud inside the lens itself.

Any ideas/options?

Attached Images

View Picture EXIF

View Picture EXIF

**boriscleto** · 05-05-2019, 05:13 PM

WR lenses are not sealed against dust. AW lenses like the * lenses are sealed against dust.

Kozlok · 05-05-2019, 05:46 PM

I recon that was in there at manufacture. I'd ask Pentax to fix it, even if you have to pay.

**Bob 256** · 05-05-2019, 06:42 PM

The dust you're seeing is typical of many lenses that have been in use for some time and usually won't affect imaging other than possibly decreasing the contrast a very small amount. These can be particularly prevalent in zoom lenses where elements move and "suck" particles in through spaces between rotating members when zooming.

The fiber on the other hand, shouldn't be there, and as you exhibited, is clearly visible in a shot taken with the lens. Its removal would require lens disassembly and I would trust that to someone familiar with lens work, or as Kozloc suggested, Pentax since they probably left it in during manufacture. In any case, if the lens is disassembled for that, a good cleaning should get most of the dust particles as well. Otherwise, you'll just have to play games with the lens and shake it while looking through it to see if you can place the fiber in a non-visual location (but it's bound to show up again just when you are taking that very important shot).

Not a Number · 05-05-2019, 06:49 PM

Try at your own risk. I assume no liability for any resulting damage

. Tap the long side of the lens against the palm of you hand and maybe the bit of dust will fall somewhere where it won't matter as much. My Takumar 50mm f/4 macro had a big flake of dust (dandruff?) near center inside and a few taps dislodged it. Of course the Takumar is wide open. You can see the helical from the back of the lens. And there are no little delicate contacts or gears to break.

Otherwise you are going to or have someone open the lens up and do a CLA (Clean, Lubricate & Adjust).

claskowski · 05-05-2019, 07:28 PM

I thought about just whacking the heck out of it and hoping that dust (and not internal components) would shift. This is one of two lenses I routinely use so to have this isn't too good... I already checked and the basic repair is roughly $212. I do have a nice 17-70mm I will be using but have come to like the extra 15mm that this lens provides. I will think about getting this lens cleaned, using some money from my K-1 fund, of course this lens is not a full-format lens so I may just bite the bullet and keep using SnapHeal on my photos.

**rogerstg** · 05-06-2019, 06:37 AM

Originally posted by claskowski

I thought about just whacking the heck out of it and hoping that dust (and not internal components) would shift.

I'd try some sort of vibration first: maybe resting it on a clothes dryer or touching it to a palm sander or any other vibration producing device you might have on hand.

claskowski · 05-06-2019, 06:51 AM

Originally posted by rogerstg

I'd try some sort of vibration first: maybe resting it on a clothes dryer or touching it to a palm sander or any other vibration producing device you might have on hand.

I like idea - will definitely give it a try!

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
K-1 ISO internals	chd	Pentax Full Frame	32	03-30-2019 12:26 PM
What is this piece called? From Pentax lens internals	Harrison	Pentax SLR Lens Discussion	18	11-13-2013 08:08 AM
Info: How the internals of K-01 look like	raider	Pentax K-01	2	08-18-2012 04:24 AM
Keep K-x buy premium lens, get K-r and get good lens, get the K-7 w/ lens or K-5?	crossover37	Pentax DSLR Discussion	19	02-06-2011 10:38 PM

05-05-2019, 05:13 PM	#2
boriscleto Loyal Site Supporter Join Date: Dec 2009 Location: North Syracuse, NY Photos: Gallery Posts: 16,475	WR lenses are not sealed against dust. AW lenses like the * lenses are sealed against dust.

05-05-2019, 05:46 PM	#3
Kozlok Pentaxian Join Date: Jun 2012 Location: Albuquerque Photos: Gallery Posts: 3,148	I recon that was in there at manufacture. I'd ask Pentax to fix it, even if you have to pay.

05-05-2019, 06:42 PM	#4
Bob 256 Site Supporter Join Date: Jun 2008 Location: Idaho Photos: Gallery Posts: 2,375	The dust you're seeing is typical of many lenses that have been in use for some time and usually won't affect imaging other than possibly decreasing the contrast a very small amount. These can be particularly prevalent in zoom lenses where elements move and "suck" particles in through spaces between rotating members when zooming. The fiber on the other hand, shouldn't be there, and as you exhibited, is clearly visible in a shot taken with the lens. Its removal would require lens disassembly and I would trust that to someone familiar with lens work, or as Kozloc suggested, Pentax since they probably left it in during manufacture. In any case, if the lens is disassembled for that, a good cleaning should get most of the dust particles as well. Otherwise, you'll just have to play games with the lens and shake it while looking through it to see if you can place the fiber in a non-visual location (but it's bound to show up again just when you are taking that very important shot).

05-05-2019, 06:49 PM	#5
Not a Number Moderator Join Date: Mar 2012 Location: Venice, CA Posts: 10,526	Try at your own risk. I assume no liability for any resulting damage . Tap the long side of the lens against the palm of you hand and maybe the bit of dust will fall somewhere where it won't matter as much. My Takumar 50mm f/4 macro had a big flake of dust (dandruff?) near center inside and a few taps dislodged it. Of course the Takumar is wide open. You can see the helical from the back of the lens. And there are no little delicate contacts or gears to break. Otherwise you are going to or have someone open the lens up and do a CLA (Clean, Lubricate & Adjust).

05-05-2019, 07:28 PM	#6
claskowski Junior Member Join Date: Aug 2008 Location: Portland, OR Photos: Gallery Posts: 34 Original Poster	I thought about just whacking the heck out of it and hoping that dust (and not internal components) would shift. This is one of two lenses I routinely use so to have this isn't too good... I already checked and the basic repair is roughly $212. I do have a nice 17-70mm I will be using but have come to like the extra 15mm that this lens provides. I will think about getting this lens cleaned, using some money from my K-1 fund, of course this lens is not a full-format lens so I may just bite the bullet and keep using SnapHeal on my photos.

05-06-2019, 06:37 AM	#7
rogerstg Loyal Site Supporter Join Date: Oct 2007 Location: Rhode Island Photos: Albums Posts: 1,168	Originally posted by claskowski I thought about just whacking the heck out of it and hoping that dust (and not internal components) would shift. I'd try some sort of vibration first: maybe resting it on a clothes dryer or touching it to a palm sander or any other vibration producing device you might have on hand.

05-06-2019, 06:51 AM	#8
claskowski Junior Member Join Date: Aug 2008 Location: Portland, OR Photos: Gallery Posts: 34 Original Poster	Originally posted by rogerstg I'd try some sort of vibration first: maybe resting it on a clothes dryer or touching it to a palm sander or any other vibration producing device you might have on hand. I like idea - will definitely give it a try!