Fingerprint on rear element, what to do?

Lev · 08-06-2019, 10:20 AM

Guys,

Never thought that I could do this myself but I somehow managed to touch the rear element of my DFA 50.

There are ways to remore it but what would be best?

Lenspen

Isopropyl alcohol + distilled water + cotton qtips

Isopropyl alcohol + distilled water + microfiber cloth

purosol + microfiber cloth

of course, blower and brush first...

I've done it before on my 16-85 but only with water and qtips on front element with good results, but there was just a tiny fingerprint mark.

**ismaelg** · 08-06-2019, 10:25 AM

Hello,

Blower or brush will not work in a fingerprint. I'd use Isop. alcohol (91%) and a lens cloth. A few drops in the cloth will do. you don't want to flood it.

Thanks,

Roadboat24 · 08-06-2019, 10:43 AM

Blow and brush, so there is no bits that may scratch. Apply cleaning solution to cloth (Not Lens). many times just a micro fiber cloth will do it without the solution.

**boriscleto** · 08-06-2019, 10:45 AM

Lens tissue

Wadded up, just a few drops of lens cleaning solution on the tissue, not on the lens.

Lev · 08-06-2019, 10:55 AM

ok guys, so no qtips, just cloth right?

I bought 99,9% IPA and clean water, I'm afraid to use just IPA with this percentage as I guess it might be harsh for coatings. Dillute it with water? like 70% IPA and 30% water? And also is there any difference how IPAs are made?

Fenwoodian · 08-06-2019, 11:48 AM

.
You're far too worried about this little issue. No big deal.

IPO and any clean cloth will work perfect (cotton or microfiber will work). Don't dilute the IPO. Q tips would work fine too.

If stain is not removed via IPO, step up to either acetone (fingernail polish remover) or naptha (aka Zippo lighter fluid).

**BigMackCam** · 08-06-2019, 11:49 AM - **1 Like**

It's nothing to worry about if you're careful

First, use a bulb blower to get rid of any dust. Then, use a clean, small, soft-bristled brush (I use very soft make-up brushes) to gently remove any remaining dust and or debris, and give it a final blast with the bulb blower, just to be sure. Then, moisten a single-use lens paper tissue or other single-use optical wipe with a couple of drops of isopropyl alcohol. Alternatively (and my preference) use a pre-packaged, pre-moistened optical wipe. I like Zeiss wipes, but they're pretty wet straight out of the packet, so I let some of the alcohol evaporate off such that it's damp but no longer wet. Wipe the rear element gently, and in a circular motion starting from the centre to the outer edge.

Unless you've abrasive debris on the rear element, or the wipe you use is contaminated from previous use (which is why I recommend single use lens tissues or wipes), it's extremely unlikely that you'll mark the glass or coatings. Even the rear elements on these modern lenses are remarkably resistant to scratching.

**sergysergy** · 08-06-2019, 11:55 AM - **2 Likes**

I normally don't clean my lenses, but when I do I use dos equis

As Fenwoodian and BigMackCam said it is not a big deal. Alcohol should work.

C_Jones · 08-06-2019, 12:19 PM

I use 50 percent of distilled water and 50 percent of isopropyl alcohol (91%). I get both from Wal-Mart. I use cotton cloth that I get from the fabric department also. I wash it, then use it. The cotton cloth is softer than the microfiber type cloth, and is also more absorbent.The reason the isopropyl alcohol is in the mixture is to clean and it also dries the distilled water along with itself fairly quickly.

Lev · 08-06-2019, 12:29 PM

god bless me

thanks to all

**marcusBMG** · 08-06-2019, 12:53 PM

Lenspen is perfect for this - exactly what its designed for.

Cleaning Accessories - Pentax Camera Accessory Review Database

swanlefitte · 08-06-2019, 01:54 PM

The latest discussion.
https://www.pentaxforums.com/forums/58-troubleshooting-beginner-help/390452-lens-cleaning.html

Lev · 08-06-2019, 01:57 PM

Originally posted by marcusBMG

Lenspen is perfect for this - exactly what its designed for.

Cleaning Accessories - Pentax Camera Accessory Review Database

I'm little sceptical about lenspen because it is completely dry way to clean the lens. Having said that I never used it and it is maybe the best way out there.

Not a Number · 08-06-2019, 02:48 PM

Just a micro fiber or chamois for cleaning lenses will remove the oil from a finger print. But blow it off first to remove and dust and dirt particles that can scratch the coating. If need be use a lens cleaning solution.

Ever since I stripped off the coating on the rear element of a teleconverter with some isopropyl alcohol back in the 80s alcohol doesn't go anywhere near my lenses. I certainly wouldn't use 75% or greater. Alcohol is rather reactive stuff - it will damage many plastics, rubbers, finishes and metallic surfaces.

stevebrot · 08-06-2019, 03:14 PM - **1 Like**

Originally posted by Fenwoodian

If stain is not removed via IPO, step up to either acetone (fingernail polish remover) or naptha (aka Zippo lighter fluid).

Naphta will often leave a residue and acetone will attach many plastics (not safe around cameras or lenses). Full strength alcohol (IPO included) is also contraindicated because of its strong solvent action.

Originally posted by Lev

There are ways to remore it but what would be best?

Blower followed by fog with breath for lubrication and clean microfibre cloth. The magic of the microfibre cloth is that it will wick oils off the glass surface. That failing, 50% isopropanol in water on a soft cotton cloth followed by gentle drying with the unwetted portion of the cloth.

Steve

(...truth be told, I use Windex on the corner of a soft cotton cloth...but I would be pilloried for suggesting such...)

08-06-2019, 10:20 AM	#1
Lev Veteran Member Join Date: Aug 2015 Location: Tbilisi, Georgia Posts: 1,197	Fingerprint on rear element, what to do? Guys, Never thought that I could do this myself but I somehow managed to touch the rear element of my DFA 50. There are ways to remore it but what would be best? Lenspen Isopropyl alcohol + distilled water + cotton qtips Isopropyl alcohol + distilled water + microfiber cloth purosol + microfiber cloth of course, blower and brush first... I've done it before on my 16-85 but only with water and qtips on front element with good results, but there was just a tiny fingerprint mark.

08-06-2019, 10:25 AM	#2
ismaelg Loyal Site Supporter Join Date: Apr 2009 Location: Puerto Rico Photos: Gallery Posts: 2,681	Hello, Blower or brush will not work in a fingerprint. I'd use Isop. alcohol (91%) and a lens cloth. A few drops in the cloth will do. you don't want to flood it. Thanks, Last edited by ismaelg; 08-06-2019 at 10:46 AM.

08-06-2019, 11:48 AM	#6
Fenwoodian Pentaxian Join Date: Apr 2015 Location: USA Photos: Gallery \| Albums Posts: 2,874	. You're far too worried about this little issue. No big deal. IPO and any clean cloth will work perfect (cotton or microfiber will work). Don't dilute the IPO. Q tips would work fine too. If stain is not removed via IPO, step up to either acetone (fingernail polish remover) or naptha (aka Zippo lighter fluid). Last edited by Fenwoodian; 08-06-2019 at 11:54 AM.

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08-06-2019, 10:43 AM	#3
Roadboat24 Pentaxian Join Date: Jul 2017 Posts: 487	Blow and brush, so there is no bits that may scratch. Apply cleaning solution to cloth (Not Lens). many times just a micro fiber cloth will do it without the solution.

08-06-2019, 10:45 AM	#4
boriscleto Loyal Site Supporter Join Date: Dec 2009 Location: North Syracuse, NY Photos: Gallery Posts: 16,475	Lens tissue Wadded up, just a few drops of lens cleaning solution on the tissue, not on the lens.

08-06-2019, 10:55 AM	#5
Lev Veteran Member Join Date: Aug 2015 Location: Tbilisi, Georgia Posts: 1,197 Original Poster	ok guys, so no qtips, just cloth right? I bought 99,9% IPA and clean water, I'm afraid to use just IPA with this percentage as I guess it might be harsh for coatings. Dillute it with water? like 70% IPA and 30% water? And also is there any difference how IPAs are made?

08-06-2019, 11:49 AM - 1 Like	#7
BigMackCam Digitiser of Film Join Date: Mar 2010 Location: North East of England Posts: 20,670	It's nothing to worry about if you're careful First, use a bulb blower to get rid of any dust. Then, use a clean, small, soft-bristled brush (I use very soft make-up brushes) to gently remove any remaining dust and or debris, and give it a final blast with the bulb blower, just to be sure. Then, moisten a single-use lens paper tissue or other single-use optical wipe with a couple of drops of isopropyl alcohol. Alternatively (and my preference) use a pre-packaged, pre-moistened optical wipe. I like Zeiss wipes, but they're pretty wet straight out of the packet, so I let some of the alcohol evaporate off such that it's damp but no longer wet. Wipe the rear element gently, and in a circular motion starting from the centre to the outer edge. Unless you've abrasive debris on the rear element, or the wipe you use is contaminated from previous use (which is why I recommend single use lens tissues or wipes), it's extremely unlikely that you'll mark the glass or coatings. Even the rear elements on these modern lenses are remarkably resistant to scratching.

08-06-2019, 11:55 AM - 2 Likes	#8
sergysergy Site Supporter Join Date: Jan 2011 Photos: Gallery Posts: 5,170	I normally don't clean my lenses, but when I do I use dos equis As Fenwoodian and BigMackCam said it is not a big deal. Alcohol should work.

08-06-2019, 12:19 PM	#9
C_Jones Pentaxian Join Date: Sep 2012 Location: NY Photos: Gallery \| Albums Posts: 6,084	I use 50 percent of distilled water and 50 percent of isopropyl alcohol (91%). I get both from Wal-Mart. I use cotton cloth that I get from the fabric department also. I wash it, then use it. The cotton cloth is softer than the microfiber type cloth, and is also more absorbent.The reason the isopropyl alcohol is in the mixture is to clean and it also dries the distilled water along with itself fairly quickly.

08-06-2019, 12:29 PM	#10
Lev Veteran Member Join Date: Aug 2015 Location: Tbilisi, Georgia Posts: 1,197 Original Poster	god bless me thanks to all

08-06-2019, 12:53 PM	#11
marcusBMG Site Supporter Join Date: Nov 2012 Location: North Wales Photos: Gallery \| Albums Posts: 2,869	Lenspen is perfect for this - exactly what its designed for. Cleaning Accessories - Pentax Camera Accessory Review Database

08-06-2019, 01:54 PM	#12
swanlefitte Pentaxian Join Date: May 2015 Location: Minneapolis Photos: Gallery Posts: 4,068	The latest discussion. https://www.pentaxforums.com/forums/58-troubleshooting-beginner-help/390452-lens-cleaning.html

08-06-2019, 01:57 PM	#13
Lev Veteran Member Join Date: Aug 2015 Location: Tbilisi, Georgia Posts: 1,197 Original Poster	Originally posted by marcusBMG Lenspen is perfect for this - exactly what its designed for. Cleaning Accessories - Pentax Camera Accessory Review Database I'm little sceptical about lenspen because it is completely dry way to clean the lens. Having said that I never used it and it is maybe the best way out there.

08-06-2019, 02:48 PM	#14
Not a Number Moderator Join Date: Mar 2012 Location: Venice, CA Posts: 10,526	Just a micro fiber or chamois for cleaning lenses will remove the oil from a finger print. But blow it off first to remove and dust and dirt particles that can scratch the coating. If need be use a lens cleaning solution. Ever since I stripped off the coating on the rear element of a teleconverter with some isopropyl alcohol back in the 80s alcohol doesn't go anywhere near my lenses. I certainly wouldn't use 75% or greater. Alcohol is rather reactive stuff - it will damage many plastics, rubbers, finishes and metallic surfaces.

08-06-2019, 03:14 PM - 1 Like	#15
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by Fenwoodian If stain is not removed via IPO, step up to either acetone (fingernail polish remover) or naptha (aka Zippo lighter fluid). Naphta will often leave a residue and acetone will attach many plastics (not safe around cameras or lenses). Full strength alcohol (IPO included) is also contraindicated because of its strong solvent action. Originally posted by Lev There are ways to remore it but what would be best? Blower followed by fog with breath for lubrication and clean microfibre cloth. The magic of the microfibre cloth is that it will wick oils off the glass surface. That failing, 50% isopropanol in water on a soft cotton cloth followed by gentle drying with the unwetted portion of the cloth. Steve (...truth be told, I use Windex on the corner of a soft cotton cloth...but I would be pilloried for suggesting such...)