focusing screen having dust & fibres

bygp · 04-27-2016, 04:29 AM

I've never been able to get rid of all fibres or dust on my focusing screen, it seems clean before puting it in its place but there's always at least 2 or 3 fibres and some dust when I look through my camera. Any advice on how placing this (genuine or ML-80 grid one) FS avoiding any dust or fibre to stick on while placing it in its slot ? What am I doing wrong ? Is this dust being in the prism room going down on the FS when placed ?
TY for any advice to have a clear dust and fiber free FS.

---------- Post added 04-27-16 at 04:38 AM ----------

plus I bought a grid pentax FS, it was sold as new but when I puted it in its slot there was dust and some fibers so I cleaned it but with the bad thing (burning alcool) which damaged the plastic on the bottom side, like giving it a brown tint like burned... any way to fix this with another chemical ?

freddyisaac · 04-27-2016, 04:45 AM - **1 Like**

Not sure about the reversal of the alcohol burn but as for the cleaning I have been using a kinetronics speck grabber. Cost about $5 I think and it seems to be pretty good at getting those individual fibres. Of course I think it is most useful with the screen in place and not fibre on the camera (prism) side of things.

Might be worth a try - it's pretty cheap so you don't stand to lose much and it is useful for those specks that a blower won't shift off the mirror also.

cheers

narual · 04-27-2016, 06:19 AM

Just a thought -- have you checked it with the focusing screen out? Maybe the stuff is stuck to the prizm.

Not a Number · 04-27-2016, 06:20 AM - **1 Like**

I never let alcohol near my camera or optical gear - it reacts with too many of the materials used in them.

There's probably no way to clean the staining without damaging the surface of the screen.

Fibers and dust may be on the pentaprism or between the screen and pentaprism. If you cleaned the area under the screen with a cloth or tissue the fibers may have gotten caught on edges or seals. The only way to remove these is to blow out as much as you can with a lens blower and then pick them out. Either with micro fine tweezers or an adhesive stick like the speck grabber mentioned above.

If for some reason you need to clean a screen I use water and just a touch of either pure soap (Ivory) or a mild dish soap and rinse with distilled water. Blot dry on a lint-less cloth or better yet blow dry with a lens blower. Never rub the surface. Always hold the screen by the tabs.

esrandall · 04-27-2016, 07:56 AM - **1 Like**

Has always been a never-ending battle for me. They drive my OCD crazy, but I've learned to just live with them, as it's usually too much hassle (for me) to pull the screen, take the time to carefully clean...and then a week later, another stray fiber appears. So long as it isn't on the sensor, and it's not too huge, I've learned to just leave them be, Not easy though -- lol

bygp · 04-27-2016, 08:05 AM

Originally posted by Not a Number

I never let alcohol near my camera or optical gear - it reacts with too many of the materials used in them.

There's probably no way to clean the staining without damaging the surface of the screen.

Fibers and dust may be on the pentaprism or between the screen and pentaprism. If you cleaned the area under the screen with a cloth or tissue the fibers may have gotten caught on edges or seals. The only way to remove these is to blow out as much as you can with a lens blower and then pick them out. Either with micro fine tweezers or an adhesive stick like the speck grabber mentioned above.

If for some reason you need to clean a screen I use water and just a touch of either pure soap (Ivory) or a mild dish soap and rinse with distilled water. Blot dry on a lint-less cloth or better yet blow dry with a lens blower. Never rub the surface. Always hold the screen by the tabs.

that's what I think, there can be some dust and fibers in the prism that fall down on the FS when set. Anyway it is on the FS otherwise I will see them blured, but I see them very sharply, so they are on the mate surface (top inner side) of the FS. Sadly my room is not a laboratory dust free room, and I don't have that so I'll have to find a trick to clean it, put a mask on it and set it fast so nothing goes on it... I'll see.
Ethylic pure 90% alcohol with 10% distilated water don't hurt stuff as far as I've tested, but once I used domestic methanol and this is bad.

**cpk** · 05-23-2016, 06:55 PM - **1 Like**

Originally posted by esrandall

They drive my OCD crazy, ...

Agreed!

bygp · 06-29-2016, 09:01 AM

found at a nice price a 1L big Isopropyl alcohol 99% and tested it on many surfaces as LCD screens, glass, plastics, it's realy the best cleaning product i've found ATM, perfect for cleaning electronic contacts too or camera LCD screen, lets no print at all, seems realy not corosive and I think it should not hurt lens coating as it even hardly removes finger dirts from my keyboard^^ Maybe someone knows more about cleaning coated front lenses...

04-27-2016, 04:29 AM	#1
bygp Veteran Member Join Date: Aug 2015 Location: Toulon, South of France Photos: Gallery \| Albums Posts: 357	focusing screen having dust & fibres I've never been able to get rid of all fibres or dust on my focusing screen, it seems clean before puting it in its place but there's always at least 2 or 3 fibres and some dust when I look through my camera. Any advice on how placing this (genuine or ML-80 grid one) FS avoiding any dust or fibre to stick on while placing it in its slot ? What am I doing wrong ? Is this dust being in the prism room going down on the FS when placed ? TY for any advice to have a clear dust and fiber free FS. ---------- Post added 04-27-16 at 04:38 AM ---------- plus I bought a grid pentax FS, it was sold as new but when I puted it in its slot there was dust and some fibers so I cleaned it but with the bad thing (burning alcool) which damaged the plastic on the bottom side, like giving it a brown tint like burned... any way to fix this with another chemical ?

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04-27-2016, 04:45 AM - 1 Like	#2
freddyisaac Forum Member Join Date: Dec 2015 Posts: 81	Not sure about the reversal of the alcohol burn but as for the cleaning I have been using a kinetronics speck grabber. Cost about $5 I think and it seems to be pretty good at getting those individual fibres. Of course I think it is most useful with the screen in place and not fibre on the camera (prism) side of things. Might be worth a try - it's pretty cheap so you don't stand to lose much and it is useful for those specks that a blower won't shift off the mirror also. cheers

04-27-2016, 06:19 AM	#3
narual Veteran Member Join Date: Jun 2013 Location: South Bend (Notre Dame), Indiana Photos: Gallery \| Albums Posts: 1,988	Just a thought -- have you checked it with the focusing screen out? Maybe the stuff is stuck to the prizm.

04-27-2016, 06:20 AM - 1 Like	#4
Not a Number Moderator Join Date: Mar 2012 Location: Venice, CA Posts: 10,526	I never let alcohol near my camera or optical gear - it reacts with too many of the materials used in them. There's probably no way to clean the staining without damaging the surface of the screen. Fibers and dust may be on the pentaprism or between the screen and pentaprism. If you cleaned the area under the screen with a cloth or tissue the fibers may have gotten caught on edges or seals. The only way to remove these is to blow out as much as you can with a lens blower and then pick them out. Either with micro fine tweezers or an adhesive stick like the speck grabber mentioned above. If for some reason you need to clean a screen I use water and just a touch of either pure soap (Ivory) or a mild dish soap and rinse with distilled water. Blot dry on a lint-less cloth or better yet blow dry with a lens blower. Never rub the surface. Always hold the screen by the tabs.

04-27-2016, 07:56 AM - 1 Like	#5
esrandall Closed Account Join Date: Feb 2014 Location: Sumner, WA Photos: Albums Posts: 965	Has always been a never-ending battle for me. They drive my OCD crazy, but I've learned to just live with them, as it's usually too much hassle (for me) to pull the screen, take the time to carefully clean...and then a week later, another stray fiber appears. So long as it isn't on the sensor, and it's not too huge, I've learned to just leave them be, Not easy though -- lol

04-27-2016, 08:05 AM	#6
bygp Veteran Member Join Date: Aug 2015 Location: Toulon, South of France Photos: Gallery \| Albums Posts: 357 Original Poster	Originally posted by Not a Number I never let alcohol near my camera or optical gear - it reacts with too many of the materials used in them. There's probably no way to clean the staining without damaging the surface of the screen. Fibers and dust may be on the pentaprism or between the screen and pentaprism. If you cleaned the area under the screen with a cloth or tissue the fibers may have gotten caught on edges or seals. The only way to remove these is to blow out as much as you can with a lens blower and then pick them out. Either with micro fine tweezers or an adhesive stick like the speck grabber mentioned above. If for some reason you need to clean a screen I use water and just a touch of either pure soap (Ivory) or a mild dish soap and rinse with distilled water. Blot dry on a lint-less cloth or better yet blow dry with a lens blower. Never rub the surface. Always hold the screen by the tabs. that's what I think, there can be some dust and fibers in the prism that fall down on the FS when set. Anyway it is on the FS otherwise I will see them blured, but I see them very sharply, so they are on the mate surface (top inner side) of the FS. Sadly my room is not a laboratory dust free room, and I don't have that so I'll have to find a trick to clean it, put a mask on it and set it fast so nothing goes on it... I'll see. Ethylic pure 90% alcohol with 10% distilated water don't hurt stuff as far as I've tested, but once I used domestic methanol and this is bad.

05-23-2016, 06:55 PM - 1 Like	#7
cpk Site Supporter Join Date: Feb 2010 Location: Montreal Posts: 638	Originally posted by esrandall They drive my OCD crazy, ... Agreed!

06-29-2016, 09:01 AM	#8
bygp Veteran Member Join Date: Aug 2015 Location: Toulon, South of France Photos: Gallery \| Albums Posts: 357 Original Poster	found at a nice price a 1L big Isopropyl alcohol 99% and tested it on many surfaces as LCD screens, glass, plastics, it's realy the best cleaning product i've found ATM, perfect for cleaning electronic contacts too or camera LCD screen, lets no print at all, seems realy not corosive and I think it should not hurt lens coating as it even hardly removes finger dirts from my keyboard^^ Maybe someone knows more about cleaning coated front lenses...