Help With lens marks

jersey_m · 01-31-2011, 08:41 PM

Staff note: This post may contain affiliate links, which means Pentax Forums may earn a small commission if a visitor clicks through and makes a purchase. If you would like to support the forum directly, you may also make a donation here.

Just bought a lens and it came with these strange brownish smear marks. It appears the marks are inside the front element and not the exposed part
The lens is a SMC Pentax-M 1:1.4 50mm

Is this something I should be worried about.
Thanks for your help in advance

- RTH

Last edited by jersey_m; 01-31-2011 at 10:12 PM. Reason: Added more photos

KxBlaze · 01-31-2011, 10:24 PM

I have no idea what those marks are (looks like some kind of a chemical burn maybe), so I would say only worry if they are noticeable on your photos. If you cannot notice them in photos then they are nothing but annoying.

**Maybe you can ask a professional camera repair/cleaner to see if they know what caused that.

**GregK8** · 01-31-2011, 10:57 PM

It shouldn't be very hard to take that front element off to see if it can be cleaned. Something like the rubber tip from a crutch can be used to turn the ring that holds the front element in place.

jersey_m · 02-01-2011, 05:29 AM

Thanks for your responses. Is removing the front element something, an inexperienced person can easily accomplish?

gp1806 · 02-01-2011, 05:56 AM

You might need something like this.
Spanner Wrench(1/32") Great Tool for Lens - eBay (item 360335584435 end time Feb-10-11 21:49:13 PST)

**GregK8** · 02-01-2011, 05:57 AM

If the marks are showing on the images, you really have nothing to lose, and it will be a great learning experience. If you cannot see the marks in your shots, just leave it alone, unless you are feeling a little daring.

If you look closely, just inside the rim of the lens you will see some threads. The ring with all the white lettering is actually a huge screw with a hole in the middle. If you unscrew that, the front element should come right out.

There is a special tool that fits into two notches on opposite sides of the ring. I forget what they call it. If you cannot get one, something that can apply friction to the ring, like the rubber tip of a crutch will work. Just press down and turn counter-clockwise.

**boriscleto** · 02-01-2011, 06:09 AM

Spanner wrenches are only necessary if the filter ring is damaged. All you need to open a Pentax lens is a lens ring.

Lens Ring Tool Set

Also keep in mind that lenses made in Japan don't use Phillips head screws, they use JIS head screws.

Screwdriver, JIS Type S Set, 5Pc Steel

jersey_m · 02-01-2011, 04:33 PM

Thanks for your responses. I am a bit apprehensive about disassembling the lens. Here are some photos taken with it. It seems the marks are not showing up on the pictures to my untrained eye. Any of the experts think otherwise?

Outside picture

Indoors

Thanks

**Ex Finn.** · 02-01-2011, 07:12 PM

Don`t take it apart yet, shoot some more in bright sunlight and see how that turns out.
Your previous images look OK to me.

KxBlaze · 02-01-2011, 08:16 PM

I have removed a front element before without incident but it was on a lens worth $15. I might be a bit more cautious with that 1.4. But keep in mind that removing any element can have dire consequences because the glass is set in a VERY precise manner and if any of them are off by a hair your focus will be out of whack. Good Luck.

**GregK8** · 02-01-2011, 08:29 PM

BTW, were these marks disclosed to you when you bought the lens? I hope it was discounted appropriately given the damage.

jersey_m · 02-01-2011, 08:33 PM

Thats why I am very apprehensive about performing any lens surgery. If the marks (which according to someone I showed (not a camera pro) thought was the coating coming off ??) are not detrimental to the image quality I would want to keep the lens and not worry too much.

Unfortunately we don't have sun in the forecast in New Jersey for another day or two, so I am unable to take pictures in bright sunlight

Thanks

**boriscleto** · 02-01-2011, 08:42 PM

Originally posted by KxBlaze

I have removed a front element before without incident but it was on a lens worth $15. I might be a bit more cautious with that 1.4. But keep in mind that removing any element can have dire consequences because the glass is set in a VERY precise manner and if any of them are off by a hair your focus will be out of whack. Good Luck.

I have disassembled a Super Tak 50/1.4 (ver. 2) including all the elements and reassembled without any change in focus. The Super Tak 50/1.4 (ver.1) is not a easy to disassemble. The elements are glued together. I have also opened a M 50/1.7, but I did not disassemble it. The M is built quite a bit differently than the Tak.

---------- Post added 02-01-11 at 10:44 PM ----------

Originally posted by jersey_m

f the marks (which according to someone I showed (not a camera pro) thought was the coating coming off ??) are not detrimental to the image quality I would want to keep the lens and not worry too much.

There are two things that it could be. One would be the elements separating and the other would be oil on the element.

jersey_m · 02-01-2011, 09:48 PM

Elements separating or oil - both are irreversible right? Without expensive repairs?

BTW i looked at the lens from the back directly at a 100W lamp. I could see the marks from from the rear they appear transparent (although I can make out the boundaries of the marks) They do not appear brown as they do from the front though and are quite faint (I have to look at the 100W bulb from the rear)

JeffJS · 02-01-2011, 10:38 PM

Separating elements would usually manifest itself at the edges first. Oil is cleanable. +1 on Boriscleto's suggestion on the lens rings. Cheap to purchase and once you get past the first lens, they'll save you a fortune.

I take lenses apart all the time to clean them of internal dust (but would never leave one like that). It, from your photos, looks like somebody scrubbed at it with some sort of pen. Perhaps a hard object wrapped with a lens tissue or something like that. It doesn't look like a 'natural' occurring anomaly.

01-31-2011, 08:41 PM	#1
jersey_m New Member Join Date: Jan 2011 Location: New Jersey Posts: 22	Help With lens marks Staff note: This post may contain affiliate links, which means Pentax Forums may earn a small commission if a visitor clicks through and makes a purchase. If you would like to support the forum directly, you may also make a donation here. Just bought a lens and it came with these strange brownish smear marks. It appears the marks are inside the front element and not the exposed part The lens is a SMC Pentax-M 1:1.4 50mm Is this something I should be worried about. Thanks for your help in advance - RTH Last edited by jersey_m; 01-31-2011 at 10:12 PM. Reason: Added more photos

02-01-2011, 04:33 PM	#8
jersey_m New Member Join Date: Jan 2011 Location: New Jersey Posts: 22 Original Poster	Thanks for your responses. I am a bit apprehensive about disassembling the lens. Here are some photos taken with it. It seems the marks are not showing up on the pictures to my untrained eye. Any of the experts think otherwise? Outside picture Indoors Indoors Thanks

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Help with marks on film.	Swift1	Film SLRs and Compact Film Cameras	13	10-05-2010 12:02 PM
Pentax K-x, marks on certain photos	Swevener	Pentax DSLR Discussion	4	09-14-2010 08:26 AM
Red Scratch marks?	BlueEyes	Troubleshooting and Beginner Help	3	11-29-2009 06:33 PM
tasty lens marks a milestone	timbo13	General Talk	15	04-14-2009 04:32 PM

01-31-2011, 10:24 PM	#2
KxBlaze Veteran Member Join Date: Feb 2010 Location: California Photos: Gallery Posts: 1,602	I have no idea what those marks are (looks like some kind of a chemical burn maybe), so I would say only worry if they are noticeable on your photos. If you cannot notice them in photos then they are nothing but annoying. **Maybe you can ask a professional camera repair/cleaner to see if they know what caused that.

01-31-2011, 10:57 PM	#3
GregK8 Site Supporter Join Date: May 2008 Location: Western New York Photos: Gallery \| Albums Posts: 614	It shouldn't be very hard to take that front element off to see if it can be cleaned. Something like the rubber tip from a crutch can be used to turn the ring that holds the front element in place.

02-01-2011, 05:29 AM	#4
jersey_m New Member Join Date: Jan 2011 Location: New Jersey Posts: 22 Original Poster	Thanks for your responses. Is removing the front element something, an inexperienced person can easily accomplish?

02-01-2011, 05:56 AM	#5
gp1806 Veteran Member Join Date: Mar 2009 Location: Chicago suburbs Photos: Albums Posts: 848	You might need something like this. Spanner Wrench(1/32") Great Tool for Lens - eBay (item 360335584435 end time Feb-10-11 21:49:13 PST)

02-01-2011, 05:57 AM	#6
GregK8 Site Supporter Join Date: May 2008 Location: Western New York Photos: Gallery \| Albums Posts: 614	If the marks are showing on the images, you really have nothing to lose, and it will be a great learning experience. If you cannot see the marks in your shots, just leave it alone, unless you are feeling a little daring. If you look closely, just inside the rim of the lens you will see some threads. The ring with all the white lettering is actually a huge screw with a hole in the middle. If you unscrew that, the front element should come right out. There is a special tool that fits into two notches on opposite sides of the ring. I forget what they call it. If you cannot get one, something that can apply friction to the ring, like the rubber tip of a crutch will work. Just press down and turn counter-clockwise.

02-01-2011, 06:09 AM	#7
boriscleto Loyal Site Supporter Join Date: Dec 2009 Location: North Syracuse, NY Photos: Gallery Posts: 16,475	Spanner wrenches are only necessary if the filter ring is damaged. All you need to open a Pentax lens is a lens ring. Lens Ring Tool Set Also keep in mind that lenses made in Japan don't use Phillips head screws, they use JIS head screws. Screwdriver, JIS Type S Set, 5Pc Steel

02-01-2011, 07:12 PM	#9
Ex Finn. Site Supporter Join Date: Nov 2007 Location: Southern Maryland. Espoo. Kouvola. Photos: Gallery \| Albums Posts: 7,975	Don`t take it apart yet, shoot some more in bright sunlight and see how that turns out. Your previous images look OK to me.

02-01-2011, 08:16 PM	#10
KxBlaze Veteran Member Join Date: Feb 2010 Location: California Photos: Gallery Posts: 1,602	I have removed a front element before without incident but it was on a lens worth $15. I might be a bit more cautious with that 1.4. But keep in mind that removing any element can have dire consequences because the glass is set in a VERY precise manner and if any of them are off by a hair your focus will be out of whack. Good Luck.

02-01-2011, 08:29 PM	#11
GregK8 Site Supporter Join Date: May 2008 Location: Western New York Photos: Gallery \| Albums Posts: 614	BTW, were these marks disclosed to you when you bought the lens? I hope it was discounted appropriately given the damage.

02-01-2011, 08:33 PM	#12
jersey_m New Member Join Date: Jan 2011 Location: New Jersey Posts: 22 Original Poster	Thats why I am very apprehensive about performing any lens surgery. If the marks (which according to someone I showed (not a camera pro) thought was the coating coming off ??) are not detrimental to the image quality I would want to keep the lens and not worry too much. Unfortunately we don't have sun in the forecast in New Jersey for another day or two, so I am unable to take pictures in bright sunlight Thanks

02-01-2011, 08:42 PM	#13
boriscleto Loyal Site Supporter Join Date: Dec 2009 Location: North Syracuse, NY Photos: Gallery Posts: 16,475	Originally posted by KxBlaze I have removed a front element before without incident but it was on a lens worth $15. I might be a bit more cautious with that 1.4. But keep in mind that removing any element can have dire consequences because the glass is set in a VERY precise manner and if any of them are off by a hair your focus will be out of whack. Good Luck. I have disassembled a Super Tak 50/1.4 (ver. 2) including all the elements and reassembled without any change in focus. The Super Tak 50/1.4 (ver.1) is not a easy to disassemble. The elements are glued together. I have also opened a M 50/1.7, but I did not disassemble it. The M is built quite a bit differently than the Tak. ---------- Post added 02-01-11 at 10:44 PM ---------- Originally posted by jersey_m f the marks (which according to someone I showed (not a camera pro) thought was the coating coming off ??) are not detrimental to the image quality I would want to keep the lens and not worry too much. There are two things that it could be. One would be the elements separating and the other would be oil on the element.

02-01-2011, 09:48 PM	#14
jersey_m New Member Join Date: Jan 2011 Location: New Jersey Posts: 22 Original Poster	Elements separating or oil - both are irreversible right? Without expensive repairs? BTW i looked at the lens from the back directly at a 100W lamp. I could see the marks from from the rear they appear transparent (although I can make out the boundaries of the marks) They do not appear brown as they do from the front though and are quite faint (I have to look at the 100W bulb from the rear)

02-01-2011, 10:38 PM	#15
JeffJS Inactive Account Join Date: Aug 2008 Location: Michigan, USA Photos: Gallery \| Albums Posts: 7,484	Separating elements would usually manifest itself at the edges first. Oil is cleanable. +1 on Boriscleto's suggestion on the lens rings. Cheap to purchase and once you get past the first lens, they'll save you a fortune. I take lenses apart all the time to clean them of internal dust (but would never leave one like that). It, from your photos, looks like somebody scrubbed at it with some sort of pen. Perhaps a hard object wrapped with a lens tissue or something like that. It doesn't look like a 'natural' occurring anomaly.