Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
10-02-2018, 11:40 PM   #16
Pentaxian
hcarvalhoalves's Avatar

Join Date: Aug 2010
Location: São Paulo, Brazil
Photos: Gallery
Posts: 1,016
Thank you for the tips. I’m in Brazil so wasn’t sure how “Canadian balsam” was marketed here, found the resin using the name of the actual pine tree species though. Apparently it has many uses, just need to make sure to get of the pure/clear type.

01-16-2019, 06:26 PM   #17
Veteran Member




Join Date: Feb 2009
Photos: Albums
Posts: 621
QuoteOriginally posted by MysteryOnion Quote
I hope the coating was not eaten away... that looks very bad.

Its been a long time since I opened my M50/1.4, but the last group should be in a holder that is threaded into the aperture assembly... outer ring hook spanner and sleeve?

You considered boiling the group apart?
Starting with a cold pan and acclimate the group to the water then slowly raise the temp. The groups should sit on a cloth or thick towel to no overheat. The glue may soften at 184 degrees, but you should have a pair of tongs that can grip the elements and exert some torque. Do not lift out of the hot water during this heating process or the temperature difference could shatter the elements. Patience is needed, this may not work the first time and require multiple sessions to get the glue to fail.
use paint remover

---------- Post added 01-17-2019 at 06:57 AM ----------

QuoteOriginally posted by hcarvalhoalves Quote
Thank you for the tips. I’m in Brazil so wasn’t sure how “Canadian balsam” was marketed here, found the resin using the name of the actual pine tree species though. Apparently it has many uses, just need to make sure to get of the pure/clear type.
tryusing without cementing it works, it centers as much as the other elements
01-17-2019, 07:41 PM   #18
New Member




Join Date: Jul 2017
Location: Penang
Posts: 14
Original Poster
QuoteOriginally posted by uttam.hathi Quote
use paint remover

---------- Post added 01-17-2019 at 06:57 AM ----------


tryusing without cementing it works, it centers as much as the other elements
yes, i'm using it now without any cementing, just that wide open at f1.4 a lot of flair, f2.8 to f5.6 is the sweet spots
04-19-2022, 12:42 PM   #19
Pentaxian




Join Date: Feb 2014
Photos: Gallery | Albums
Posts: 405
QuoteOriginally posted by hotfoo36 Quote
yes, i'm using it now without any cementing, just that wide open at f1.4 a lot of flair, f2.8 to f5.6 is the sweet spots
I know that the thread is old, but the problem still exists in some lenses, and solutions still need to be looked at. Literally...
I suggest using Edmund Optical Norland 61 UV-cured adhesive to re-cement elements, and if this needs removing, Dichloromethane, which can be obtained pure, but is also the main constituent of some paint strippers. Just pop the elements to be separated in a dish not affected by the solvent-glass will do, and leave until the elements separate. This can take up to 24 hours since the solvent has to reach the thin layer of 'cement'. If you buy the pure chemical, ensure the bottle is tightly closed because the chemical is VERY volatile! For curing the adhesive, a cheaply available UV emitting nail varnish hardening light works well, and often runs off a usb port.

04-27-2022, 11:52 PM   #20
New Member




Join Date: Jul 2017
Location: Penang
Posts: 14
Original Poster
QuoteOriginally posted by martin42mm Quote
I know that the thread is old, but the problem still exists in some lenses, and solutions still need to be looked at. Literally...
I suggest using Edmund Optical Norland 61 UV-cured adhesive to re-cement elements, and if this needs removing, Dichloromethane, which can be obtained pure, but is also the main constituent of some paint strippers. Just pop the elements to be separated in a dish not affected by the solvent-glass will do, and leave until the elements separate. This can take up to 24 hours since the solvent has to reach the thin layer of 'cement'. If you buy the pure chemical, ensure the bottle is tightly closed because the chemical is VERY volatile! For curing the adhesive, a cheaply available UV emitting nail varnish hardening light works well, and often runs off a usb port.
thanks for the guidance. I'm too lazy to do now, lol
07-02-2022, 01:04 PM   #21
New Member




Join Date: Dec 2019
Posts: 1
QuoteOriginally posted by hotfoo36 Quote
Some in progress photos for the lens disassembly:
Code:
Code:
Code:
Code:
Hello hotfoo36! Can you share how you separated the cemented lenses? My Pentax-m 50 1.4 requires the same and I hope to fix it.
07-03-2022, 07:56 PM   #22
New Member




Join Date: Jul 2017
Location: Penang
Posts: 14
Original Poster
QuoteOriginally posted by abubela Quote
Hello hotfoo36! Can you share how you separated the cemented lenses? My Pentax-m 50 1.4 requires the same and I hope to fix it.
Hello abubela,

It has been a few years when I did this and I can't remember correctly how I separate the cemented lenses. If my memory serve me well, I use a hot air blower to separate them, not using the boiling water method.

09-04-2022, 03:50 AM   #23
New Member




Join Date: Sep 2022
Posts: 1
smc pentax m 50mm f1.4

good day sir could tell me how do you clean the middle element of smc pentax m 50mm f1.4 i am confused how toclean this lens what materials do you used i saw your post last time
01-27-2024, 07:03 PM   #24
New Member




Join Date: Jan 2024
Posts: 3
1) I have reticulation or mycelial webbing between the fused elements in an asahi pentax K 50mm 1.4 k mount
2) any tips or reference by model/year for guessing whether the cement is balsam or synthetic?
3) I might just steam and squeeze the central elements of the 50mm too see if maybe it can sort of smooth-out or minimize the funk in between the elements — assuming it's balsam...
4) But i don't have access to a vented space where i could really soak them in solvent if it's not balsam, and the 50mm is currently my main lens. the only way i can afford lenses rn is to bid on fungus & broken ones and overpay and then try to restore them myself, so i have to make this work or i can't shoot
01-28-2024, 07:31 AM   #25
Pentaxian
hcarvalhoalves's Avatar

Join Date: Aug 2010
Location: São Paulo, Brazil
Photos: Gallery
Posts: 1,016
QuoteOriginally posted by lensfungus Quote
1) I have reticulation or mycelial webbing between the fused elements in an asahi pentax K 50mm 1.4 k mount
2) any tips or reference by model/year for guessing whether the cement is balsam or synthetic?
3) I might just steam and squeeze the central elements of the 50mm too see if maybe it can sort of smooth-out or minimize the funk in between the elements — assuming it's balsam...
4) But i don't have access to a vented space where i could really soak them in solvent if it's not balsam, and the 50mm is currently my main lens. the only way i can afford lenses rn is to bid on fungus & broken ones and overpay and then try to restore them myself, so i have to make this work or i can't shoot
1) can you post a picture? It probably isn’t fungus, when the balsam separates it creates patterns also.

2) I believe all these lenses prone to separation used the vintage balsam, the newer UV cured resins are really strong and hard to separate even if you try

3) if the balsam is dried up (got in contact with air) it gets brittle and I’m not sure just heating it will make it viscous again

4) i’ve managed to separate elements by boiling it, and managed to recement with synthetic balsam (not UV-cured, the one used on microscopes)
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
50mm, 50mm f1.4 lens, aperture, asahi pentax-m 50mm, balsam, balsam separation, center, cure, elements, f1.4 lens haze, fungus, glue, haze with balsam, k-mount, lens, pentax lens, pentax-m, pentax-m 50mm f1.4, press, slr lens, thanks, time, uv, water
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
M-1.7 balsam separaion. SalPro Pentax SLR Lens Discussion 11 02-15-2021 10:47 AM
When you have a balsam/cloud/fungus lens............ Kenneth3aracing Repairs and Warranty Service 4 11-29-2016 12:26 PM
Light haze - is the bargain second hand lens with haze worth it? awscreo Pentax SLR Lens Discussion 4 11-05-2016 12:56 PM
Suspected aperture lever misalignment on A-lens - easy fix? Ikarus Pentax SLR Lens Discussion 3 03-16-2014 04:15 PM



All times are GMT -7. The time now is 02:36 AM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top