Approve the Cookies
This website uses cookies to improve your user experience. By using this site, you agree to our use of cookies and our Privacy Policy.
OK
Index  •   • New posts  •   • RTAT  •   • 'Best of'  •   • Gallery  •   • Gear  •   • Reviews
Guest
New posts  •   • RTAT  •   • 'Best of'  •   • Gallery  •   • Gear  •   • Reviews
Register to forums    Log in

 
FORUMS Canon Cameras, Lenses & Accessories Canon EF and EF-S Lenses 
Thread started 03 Aug 2012 (Friday) 18:29
Search threadPrev/next
sponsored links
(this ad will go away when you log in as a registered member)

Yet another Is This Fungus thread: 28-70mm f/2.8L

 
hk300
Senior Member
253 posts
Likes: 2
Joined Dec 2007
     
Jun 22, 2013 10:26 |  #16

The 28-70 has a lens element (consisting of 2 parts glued together) which easily oxidated. I guess for this reason this lens element part was quickly used up and is no longer available.




  
  LOG IN TO REPLY
sponsored links
(this ad will go away when you log in as a registered member)
xraqs
Hatchling
1 post
Joined Nov 2013
     
Nov 28, 2013 18:37 |  #17

discojuggernaut wrote in post #14811047 (external link)
Please click here for full size image (external link)

[URL="[URL]https://dl.​dropbox.com/u/2002065/​28-70mm.JPG"]Here's the lens in question[/URL}

I got this as a real cheap craigslist deal but didn't have a flashlight with me nor did i do the due diligence that i should have with a high-ticket as-is item. AF and aperture work fine on it, but there is a yellowish haze cast on images at all apertures and FL, and is clearly visible through the viewfinder. I included some shots at 70mm with other 70mm shots from a different lens.

Is it condensation, oil, broken down lens cement, fungus? Looks like little yellow inorganic spots in my layman's eyes.

I really want to get this fixed, would a cleaning suffice, or would it be impossible if it's between elements?

It shows up in the rear end (the mounting end) of the lens. Otherwise the lens is pristine.

Thanks in advance

Would you buy it? need to repair mine and part i need is not on the market anymore. Please email me at raqs_26@hotmail.com




  
  LOG IN TO REPLY
NemethR
Senior Member
Avatar
874 posts
Gallery: 1 photo
Likes: 266
Joined Jun 2012
Location: Pécs, Hungary
     
Nov 29, 2013 07:17 |  #18

I have a 28-70 2.8, wit the same issue.
Sorry to say that bro, but it cannot be repaired,there are no more spare parts anymore :(

Its a known issue with the 28-70 f2.8, the coating of the element is oxidated, and sadly all spare parts have been used up, Canon does not make them anymore, so no chance to repaired. :(

Maybe if you can get another deect copy, that is optically good, you can extract that lens element, and let it be fixed.


Roland | Amateur Photographer
Nikon D850 | Nikon D80 | Nikon 70-200 f/2.8G ED VR II | Nikon 24-70 f/2.8G ED

  
  LOG IN TO REPLY
discojuggernaut
THREAD ­ STARTER
Junior Member
21 posts
Joined Aug 2012
     
Dec 09, 2013 15:43 |  #19

Just an update, i had it repaired by a 3rd-party repair shop that happened to have that cemented doublet in stock. Lens has been working great for over a year and a half. Will eventually sell to fund the 24-70 mkII, but the 28-70 has been a great workhorse.


My Smugmug (external link)

  
  LOG IN TO REPLY
Camarinho
Hatchling
Avatar
6 posts
Joined Mar 2014
     
Mar 25, 2014 08:29 |  #20

Hello
I've bought a 28-70 L, with a very similar problem. The solution is rather complicated bu I managed to Fix the lens up to... I'd say 85%. I tryed asking Canon for a replacement part... the part number is: CYI-2532, but is no longer available.
So I desassembled the lens, to the most inner elements doublets and separeted them with acetone... It took me 2 weeks in acetone, because the glue is almost 20 years old. And replaced the glue with a resin used in Histology for microscopic slides. And now the lens Is crystal clear... but I think at 2.8 it is way too soft. I'll soon disassemble it again... remove the DPX resin and replace it with a UV curing special glue for optical lenses.

Hope this helps




  
  LOG IN TO REPLY
ZoneV
Goldmember
1,644 posts
Gallery: 5 photos
Best ofs: 1
Likes: 238
Joined Dec 2010
Location: Germany
     
Mar 25, 2014 10:37 |  #21

Camarinho wrote in post #16784652 (external link)
... I'll soon disassemble it again... remove the DPX resin and replace it with a UV curing special glue for optical lenses...

Probably my way of lens bonding could help: I use cheap cheap UHU glass glue instead of optical UV curing glue or Canada Balm (external link).


DIY-Homepage (external link) - Image Gallery (external link) - Gear List

  
  LOG IN TO REPLY
Camarinho
Hatchling
Avatar
6 posts
Joined Mar 2014
     
Mar 25, 2014 11:59 |  #22

ZoneV wrote in post #16784911 (external link)
Probably my way of lens bonding could help: I use cheap cheap UHU glass glue instead of optical UV curing glue or Canada Balm (external link).

IMAGE: http://s25.postimg.org/4u5zl10v3/IMG_1018_f2_8_Normal.jpg

IMAGE: http://s25.postimg.org/3vpmiqnj3/IMG_1018_f2_8_Crop.jpg

IMAGE: http://s25.postimg.org/s24v7lz1b/IMG_1020_f8_crop.jpg


The first shot is wide open, the second is Crop. The thir is a crop of the same picture taken at f/8.
Since this my first repair of L glass... do you think that this fits the standards? Any other advice when applying the glue?
Thanks for the advice



  
  LOG IN TO REPLY
ZoneV
Goldmember
1,644 posts
Gallery: 5 photos
Best ofs: 1
Likes: 238
Joined Dec 2010
Location: Germany
     
Mar 26, 2014 10:25 |  #23

Camarinho wrote in post #16785109 (external link)
...Since this my first repair of L glass... do you think that this fits the standards? Any other advice when applying the glue?
Thanks for the advice

Don´t know how this lens should be, but I would not be statisfied with it with this images wideopen.
I apply too much glue, and press / move the lenses to get air outside. And to get lenses as much as possible together. Glue should not be a millimeter thick :-)
both lenses need to be very, very exact in right position one to another!


DIY-Homepage (external link) - Image Gallery (external link) - Gear List

  
  LOG IN TO REPLY
Guto
Member
43 posts
Gallery: 1 photo
Likes: 9
Joined Sep 2008
     
Mar 26, 2014 12:04 |  #24

hk300 wrote in post #16054590 (external link)
The 28-70 has a lens element (consisting of 2 parts glued together) which easily oxidated. I guess for this reason this lens element part was quickly used up and is no longer available.

Thats it. I had same problem.


2 X Fujifilm X-T3 | 16mm f/1.4 | 23mm f/1.4 | 35mm f/1.4 | 56mm f/1.2 |

  
  LOG IN TO REPLY
Camarinho
Hatchling
Avatar
6 posts
Joined Mar 2014
     
Mar 26, 2014 18:09 |  #25

ZoneV wrote in post #16787676 (external link)
Don´t know how this lens should be, but I would not be statisfied with it with this images wideopen.
I apply too much glue, and press / move the lenses to get air outside. And to get lenses as much as possible together. Glue should not be a millimeter thick :-)
both lenses need to be very, very exact in right position one to another!

Tomorrow i'll buy the UHU glass glue and follow your "protocol" for doublets cementing! ;)
I'll Post new pictures here as final result.

During this process I did take some pictures of the disassembly, lens separation and cleaning. So I might make a tutorial on how to fix this lenses, as canon stop servicing them and a lot of people has this issue!

:D




  
  LOG IN TO REPLY
ZoneV
Goldmember
1,644 posts
Gallery: 5 photos
Best ofs: 1
Likes: 238
Joined Dec 2010
Location: Germany
     
Mar 27, 2014 02:56 as a reply to  @ Camarinho's post |  #26

Take care for exact element alingment!
In industry special machines are used to optical center the lenses together - for example down to 2 microns tolerance.
Likely you dont get that exact, but try to work as exact as possible.


DIY-Homepage (external link) - Image Gallery (external link) - Gear List

  
  LOG IN TO REPLY
michelten
Hatchling
3 posts
Likes: 2
Joined Apr 2021
     
Apr 07, 2021 14:57 as a reply to  @ Camarinho's post |  #27

Hello Camarinho. I have exactly the same problem - see pic.
I cannot locate a replacement doublet lens.
Would you describe in your experience the best process/materials to separate the two elements of the doublet and then join them together. I am very attached to my lens and want to do everything possible to keep it, but cannot tolerate haze.
Many thanks


HOSTED PHOTO
please log in to view hosted photos in full size.




  
  LOG IN TO REPLY
devixluvic
Hatchling
3 posts
Joined Apr 2021
     
Apr 11, 2021 12:13 as a reply to  @ michelten's post |  #28

Sorry for bumping a dead thread, but seeing as it was already bumped I thought I'd chime in -

I recently picked up a 28-70 that had undisclosed haze. Kinda upset about that, but life goes on. I found this blog post: https://canonrepair.wo​rdpress.com …-problem-caused-by-aging/ (external link) that discusses in the comments a mixture of chemicals that may be able to get the doublet apart. If you have luck, please report back!

Alternatively, I found this blog http://lens-cla.blogspot.com …0mm-f28-l-lens-group.html (external link) of a guy in Taipei who seems to do lens re-cementing as his bread and butter. I've reached out to see if he'd be willing to work on my lens. Would much prefer someone with experience to do the job, since I am a bit iffy about fully disassembling a zoom... but if it comes down to it I'd be willing to give home recementing a go.




  
  LOG IN TO REPLY
iroctd
Senior Member
315 posts
Likes: 45
Joined Aug 2013
Location: East coast
     
Apr 11, 2021 14:05 as a reply to  @ devixluvic's post |  #29

I've disassembled two 28-70 f2.8 L lenses previously. There are at least 3 elements inside that can have issues. The aperture element has haze/separation. The others have what looks like 1,000s of tiny air bubbles. Two of those elements show up on ebay but the 3rd next to the aperture always goes bad and is very difficult to find.

Zooms aren't as easy to disassemble than primes. The extending zoom outer shell is a bit of a pain the way the screws go into 3 floating pieces. Then there is a inner element that wants to stay where you put it and ends up a bit tight being that it has adjustment collars for it.

The best piece of advice for disassembly is when you come across the shallow slotted screw head, get the nearest fitting screwdriver and then use a dremel tool to make it a exact fit for depth as well as width. If you slip on those, the screw metal falls apart fast and they are a pain!

I believe that is the same guy I found before. I was a bit hesitant sending him the amount of money he wanted. I didn't know him at all, had no guarantees. Oh and not to mention the shipping to china was costly. I basically waited months checking ebay everyday for that aperture element to show up. I did look up about fixing those doublets, if you boil them apart there is a high chance they can fracture. For reassembly, you need a jig to line them up and have to use a UV reactive glue. The hard part of it is getting that doublet out of the plastic it is in and then being able to still put it back.

It appears I still have 2 of the aperture doublets among other parts. The one in the large helicoid assembly is really bad. The one in the inner helicoid isn't too bad. If you want to try your luck fixing one before going into disassembly I can send you one, just cover shipping cost. There is a repair guy on facebook I used to fix/solder a compact flash assembly. You could find someone who would take your lens and the repaired element and swap it out. Just realize whether you do it or a repairman it is a complete disassembly.


HOSTED PHOTO
please log in to view hosted photos in full size.


HOSTED PHOTO
please log in to view hosted photos in full size.


-Feedback-

  
  LOG IN TO REPLY
devixluvic
Hatchling
3 posts
Joined Apr 2021
     
Apr 11, 2021 19:32 as a reply to  @ iroctd's post |  #30

Thanks for your tips on disassembly. I'm experienced with small electronics work (laptops, game consoles) but my only attempted lens repair was the sticky focus on my EF 50mm 1.4 USM - a common problem with well-documented steps for the repair. Something like this would be a lot more intense, but probably doable. My biggest concern would be putting everything back together such that all the elements are still aligned/centered properly.

Do you remember what the quote you got for the repairman in Taiwan was? I emailed a few days ago, haven't heard back yet... I have a friend from university who is from Taipei and I could likely ask a favor to have them bring my lens in-person when they go back, likely later this summer. If costs are too high i might just try my hand at repairing it myself though and accept whatever happens.

I'd be down to give the recementing of a spare aperture doublet a try first though - I can't send PMs yet since I registered for this site today, but I'd be able to reply if you sent one first. Thanks!




  
  LOG IN TO REPLY
sponsored links
(this ad will go away when you log in as a registered member)

15,509 views & 3 likes for this thread
Yet another Is This Fungus thread: 28-70mm f/2.8L
FORUMS Canon Cameras, Lenses & Accessories Canon EF and EF-S Lenses 
AAA
x 1600
y 1600

Jump to forum...   •  Rules   •  Index   •  New posts   •  RTAT   •  'Best of'   •  Gallery   •  Gear   •  Reviews   •  Member list   •  Polls   •  Image rules   •  Search   •  Password reset

Not a member yet?
Register to forums
Registered members may log in to forums and access all the features: full search, image upload, follow forums, own gear list and ratings, likes, more forums, private messaging, thread follow, notifications, own gallery, all settings, view hosted photos, own reviews, see more and do more... and all is free. Don't be a stranger - register now and start posting!


COOKIES DISCLAIMER: This website uses cookies to improve your user experience. By using this site, you agree to our use of cookies and to our privacy policy.
Privacy policy and cookie usage info.


POWERED BY AMASS forum software 2.1forum software
version 2.1 /
code and design
by Pekka Saarinen ©
for photography-on-the.net

Latest registered member is Toyokawa
1052 guests, 146 members online
Simultaneous users record so far is 15144, that happened on Nov 22, 2018

Photography-on-the.net Digital Photography Forums is the website for photographers and all who love great photos, camera and post processing techniques, gear talk, discussion and sharing. Professionals, hobbyists, newbies and those who don't even own a camera -- all are welcome regardless of skill, favourite brand, gear, gender or age. Registering and usage is free.