visualopsins
Joined: 05 Mar 2009
Posts: 10530
Location: California
Expire: 2025-04-11
|
 Posted: Fri Mar 26, 2010 1:09 am Post subject: |
 |
|
visualopsins wrote:
Watching this topic for replies...
Moire patterns show imperfectly mated surfaces. Cement acts as filler, to prevent/eliminate moire; maybe too much clamping pressure was applied, squeezing out too much cement leaving moire air gap.
Early cement is Canadian Balsam tree sap, melts at low temperature below water boil point, hard at ambient temperatures. Caution: heat lens glass very very slowly & evenly to avoid fracture.
Realignment is difficult without expensive tools; both axial & rotational alignment. I guess many of these were hand assembled originally, however, on an alignment jig.
_________________
☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮ like attracts like! ☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮
Cameras: Sony ILCE-7RM2, Spotmatics II, F, and ESII, Nikon P4
Lenses:
M42 Asahi Optical Co., Takumar 1:4 f=35mm, 1:2 f=58mm (Sonnar), 1:2.4 f=58mm (Heliar), 1:2.2 f=55mm (Gaussian), 1:2.8 f=105mm (Model I), 1:2.8/105 (Model II), 1:5.6/200, Tele-Takumar 1:5.6/200, 1:6.3/300, Macro-Takumar 1:4/50, Auto-Takumar 1:2.3 f=35, 1:1.8 f=55mm, 1:2.2 f=55mm, Super-TAKUMAR 1:3.5/28 (fat), 1:2/35 (Fat), 1:1.4/50 (8-element), Super-Multi-Coated Fisheye-TAKUMAR 1:4/17, Super-Multi-Coated TAKUMAR 1:4.5/20, 1:3.5/24, 1:3.5/28, 1:2/35, 1:3.5/35, 1:1.8/85, 1:1.9/85 1:2.8/105, 1:3.5/135, 1:2.5/135 (II), 1:4/150, 1:4/200, 1:4/300, 1:4.5/500, Super-Multi-Coated Macro-TAKUMAR 1:4/50, 1:4/100, Super-Multi-Coated Bellows-TAKUMAR 1:4/100, SMC TAKUMAR 1:1.4/50, 1:1.8/55
M42 Carl Zeiss Jena Flektogon 2.4/35
Contax Carl Zeiss Vario-Sonnar T* 28-70mm F3.5-4.5
Pentax K-mount SMC PENTAX ZOOM 1:3.5 35~105mm, SMC PENTAX ZOOM 1:4 45~125mm
Nikon Micro-NIKKOR-P-C Auto 1:3.5 f=55mm, NIKKOR-P Auto 105mm f/2.5 Pre-AI (Sonnar), Micro-NIKKOR 105mm 1:4 AI, NIKKOR AI-S 35-135mm f/3,5-4,5
Tamron SP 17mm f/3.5 (51B), Tamron SP 17mm f/3.5 (51BB), SP 500mm f/8 (55BB), SP 70-210mm f/3.5 (19AH)
Vivitar 100mm 1:2.8 MC 1:1 Macro Telephoto (Kiron)
|
|
Photomac
Joined: 11 Jan 2008
Posts: 47
Location: Sutton Benger, UK
|
| Posted: Sat Mar 27, 2010 8:02 pm Post subject: fixing cemented lenses |
|
|
Photomac wrote:
Hi there,
Split elements with methylene chloride (paint stripper, caustic) or Methyl Ethyl Ketone (MEK, toxic).
Clean with acetone.
Re-cement with Norland Optical Adhesive NOA61 - UV-curing (10 minutes on a window ledge in British summer sunshine!).
If elements are same diameter, use a small engineer's V-block to hold alignment.
Have fun!
Regards
Angus |
|
Search
Memberlist
Register
Profile
Log in to check your private messages
Log in
