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a20010494
Joined: 15 Feb 2010 Posts: 396 Location: Perú.
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Posted: Wed Apr 07, 2010 8:46 am Post subject: Which canadian balsam? |
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a20010494 wrote:
I see there're many on ebay, but which ones are the good/bad ones?
Or, i can buy an used bottle (or fraction) from any of you, as i only need a small little . _________________ www.estudiocaleidoscopio.com |
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unclemack
Joined: 21 Jun 2009 Posts: 51 Location: UK frozen north
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Posted: Wed Apr 07, 2010 9:59 am Post subject: |
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unclemack wrote:
I've found Canada balsam to be less reliable than the modern ultraviolet-setting alternative.
Balsam varies in quality and grade because of its organic nature.
A search of the forums for "separation" or "balsam fault" will give results of others' experience. |
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a20010494
Joined: 15 Feb 2010 Posts: 396 Location: Perú.
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Posted: Wed Apr 07, 2010 4:54 pm Post subject: |
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a20010494 wrote:
and where can i get that?
-Also, i see they are used to "repair" glass? Is that true? anyone has experience with it? _________________ www.estudiocaleidoscopio.com |
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Sevo
Joined: 22 Aug 2008 Posts: 1189 Location: Frankfurt, Germany
Expire: 2012-12-03
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Posted: Wed Apr 07, 2010 8:18 pm Post subject: |
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Sevo wrote:
Liquid Canada Balm is the wrong kind - you need the solid rosin to cement lenses with. I've sometimes seen it at astronomy online stores, while the liquid stuff typically is sold by microscopy suppliers (where it is used as a neutral immersion liquid).
I'd strongly recommend optical UV curing cements - that stuff is already hard enough to handle for a beginner, no need to get any more complex. But I have no idea where you could get hold of it in Peru - hereabouts it takes some talking skills to get a vendor to split with "samples", minimum industrial quantities being beyond the amount even a large scale camera repair workshop could use up in time before expiration. _________________ Sevo |
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unclemack
Joined: 21 Jun 2009 Posts: 51 Location: UK frozen north
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Posted: Wed Apr 07, 2010 9:04 pm Post subject: |
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unclemack wrote:
I'm in the United Kingdom.
The one I use is made by Loctite and is called Glass Bond.
I have no idea what may be available in Peru.
Listed at less than £5 on ebay UK.
Someone who repairs cars may have some, or someone who makes fish tanks. |
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Sevo
Joined: 22 Aug 2008 Posts: 1189 Location: Frankfurt, Germany
Expire: 2012-12-03
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Posted: Wed Apr 07, 2010 11:39 pm Post subject: |
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Sevo wrote:
unclemack wrote: |
I'm in the United Kingdom.
The one I use is made by Loctite and is called Glass Bond.
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That should be available pretty much anywhere, but it is not even up to the standards set by the glues car glass repair shops use, and lens glues are a grade or two above that (and come in a variety of defined refractive indices). _________________ Sevo |
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unclemack
Joined: 21 Jun 2009 Posts: 51 Location: UK frozen north
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Posted: Thu Apr 08, 2010 12:23 am Post subject: |
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unclemack wrote:
Hi Sevo.
I expect you would agree, though, that it's a better solution than Canada balsam and also a better solution than something that is completely unobtainable?
How would one decide on the appropriate refractive index to choose given access to a selection?
Any of these available in small quantities? |
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a20010494
Joined: 15 Feb 2010 Posts: 396 Location: Perú.
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Posted: Thu Apr 08, 2010 12:31 am Post subject: |
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a20010494 wrote:
I'm sorry, but im more lost than the beginning.
What should i do now- _________________ www.estudiocaleidoscopio.com |
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visualopsins
Joined: 05 Mar 2009 Posts: 10526 Location: California
Expire: 2025-04-11
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Posted: Thu Apr 08, 2010 3:15 am Post subject: |
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visualopsins wrote:
UV Curing Optical Cements and Photopolymers
"Canadian Balsam" (CB) is Spruce tree sap purified by slow heating and skimming, and sometimes by adding & evaporating solvents & filtering. CB has a known refractive index. Other tree saps have been used for lens cement. In Perú Copal resin could be similarly purified & used; the refractive index is likely similar to CB.
In any country try finding CB in the oldest camera shops, preferably one with old large format cameras; some may have pieces of CB. _________________ ☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮ 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)
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Scheimpflug
Joined: 06 Feb 2010 Posts: 1888 Location: New Zealand / USA
Expire: 2011-11-18
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Posted: Thu Apr 08, 2010 5:35 am Post subject: |
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Scheimpflug wrote:
Sevo wrote: |
unclemack wrote: |
The one I use is made by Loctite and is called Glass Bond. |
That should be available pretty much anywhere, but it is not even up to the standards set by the glues car glass repair shops use, and lens glues are a grade or two above that (and come in a variety of defined refractive indices). |
There's an interesting bit of history here... Cyanoacrylate adhesives, such as what siriusdogstar linked to, were actually invented & developed by Kodak in the 1940s. Through the 60s and into the early 70s, Loctite was a major distributor of Kodak-produced cyanoacrylate adhesives, all the way up until they figured out how to manufacture it themselves.
I'm certainly not saying that modern Loctite is optics-grade, but the optics history surrounding it is still interesting. _________________ Sigma DP1, Nikon D40 (hers ), Polaroid x530, Pentax P30t, Pentax P50, (P30t/P50 K-A to Nikon F body mount conversion)
Nikon: 18-55/3.5-5.6 "G ED II DX" (F) Soligor: 28/2.8 (FL->F converted), 135/3.5 (F), 3x TC (F, modified) Kalimar: 28-85/3.5 (F)
Vivitar: 70-210/2.8-4.0 Version 3 (F), Tele 500/6.3 Preset (F), 19/3.8 (F) Minolta: 300/5.6 (SR/MC/MD pending F conversion)
Tamron: 28/2.8 (Adaptall) Panagor: 28/2.5 (FD) Aetna: 300/5.6 (F) Osawa: MC 28/2.8 (F)
Vintage Lenses: Dallmeyer: 1940s A.M. 14in 356mm f4 (ULF->M42) 1930s Adon Telephoto Taylor, Taylor & Hobson: 1880s Rapid Rectilinear 8 1/2 x 6 1/2 11.31in f/8 (LF->?)
Parts Lenses: Nikon 35-135/3.5-4.5 (F), Sigma 70-210/4.5 (F), Nikon 50/1.8 Series E (F) |
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a20010494
Joined: 15 Feb 2010 Posts: 396 Location: Perú.
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Posted: Thu Apr 08, 2010 5:52 am Post subject: |
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a20010494 wrote:
er... what should i buy then... _________________ www.estudiocaleidoscopio.com |
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unclemack
Joined: 21 Jun 2009 Posts: 51 Location: UK frozen north
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Posted: Thu Apr 08, 2010 8:20 am Post subject: |
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unclemack wrote:
Hi, since you asked for answers from over 2000 possible contributors you shouldn't be too surprised to find that opinions differ.
Canada balsam works, so do the newer products.
Neither is exactly easy to use but they're difficult in different ways. Some people say they've had success with shortcuts like reheating the balsam couplet - there's plenty of information available but you have to search for it. |
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Photomac
Joined: 11 Jan 2008 Posts: 47 Location: Sutton Benger, UK
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Posted: Thu Apr 08, 2010 5:51 pm Post subject: Lens cement |
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Photomac wrote:
I suggest you try Norland Optical Adhesive, NOA 61, UV-curing, and available in small bottles from Edmunds Optical - a division of Edmunds Scientific - mail order for about US$25.
Regards
Angus |
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