p.15 #3 · lens repair, modification and disassembly guide thread
thanks guys.
i've also made measurements to make rings for the g35 similar to those made for the g28 and g45. if anybody is interested in ordering some along with me let me know...
p.15 #4 · lens repair, modification and disassembly guide thread
sebboh wrote:
thanks guys.
i've also made measurements to make rings for the g35 similar to those made for the g28 and g45. if anybody is interested in ordering some along with me let me know...
Count me in on the G35 order, is it the same Rokkor donor lens?
Thanks for posting your G90 conversion, looks good.
p.15 #6 · lens repair, modification and disassembly guide thread
Hello, guys! kind of late into the party. Here is my Nikkor maintenance blog (richardhaw.com) where I share my notes. I am not a pro at this so only use my posts as supplements to help you get the job done. Some pros who have decades of experience have benefitted from my blog because they see how stuff has been put together and that saves them plenty of time, leaving all the guesswork to me. Anyway, here is the blog www.richardHaw.com. I update it around 2-3x a month. Cheers!
p.15 #7 · lens repair, modification and disassembly guide thread
richardHaw wrote:
Hello, guys! kind of late into the party. Here is my Nikkor maintenance blog (richardhaw.com) where I share my notes. I am not a pro at this so only use my posts as supplements to help you get the job done. Some pros who have decades of experience have benefitted from my blog because they see how stuff has been put together and that saves them plenty of time, leaving all the guesswork to me. Anyway, here is the blog www.richardHaw.com. I update it around 2-3x a month. Cheers!
Thanks for the link to your blog, looks like some very useful stuff there. I haven't needed to take a Nikon lens apart yet although I have been inside an old Schneider Tele Xenar.
p.15 #8 · lens repair, modification and disassembly guide thread
gyoung143 wrote:
Thanks for the link to your blog, looks like some very useful stuff there. I haven't needed to take a Nikon lens apart yet although I have been inside an old Schneider Tele Xenar.
Gerry
Cheers, Gerry! Glad that you liked it! Most of my readers just read it for the entertainment value of seeing somebody else get screwed and telling people not to do this or that and engineering geeks like me who just want to see how stuff works and look like when taken apart. Ric
p.15 #9 · lens repair, modification and disassembly guide thread
Thanks for posting the link to your repair posts, I've attempted Nikkor CLS's in the past, I always seem to get stopped by a stuck screw or not seeing a way forward, so this may help me immensely.
p.15 #10 · lens repair, modification and disassembly guide thread
LightShow wrote:
Thanks for posting the link to your repair posts, I've attempted Nikkor CLS's in the past, I always seem to get stopped by a stuck screw or not seeing a way forward, so this may help me immensely.
Thank you very much and I am glad that you liked it. To prevent situations like that, I always (almost) check the net first for schematics, other people's work or videos. It saves a lot of time sometimes but there are times when the schematics do not really tell anything. If you get stuck, you can request a teardown from me or you can show me a picture of where you are currently stuck. Regards, Ric.
p.15 #11 · lens repair, modification and disassembly guide thread
Has anyone taken apart the old Sigma 15mm f/3.5 EF mount lens? I've had one for about a year now that has severe yellowing/haze on it, so I don't use it. I got it as a package deal with a Canon 1N that was really why I bought them, so if I can't put it back together, I won't lose sleep over it. I just thought, why not try to fix it? I searched the thread but "Sigma 15" didn't yield anything. Derek's DIY site only had one article about a different (newer?) Sigma 15mm but it was in German and I had no idea what they were talking about, even after using Google Translate.
p.15 #12 · lens repair, modification and disassembly guide thread
Max_Pain wrote:
Has anyone taken apart the old Sigma 15mm f/3.5 EF mount lens? I've had one for about a year now that has severe yellowing/haze on it, so I don't use it. I got it as a package deal with a Canon 1N that was really why I bought them, so if I can't put it back together, I won't lose sleep over it. I just thought, why not try to fix it? I searched the thread but "Sigma 15" didn't yield anything. Derek's DIY site only had one article about a different (newer?) Sigma 15mm but it was in German and I had no idea what they were talking about, even after using Google Translate.
Hello, Max. you can try bleaching it by placing the lens under the hot morning to afternoon sun. be sure to wrap the lens with insulation (foil?) so that the glass gets all the sun. exposure to direct sunlight for prolonged periods will also bleach the rubber and plastic parts or paints as you can see in cameras that were left in the display cases on the street.
as you mentioned, since it is a throw-away lens then you can try doing this. this is what people do to mitigate the "sigma yellow" some years ago when you buy a sigma lens brand new. I was also told that this will also work with thorium glass yellowing. the people who tried this left their lenses under the sun for hours for a period of a few days until the stain is gone.
I tried this as well but for fungus-damaged lenses that I restored so i am just using sunlight to kill whatever was left if that actually does anything which i doubt.
p.15 #13 · lens repair, modification and disassembly guide thread
by the way, are you sure that the haze is not condensation of the lubricant? 80s sigma lenses sometimes do that. my first lens teardown was with an 80s super 24mm and it was condensation in the middle element.
i do not think that there is any harm sun bathing the lens, maybe evaporation and migration of the grease at worse. (which is bad.)
p.15 #14 · lens repair, modification and disassembly guide thread
I tried sunbathing for a few days with no noticeable change. So I'll give a try disassembling it to see what I can figure out. Luckily I have a perfect Rokinon 14mm f/2.8 and a Canon 16-35mm f/4L IS, so if this old Sigma 15mm f/3.5 gets messed up, I won't be too sad.
p.15 #17 · lens repair, modification and disassembly guide thread
Thread awaken!
I'm currently communicating with Hawk to try and get a satisfactory solution to converting a G21 Biogon using his expensive helicoid LM conversion kit. That is so far off achieving infinity focus it's untrue, and the kit has absolute minimal (no text) documentation, but that's another story.
Having read through all of the pages in recent days, I somehow escaped the comments that your G28 -> MC PF 55 Frankenzeiss conversion did not have helicoid focussing, until after I had ordered a donor 55 f1.7
Anyway, it's been informative and I am now excited to tackle the approach documented by KOJI.
KOJI wrote:
Guess it would help someone who are interested in some conversions without a NC machine.
My interest in conversion principally lies in using a G45 lens on a Leica M9, but also a Ricoh GXR. I've previously owned a G45, with helicoid conversion by Jieyang (he no longer offers that service).
Let me say how great it is to have both Sebboh and KOJI's conversions so fabulously documented; it makes all the difference in terms of confidence at tackling such a job.
I committed to buying a G45 today that has inoperable AF, MF and shutter, at least that's what the advert implied. With the experience gained so far with the G21 conversion process, I predict that any MF and shutter issues will be readily circumvented during either of this thread's conversion processes, and it was really cheap!
I've also bought the M42 lens --> M39 helicoid adapter, 42-52 and 39-49 step-up rings, and have already got LTM-LM adapters in the 50mm setting.
p.15 #18 · lens repair, modification and disassembly guide thread
Having read through all of the pages in recent days, I somehow escaped the comments that your G28 -> MC PF 55 Frankenzeiss conversion did not have helicoid focussing, until after I had ordered a donor 55 f1.7
The helicoid in the 55/1.7 is used to focus... I'm not sure what you mean... Unless you mean RF coupling.
AFAIK, Sebboh's engineering drawing for the G45 still requires a couple modifications, one is to add some thickness to the back edge to hide a gap when the lens is focused to MFD.
The other is to change the location of the screw holes that the LTM to M-mount adapter use to secure it to the rear ring, one of the holes lands on the 6bit location.
Hey Sebboh, do you mind if I get the transplant rings drawing converted to a 3D print format?
p.15 #19 · lens repair, modification and disassembly guide thread
LightShow wrote:
The helicoid in the 55/1.7 is used to focus... I'm not sure what you mean... Unless you mean RF coupling.
AFAIK, Sebboh's engineering drawing for the G45 still requires a couple modifications, one is to add some thickness to the back edge to hide a gap when the lens is focused to MFD.
The other is to change the location of the screw holes that the LTM to M-mount adapter use to secure it to the rear ring, one of the holes lands on the 6bit location.
Hey Sebboh, do you mind if I get the transplant rings drawing converted to a 3D print format?...Show more →
go ahead, i've been meaning to do that for a while myself, but have been quite distracted. i did correct the length of the rings on the g45 conversion at some point (but not screw locations [i use m-mounts without the bit coding]), but don't believe i ever posted them (?). i also have g35 ring measurements that i can post if people want.
regarding rangefinder coupling – my conversion doesn't have it, but it would be easy to add to the g45 conversion, though not the other focal lengths.
