NikonGear'23
Gear Talk => What the Nerds Do => Topic started by: richardHaw on February 22, 2016, 04:52:54
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http://richardhaw.com/2016/02/22/repair-micro-nikkor-55mm-f2-8-ai-s/
I hope that you enjoyed it!!! :o :o :o
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Very nice write-up and images to document it!
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Nice write up Richard. Thank you.
When you say "When lubricating your helicoids, be sure to use a light general purpose grease", I am assuming that you have some photographic friendly grease in mind?
The oily aperture blade problem with the 55mm f/2.8 lens was attributed to both the wrong type of grease being used by Nikon as well as excessive quantities being used.
What grease can you, or other NG readers, recommend please? Is there a recognised replacement grease that doesn't lead to the same problem?
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Very nice write-up and images to document it!
Thanks! it took me a long time to do this. lens is a bit complicated :o :o :o
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Nice write up Richard. Thank you.
When you say "When lubricating your helicoids, be sure to use a light general purpose grease", I am assuming that you have some photographic friendly grease in mind?
The oily aperture blade problem with the 5mm f/2.8 lens was attributed to both the wrong type of grease being used by Nikon as well as excessive quantities being used.
What grease can you, or other NG readers, recommend please? Is there a recognised replacement grease that doesn't lead to the same problem?
Hi! I use a light lithium type grease, generically being sold here as S10 :o :o :o
you can type S10 grease in ebay and this will show up. this is repacked, being sold as lens grease.
yeah, i am aware that the early production ones use a light runny grease, so grease migration became the problem and then nikon used a stiffer one. I tried using silicone grease (S30), it is a stiffer type of grease that i use for tele lenses so my turn is more precise but i ended up with a ceased lens where turning it required considerable effort. I re-greased the poor thing and this time, used the lighter S10 grease and it's all fine.
the actual grease that Nikon uses is called NPC FC-11 i think. You can read my blog post regarding grease and it was discussed there. I havent had the experience of using that but i know some people who do. also, there is this russian grease being sold on the net and they say that it is good also according to somebody i talked to. personally, I am going to stick with the tried and tested S10 grease. i usually do not apply to much of it so grease migration is at the minimum. it is not runny as well despite being light. it is more viscous than honey
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Thank you Richard - much appreciated.
My 55mm f/2.8 is showing very slight oilyness on the aperture blades, but not enough to slow up the speed at which they operate - expoures seem to be spot on, so the blades are not causing issues yet.
I can however see the day approaching when your write up will become very valuable to me, so thank you for the effort that you have put into your instructions and images - especially given that English is probably a foreign language for you as well. Well done.
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Thank you Richard - much appreciated.
My 55mm f/2.8 is showing very slight oilyness on the aperture blades, but not enough to slow up the speed at which they operate - expoures seem to be spot on, so the blades are not causing issues yet.
I can however see the day approaching when your write up will become very valuable to me, so thank you for the effort that you have put into your instructions and images - especially given that English is probably a foreign language for you as well. Well done.
that's fine. are you sure it's oil and not scratches on the aperture blades themselves? the scratches are OK since its just bare metal. if you do need to clean the iris assembly, you have to clean the housing as well, better yet, clean it thoroughly! you only ever need to do it once anyway :o :o :o a properly overhauled lens will last for decades. that russian grease, i forgot it's name but it is supposed to be good and is used in aircraft and some other precision equipment
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Thanks Richard - unfortunately it is definitely oil. Only small areas at this stage and it has been slowly forming for about three years. I am watching it and if it doesn't cause bother I will leave it as is. However if it degenerates to a point where it is causing trouble, your tuturial will be invaluable.
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Thanks Richard - unfortunately it is definitely oil. Only small areas at this stage and it has been slowly forming for about three years. I am watching it and if it doesn't cause bother I will leave it as is. However if it degenerates to a point where it is causing trouble, your tuturial will be invaluable.
be careful by the way, because of the grease started evaporating, it can end up making the nearest lens element look cloudy or milky (which you can easily clean off anyway) :o :o :o
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S30 grease is nice for lenses with a short focusing helicoil, like f/2.8 or 3.5 28mm 35mm 50mm lenses.
S5 is nice for really long focusing helicoils like the one here, but also other Micro Nikkor and APO Lanthar 2.5 for instance. Also non-IF lenses like 105mm 180mm 200mm,,,
S10 can be used for anything in-between and for IF lenses,,,
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Thanks for the write up.
I would love to her the explanation for this little snip at the end:
... Just remember to always store this lens facing up and set to f/5.6 or f/8 so that the aperture will not get stuck wide open or fully stopped down...
Why? :o :o :o
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Thanks for the write up.
I would love to her the explanation for this little snip at the end:
... Just remember to always store this lens facing up and set to f/5.6 or f/8 so that the aperture will not get stuck wide open or fully stopped down...
Why? :o :o :o
ah,haha! that is an "old wive's tale" from the where i came from. i am sure that this came from a long time ago when aperture blades would rust quickly when not in use. if the rust form when the lens is at middle aperture then it is easier to just flick it off when you play with the aperture. i have seen one in the junk box wherein the aperture has rusted and the iris is wide open. the blades were fused together by the rust that formed. i believe it's a rangefinder lens that i know nothing of. :o :o :o
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S30 grease is nice for lenses with a short focusing helicoil, like f/2.8 or 3.5 28mm 35mm 50mm lenses.
S5 is nice for really long focusing helicoils like the one here, but also other Micro Nikkor and APO Lanthar 2.5 for instance. Also non-IF lenses like 105mm 180mm 200mm,,,
S10 can be used for anything in-between and for IF lenses,,,
i actually prefer feather-light focusing on my small primes :o :o :o
but yes, the 50mm f/1.2 that I bought brand new is kind of stiff, feels like the S30 was used. i personally like the S10 as it is not so thin yet not too think. i skipped the lighter one because i find it too light. they are being sold here in small tubs. which reminds me, i am running out of S10 now and i need to buy one soon ::)
the technicians back home use the cheaper grease for use with the shimano fishing gear. they say that it is very good and cheap! have you tried it before? these guys will cut corners whenever they can since they do not earn a lot from doing this.
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http://page19.auctions.yahoo.co.jp/jp/auction/x437168743
this looks like it's priced just right :o :o :o
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The Fast 50mm 1.2 has a medium long helicoil so yes: S5 - And yes a brand new, Nikon still make them, is kind of heavy in the focus feel.
I was referring to short f/2.8 3.5 lenses.
The 50mm 1.2 Ais is actually super nice to chip with a Dandelion CPU from within the mount itself since the 'light baffle' part protrudes and forms an outer metal shell exactly in the right position as a contact block.
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The Fast 50mm 1.2 has a medium long helicoil so yes: S5 - And yes a brand new, Nikon still make them, is kind of heavy in the focus feel.
I was referring to short f/2.8 3.5 lenses.
The 50mm 1.2 Ais is actually super nice to chip with a Dandelion CPU from within the mount itself since the 'light baffle' part protrudes and forms an outer metal shell exactly in the right position as a contact block.
why do some dandelion chips fail? i read some people in dpreview having trouble with them down the road :o :o :o
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Because they are glued on and extremely fragile, they are glued together by two half's and the plastic is so thin due to the extremely tight design.
Is you are not careful when changing lenses you can easily bump it and it will break,,,
I have chipped a lot of lenses and extension rings with them, most of them still work,,,
Some are very easily broken just by touching them, since the design with the tiny golden coil spring fails, the spring is simply too weak or the is a problem inside the hollow pin design, some have' fallen of' and got a re-glue.
Customers have often reported broken chips, most I see as rough handling when mounting,,,
The Nikon TC16A with AF has a similar design with coil springs inside the pins,,, A very different design of the whole contact block than to the rest of the Nikon Nikkor Af and AFS lenses and TC's
But for the 50mm 1.2 Ais and Noct-Nikkor and a few specialist applications like extension rings the Dandelions are nice enough
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Rick, I'm impressed by this very thorough write up. I wouldn't do this kind of restoration work myself, but it is still well worth reading through. Thanks for sharing it here!
I'm just curious: how is the aperture lever of the 55/2.8 you restored? I've heard that there are three different versions of Ais 55/2.8 according to the period of production. If the lever consists of two separate parts, the 55/2.8 is a second version. The first and the third have one-piece levers.
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why do some dandelion chips fail? i read some people in dpreview having trouble with them down the road :o :o :o
Could be the quality of a particular dandelion batch made at any one time?
Like Erik said, they are very fragile and break all too easily.
I got one as a test for the 500/8, as it's a simple matter of aligning it properly and gluing it to the rear filter.
Easy as using a good epoxy mix. Strong hold on the chip body itself, but having a strong grip on the chip body is futile when the body of the chip is easily broken!
(http://www.ausphotography.net.au/forum/dbtgallery.php?do=gallery_image&id=3771&gal=gallery&type=full)
CPU just fitted onto the filter.
Waited till it cured properly and it worked fine for all of about 2 months. I'm not 'rough' with my lens fitting/removal procedure, but at some point I could feel that it felt a bit weird/strange the way the lens mounted onto each camera.
The strange feeling wasn't that the lens fitting/removal procedure was rough, it was that the cheap thin weak plastic body of the CPU wasn't up to par, and that the design of the square holes with round pins poking through them wasn't ideal either.
After the last couple of attempts at fitting the now CPU'ed 500/8, I then checked the dandelion with my macro lens and noted that the pins were falling out of their holes. At first, not completely just goofy alignment, which I pushed back into line, but then one literally popped out.
On closer inspection, the cause was the distorted body of the dandelion, making the non ideal square hole-round protruding pin even less ideal! .. to the point of disastrous failure.
(http://www.ausphotography.net.au/forum/dbtgallery.php?do=gallery_image&id=3772&gal=gallery&type=full)
Basically the square opening got so badly distorted, that it was no longer square(and thus only JUST) retaining the spring loaded pin.
The square openings were so badly distorted that the pins literally pushed out of their receptacles just enough so that they would bind against the camera body when being mounted/dismounted, which then distorted the dandelion body even more so, which added to the amount that the pin protruded .. and within a very short time the cpu was basically dead weight and the lens couldn't be mounted at all(well without a lot of force, which I'm not willing to attempt!)
I still have the chip tho. I have cut away the broken body section to reveal the insides as a memorial to be more doubtful on some of the things I want to achieve! ;)
I have to say tho, I'm still interested in chipping many/all of my manual lenses, especially the 105/1.8, as the benefits are many and varied.
The one aspect of the dandelion CPU that I really liked, and appreciated with the 500/8 was the focus trap feature.
It allows you the option to hold the AF button during focusing whilst in AF-S mode, and as soon as the target is 'in focus' according to the AF range finder(green dot indicator) the shutter is triggered automatically.
With the 500/8 this can be vital to get a sharp shot or not, simply because it's such a dark lens to view through the vf .. less of a problem with the other faster manual lenses I have.
And a question for Erik on the topic of a dandelion for the 50/1.2. Is there really enough room between the mount and the rear lens for the dandelion?
Even tho my experience with the dandelion wasn't a positive one, I'm always willing to have another go at them if I perceive a shift upwards in quality in the product.
My main concern is always that sub optimal square opening for the round pins of course!
ps. my dandelion experience is from 2012-2013(exif in the images attached).
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"Is there really enough room between the mount and the rear lens for the dandelion?" [50/1.2]
Yes, it is for the 50/1.2 AIS. Not the AI.
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As to the Dandelions, I have seen a fair number of them become broken over the years. Usually when people contact me for help to get the problem fixed .... The standard remedy is to dump the Dandelion and replace with more sturdy stuff. Nikon's contact blocks have metal backing and are held in place by metal screws.
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"Is there really enough room between the mount and the rear lens for the dandelion?" [50/1.2]
Yes, it is for the 50/1.2 AIS. Not the AI.
Well when I finished removing the whole front of the Dandelion and sanded down the rear towards the glass there was room, I might have trimmed the rear housing a bit, can't recall, Bjørn has the lens now, maybe he can shoot a couple of closeup pictures of it ;)
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that's interesting. specially the focus trap thing. :o :o :o
maybe one day somebody will produce a tougher version? maybe somebody should start a crowd funding program for this ::)
for such a high wear and stress item, i do expect that they use better materials for the dandelion chips. the coil spring could be replaced by a simple cantilever spring instead.
this feels like squeezing too many things in a tiny package and this might be the reason that they break over time.
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Rick, I'm impressed by this very thorough write up. I wouldn't do this kind of restoration work myself, but it is still well worth reading through. Thanks for sharing it here!
I'm just curious: how is the aperture lever of the 55/2.8 you restored? I've heard that there are three different versions of Ais 55/2.8 according to the period of production. If the lever consists of two separate parts, the 55/2.8 is a second version. The first and the third have one-piece levers.
Thank you, Akira! it is not difficult at all. to be honest, this lens is the first one that i restored. :o :o :o some a-hole from yahoo! auction sold me bad sample and i had to open it up...
I am not sure about the aperture lever/horns. but i can tell you that the 55mm f/3.5 (metal to rubber focusing ring) has A LOT of variation inside throughout the years. this includes changes made to the helicoid key design and mounting,etc.
the Nikkor-S 50mm f/1.4 also has a lot of internal changes sometimes in between batches.
the changes were minir but will prevent you from swapping parts without modification ::)
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that's interesting. specially the focus trap thing. :o :o :o
maybe one day somebody will produce a tougher version? maybe somebody should start a crowd funding program for this ::)
for such a high wear and stress item, i do expect that they use better materials for the dandelion chips. the coil spring could be replaced by a simple cantilever spring instead.
this feels like squeezing too many things in a tiny package and this might be the reason that they break over time.
The Nikon contact blocks are mad out of completely other materials, much more sturdy almost unbreakable,,,
The coil spring design is what makes it so compact, not room for the Nikon cantilever pins in the Dandelion at all... The parts and electronics inside are tiny!
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Thank you, Akira! it is not difficult at all. to be honest, this lens is the first one that i restored. :o :o :o some a-hole from yahoo! auction sold me bad sample and i had to open it up...
I am not sure about the aperture lever/horns. but i can tell you that the 55mm f/3.5 (metal to rubber focusing ring) has A LOT of variation inside throughout the years. this includes changes made to the helicoid key design and mounting,etc.
the Nikkor-S 50mm f/1.4 also has a lot of internal changes sometimes in between batches.
the changes were minir but will prevent you from swapping parts without modification ::)
Rick, sorry about your unfortunate experience with yahoo! auction, but the sense of emergency seems to have helped...
As for the aperture lever of 55/2.8, I heard that the two-piece aperture lever was replaced with the one-piece one because the two-piece version couldn't synchronize with the 10 fps continuous shooting mode of F2H.
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The proof that you can fit a Dandelion to the 50/1.2 AIS. Erik at his best :D
This method of attaching the Dandelion alleviates most if not all problems and weakness of the usual positioning, in which the chip will be exposed to excessive wear and tear. Still, the pins are on the long side so their tips will wear rapidly.
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thanks for the image Bjørn, the sleeves that house the coil springs for the pins are clearly visible.
Yes the pins are very far ouy as to not remove too much of the Dandelions very thin contact block and to not grind the element,,,
Can you check if I have removed a slight bit of the housing as well?
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"Can you check if I have removed a slight bit of the housing as well?"
Apparently you did.
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I thought so ;) Thanks for confirming! It's tight the F-Mount
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The proof that you can fit a Dandelion to the 50/1.2 AIS. Erik at his best :D
This method of attaching the Dandelion alleviates most if not all problems and weakness of the usual positioning, in which the chip will be exposed to excessive wear and tear. Still, the pins are on the long side so their tips will wear rapidly.
this looks fine but it's going to void the warranty of my 50 :o :o :o
do the contacts have to be protruding? how difficult is it to manufacture the chips at home? maybe i can find parts in akihabara and photoetch a board for that? (if it is indeed that easy)
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Rick, sorry about your unfortunate experience with yahoo! auction, but the sense of emergency seems to have helped...
As for the aperture lever of 55/2.8, I heard that the two-piece aperture lever was replaced with the one-piece one because the two-piece version couldn't synchronize with the 10 fps continuous shooting mode of F2H.
i have now become wise and now know who are the dishonest people in Yahoo! auctions :o :o :o
i looked over all of my notes and it seems that all of the 55mm f/2.8's that I serviced all have 2 parts aperture lever...these are all early ones since they are usually the ones that need fixing and end up being sent to be or me finding them in the junk box. another weakness of this lens is the front cowl. it is easily bent and will prevent you from focusing.
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Very nice work on Erik's part. Well done both of you.
Bjørn, did you re-program the micro code in the Dandelion chip so that it now behaves like your own PCBs, or did you simply set those basic lens parameters that the Dandelion allows users to enter via the camera body?
I am guessing that some of the more subtle parameters such as exit pupil information that your PCBs have coded into them are less important for a 50mm lens. IIRC, the Dandelion is essentially a "G" type chip.
Would the spring loaded nature of the Dandelion pins help lessen the wear I wonder?
The proof that you can fit a Dandelion to the 50/1.2 AIS. Erik at his best :D
This method of attaching the Dandelion alleviates most if not all problems and weakness of the usual positioning, in which the chip will be exposed to excessive wear and tear. Still, the pins are on the long side so their tips will wear rapidly.
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this looks fine but it's going to void the warranty of my 50 :o :o :o
do the contacts have to be protruding?...
I have never heard of anybody ever needing to have warranty work done on a Nikon MF lens,,, :o :o :o
The geometry and the position of the pins are given, they need to move to make a good solid contact with the contact surface on the camera, design and tolerances dictate this,,,
Good luck making your own CPU! :D
Bjørn has several types of layout of the prints to accommodate for different mount designs.
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Very nice work on Erik's part. Well done both of you.
Bjørn, did you re-program the micro code in the Dandelion chip so that it now behaves like your own PCBs, or did you simply set those basic lens parameters that the Dandelion allows users to enter via the camera body?
I am guessing that some of the more subtle parameters such as exit pupil information that your PCBs have coded into them are less important for a 50mm lens. IIRC, the Dandelion is essentially a "G" type chip.
Would the spring loaded nature of the Dandelion pins help lessen the wear I wonder?
You cant reprogram Dandelions, they are a stand alone product.
Yes no nodal point info.
I don't understand why there should be any wear on the pins?
The cut that one of the pins appears to have in the close up is most likely from my Dremel when cutting the Dandelion apart before the implantation into the mount.
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I have never heard of anybody ever needing to have warranty work done on a Nikon MF lens,,, :o :o :o
The geometry and the position of the pins are given, they need to move to make a good solid contact with the contact surface on the camera, design and tolerances dictate this,,,
Good luck making your own CPU! :D
Bjørn has several types of layout of the prints to accommodate for different mount designs.
that was what i thought. until i got this one :o :o :o
the optics was not up to par with the 50 1.2s that i have used and i insisted that nikon fix mine. after some pressure they finally swapped the internals with another one from the production line and i am currently very happy with my 50 1.2's results wide open
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Bjørn, did you re-program the micro code in the Dandelion chip so that it now behaves like your own PCBs, or did you simply set those basic lens parameters that the Dandelion allows users to enter via the camera body?
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Would the spring loaded nature of the Dandelion pins help lessen the wear I wonder?
I just programmed the Dandelion of the 50/1.2 from the usual (and very awkward) camera-based interface. These chips are essentially "G"-type, the newer incarnations of which can be altered to "P" by additional user programming. However, conflicting reports of their ability to operate successfully in "P" mode are seen. Alarming reports of massive underexposure in "P" mode have been posted on the 'net.
Spring-loaded signal pins are a prerequisite for any CPU of an F-mount lens, otherwise you cannot safely attach the lens to the camera. However, the Dandelion spring-loading has extensive travel and the pins really stick out too far, so they grate on the camera-side contact surfaces. The pins of a Nikon contact block only travel a very short distance and the force they bring to bear onto the camera side is minute. Thus it is far more likely that Dandelion chips are subjected to excessive wear over time. The Dandelion of the 50/1.2, however, is seated deeper than normal for this kind of chip and the pins accordingly don't protrude more than with the standard contact blocks.
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....... that the design of the square holes with round pins poking through them wasn't ideal either. ........
.....Basically the square opening got so badly distorted, that it was no longer square(and thus only JUST) retaining the spring loaded pin.
The square openings were so badly distorted that the pins literally pushed out of their receptacles just enough so that they would bind against the camera body when being mounted/dismounted, which then distorted the dandelion body even more so, which added to the amount that the pin protruded ........
Sorry for snipping out, but I want to address design of the Dandelion;
The square holes you see are just the housing, they don't keep the pins/tubes in place.
The pins are held into position inside the small tubes you see inside the square.
The tubes are glued into position inside the housing together with the electronics.
Most likely there has been to little glue inside the housing to firmly hold onto the tubes in your Dandelion.
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Sorry for snipping out, but I want to address design of the Dandelion;
The square holes you see are just the housing, they don't keep the pins/tubes in place.
The pins are held into position inside the small tubes you see inside the square.
The tubes are glued into position inside the housing together with the electronics.
Most likely there has been to little glue inside the housing to firmly hold onto the tubes in your Dandelion.
well, that sounds flimsy :o :o :o
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The Dandelion didn't get its tainted reputation for no reason ....
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OK, good news. looks like the chinese internet is full of OEM replacement parts for Nikon :o :o :o (including contacts)
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There is a huge difference between Nikon 'plastic' and OEM 'plastic' in some cases :o
The plastic Nikon use is very flexible and tough - It is not brittle or hard in any way...
Nikon Pins are silver coated,,,
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For a long time I've thought about a solution like this for the contacts in a chipped 50-58/1.2...
The red represents the new design with contact pins made of spring steel material. The orange bit is the CPU itself.
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I remember the ideas Sten ;)
I even build a set of very similar contact pins, they where ripped off when I rotated the lens,,,
BTW this sectional view is not a Noct,,,
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I remember the ideas Sten ;)
I even build a set of very similar contact pins, they where ripped off when I rotated the lens,,,
BTW this sectional view is not a Noct,,,
There would have to be some sort of guide/slot to prevent the sideways movement when mounting the lens.
As for the diagram: Tis a composite of the Noct's barrel with the 50/1.2's lenses.
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Sten I have the right drawing I'll find it for you.
But there is not much room in that area ;)
I did look at it back then.
It's like the opposite of anything normal I think,,,
The optics has to go in last piece of the puzzle for this to work.
The CPU must be on the helicoil part somewhere then the wiring comes up to the contact block then mount the wires/flat to the contacts then assemble the contact and then put it on the mount arggggggg
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The signal pin tips being nice rounded will help as well.
I suspect the tip shape is one (out of several) reasons the Dandelion chips feel more grating when these lenses are mounted on the camera.
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It would be fun to explore this even further and not least; prove it CAN be done 😊
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The signal pin tips being nice rounded will help as well.
I suspect the tip shape is one (out of several) reasons the Dandelion chips feel more grating when these lenses are mounted on the camera.
I've had may fair go with these Dandy things. Brittle and breaks too easily. The little brass parts are as pointed out, to long and wobbly and require very careful lens mounting. And when temperaturea drop to minus 'a lot' the plastic material becomes REALLY fragile.
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It would be fun to explore this even further and not least; prove it CAN be done 😊
He he, well that's one of the reasons I chipped the Noct in the first place! ;D
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Here is the sectional view of the Noct-Nikkor 58mm 1.2 Ais
There is a tiny space near the aperture ring below 63 above 58