NikonGear'23
Gear Talk => What the Nerds Do => Topic started by: Erik Lund on March 05, 2016, 11:01:55
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I am starting to prepare for the Scotland NikonGear Workshop and in this connection I wanted to work on Nikkor 10.5mm f/2.8 adding 62mm filter threads, to give the possibility to make the usual FX hack more flexible and the added benefit of using a standard 62mm lens cap.
Now it is the usual 'almost' circular fisheye after the 'hack' cutting off the petal lens hood ;)
By adding 62mm 'filter rings' the lens becomes a circular fisheye by cropping,,, naturally.
The donor was a Close up nr. 6T filter housing relieved from the glass and the male 62mm threads are used as a spacer inside to make the filter slide on to the lens and position, seat correctly.
A bit of Dremel work,,, and the filter ring slides into position solidly.
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An interesting twist. The "shaved" 10.5 mm has a front lens highly susceptible to knocks and bumps besides being a magnet for finger prints. I assume the filter "holder" can slide back and forth?
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The filter threads are fixed on this modification so extension rings are needed, it is set not to vignette even at infinity.
It would be possible to make it slide for instance with a tight fit and felt ;)
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Aha, the K-ring set comes to the rescue - yet again ....
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The D810 looks like new *ggg*
Great work!
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Thanks ;)
Yes 'K-Rings' but 62mm ones!
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sorry - I overlooked that size is expanded from the usual 52 mm.
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Amazing job, as always, Erik!
So, you would need some stacked filter rings without the glasses to use a cap?
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Thanks!
Yes, a couple of filter rings to avoid the lens cap touches the glass front!
Or now I use an old Nikon 62mm 'glass-less' CPL it has 72mm front filter threads :)
Especially for these Fisheye and ultra wides this I mandatory! Otherwise specs will show up in the images.
I'm in the final process of negotiating with Photografica.dk to rent their 6mm f/2.8 for the Scotland Workshop ;)
So I'm also looking into collecting all the bits and pieces for my off center tripod to balance it on, without the feet showing up in all the pictures,,, ;)
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Does that might Fish 6/2.8 come with its own truck and dedicated driver ??? :D
I have seen this massive lens three times now: Tokyo, London, and Copenhagen. Never taken a picture through it though. Yet.
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It's 5 kg or 10 Lb so yes it's appropriate we have rented a big car ;)
I'm sure your up to the task of shooting it - I'm just facilitating that the lens will appear in the Scotish landscape ;)
For sure we need to do a star sky shot amongst many others!
Now I'll shoot away with the tiny 10.5mm to get re-accustomed to the unique Fisheye perspective ;)
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BTW; The original petal lens hood that is cut off can after the modification be refitted again whenever DX shooting is needed, the petal lens hood fits inside the 62mm filter threads or in a separate filter ring- Quite neat IMHO
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Here it is;
(https://farm2.staticflickr.com/1633/24902585294_06fe592f0c_h.jpg) (https://flic.kr/p/DWyg1S)NIKKOR 10.5mm re use hood (https://flic.kr/p/DWyg1S) by Erik Gunst Lund (https://www.flickr.com/photos/erik_lund/), on Flickr
If mounted in a filter ring trimming of the ring is needed,,,
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I can hardly wait to go fish-eyeing in Scotland!
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Looks nice. I've been thinking about the shave as well for my 10.5, but now it is almost unnecessary since I've once again added more gear and now my "fishy" alternatives are
- Sigma 8/3.5 AF
- Samyang 8/3.5 MF
- Nikkor 10.5/2.8G
- Nikkor 16/2.8 AF D
MF works well with Fish...
I have my old signature still, but have to update that due to changes in my gear - probably need to remove the gear list as I tend to add more stuff instead of selling it...
New stuff
- the Samyang mentioned above
- Nikkor 24/1.4G - cheap second hand, no signs of wear
- D800 body - second hand and cheap - was looking for a used D3x and found it, but the same shop had the D800 a lot cheaper
Additionally some non-Nikon stuff
- Wacom Intuos Pro tablet (had to take the small version as it was the only size I could fit to my desk)
- Adobe Photoshop CC and Lightroom CC included with the Wacom deal
- old cameras I used to own but sold away - found dirt cheap ones - Canon FTb (bought one in 1970 - bought one now as a working sample with 50/1.8 lens for 70 euros), Canon A-1 (sold mine when bought my first Canon F-1n - paid only 5 euros for the "new sample", inserted a battery and it works), one Yashica 4x4 gray (found almost unused one at my wife's relatives - they know I love gear, so got it), one Kodak Brownie C (have used this type in the 60's), had my old F-1n cleaned + motor drive battery replaced (bought the camera + motor drive second hand in 1985 and used it as my main SLR until 2003 before switching to Nikon), bought a second F-1n as well a couple of weeks ago
- one Lytro Illum - cheap, second hand, remains to be seen will it be a display cabinet piece or something to be used. Funny issue though that the Lytro software is not comptible with my Nvidia Quadro
- writing this on my new iPad Air 2
Serious GAS/NAS but
I actually started my own company about one month ago. I can retire in two years and I needed a "hobby" for retirement time. I added all my interests to the business description so I'll get sales tax away from purchases like photo gear...
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Here is a quick shot, composite of two images with the 10.5mm, one in vertical and one in portrait direction.
A gimbal head can be used for this type of shot to avoid misalignment.
(https://c7.staticflickr.com/2/1703/25959258726_c4aca2dd26_h.jpg) (https://flic.kr/p/FxVZdj)Rotunde10_5_2 (https://flic.kr/p/FxVZdj) by Erik Gunst Lund (https://www.flickr.com/photos/erik_lund/), on Flickr
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Erik,
Great result!
A bit of explanation would help. Why did you take the two images in different orientations? Why not just two vertical ones? How do do you handle the alignment? How did you do the stitching? Is the "shaved" version of the 10.5 mm needed for this task?
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Erik is an expert in using fish-eye lenses :)
Kim, I may perhaps answer your first question.
When you shoot the 10.5 in landscape mode, the top and bottom part of the photo is not fully round, parts are missing.
So you rotate the camera and lens 90 degrees to fill in the blanks in order to get a full circular image.
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Thanks Jakov!
I think I am understanding it now. So even with the shaved version, parts of the full circle is cut off. The landscape and the portrait pictures supplement each other, provided the two pictures are centred at the same point?
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Yes, that is it. Thanks Jakov ;)
And yes cantered along the optical axis
The 10.5 is designed as a 'Full frame' Fisheye on DX it just turns out that when rotating it 90 degrees you get the full circle, the two missing top and bottom bits of the image.
The advantage is that you can use a much larger area of an FX sensor than an 8mm Circular Fisheye lens on FX, this gives you much more 'pixels in use' so to say and the 10.5mm is a remarkably sharp performer!
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Erik, I am bringing this old thread to life again as when shaving my 10.5mm, I realized that with the material removed, there is very little left to keep the original cap in place (with the intact shade part inserted) to hold it in place even after adding tape, and I like your approach to this. So on a whim, but without fully understanding the description :) , I acquired a set consisting of a 6T and 5T ring with elements (to be removed) showing separation in order to try replicate your filter ring attachment modification,. After receiving the 6T (that differs slightly in the labeling from Erik's) here is my understanding of the dremeling modification that I would appreciates some feedback on. The 6T ring is hereafter just called the "Ring".
0. The retaining ring is loosened and put aside, the optical element is taken out of the Ring not to be used.
1. As the male thread on the Ring would extend too far and cover the focus collar on the 10.5mm, it is to be dremeled off to the base of the ring. (No threads shown in your image on the lens side)
2. The part of the ring that seats the optical elements (not sure how much is left of it after removing the male threads) is too narrow and has to be dremeled down to slightly wider diameter than the female threads of the Ring.
3. The female threads on the Ring might have to be slightly dremeled down a bit to fit tightly over the 10.5mm front.
(Additinoal question: is it to be pushed linearly in, or be fitted by rotating and sort of screwed on the the front of the 10.5mm)
4. Not so sure about this but from the following: The donor was a Close up nr. 6T filter housing relieved from the glass and the male 62mm threads are used as a spacer inside to make the filter slide on to the lens and position, seat correctly. A bit of Dremel work,,, and the filter ring slides into position solidly.
The male 62mm threads that are used as a spacer inside, you mean the retainer ring, right?
If used with a standard lens cap, it seems the added filter ring (that has to be added to the Ring) has to be unscrewed at every use unless a circular crop of the field is wanted?
About the shade: If mounted in a filter ring trimming of the ring is needed
Is this pointing to a regular filter ring opposed to the Ring as the Ring is wider or has already threads partly reduced?
Hope some of this makes sense. Outside and inside of the Ring shown below.
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The male 62mm threads that are used as a spacer inside, you mean the retainer ring, right?
If used with a standard lens cap, it seems the added filter ring (that has to be added to the Ring) has to be unscrewed at every use unless a circular crop of the field is wanted?
Yes, by spacer i meant like sleeve -But yes a retainer.
Yes, it will be like an old school Nikon lens cap, screw on - off.
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Thanks for confirming, Erik, looks like I was on the right track after inspecting the details of the Ring. I already have a 62mm filter stacking cap that can be used with a filter ring as part of that makeshift classical screw-in Nikon cap.
And after more considerations regarding #2-3, it looks like the Dremel approach will be to remove material from inside at the non-female-threaded portion of the Ring, and the male thread of the Ring (closest to the mount) will go away by itself, so hopefully no need to make a vertical cut from the outside to remove those threads, which could be difficult to do cleanly. It will be quite a bit material to remove so this project might take some time and patience and the need to borrow or acquire something more powerful than my old Dremel with its ailing batteries, or perhaps use the abrasion tool in a drill press for more control.
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Øivind, I can see a lathe and a milling machine and a whole lot of related tooling & jigs coming into your life sometime in the not distant future....
;D ;D ;D
BTW, Good luck with this project,
............................................
so this project might take some time and patience and the need to borrow or acquire something more powerful than my old Dremel with its ailing batteries, or perhaps use the abrasion tool in a drill press for more control.
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Thanks, as I have access to a heavy duty drill press at work that had to do. The speed was quite slow so it took "a while", also as I first forgot that it had a gear in addition to the electric speed adjustment. As expected the male threads of the ring came off once enough material had been removed. Unfortunately my stepwise approach to remove material resulted that the fit became too loose at the part nearest the mount, but nothing that could not be compensated by a couple of thin layers of epoxy that was allowed to set before fitting.
The final result is a very secure press fit that aligns the back of the 6T Ring with the edge next to the focusing collar. A note is that while the retaining ring was used to allow correct seating, it takes up too much space to allow anything to be attached to the filter threads, and thus had to be removed once desired position was achieved. The font of the T6 Ring is now positioned so that at infinity setting there is no cutoff corners in DX mode, and the circle in FX mode has a minimal circular crop, which takes away a little of the blurriness at the edge. I need to repaint the threads and the front though as there are some reflections from exposed metal.
For completeness I first also include a few of images from the shaving process. Note the multiplayer tape guiding the cut. The perfect fit of the soda can (a taller slender version but same volume as standard cans) shown after completing the cut and removing tape from the shade to release it. I have not seen that mentioned anywhere else. Continued in next post...
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-The ring in final position.
-A 5T ring + a filter stacking cap provides a nice classical screw-in cap. Note that with the lens set a close focus, there would be very little clearance to the cap, so I used a retaining ring to provide more clearance to the stacking cap and added some flocking tape inside for safety.
-The shade fits inside the ring if wanted for DX mode as shown above by Erik.
-The image at infinity setting has some reflections at the minimal circular crop, so some paint work will be needed on the threads.
Again thanks to Erik for providing the idea for this.
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Oops I got an extra unintended post, can as well use it to display another image. At close focus the ring will not cause a minimal circular crop.
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Thanks, as I have access to a heavy duty drill press at work that had to do. The speed was quite slow so it took "a while", also as I first forgot that it had a gear in addition to the electric speed adjustment. As expected the male threads of the ring came off once enough material had been removed. Unfortunately my stepwise approach to remove material resulted in that the fit became too loose at the part nearest the mount, but nothing that could not be compensated by a couple of thin layers of epoxy that was allowed to set before fitting.
The final result is a very secure press fit that aligns the back of the 6T Ring with the edge next to the focusing collar. A note is that while the retaining ring was used to allow correct seating, it takes up too much space to allow anything to be attached to the filter threads, and thus had to be removed once desired position was achieved. The font of the T6 Ring is now positioned so that at infinity setting there is no cutoff corners in DX mode, and the circle in FX mode has a minimal circular crop, which takes away a little of the blurriness at the edge. I need to repaint the threads and the front though as there are some reflections from exposed metal.
For completeness I first also include a few of images from the shaving process. Note the multiplayer tape guiding the cut. The perfect fit of the soda can (a taller slender version but same volume as standard cans) shown after completing the cut and removing tape from the shade to release it. I have not seen that mentioned anywhere else. Continued in next post...
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Something strange happening, I get a new quote when I click Modify to edit a post. Please delete these ghost posts.
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Øivind, the other day I bought a Nikon 10.5mm lens, I don't know if I'll be able to convert it,
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I already have the lens,
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The shaving conversion is not difficult, just make sure to use an aluminum soda can/sheets from a aluminum can to protect the optics, tape against dust intrusion, measure accurately and go slowly.
While I found a trick to force FX mode on the Z8 and set the aperture on the 10.5mm as posted here: https://nikongear.net/revival/index.php?topic=11224.msg209380#msg209380 (https://nikongear.net/revival/index.php?topic=11224.msg209380#msg209380), I finally broke down and bought a cheap dumb adapter to dedicate to the 10.5mm. I liked the design better than the one in that link, price was $25 lower, but might need to add front/rear caps that do not come with it. The F-mount fit is nice and tight, while the Z-mount side is looser than the FTZ II adapters I have, more the same resistance as mounting the 24-120mm. An Amazon review stated that it has a plastic Z-mount, but I am pretty sure mine is made of coated metal. The register distance seems OK. I was able to calibrate the aperture clicks to a mid range setting of about f/ 5.6-8. The ring has a dampened feeling to it, probably due to generous application of grease to provide the illusion of a precise mechanism.
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Very nicely done! Looks super nice ;)
I like the soda can approach ;D
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Very nicely done! Looks super nice ;)
I like the soda can approach ;D
Thanks Erik, much appreciated, especially coming from you. The first thing that came to my mind when I was searching for that soda can was the classical thread with Jacov and all the the soda cans, wondering if one of the cans in that collection would fit the 10.5 mm. ;D https://nikongear.net/revival/index.php?topic=66.msg252#msg252 (https://nikongear.net/revival/index.php?topic=66.msg252#msg252). Again thanks for putting me on the path to this conversion.
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He he, I often think of that image with the Can shower ;D
Thank you!
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Nice work all. Thanks to this thread, I've been inspired to find a 10.5mm lens. I managed to snag a used 10.5mm for a nice price. It will arrive soon and will be under the Christmas tree for me to open later and be surprised or at least very thankful.
Since this is for use with a Nikon D610 and I already have a Nikon 16mm f/2.8 fisheye, the 10.5mm will be going under the knife to remove the petals for full frame use.
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While surfing the topic, I ran across two interesting sites and a copy of a service manual for the 10.5mm f/2.8 G lens.
The video I found had to do with adding helicoid grease to allow for smoother manual focusing. Based on the feel of the manual focus, this sounded like a nice addition. The video is at https://www.youtube.com/watch?v=LhCr8vdLzm4 (https://www.youtube.com/watch?v=LhCr8vdLzm4) Long story short, the author stripped the lens down further than I want to do to grease the helicoid. Also, from the service manual I found it warns in bright red text:
Caution：
In case the rear lens group is detached, it is necessary to inspect the resolving power after assembly.
Therefore, if such an inspection cannot be made at service agencies, do NOT detach the rear lens group.
He went so far as to remove the rear elements, the aperture blade unit, and more, and split the front element group before removing it. All in all, the video is missing some key steps such as when the hood was removed. Also, probably much more may have been disassembled than needed to access the helicoids but that is not clear.
The second post relevant to trimming the hood is https://blog.captivephotons.com/cutting-the-nikon-10-5-fisheye/ (https://blog.captivephotons.com/cutting-the-nikon-10-5-fisheye/) The interesting point of this post is that the author detaches the screws holding the hood to manage to move the hood somewhat forward to cut the hood with the lens somewhat out of the way. They thought maybe the hood could come off but couldn't see how.
Based on these three sources, it appears that the front element group can probably be unscrewed (assume but not sure) using the outer spanner wrench slots. From the service manual it appears that may allow the hood to be removed by removing the screws as shown in the post sited. What was not stated in the video but I implied from the things that were not shown was that the front lens group was difficult to remove and that may be why the front element was removed to allow some acetone to be used to loosen the assembly and they had to split the front element to access the threads. Warning as was noted in the video acetone will ruin the plastic lens finish.
So two reasonable methods to cut the hood may be to
1) use a can to protect the lens. (Probably still the simplest and safest if done with care.)
2) the front lens assembly can be removed by unscrewing and hood can be removed next by removing three screws hidden under the rubber focus ring to allow the hood to be cut while not on the lens.
Not sure if number 2 is feasible but certainly looks interesting. (One of the comments implies that the front lens assembly is difficult to impossible to remove.)
While applying helicoid grease is tempting, in the spirit of "If it's not broke, don't fix it" the level of disassembly in the video is a step too far for me at this time.
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I recently noticed that my copy of the 10.5mm actually has a slightly loose front lens group that can be rotated just by the light force of cleaning with a fiber cloth. I tried to carefully tighten what looks like the retaining ring to no effect (it did not move and appeared tight). The performance does not seem to be affected and is still excellent on my Z8. Another note is that it for a long time has developed what I initially thought could be beginning separation, which is visible slightly below the center in the 3rd image in post #24. However after inspection of the optical diagram it appeared to my relief to be a shard or other anomaly at the back lateral edge of the front element and does not affect image quality.
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A caution regarding the disassembly video linked to in my previous post and the use of acetone. The video stated the acetone ruined the finish on the exterior but they used acetone to help remove the rear section of the front lens assembly. However if the interior parts are also of the same type of plastic, acetone could weld the threads together rather than loosening them. Since I have not opened up the lens, I cannot comment further, but this is just a caution.
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The calibration of the rear elements of all of the fisheye lenses should be avoided, it's very difficult to recalibrate them.
I recall the huge challenge we had with Jacov's 16mm - Near impossible to get reliable focus back,,, Even though they have a huge depth of field!
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Thanks for the info. Based on the warning on the service manual and your confirmation, I definitely will not remove the rear element group until there is no other option and the need is great which hopefully will never happen.
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Doesn't look like the front element group will easily unscrew, so I'll go with the can trick to protect the lens. Will update when I get around to cutting the hood petals in a few days or so. Thanks to Øivind Tøien for discovering that the tall thin cans are a fit to protect the lens. Found some metal screw-in hoods on e-bay that may serve to make a screw in lens cap assembly. Will detail when I update after cutting the hood petals.
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I assume that some of you may have found these sites but these were new to me. Definitely appropriate for this forum and thread, lots of technical details on this lens can be found at
https://web.archive.org/web/20161101215952/http://www.pierretoscani.com/echo_fisheyes_english.html (https://web.archive.org/web/20161101215952/http://www.pierretoscani.com/echo_fisheyes_english.html)
and
https://web.archive.org/web/20211028185202/http://michel.thoby.free.fr/Blur_Panorama/Nikkor10-5mm_or_Sigma8mm/Sigma_or_Nikkor/Comparison_Short_Version_Eng.html (https://web.archive.org/web/20211028185202/http://michel.thoby.free.fr/Blur_Panorama/Nikkor10-5mm_or_Sigma8mm/Sigma_or_Nikkor/Comparison_Short_Version_Eng.html)
The first link looks at the "shaved" version while the second is a reference for the first and dealt mainly with the unmodified lens.
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Mostly finished with the mod.
First the slightly bad news, I am not completely happy with where I trimmed the hood, however this is probably where it needs to be cut for the lens hood assembly that I decided to use. If I were to do it all over again, I might do it a bit differently. What I don't like is that the felt dust ring no longer seals against the body when the lens is at its closest focus position.
(https://astronomy.toups.info/shared_images/close_focus_post_trim.jpg)
In order to maintain the seal at the closest focus point, the lens hood would need to be trimmed so that it extends about 7 or maybe 8 mm above the gold ring. (However that is probably not far enough for the rings I added, see later discussion.)
I used a tall thin drink can to protect the lens and that worked perfectly!
(https://astronomy.toups.info/shared_images/trimming.jpg)
I used a Dremel grinding wheel since the cut off wheels were not big enough to clear the drill press collet holder. The grinding wheel is thicker than the cutoff wheels but worked well enough. With the can I managed to not damage the lens housing.
I used a "58mm Meta Screw-in Hood with 62mm Cap for Olympus Pentax Leitz Panasonic Sony" https://www.ebay.com/itm/267053775696 (https://www.ebay.com/itm/267053775696) (Note the misspelling of Metal) Note this has a 62 mm thread end that I cut to make a 8.5 mm thick ring. I used a product by Bircfhwood Casey called Aluminum Black Metal Finish to somewhat darken the cut edge. Not as good as a true anodized and dyed surface but removes the gloss and blackens it somewhat.
(https://astronomy.toups.info/shared_images/trim_hood_1.jpg)
I had to file the 62 mm inner surface slightly and ended up with a very tight press fit. (In fact not sure I want to try to remove it again. If it ever comes off I'll add a drop of glue.)
In order to cap the lens I use a "62mm Meta Screw-in Hood with 67mm Cap for Olympus Pentax Leitz Panasonic Sony" https://www.ebay.com/itm/267053775827 (https://www.ebay.com/itm/267053775827) This hood is a bit longer than needed but was the closet I could find. Right now I am using the plastic snap in cap but have ordered a "(2 Pcs) 67mm Metal Front Screw-in lens Cap Nikon Sony Pentax Minolta Lenses" [url]https://www.ebay.com/itm/225469187197[/ur/] that I might glue to the 2nd lens hood to make the screw off cap. Actually I could probably make the original Nikon lens cap work with some effort and some shims. Here is the lens with the hood/cap using the plastic cap that came with the hood. Waiting for the metal cap to arrive.
(https://astronomy.toups.info/shared_images/lens_with_hood_2.jpg)
Here is the lens uncapped.
(https://astronomy.toups.info/shared_images/lens_without_hood_2.jpg)
Long story short, I am very happy with the way it turned out. I'm just wondering if I should do something with respect to the dust seal. Other than that I love it. Thanks to all for the suggestions and details in this thread. Will post an updated picture when the metal cap comes in.
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You definitely cut too much off. I’m afraid it’s not really possible to uncut :o
Only fix is to glue on a ring to reseal it.
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So I noticed. ;)
Thinking that I may use the can to cut a ring and insert it as was done to originally protect the lens. This should allow room the hood/cap to screw into the modified hood ring pressed onto the lens but still protect the dust seal. Will investigate more later. and update.
Of course there may not be enough clearance for that.
Not overly concerned but figured I'd post the info as a warning.
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For the auto focus to work the fit must be frictionless or close to. Otherwise there will be strain on the gears that are not meant to bee.
There is no space for anything between the felt seal and the lens hood tube.
Also the front element group will bee loose to rattle around.
Yes you have raised a warning.
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Yes looks like I need to add a ring without adding friction. Need it to be a bit thinner than the existing petal ring in order for the hood/cap male threads to clear whatever ring I may add. Unfortunately, the press fit is too good (too tight) so won't try to remove the ring on the lens although I would have liked it be a millimeter or two higher. Thanks for the warnings. From a quick test with a shim, it was clear there is no room between the lens hood and the felt seal. I do have the petals on enough of a ring that I could cut a ring from that.
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A ring cut from the original petal hood would possibly work. A bit tricky to glue though.
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Yes that is my current plan. Managed to remove the press fit ring cut from a lens hood. Have errands to run today but may be able to work on it today or tomorrow. Erik, thanks for the suggestions. :)
Was debating removing the front element group for the glue step but thinking I don't need to go there. Trying to do as little harm as possible.
All that being said, from various test shots during the modification, I really like this lens in FX mode!
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Third attempt to reseal was the charm. First attempt was to use the existing left over piece from the petal removal. That would have been fine but I wanted to get too cute to machine it like the final result, however, it was clear that I couldn't make it thin enough for what I wanted. Second attempt ended up too tight so I started over. Here is the third attempt. As will be clear, and is appropriate the the title of this forum, I probably made things much more complicated than they needed to be since I wanted to be able to screw in the lens hood cap and not limit the field of view with the added assemblies.
First I built up a ring using layers of plastic shim stock. The idea is that the inner ring is the surface while the outer ring matches the lens outer diameter. There is now room for the hood to screw in between the inner ring and the aluminum ring cut from the 58 mm lens hood (that has a 62 mm filter thread. After lots of work, the key parts are from left to right, the ring made of layers of plastic shim stock assembled with super glue, the ring to attach to the lens cut from a 58 mm lens hood and the 62 mm lens hood. Not shown is the metal 67 mm lens cap.
(https://astronomy.toups.info/shared_images/final_3_parts.jpg)
Note the ring fits easily into the 62 mm lens hood that serves as the lens cap.
(https://astronomy.toups.info/shared_images/final_ring_in_cap.jpg)
Now the shim stock ring is put into the the ring that will be press fit onto the lens and the hood cap is screwed on the shim stock ring is pushed until the orange ring is against the hood cap edge. This positions the black portion of the shim stock ring to be just above the edge of the press fit ring.
(https://astronomy.toups.info/shared_images/final_ready_to_pess_fit.jpg)
Here is the lens with the lens cap including the metal cap after press fitting everything together.
(https://astronomy.toups.info/shared_images/final_all_together.jpg)
Without the lens cap at far focus and close focus.
(https://astronomy.toups.info/shared_images/final_inf.jpg)
(https://astronomy.toups.info/shared_images/final_close.jpg)
Of course this sounds easier than it turned out to be. First, the orange shim ring was originally much wider than the final version to allow the assembly to be glued together. In the this image are the raw parts.
(https://astronomy.toups.info/shared_images/final_preassembly.jpg)
Next the orange ring was placed in the press fit ring and the smaller black shim was glued to it. In this image the two larger black shims that form the inner ring have been placed inside the orange/black ring but haven't been slid to the proper position. Note these are all over length compared to the final assembly.
(https://astronomy.toups.info/shared_images/final_shim_assembly.jpg)
After some sanding of the orange black ring to square up the surfaces and positioning and gluing the larger black inner ring shims, the ring was sanded until it reached the final 1.75 mm orange ring thickness. Then the entire assembly was sanded until about 4.25 mm tall. This was done so that the shim ring sticks just past the end of the press fit ring. The complicating factor is that I wanted the shim assembly and the press fit assembly to not limit the field of view of the lens but the inner shim ring to cover the entire felt seal ring when the lens is at close focus. The good news is that this is possible if the shim ring extends to the shoulder of the lens at infinity focus, it will then just completely cover the felt ring at closest focus. This does not leave a lot of room for error. Speaking of room for error, I had to sand the inner shim ring a bit so that I ended up with the correct fit where there is some but very little drag due to the felt ring touching the inner shim ring. This was in spite of test fitting all the shim stock pieces before assembly. Somehow after gluing, it ended up a bit too small so some sanding was needed.
All in all, I happy with the way this turned out; it just turned out to be a longer project than originally anticipated. Of course a lot of the difficulty was self inflicted.
P.S. In spite of good hopes for the Bircfhwood Casey Aluminum Black Metal Finish, it really didn't leave much of a permanent finish for me.