NikonGear'23

Gear Talk => What the Nerds Do => Topic started by: richardHaw on May 28, 2016, 18:22:18

Title: Dismantling the 35mm f/2.8 Ai
Post by: richardHaw on May 28, 2016, 18:22:18
https://richardhaw.com/2016/05/28/repair-nikkor-35mm-f2-8-ai/
Just finished the latest post in my repair blog :o :o :o
pretty simple lens.
Title: Re: Dismantling the 35mm f/1.2 Ai
Post by: Thomas G on May 28, 2016, 19:09:12
Richard, the title says: 35/1.2  :o I think I may like one  8)

The article is a pleasure to read and full of valuable knowledge, even if you consider it a simple lens yourself.
Thank you.
Title: Re: Dismantling the 35mm f/1.2 Ai
Post by: Jacques Pochoy on May 28, 2016, 19:11:46
As for each of your articles, this one is a real pleasure to read, almost as mesmerizing as a Conan Doyle novel :D. While I don't mess anymore with my lenses and cameras, I do find those mechanical and optical feats fascinating !
I'm happy now, as I have a very good shop with Nikon credentials that do it for me, as he even salvage old parts (to his boss annoyance, about using space in the shop) so I can have some AI'sed lenses with the original second hand parts, just as some thorough cleaning of my lenses.

Still, I think it's almost a lost art in our kleenex world and applaud your sharing it with the rest of the world... :)
Title: Re: Dismantling the 35mm f/1.2 Ai
Post by: richardHaw on May 29, 2016, 02:11:04
Richard, the title says: 35/1.2  :o I think I may like one  8)

The article is a pleasure to read and full of valuable knowledge, even if you consider it a simple lens yourself.
Thank you.

Thanks, Thomas!
The title was corrected :o :o :o
It is pretty simple. Its like a VW beetle for people who wanted to start car restoration or a seiko 5 for watchmakers ::)
but as usual, beginners will screw their first attempt. that's normal :D
Title: Re: Dismantling the 35mm f/1.2 Ai
Post by: richardHaw on May 29, 2016, 02:14:50
As for each of your articles, this one is a real pleasure to read, almost as mesmerizing as a Conan Doyle novel :D. While I don't mess anymore with my lenses and cameras, I do find those mechanical and optical feats fascinating !
I'm happy now, as I have a very good shop with Nikon credentials that do it for me, as he even salvage old parts (to his boss annoyance, about using space in the shop) so I can have some AI'sed lenses with the original second hand parts, just as some thorough cleaning of my lenses.

Still, I think it's almost a lost art in our kleenex world and applaud your sharing it with the rest of the world... :)
Thanks, Jacques! that was very encouraging!
i hope that my guides are useful for beginners and veteran repairmen. it is always nice to see someone do it before you do so that you know what to fix and expect. just last night, my notes came in handy for a repairman of 40 years :o :o :o somebody gave him a lens with the helicoids undone and with my notes, he saved plenty of time looking for where the helicoids should mate ::)
Title: Re: Dismantling the 35mm f/2.8 Ai
Post by: Akira on May 29, 2016, 02:34:11
A thorough write up, as always, Rick!

The Ai 35/2.8 is allegedly the best 35/2.8 ever made.  I'm looking for one, but it is rarely seen.  I actually see one less often than Ais.
Title: Re: Dismantling the 35mm f/2.8 Ai
Post by: richardHaw on May 29, 2016, 04:28:29
A thorough write up, as always, Rick!

The Ai 35/2.8 is allegedly the best 35/2.8 ever made.  I'm looking for one, but it is rarely seen.  I actually see one less often than Ais.

Thanks, Akira. I see them from time to time here in Shinjuku. I saw one yesterday at the camera bazaar in Shibuya Tokyo selling for 8,000 :o :o :o
If you want, I can buy one for you when I see one. just give me your max budget and you can just get it from me in Shinjuku.
Title: Re: Dismantling the 35mm f/2.8 Ai
Post by: richardHaw on May 29, 2016, 08:49:28
 :o :o :o
Title: Re: Dismantling the 35mm f/2.8 Ai
Post by: Roland Vink on May 30, 2016, 02:18:03
The Ai 35/2.8 is allegedly the best 35/2.8 ever made.  I'm looking for one, but it is rarely seen.  I actually see one less often than Ais.
There are two AI 35/2.8 versions which are quite different:

The first continues from the K (New Nikkor) version. It can be distinguished by DOF scale under the focus ring. The K version has serial numbers from 773111 (many of these are AI converted), continuing to the AI version 851001. This is the version with 6 elements in 6 groups which is said to be the best among the 35/2.8 versions. Distortion is very low and sharpness is good, I think bokeh is smoother for the old version though.

Mid way during AI production the 35/2.8 was replaced with a new model. It has a shorter focus throw and DOF scale level with the focus ring, serial numbers from 350001. This is the one Richard is repairing. It has 5 elements in 5 groups. It has a less good reputation, barrel distortion is a bit higher and sharpness may be less, but in my limited use it performs very well. The AIS has the same optics and a slightly longer focus throw.
Title: Re: Dismantling the 35mm f/2.8 Ai
Post by: richardHaw on May 30, 2016, 03:10:25
There are two AI 35/2.8 versions which are quite different:

The first continues from the K (New Nikkor) version. It can be distinguished by DOF scale under the focus ring. The K version has serial numbers from 773111 (many of these are AI converted), continuing to the AI version 851001. This is the version with 6 elements in 6 groups which is said to be the best among the 35/2.8 versions. Distortion is very low and sharpness is good, I think bokeh is smoother for the old version though.

Mid way during AI production the 35/2.8 was replaced with a new model. It has a shorter focus throw and DOF scale level with the focus ring, serial numbers from 350001. This is the one Richard is repairing. It has 5 elements in 5 groups. It has a less good reputation, barrel distortion is a bit higher and sharpness may be less, but in my limited use it performs very well. The AIS has the same optics and a slightly longer focus throw.

aaaaarg  :o :o :o

now i have to look for it ::)
Title: Re: Dismantling the 35mm f/2.8 Ai
Post by: Akira on May 30, 2016, 04:45:09
Thanks, Akira. I see them from time to time here in Shinjuku. I saw one yesterday at the camera bazaar in Shibuya Tokyo selling for 8,000 :o :o :o
If you want, I can buy one for you when I see one. just give me your max budget and you can just get it from me in Shinjuku.

Rick, thanks very much for your kind offer.  At this moment, I have to spend my money for different stuffs, so my camera equipment purchase plan is on hold now (for a good reason, though).

There are two AI 35/2.8 versions which are quite different:

Roland, thanks for sharing your insight.  I took it granted that the optical design was changed along with the Ai was replaced with Ais.  Of course, I was looking for the 6-element version.  I'll be careful if any chance arises.
Title: Re: Dismantling the 35mm f/2.8 Ai
Post by: richardHaw on May 30, 2016, 05:59:08
i might get one tonight :o :o :o
new-nikkor
Title: Re: Dismantling the 35mm f/2.8 Ai
Post by: richardHaw on May 30, 2016, 17:39:13
OK, i just bought 2. a really nice K version and a beat-up Ai. Now, can I just swap the aperture rings on these 2? :o :o :o
Title: Re: Dismantling the 35mm f/2.8 Ai
Post by: John Geerts on May 30, 2016, 17:55:15
I think so, I swapped it with a 24/2.8 AI and that worked perfectly.
Title: Re: Dismantling the 35mm f/2.8 Ai
Post by: richardHaw on May 30, 2016, 18:04:10
From a 35mm?  :o :o :o
I hope it works, sometimes nikon would update the insides without people knowing. This is prevalent during the pre ai days
Title: Re: Dismantling the 35mm f/2.8 Ai
Post by: John Geerts on May 30, 2016, 18:13:34
Yes, I made the 35/2.8 ai  and the 24/2.8 non-ai by swapping the aperture rings.
Title: Re: Dismantling the 35mm f/2.8 Ai
Post by: richardHaw on May 31, 2016, 02:22:19
Yes, I made the 35/2.8 ai  and the 24/2.8 non-ai by swapping the aperture rings.
i see. if they have the same Ai kit then it should be OK :o :o :o
that was interesting by the way
Title: Re: Dismantling the 35mm f/2.8 Ai
Post by: pluton on May 31, 2016, 20:27:08
Just a note about optical performance of the 6 element 35/2.8 K/Ai based ONLY on my two samples of the 6 element Ai version.
I recently took both lenses out for a comparative test spin and found that on a flat subject at about 3 meters, and again at about infinity, the area at the frame margins (the edge to about 5 or 6mm in) is noticeably blurrier than the center area. Stopping down improves contrast and therefore the impression of 'SDS' (small detail sharpness), but the slight blur...in comparison to center... never completely goes away.  I suspect, but presently have no way to determine, that in the later 5-element version, the designers may have sacrificed the distortion correction of the 6 element unit for improved edge SDS.  Subject for future research...
Title: Re: Dismantling the 35mm f/2.8 Ai
Post by: Akira on May 31, 2016, 22:20:35
Just a note about optical performance of the 6 element 35/2.8 K/Ai based ONLY on my two samples of the 6 element Ai version.
I recently took both lenses out for a comparative test spin and found that on a flat subject at about 3 meters, and again at about infinity, the area at the frame margins (the edge to about 5 or 6mm in) is noticeably blurrier than the center area. Stopping down improves contrast and therefore the impression of 'SDS' (small detail sharpness), but the slight blur...in comparison to center... never completely goes away.  I suspect, but presently have no way to determine, that in the later 5-element version, the designers may have sacrificed the distortion correction of the 6 element unit for improved edge SDS.  Subject for future research...

Keith, thanks for sharing your real-world impression.  I've never used any Nikkor 35/2.8 from any generation.  So, I would hold off one until I receive any further info either from you or the others.
Title: Re: Dismantling the 35mm f/2.8 Ai
Post by: richardHaw on June 01, 2016, 02:28:09
yaiks. OK, I will do a test when mine comes. I ordered 2  :o :o :o
Title: Re: Dismantling the 35mm f/2.8 Ai
Post by: Hugh_3170 on June 01, 2016, 03:03:16
Some of these possibilities are also alluded to in the Ai Conversion section of Roland Vinks excellent Nikon lens web site.

Handy to know information, since the factory made Ai rings are getting very hard to find now.

Yes, I made the 35/2.8 ai  and the 24/2.8 non-ai by swapping the aperture rings.

i see. if they have the same Ai kit then it should be OK :o :o :o
that was interesting by the way
Title: Re: Dismantling the 35mm f/2.8 Ai
Post by: richardHaw on June 01, 2016, 03:44:15
Some of these possibilities are also alluded to in the Ai Conversion section of Roland Vinks excellent Nikon lens web site.

so, should i referencing it by the Ai kit number?  :o :o :o
Title: Re: Dismantling the 35mm f/2.8 Ai
Post by: Roland Vink on June 01, 2016, 04:11:58
Reference for Nikon AI modifications:
http://photosynthesis.co.nz/nikon/aimod.html

Comment:
"The New Nikkors (K type) have very uniform styling but every model still has a different part, even lenses with the same general form and aperture range such as the 300/4.5 and 300/4.5 ED, and the 24/2.8, 28/2.8 and 35/2.8. It might turn out that some of these can be interchanged with little or no modification."

I haven't had a chance to check whether this is true or not...
Title: Re: Dismantling the 35mm f/2.8 Ai
Post by: richardHaw on June 01, 2016, 04:37:57
I see. the older generation is very different. I have opened no less than 30 of them and sometimes, from the same model there would be small differences inside like how the objective was secured, if a part was chromed or not, tolerances and how the aperture fork worked,etc. very small details but enough to prevent people from interchanging parts. :o :o :o
Title: Re: Dismantling the 35mm f/2.8 Ai
Post by: John Geerts on June 01, 2016, 08:00:30
Just a note about optical performance of the 6 element 35/2.8 K/Ai based ONLY on my two samples of the 6 element Ai version.
I recently took both lenses out for a comparative test spin and found that on a flat subject at about 3 meters, and again at about infinity, the area at the frame margins (the edge to about 5 or 6mm in) is noticeably blurrier than the center area. Stopping down improves contrast and therefore the impression of 'SDS' (small detail sharpness), but the slight blur...in comparison to center... never completely goes away.  I suspect, but presently have no way to determine, that in the later 5-element version, the designers may have sacrificed the distortion correction of the 6 element unit for improved edge SDS.  Subject for future research...
I am not sure what you exactly mean. I haven't noticed anything serious, but I didn't really test it thoroughly.

This is an uncorrected file from the 35/2.8  serial 791138
Title: Re: Dismantling the 35mm f/2.8 Ai
Post by: pluton on June 06, 2016, 07:07:24
John, here's a full D800E resolution file that shows what I saw.  Shot at f/8 and long focus distance...the closer 3-meter test shots are deleted.  Both my lens samples performed identically.
At small size or low resolution output, it doesn't matter.  But if you were constructing compositions where it had to give the impression of constant "sharpness" all the way from the center to the FX frame edge, it might matter.
Title: Re: Dismantling the 35mm f/2.8 Ai
Post by: richardHaw on June 06, 2016, 08:09:04
Now that I have both lenses. I can probably make a test as well.

I did check for the smearing but it seems to be OK on mine. I may have to do some more tests. Can you please give me some parameters to work with? :o :o :o
Title: Re: Dismantling the 35mm f/2.8 Ai
Post by: pluton on June 06, 2016, 20:24:05
Find a convenient wall or side of building that has lots of texture.  Tripod about 4 or 5 meters away, camera sensor parallel to wall, live view focus (or your best eye focus) at the center only, shoot f/2.8, 4, 5.6, 8, etc. without changing the focus at all.
Repeat with second lens, without moving camera in any way.
Repeat, if possible, in a different location featuring long distance subject, say, buildings across a wide street or a rooftop view of the city.
Here's my convenient testing wall, shot with iPhone:


 By the way, thanks for sharing your lens dismantling experience here and in the blog!
Title: Re: Dismantling the 35mm f/2.8 Ai
Post by: richardHaw on June 07, 2016, 03:42:54
Thanks, Pluton!

silly me, I was dismantling a different lens for this post! but nevermind, I will write a proper dismantling of the earlier 35mm f/2.8 as both lenses are very different mechanically. :o :o :o
Title: Re: Dismantling the 35mm f/2.8 Ai
Post by: pluton on June 07, 2016, 06:31:26
At the risk of going overboard with lens comparisons after already have committed the infraction of going off subject, here is a link to a Dropbox folder of full size, minimum compressed JPEG files of a series I did this afternoon at my usual test spot.  D800E, Aperture Priority AE, ISO 100, tripod, exact same raw treatment to all. Featuring the 35/2.8 K/Ai, the 17-35/2.8@35mm, the Zeiss ZF35/2, and the last [and, the last choice] lens I have capable of 35mm, the Zoom-Nikkor 25-50/4@ 35mm.  The file names contain the necessary ID for the frames.
https://www.dropbox.com/sh/wmvl0w890kw5z77/AACra_JYhRzBaLlzLuQqqorWa?dl=0 (https://www.dropbox.com/sh/wmvl0w890kw5z77/AACra_JYhRzBaLlzLuQqqorWa?dl=0)
Title: Re: Dismantling the 35mm f/2.8 Ai
Post by: pluton on June 07, 2016, 06:36:22
Thanks, Pluton!

silly me, I was dismantling a different lens for this post! but nevermind, I will write a proper dismantling of the earlier 35mm f/2.8 as both lenses are very different mechanically. :o :o :o
I need to adjust the infinity focus on both of my copies...one is really way off.  It's an ideal lens for zone focusing due to the expanded focus scale.  Please include a mention of how to do it in your now-hotly anticipated write-up.
Title: Re: Dismantling the 35mm f/2.8 Ai
Post by: richardHaw on June 07, 2016, 07:28:27
Hi, for which lens? I could post my notes here since i have opened both now. :o :o :o
mine is a little off after i fixed it but it looks OK on my test (shooting out of my window focusing on a far away building)
Title: Re: Dismantling the 35mm f/2.8 Ai
Post by: Erik Lund on June 07, 2016, 11:09:15
Shooting through glass is really not recommended for infinity focus test/calibration,,,
Title: Re: Dismantling the 35mm f/2.8 Ai
Post by: richardHaw on June 07, 2016, 11:32:13
i open the window of course :o :o :o

for now its safe. no mosquitoes yet.
Title: Re: Dismantling the 35mm f/2.8 Ai
Post by: pluton on June 07, 2016, 19:01:56
Mine are the earlier, 6-element K/Ai.  My JIS screwdrivers are too fat to access some of the screws.