36~72mm f/3.5 Nikon Lens Series E. What I couldn’t have then and now I have two!
Looking at the universe of Nikon lenses, for a beginner to tinker on lenses, I have no doubt this should be the first zoom lens a new comer could work on. Why not first lens? Well, the first should be a short prime lens, like a 50mm f/1.8, simpler to learn from. Why not some other kit lenses? The 43-86/3.5 is very complex, the AFD, AFG and AFS zoom lenses are a pain to work on (I have worked on 3 AFG lenses). Other lenses like the 35-70mm f/3.3-4.5 AiS could be other first zoom disassembly pieces, but they are more expensive and so mistakes can be more costly. The 75-150/3.5 E is also suitable, cost wise, for first time assembly, but it is more complex than this lens.
A short history: along with EM, affectionately known as the “Little Nikon”, Nikon released a then new series of lenses made affordable by choosing plastic parts, simplified constructions, simpler optical design. The Nikon Lens Series E was born. A few of the lenses were rated highly (e.g 75-150mm f/3.5 E – I have 3 copies), others were average (e.g. 28mm f/2.8 E – I had one which I used extensively until I bought a 28mm f/2.8 Ai). Inferior in built as per 1979, they are in 2016 far better built than current plastic AFS lenses. I had limited experience with this series, having used only the 2 lenses mentioned earlier, now 3. Anyhow, a desire to play with affordable equipment of yesterday and tinker with lens repair brought me to some lenses in this series.
Price on the advert (RRP): 36-72mm f/3.5 E ¥45,000. Price in January 1985 was US$111.95 (Adorama advertisement, Modern Photography Jan 85 issue). In comparison the 35-105mm f/3.5-4.5 AiS was US$219.95, about double in price.
While the purpose of this write-up is not about the optical performance, some short review is probably desirable.
In general the reviews are mixed in responses. Some like it a lot, e.g. Bjørn Rørslett (someone I respect highly) calls it a true gem (Lens “porn” with the Df: 36-72 mm f/3.5 Nikon SE http://nikongear.net/revival/index.php?topic=576.0). In another NikonGear thread, Nikon Series E – 36-72/3.5 (http://nikongear.net/revival/index.php?topic=694.0), wonderful photos taken by this humble lens can be seen. I might add that Bjørn likes to use it reversed, “Among its lesser known capabilities is applying it as a true ‘macro’ lens.” When used reverse, “What you need is the 36-72 itself, and paraphernalia such as a +4T achromatic close-up lens, a few K4/K5 rings to act as spacers, a BR2/2a or equivalent , and preferable something to act as lens shade in front.” (Lens “porn” thread).
One internet reviewer said that it is a good lens considering its cheap price point, not the best choice for consistent performance in multiple scenarios (paraphrased, note quoting source as I am not familiar enough with the reviewer’s technique to draw conclusions, the reader can easily do an internet search and find that and other reviews).
My 3-line review:
- Nice and adequately sharp, but not at the modern zoom standard
- Flares easily, need do re-evaluate after thorough cleanup?
- No third line yet, haven’t tried it reversed
Enough talk, some photographs.
It was August when I bought this lens. Singapore’s National Day was on 9 August 1965. Nikon Df, 36~72mm f/3.5 E, ISO 100, 1/60 f/8
High Rise Living. Nikon Df 36~72mm f/3.5 1/250 f/11, ISO 100
Optical and Mechanical Constructions
Optical construction (8/8) (diagram at 72mm).
Exploded Diagram. Looks complicated (red annotation mine).
Major parts of the lens:
- 2-piece focusing ring: collar with rubber grip, and ring with distance scale
- 3-piece zoom mechanism: front zoom tube, zoom helicoid and zoom ring; under the DOF/Index collar (total 4 parts)
- FOU (front optical unit) with helicoid couples with front zoom tube
- MOU (mid optical unit), AU (aperture unit) and ROU (rear optical unit); together as “inner group” couples with zoom helicoid
- Zoom ring when moves from 72mm (shortest) to 36mm (longest) pushes FOU forward and inner groups backwards
- Bayonet mount is of 2-piece construction (unusual)
- 3 optical units – FOU with 3 elements, MOU with 1 element and ROU with 4 elements.
Before we begin
Disclaimer: all information in this blog is meant for sharing of experience and not as instruction, and is no substitute for diligent learning and assessment of competence. I have messed up my fair share of lenses, and will not be held responsible for any damage caused in the reader’s venture into this fascinating world of mechanical and optical marvel.
You should be conversant with lens repair techniques; beginners should read my earlier blog posts – the Lens Repair series, and Richard Haw’s excellent write-ups (Camera and Lens Repair Essentials, Best Practices (part 1), Best Practices (part 2), Best Practices (part 3) and Working with Helicoids).
We will start from the front. Set lens focusing ring to infinity and aperture to minimum.
Do note that the photographs were not taken in sequence – some photos have other parts of the lens disassembled (or not); I will note them as we go along.
3 tiny set screws hold the FOU to the focusing collar, loosen these screws (don’t need to remove). These 3 set screws are used to set infinity. Lift off the focusing collar. Examine the collar for an internal bar that will couple with the focusing ring.
Slot on the left couples with the focusing collar so the ring turns with the collar. FOU helicoid just visible. Left hand thread, slowly turn the FOU clockwise (view from top) and observe the point when the helicoids separate
X marks the spot with respect to index to take guess work out of reassembly. Set FOU aside.
A little shim holds the focusing ring to the front zoom tube. Remove the screws, note orientation. MOU visible. Pull out the focusing ring – note felt that gives resistance to zooming and focusing (no photo).
Photo with focusing ring taken off, and front zoom tube fully extended (36mm) – note helicoid grooves that couple with the FOU. Locate the three screws on the chrome grip, remove these screws and pull the DOF/Index tube out.
DOF/Index tube out and front zoom tube fully extended, marked 36 to the index dot on chrome grip. (Note: photograph taken out of sequence – you should still have your rear mount if you are following this step-by-step). When one touch zooming, the front zoom tube is pushed forwards or backwards, and the rollers move along the helicoid grooves, rotating the zoom ring along the grooves.
Fully retracted at 72mm (ditto photo taken out of sequence)
Coming from the rear…
Turn lens the other way round, and note there are 5 screws. Photo orientation – top is aligned with Index Mark. Look carefully you will see 3 through holes for long screws holding the bayonet plate and 2 non-through hole, short screws holding the shims.
Use a tweezer and lift up the bayonet plate. Remember the bayonet mount is of 2-piece construction!
Gently pull out the aperture ring – if you pull too hard the bayonet mount will come as well, and there is additional coupling to observe there. Note the leaf spring and the slot (just in sight within the right inner part of the ring) for aperture clicking and coupling.
Time to review the rear without removing the bayonet mount. (Photo not taken in sequence – this was an early photo before I cleaned out the rear). Of particular interest is the coupling on the left that goes into the groove in the aperture ring. Also see the ridges that couple with the leaf spring for aperture detent. (also the focusing ring, DOF/Index Tube should have been removed in this photo).
Now lift off the bayonet mount, there may be a slight tug by the stop-down lever so tilt the lifting slightly to allow the hook to disengage from the lens stop-down coupling. Some shims may come off with the bayonet mount as well.
A few shims line the interface between the bayonet mount and the chrome grip. (Note: photo taken out of sequence – focusing ring removed).
Remove shims and note couplings. There is a removable aperture coupling ring here. Clockwise from top – aperture coupling from aperture coupling ring (soon to be removed) to aperture mechanism, aperture coupling ring to the aperture ring, post to align shims (arrow) and stop-down coupling. Note the slanted groove to keep aperture constant while zooming. I think the lens if constructed today will have a straight groove, and marketed as a f/2.8-3.5 zoom, which it is if the lens is not forced to close down a little at wide end. Lift off the aperture coupling ring.
Aperture coupling ring mentioned in previous step. One of these couples with the aperture mechanism, the other with the aperture ring.
This is a good point to use a lens spanner to remove the ROG. Set aside.
Where we are now. 3 tubes – front zoom tube (inner most), zoom helicoid (centre), zoom ring (outer). Note the zoom rollers – long grooves to move front zoom tube, short grooves to move MOU/AU/ROU. MOU/AU still within this assembly.
View from front, zoom guide roller, groove and plate.
View from front, zoom guide roller screws holding MOU/AU/ROU
Note and mark orientation of front zoom tube (photo taken out of sequence). Screw hole aligns with Index Mark.
Set lens at 36mm (longest), using finger to hold the plate, carefully unscrew the zoom guide roller for the front zoom tube (long grooves). 3 guide rollers and 3 plates.
Again note orientation, remove 3 guide rollers for the MOG/AU (support it while doing this) and the MOU/AU comes off. O dear, one of the guide rollers is different!
Front view of MOU/AU. Straight line marks orientation with Index Mark, x marks the spot where guide roller is different.
Rear View of MOU/AU. Spring for aperture actuation.
Note orientation between chrome grip and zoom helicoid. Remove 3 screws holding the chrome grip to the zoom helicoid (the only parts fixed aside from the mount when zooming), remove chrome grip. May need solvent and a bit of gentle knocking.
2 shims between chrome grip and zoom ring. Zoom ring is confined by the chrome grip and the zoom helicoid. Slide the zoom helicoid forward to separate it from the zoom ring.
Mechanical Disassembly complete!
There should be 2 parts to clean and re-grease:
- FOU/front zoom tube greasing for focusing ring action
- Zoom helicoid and zoom ring, as evident with some gooey stuff
FOU/front zoom re-greasing please follow Richard Haw’s instruction in links given earlier.
Note sure how to deal with the zoom helicoid and zoom ring. I will update this when I figure this out!
Cleaning of lens elements
Front optical unit (FOU)
FOU – pardon the markings, too many is better than too few, in pencil, easily erased. Note the twin short grooves – lens spanner to access elements.
Retainer, E1/E2, spacer E3. Note orientation of elements with pencil at the side of the lens elements. Clean them, and reassemble.
Mid optical unit (MOU)
2 sets of dimples – outer removes the group (exposing the aperture mechanism), inner to access element 4. Note: photo taken out of sequence – in this case E4 was removed without getting to the zoom helicoid.
Use sucker to remove E4. Pencil mark orientation – arrow points away from camera. Clean it, reassemble.
Rear optical unit (ROU)
Lens spanner to open retainer to E8.
E5 – some solvent treatment needed to soften adhesive, the retainer ring can be removed. Use sucker to remove E6, E7. I later found that I could carefully pour out all the elements (E5 through E8) from the front after removing the retainer ring.
From Left: retainer, E5, E6, E7, ROU casing
From Left: ROU casing, spacer, E8, retainer. Clean them, reassemble.
What is not provided
- Instructions on cleaning, re-greasing (see Richard’s guidance)
- Guidance on accessing and cleaning aperture assembly – still learning this part
- Assemble FOU, set aside
- Assemble ROU, set aside – place E8 on retainer, put spacer and then E7, slip the ROU casing over it and carefully fasten the retainer ring. Place E6 and let it slide in, slow, then E5, again it slide, tighten retainer ring.
- Return MOU to AU, set aside
- Insert zoom helicoid into zoom ring, replace shims
- Align chrome grip with zoom helicoid, fasten 3 screws
- Turn zoom ring to align 36mm with index mark
- Align MOU/AU with zoom helicoid, put it into inside and align screw hole with zoom helicoid/zoom ring, replace guide roller, partially fasten, replace 2 other zoom rollers, noting the position of unique guide roller. When all in place, fasten all 3 zoom rollers
- Insert front zoom tube (fully extended) into zoom helicoid, align, with finger holding plate, replace and fasten partially guide roller, repeat for all 3 rollers. When all in place, fasten all 3 zoom rollers.
- Screw in the ROU.
- Replace aperture coupling ring, ensuring the coupling fit into AU coupling. Align and move coupling to minimum aperture (or maximum aperture).
- Replace shims, using shim guide post to position shims.
- Replace bayonet mount, carefully coupling (angling) the stop-down coupling into the stop-down lever. Align lens mount screw holes.
- Replace aperture ring, ensuring coupling slot on aperture ring engages aperture coupling ring correctly.
- Replace bayonet plate, carefully aligning the screw holes.
- Partially fasten 3 long screws (positions 0, 120, 240 deg), then 2 short screws. When all in place, fasten completely, making sure screw heads are flushed.
- Replace DOF/Index tube, aligning the marking and screw holes on chrome grip. Fasten 3 screws.
- Align focusing ring (distance scale) and insert into lens body, replace shim, note orientation, fasten 3 screws.
- Find helicoid separation point on FOU, re-engage the helicoid with the front zoom tube, return to minimum position.
- With focusing ring set at infinity, replace focusing collar by aligning the strip and the groove.
Infinity focus adjustment
- Mount lens on camera, and adjust for infinity focus (far away subject) by adjusting the FOU helicoid position.
- Tighten 3 set screws to fix the infinity point.
Well, the proof of the pudding is in the eating – does it work or have I made some mistakes along the way?
A mistake I did make and this is the result.
Backed to the work bench, removed ROU, removed all lens elements and examined markings, hah E7 was oriented wrongly. So I reassembled the lens, and out again to test the lens.
Hey it works – how many pointed stars?
This was my first complete disassembly of a zoom lens and working from no instructions no less (other than some over simple description and 2 partial disassembly Japanese blog). The exploded diagram was quite useless to me, although when done I could see where everything was and understood the exploded diagram.
The venerable 43-86/3.5 was too complex for a first lens to disassemble, even with detailed instructions (Richard Haw’s blog and Daito Camera’s Youtube video). And I stopped work, re-assembled (and checked that they worked). I will return to work on them on a later date (both non-Ai and Ai versions, slightly different in construction).
My cautious nature has prevented me from disassembling the 75-150/3.5 E, 80-200/4.5 Ai (square baffle), at least not yet, until I am more certain of my skills, and I hate disassembly for the sake of disassembly, for there is nothing really wrong with these lenses in my possession.
The fact that the present 36-72/3.5 E had fungus infestation, albeit a mild one, gave me the motivation to work on it. In a month I will have a sample each of 75-150/3.5 E and 80-200/4.5 (along with a few primes) with some fungus infection (from Richard Haw, who kindly purchased them for me), and I will gleefully accept the challenge to disassemble, clean and restore these lenses. I will make extensive records and take many photographs, but will likely not blog the experience, as Richard Haw had done an excellent job on the 75-150/3.5 E and a similar 80-200/4 AiS.
Until then. Good hunting.
Acknowledgement: Richard’s (remote) guidance gratefully acknowledged. Him being in Tokyo and me in Singapore did not hinder the tutoring process!
- Nikon Series E – 36-72/3.5, NikonGear thread http://nikongear.net/revival/index.php?topic=694.0
- Bjørn Rørslett, Lens “porn” with the Df: 36-72 mm f/3.5 Nikon SE, NikonGear thread http://nikongear.net/revival/index.php?topic=576.0
- Nikon Lens Series E Lenses, Photography in Malaysia, http://www.mir.com.my/rb/photography/hardwares/classics/emfgfg20/eserieslenses/htmls/36150mm.htm
- Nikon 36-72mm f/3.5 Series-E 修理 (in Japanese) http://d.hatena.ne.jp/Hie/touch/20151205
- ジャンクレンズ清掃 Nikon LENS SERIES E Zoom ３６－７２㎜ Ｆ３．５http://upa.get.ph/wp/%E3%82%B8%E3%83%A3%E3%83%B3%E3%82%AF%E3%83%AC%E3%83%B3%E3%82%BA%E6%B8%85%E6%8E%83%E3%80%80nikon-lens-series-e-zoom-%EF%BC%93%EF%BC%96%EF%BC%8D%EF%BC%97%EF%BC%92%E3%8E%9C%E3%80%80%EF%BD%86%EF%BC%93