Repair: Zoom-Nikkor 28-85 f/3.5-4.5 Ai-S

Hello, everybody! I love underdogs. In fact, I always cheer for them in every sport. Underdogs aren’t expected to win but they usually do and even if the other side won they usually exhibit admirable traits that you could say that they have won the game in the hearts of everyone watching the game. They are usually held in great esteem by both sides due to this trait, you can even say that they are crowd favorites. Today, we’ll talk about such an underdog, a lens that many people don’t expect to perform well just because it’s an old, variable-aperture zoom but it does its job, it does it better than expected. It’s also cheap these days and that adds to its appeal.

Introduction:

The Zoom-Nikkor 28-85mm f/3.5-4.5 Ai-S debuted in 1985 but it was still for sale new up until 2005, 20 years after it was unveiled. It’s a practical lens, it has a useful focal range and a useful gimmick wherein it can extend itself at 28mm, giving it the ability to focus even closer, like having a built-in macro extension ring. The maximum speed is merely f/3.5 at 28mm and f/4.5 at the 85mm end. While a 28mm f/3.5 lens is acceptable, an 85mm f/4.5 lens can be a bit awkward to use. This limits its usefulness at the long-end but this is an industry-standard these days for cheap zooms.

Unlike many Zoom-Nikkors of its time this one isn’t a “pumper-zoom”, it has a proper zoom ring and a separate focusing ring like most modern zooms. It also has a 3rd ring near the aperture ring that enable you to extend it just a bit more at 28mm so you can take close-ups. There are 2 more lines near its centerline indicating the centerlines for infrared photography. There are 2 dots indicating the real aperture of the lens at either end of the focal range, green for 28mm and orange for 85mm. I don’t like variable-aperture zooms, it makes manual exposure a bit more difficult since you have to factor-in its real aperture when taking an exposure.

Like most zoom lenses this one has a complicated optical formula. This one has a 15-elements-in-11-groups design, not a lot more complicated than the usual zoom lens of its class but it had to be this way. It could’ve been a more complicated design if the engineers were allowed to make a bigger lens but compromises have to be made so it ended-up having modest specifications but it’s still useful despite that fact.

The build quality is not bad at all specially if you consider how things are in modern times but the build feels a bit cheap compared to premium Nikkors like the Zoom-Nikkor 80-200mm f/4 Ai-S. The focusing ring feels comfortable to handle with its broad rubber grip, the zoom ring feels cheap because the ribbed pattern was molded-into the ring itself, making it confusing since it’s easy to mistake it for the macro ring and vice-versa. Plastics were also used and that’s one of the reasons why it feels cheap.

Who’s complaining now? The AF-Nikkor 28-85mm f/3.5-4.5 was mostly made from cheap plastic like many things that were made in the late 1980s. These seem to share the same optical formula if I am not mistaken and they even share the same “macro” gimmick. The dimensions look similar and you can see the relationship between the two.

It’s a great lens to pair with a smaller Nikon like the Nikon FM3A but it’s also a good partner for bigger Nikons such as a Nikon F4. It balances really well with most Nikons to say the least.

This is how compact it is at when collapsed. It’s not small at all but it’s not a big lens that you can’t fit inside a little camera bag, it’s still small-enough for travel but its weight may stress your neck at the end of a long day.

It extends to this length at 28mm, it’s still “compact” but I wish that it would remain small at the other end of the focal range.

It’s going to be front-heavy for smaller setups, an autowinder would be nice and that would balance things out.

It’s going to be awkward when you extend it to 28mm but thankfully you’ll have the luxury to use slower shutter speeds at the wide-end to counter the offset in balance when the barrel is extended.

(Click to enlarge)

This is how different the framing is at both ends of the focal range for those who are wondering. It’s ample and it gives you the flexibility needed when shooting random things for general photography. All you need is one lens in place of 3 separate prime lenses. A zoom lens enables you to experiment or play with your composition, this convenience alone makes zoom lenses the choice for shooting news, events or wedding photography where you won’t have the luxury of changing lenses.

It’s important to understand how your lens work in order to maximize it so take your time to know more about it. I took these photos with the iris set to f/3.5 (f/4.5), f/5.6 and f/8 from left-to-right, these are the most common f-stops that most people will want to use this lens with (I assume). These shots will help you see its weaknesses and its strengths so you’ll know when to use it and how to avoid or maximize its weaknesses. I shot this with a Nikon Df.

(Click to enlarge)

As expected, the distortion looks horrible at 28mm. Vignetting is heavy, too. It’s terrible wide-open and you’ll still see traces of it by f/5.6 and f/8. Lots of zoom lenses fare terrible in this aspect.

By around 58mm or so the distortion is near-negligible. To be honest, this is not as bad as the Zoom-Nikkor 43-86mm f/3.5 Ai where things can look a bit wacky depending on what you’re shooting and which focal length it’s in.

You’ll get the classic pincushion-type distortion profile at 85mm. Needless to say, you can use the horrible distortion at both ends to your creative vision. You can use this to make your subjects look slimmer/wider if you know the trick.

(Click to enlarge)

Ghosts aren’t much of a problem for this lens but flaring is. I’m impressed at how it manages to keep the ghosts under-control but at the same time I hate seeing flare and how it lowers the contrast of my frame.

You won’t get much in terms of blobs but you will get this rainbow-colored ring if you have strong light sources in your scene such as the sun. You will want to use a hood for this just-in-case.

I am actually impressed by the image quality of this lens, it’s not the best, it has plenty of flaws that you get to expect from most zoom lenses but they’re not as bad as I expected.

(Click to enlarge)

Sharpness is more than decent wide-open but this won’t rival prime lenses. It can produce a delicate “blooming” effects caused by spherical aberration which you can see in some of the out-of-focus details. Chromatic aberration seems to be well-controlled which I wasn’t expecting to be honest. Another surprise is the bokeh quality doesn’t look bad at all. In fact, it looks great for a zoom lens from this era. Contrast is good but it’s nothing like what people are used to seeing from modern lenses, this still retains a vintage-look to its photos which you will either love or hate. Stopping the iris down to f/5.6 can give you great results as the lens can resolve details much better and you’re able to focus on more things due to the deeper depth-of-field. You won’t get any spherical aberration from this point or at least you won’t notice it much unless you really tried hard to look for it. This is the best aperture if you ask me, the image quality looks great but you still retain a bit of “character” and your photos won’t look as boring. This seems to operate at its peak by f/8, it’s very sharp at the center and the edges don’t look bad, too. Of course, prime lenses will perform much better but this doesn’t look bad either.

I shot this expecting to see some chromatic aberration but I didn’t get any or at least they’re not that obvious, impressive for a zoom lens from this era.

One of the appealing points of this is the ability to shoot “macro photos” at 28mm, just twist the ring to enable this to shoot at macro mode and you can focus a lot closer at 28mm. It’s a handy feature that you’ll use a lot. It’s sharp and you can see how nice the resolution is despite being shot wide-open. It’s going to improve once you stop the iris down a bit.

Here’s another sample photo, this is useful for wedding photographers who like to shoot small details such as wedding rings and the details of the cake or the contents of the invitation. The bokeh balls have some outlines but it’s not bad at all. The transition from what’s focused to what’s not seems nice, it looks smooth as far as I can see.

This is another example showing the focus transition qualities of this lens. I like how natural the scene looks, you won’t get a “wall-of-focus” from this. It is a very capable lens in most regards.

(Click to enlarge)

Here are more photos that were taken up-close at the shortest distance with the macro gimmick. I initially poo-poo’d this but it seems to be the feature I use the most with this lens.

Let’s now see some photos that were taken with film. This was designed for film so we should judge it with its intended medium. Film has a unique look that’s hard to simulate with a digital camera because of grain. It helps hide flaws or amplifies some things depending on the situation. I love using film, I think it’s the best way to enjoy photography. I used Fujifilm Industrial 100 and my Nikon FM3A for these photos.

This is how that rings and flare look like with film. I’m OK with the flare but the rings are distracting. I took this photo intentionally to demonstrate this, my daughter looks so happy here despite the lighting condition.

I finally managed to make this lens render ghosts, I had to shoot this scene just to get this to show some blobs. This is great news since you won’t see it do this on normal shooting conditions.

This was taken at 1/30s or so, it was hard to do this hand-held but I got away with it. You won’t notice any distortion in this photo because there’s no lines here or should I say that there are no straight lines here in the scene.

You can always shoot at around 60mm if you want to avoid distorting lines. I would never shoot this with either end of the zoom range.

This shot was a bit over-exposed, unfortunately. The focus transition is nice, it’s smooth and it’s not distracting at all. What’s distracting is the character of the bokeh, it’s not bad at all.

Despite not having straight lines that are parallel to the frame you can still see some of it here at the top of the scene.

Using this lens in low-light situations can be challenging specially if you are using a low-ISO film. The maximum aperture of this lens is slow, shooting at f/3.5 or f/4.5 can be problematic in this scenario.

(Click to enlarge)

Please enjoy the rest of the set here. It perfectly demonstrates just how good this lens is and the practical applications for it. It’s handy for travel and you can get more shots with it compared to a prime lens because of its flexibility and the macro gimmick. I enjoyed using this lens a lot.

I highly recommend this lens to everyone, from beginners to professionals. It’s a nice lens for documentary work in the field, being a manual-only lens means that there are less things that will get broken and dust or water will not foul anything unlike the more-complicated autofocus lenses which are more fragile than this thing. While not having professional-looking specs, it is more than sufficient to satisfy a pro’s needs in good lighting conditions. It is also inexpensive so you can treat it as a disposable lens when working in hostile or unsafe areas of the world, you won’t feel that bad losing one, the pictures in the camera are actually more valuable than this lens. It’s a great lens for students or amateurs on a budget, you’ll learn a lot from using it. It is a great lens for teaching you how to be patient, the practical focal range is handy so it means that you can make a living with this lens alone. When it’s time to shop for one, make sure that you get the accessory hood, too. That is necessary if you want to counter its biggest weakness – flaring. The only bad side to this lens in terms of cost is the expensive 62mm filters it takes which is more expensive than the traditional 52mm ones. It’s an off diameter and they sometimes cost more than the bigger ones depending on availability. It also makes them a bit more difficult to source in the used market. I am sure that somebody reading this will find this to be the perfect lens for them and I hope that my article will help guide them in their decision.

Before We Begin:

If this is your first attempt at repairing a lens then I suggest that you check my previous posts regarding screws & driversgrease and other things. Also read what I wrote about the tools that you’ll need to fix your Nikkors.

I suggest that you read these primers before you begin (for beginners):

Reading these primers should lessen the chance of ruining your lens if you are a novice. Before opening up any lens, always look for other people who have done so in Youtube or the internet. Information is scarce, vague and scattered (that is why I started this) but you can still find some information if you search carefully.

I highly recommend that you read my working with helicoids post because this is very important and getting it wrong can ruin your day. If I can force you to read this, I would. It is that important!

For more advanced topics, you can read my fungus removal post as a start. This post has a lot of useful information and it will be beneficial for you to read this.

Disassembly (Exterior Barrel and Optics):

This is probably the easiest part of the whole teardown but you should be a bit more careful when you remove a few things specially the rear elements assembly and the middle elements assemblies. These things were aligned at the factory, if you got them wrong you will end up with a lens that can only focus to infinity properly at one end of the focusing range. Making marks is a nice idea, the marks don’t have to be deep but they should be easy to see. I also take photos just in case. Some parts were sealed with lacquer or paint, I would usually scratch the parts that were sealed with paint since they don’t react to solvents. Parts that were sealed with lacquer is easy since alcohol is sufficient enough to soften the seal. There are many shims that you will find in this step and you should never lose or warp any of them. You’ll encounter some plastic parts here and you should be careful not to melt or craze their surfaces with solvent or heat. Needless to say, this lens is not for beginners. I would highly recommend that you send this to a qualified repairman for a real overhaul. If you don’t have the tools or skills then just skip this for now.

The front elements assembly can be removed with a lens spanner. If this is stuck simply apply a few drops of solvent to soften the seal and try again at a later time.

Here’s another view showing how it was sealed. It’s sealed with black paint, a sharp knife will help you break the seal.

Carefully remove it and store it in a safe place.

Never misplace any of these shims. These are used for adjusting the focus of this lens.

The 2nd optical assembly is recessed, you should zoom the lens in-or-out to make it rise and use a lens spanner with longer bits to reach it. This can be tricky to remove because you may scratch the glass.

Extract it with a lens sucker.

There’s a shim here as well, don’t lose it.

Before you do anything with the bayonet, study how deep or shallow it goes into the barrel.

The bayonet can be removed after extracting these. Only use JIS drivers, if you are new to lens repair please read my article on how to remove bayonet screws. Many people strip these because they don’t know how to work with these, follow my article to prevent this from happening to you.

It should come-off rather easily, be careful with the long stop-down lever as it can catch on something within the lens.

The aperture ring can then be removed.

Next is the base for the bayonet.

There are more shims here, never lose or warp any of these.

This is the iris regulator ring. Carefully remove it and don’t forget to put this back the right way.

The rear elements assembly can be removed with a lens spanner or with a gloved hand if your grip is strong enough.

Note that there’s another shim here.

The 3rd optical assembly can be reached with the help of a lens spanner. It’s deep-within the barrel and only a lens spanner with long bits will reach it.

Zoom the barrel until it’s shallow-enough for you to reach it.

This part is adjustable so make a mark to remind you how it should fit. I use a small mark as a reminder. Extracting the screws will allow you to remove it.

The grip is secured by these screws.

Carefully remove it and clean any dirt you find here.

This is a beautifully-casted part, it’s intricately molded.

Carefully remove the rubber grip to reveal the screws underneath it. This is a delicate part so make sure not to tear it.

These screws secure the focusing ring.

You can easily remove the focusing ring once the screws are gone. I made a small mark to note the infinity mark but it’s pointless here, really.

I made a small mark to note how the inner barrel should be aligned with its centerline. This is very important and will come in handy later.

Set aside all of the assemblies that have optics in them and put them inside a container for safety. Clean all of the parts very well and make sure to get rid of all of the residue from any old grease or oil so they won’t contaminate the lens later.

Disassembly (Cams and Inner Barrel):

This is the most confusing part of the whole thing because it’s like a puzzle. I am used to working with zooms but I always hated working on this part. It is easily the most time-consuming part of the process. You will have to note all of the parts and their alignment at infinity just so you’ll have a reference later during reassembly. There are many rollers here and you should not be confused with where they should go. You’ll have to deal with rollers, too. It’s annoying to remove them and you can’t use strong solvents or heat to work with these. You should take plenty of photos of the cams and barrels before you remove any part, you really have to treat this like a mini-puzzle.

These screws secure the rails of the cam, you can remove them now or later depending on your mood.

Carefully extract these to remove the holder of the 3rd elements assembly.

Make sure that you put this back the right way later. Note that it’s greasy, oil can easily migrate to the iris and optics from this part.

The rails/cradle can be easily removed, it also houses the iris mechanism.

This is the helicoid key, it’s being secured by these screws.

Like all helicoids you will want to mark where it separated because this will also be the same place where it should mate. Many people don’t do this and they end up stuck so read my article on how to work with helicoids.

Remove the helicoid key. The grease looks fine but it should be replaced just to make sure that this lens will stay working for a long time.

The grease is starting to migrate and it’s not a good sign. Remove the screws you see here and you can remove the sleeve.

The sleeve can be removed like this, revealing the delicate cams under it.

It’s a good idea to make small marks here so you’ll know how things align. I usually make several of these just to make sure.

This is the spring for the macro feature of this lens.

You can remove this ring if you want to.

Extracting the screw will allow you to remove the spring, revealing a small ball-bearing. It’s a good thing that it didn’t fall to the ground or I might have lost it.

This photo shows how complicated the zoom/macro cam mechanism is. It’s not an easy task to put this back together again once you disassembled it.

Carefully remove these rollers. These are usually sealed so it’s best to use a bit of alcohol to soften the seals, never heat these as the heat may melt them and cause an even bigger damage.

Clean the rollers ver well. Note the white residue on the threads, that’s what is left of the seal that I was talking about.

This is another roller that you should removed.

Here’s another one.

These rollers are shorter. Clean these really well before putting them back.

The basket for the front elements assembly can now be removed. Clean the helicoid very well.

I made a scratch so I will know how things should align when I reinstall it.

Remove these large rollers.

These are the largest rollers in the barrel.

You can now remove the inner barrel.

This is the mechanism for the “macro” feature, it’s basically just a ring that extends a cam.

This is the adjuster for the spring that secures the ring. You’ll have to take a lot of notes or make some marks like I did so you will know how to put this back again later in the right position.

The ring can now be removed after carefully wiggling it out.

This is how the spring looks like, it’s basically a cantilever spring with a tab that locks the ring into place at either end of the macro cam’s range. If you look at the photo you will notice that one’s longer, that’s the button.

Take plenty of notes before you proceed so you’ll know how to put this back together again.

This is just a mark so I’ll know how things should align at a given end.

Remove these rollers.

These ones, too.

This is the guide nut.

Carefully remove the base and clean everything really well.

The parts here are greasy and the only way to clean them is to soak them in strong kitchen detergent for some time and then scrub them clean using the stiffest brush you have at home. I usually finish the process by soaking the lot in an alcohol vat, that will kill all the germs, take care of residue and also remove any smell.

Disassembly (Optics):

You won’t have to follow this part if all you need to do is to re-lubricate your lens. If there’s just a bit of dust inside these optical assemblies then you can just leave them alone, opening these up can be risky, these were adjusted at the factory so you can focus the lens perfectly at either end. You will have to be very careful with the rear optical assembly and the central ones, they’re responsible for proper focus. If you got rear optical assembly off, even by a little bit, the focus won’t be perfect, resulting in a lens that will focus fine on one end of the focal range and miss on the other end. It can be annoying to adjust this so do this at your own risk.

The front element is being secured with by a retainer ring, a lens spanner is required to open this up.

Remove the retainer carefully, if it’s sealed you’ll have to apply alcohol to it and wait for it to melt the seal.

Remove the front element carefully.

This is simple enough to open-up.

This one, too.

Avoid opening the rear optical assembly if you have to but if you must, just apply a drop of alcohol on the thread to soften the seals. Using a pipe-key is the best way to open this part.

This is where you should apply some alcohol if you have to open this thing up but only if you have to.

I won’t do this if I have to, zoom lenses can be delicate and the alignment of the parts are crucial. Clean everything really well if you can to get rid of any germs and oil before you put anything back.

Conclusion:

I always hated working with zoom lenses, even using them isn’t enjoyable. I prefer prime lenses and will use one any time of the day over a zoom. There will be times when working with a zoom lens is interesting and this is just a good example of that since the assembly isn’t as complicated as the others. I probably spent around 4-5 hours on this thing, an average for zoom lenses since it takes a lot of time cleaning everything.

It’s now time to adjust the focus. Put everything back to this state and you’re able to adjust the focus, make sure you do it for both ends of the focal range to make sure that you got it right. To know more about how to do this, read my article on how to adjust a lens’ focus.

Thanks for all the support, this blog is now more than 5-years-old and this won’t last this long without your help. To enable this blog to continue and help more people in the future, please help support this blog. That is going to help me offset the cost of maintenance for this blog and the cost of film and its development. The most important thing is we continue to help and entertain the next generation of photographers. See you again, Ric.

Help Support this Blog:

Maintaining this blog requires money to operate. If you think that this site has helped you or you want to show your support by helping with the site’s upkeep, you can make a small donation to my paypal.com (richardHaw888@gmail.com). Money is not my prime motivation for this blog and I believe that I have enough to run this but you can help me make this site (and the companion facebook page) grow.

Buy me a roll of film or a burger?

Thank you very much for your continued support!

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Helping support this site will ensure that this will be kept going as long as I have the time and energy for this. I would appreciate it if you just leave out your name or details like your country’s name or other information so that the donations will totally be anonymous. This is a labor of love and I intend to keep it that way for as long as I can. Ric.

1 Comment (+add yours?)

  1. Trackback: Repair: Zoom-Nikkor 28-50mm f/3.5 Ai-S | Richard Haw's Classic Nikon Repair and Review

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