Teardowns and Disassembly

Silent Changes

Published July 15, 2013

Every so often I get an email asking me to jump in on some forum argument or other. I rarely do that because of the language barrier.

Two of the common languages spoken on forums are CAKWAF (Complete, Absolute Knowledge Without Any Facts) and AFIDAWAB (Any Facts I Don’t Agree With Are Bullstuff). Since I am not fluent in those languages, I tend not to get involved in the more, uhm, enthusiastic online discussions. But sometimes I can’t help myself, repeating the behavior of adding facts to a ‘vigorous’ discussion and always expecting a different result.

This happened recently when a discussion occurred about what the original poster called ‘silent upgrades’ to lenses. As someone who takes apart lenses and cameras for my day job, I did confirm to that person that over the lifespan of a lens, some internal changes may occur and the camera companies don’t make announcements about them. (I don’t like the term ‘silent upgrade’ because such changes aren’t always an upgrade, it may be something as simple as a new vendor supplying a slightly different part. There also seem to be times when the change is actually a downgrade.)

Most of the responses to my statement were written in CAKWAF and AFIDAWAB. Responses claimed with absolute certainty there were laws that prevented any changes once a lens was released unless they were announced (there aren’t). Other people, based on owning two different copies of a certain lens, stated with absolute certainty there were never any changes in the 10-year production cycle of that lens (there were, I’ve seen them). Rather than responding with words, I thought it would be simpler to just take apart a couple of lenses.

The Canon 85 f/1.8 is a very good, reasonably priced lens that’s been popular for two decades. Its external appearance and optical formula have been unchanged for that entire time. It also has a tendency to get dust under the front group, so (because we’re a rental house and people expect to rent clean lenses – not because the dust mattered to photographs) we take them apart to clean them quite often. So here are two copies of the Canon 85mm f/1.8 with the front group removed for cleaning. One of these things is not quite like the other.


A 6-month old Canon 85mm f/1.8 (left) and an 18-month old copy (right).


While identical on the outside, identical optically, and identical in function, the newer one seems to be missing a circuit board. Notice the slot that the connecting wires go through on their way to the main PCB (circuit board) on the back of the lens is still there. There just aren’t any wires going through it.

If we take the mount of the two lenses off, we can see other differences in the PCBs.


A 6-month old Canon 85mm f/1.8 (left) and an 18-month old copy (right).


Obviously the newer version doesn’t have the 5 soldered wires coming up from the accessory board (6 o’clock on the older version) because the circuit board isn’t there. The new PCB board doesn’t even have the solder points to attach those wires and there are some other minor differences in the circuit traces on the PCBs. I didn’t take the PCBs out to show you the bottom side, but if I had you would notice that all the functions of the DC/DC conversion board (the board missing from the newer copy) have been added to the main PCB in the newer copies.

Does it make any difference whatever in how the new copies work compared to the old copies? Nope. I suspect it’s simply that advances in electronics since the lens was first released make it simpler and more cost effective to eliminate the secondary DC/DC conversion board and incorporate those functions into the main PCB. It hasn’t been done to address any reliability issues (the 85 f/1.8 is a rock, it  hardly ever breaks), it doesn’t change function at all, it’s probably just more cost effective.

Sometimes changes like this that occur during the life of a lens (or camera) are done to address a problem. I can think of a half-dozen examples off of the top of my head; a few announced by the manufacturer but most not announced.

These aren’t always ‘secret upgrades’ as the paranoid among us like to think, but sometimes they are. Most often, though, they’re simply a change in subassembly supplier or a more effective way to manufacture a part, like this one.


Roger Cicala


July, 2013

Author: Roger Cicala

I’m Roger and I am the founder of Lensrentals.com. Hailed as one of the optic nerds here, I enjoy shooting collimated light through 30X microscope objectives in my spare time. When I do take real pictures I like using something different: a Medium format, or Pentax K1, or a Sony RX1R.

Posted in Teardowns and Disassembly
  • Deron

    Hi Roger…

    Do you know if Sigma do this as well…I’m very tempted by an 85mm 1.4 of theirs but hear horror stories about focusing.

    If I knew they’d upgraded their process, I’d be inclined to dip my toe in the water.

  • Bill

    To Lyle, regarding the D600. I sent mine into Nikon on July 29th. They suggested I send it in after looking at samples of my spots on images taken before and shortly after a professional cleaning. The repair is covered by warranty and is categorized as B2, meaning “Moderate Repair: Major Parts Replaced.” It is now on a “Parts Hold” status because their major east coast repair facility is awaiting the part. They haven’t told me what the part is, but Thom Hogan on his site says he has received several messages from readers that their shutter mechanism was replaced. So I suspect there has been an upgrade to some part, possibly the shutter mechanism.

    On a separate note, the recent Lens Rentals article about repair rates mentions that Nikon has one of the longest repair times. I’m certainly experiencing that. My camera has been “Parts Hold” for about a week and they told me after I called yesterday that it wasn’t expected until 8/21, more than another week from now. It’s unbelievable that any parts needed for repairs are out of stock that long. Since I’m trying to establish myself as a photographer, it’s very disruptive to be without my best camera for so long. Obviously I need a second quality body. Despite the expense involved, I may switch to Canon because of this experience. Maybe not, but I’m giving it serious consideration.

  • Mika

    Thanks, I have to say you are doing invaluable service just by listing so many data points on your rental catalogue, not to mention adding some pressure to the manufacturers to improve the quality of service and the overall build quality of their lenses. It’s great to hear about the under the hood changes too!

  • Roger Cicala


    On both of those I haven’t seen any changes in the last 4 years, but it’s possible some were made before that. I’ve only been taking things apart for about 4 years.

  • Mika

    Hey Roger, a long time lurker here, thanks for the great work you have done on this blog! I’m a bit curious whether Canon 24-70 mark 1 has actually been changed silently, what I heard is that the newer objectives performed better?

    I should ask the same question of 50/1.2L, for a long there seems to have been rumors swirling that a later change in the internal lens construction has decreased the focus inconsistency. I have no idea whether this holds any truth at all, and if the change is simply because of better AF routines in newer camera bodies?

  • Chester

    Thanks for the article!
    I guess it’s reasonable to expect changes to a lens model that has been in production for a long time. I’m curious about whether Nikon does this too. If I took apart a 20 year old 50/1.4 AF-D and compared it to a new one, the differences (if any besides more dust/wear in the older one) would be interesting.

    Off topic…but your robots.txt file is awesome. I was curious and got rickrolled 😀

  • BryanM

    I guess the ‘light leak’ fix on the 5D 3 wasn’t quite so silent! Or do I have a 5D 3.1 ??

  • Interesting and useful post… excellent comments too. Thanks!

  • Roger Cicala

    You guys busted me – I thought I’d sneak that 855 out before anyone noticed. Ah, well, it’s kind of like a fingerprint: you can tell I really wrote it because there are always a couple of typos.


  • Arun H

    Chris – re the 855mm f/1.8 lens… I saw it too, but observe that it has been corrected. A silent change to an article about silent changes. How cool is that!

  • Roger Cicala

    Hi Will,

    I do the Lens Repair report every year that shows the most frequently repaired lenses (2013 should be done by the end of the month), but 2012 is here: http://wordpress.lensrentals.com/2012/09/lensrentals-repair-data-january-july-2012

    The most reliable lenses tend to be prime lenses without IS systems, especially primes that are f/1.8 or less maximum aperture.

  • Will Frostmill

    Hi Roger,
    I thought the most interesting thing was your offhand comment about the lens being a ‘rock’, that it hardly ever breaks. Do you suppose you could tell us about other notably durable lenses?

  • Lyle


    I wonder if you have noticed any internal changes to the D600 (recent copies) given all the dust issues. I have one of the original, so clean as required however, would be interesting to see if Nikon did make any changes to mitigate the issue.



  • Chris Stone

    Silent upgrades not only happen to lenses, but also to cameras. The Pentax LX was in production for just over twenty (20) years. There are some reports that during this twenty year production period the Pentax LX underwent some 300 changes of which only about 10 were visible without disassembling the camera.


    Chris Stone

  • Dr Croubie’s reply is the most entertaining, and I can only imagine how hard it is to keep components the same over 20+ years for some of these products. How many suppliers have gone out of business alone over those years.

    I also wonder how many changes might have been made by necessity after the earthquake.

  • Bob Dobbs

    Hey, even people with decades of engineering experience can’t come to a consensus! At least the vocabulary is more elegant than your typical forum participant’s is.

  • Paul Pantea

    Great article, very interesting.
    I think you meant July 2013, though.

  • Bruce Rubenstein

    I work for an aerospace company. I’m a certified Configuration Management specialist. I manage engineering change control for our supplier manufactured equipment. There are differences between the commercial world and the one I’m in, but the concepts are the same.

    Of the thousands of changes I’ve looked at, the number one reason for change of electronic related equipment is some form of obsolescence of active components. RoHS Compliance is also significant factor in components no longer being available. At the point that obsolescence requires a redesign, a more comprehensive redesign may be done for reasons such as cost savings. Most changes have a number of associated costs, so saving a few cents on a part (particularly lowish volume items like camera lenses), make little economic sense. Changes for reliability or manufacturing reason are much less common and generally take place early in a product’s life.

    When a manufacturer re-identifies an item (lens/body) with a new part number is mostly a marketing move. Lenses and cameras are not end user reparable, so there is no need, or requirement, to publicize internal changes. Only authorized, independent repair companies need to know about the changes that effect repairs.

  • Dr Croubie

    Already mentioned are price-savings and obsolesence as reasons for silently changing things.
    There’s also the third option, which has constituted most of my experience in PCB design, “crap, this doesn’t all fit on the one board!” … “Just put it on an ‘add-on’ board, we’ll fix it in Rev 2”.

  • “I suspect it’s simply that advances in electronics since the lens was first released make it simpler and more cost effective to eliminate the secondary DC/DC conversion board and incorporate those functions into the main PCB.”

    It could also be that some of the components used became obsolete and the board was tweaked to accommodate the change. That’s something that you have to deal with when you produce electronics.

  • BozillaNZ

    Electrical upgrade happens a lot, at least in Canon lenses. 50 1.4 has two versions of PCB, the newer one has less IC’s on it so it’s more integrated and likely cheaper. The 300 F4L has two types of electronic guts, old one is a mess, it has several soft flex PCB’s intervened together with IC’s soldered ON the soft flex cables, a nightmare to maintain. The newer one is just a single circular cut PCB like a modern models. I suppose most of the electrical changes are indeed ‘upgrades’. But for other mechanical or optical ones I can’t be sure.

  • As a retired quality engineer from the old space biz, I have read that the japanese are famous for requiring departments to suggest ways to reduce product cost by 5%/year (hey, it’s a Kaizan thingy). Since I do not work for Canon on the EF 85 f:1.8 project/program, I would simply suggest Roger is correct most of the mods are for cost savings.

    Of course Kevin Purcell is correct that component obsolescence may also be responsible. We faced this issue all the time and were forced to make modifications while continuing to meet the original product requirements.

    While there are many reasons for form, fit and function changes, many will be minor and do not change the primary requirements for the product. Since the modification did not change a requirement, there is no reason to change the model number, and the customer expectations/perception for performance are the same. Most companies will manage the parts using traceability methods such as serial numbers and/or date codes to maintain (repair) the many changes during a products life cycle.

    Most engineers despise configuration management (they hate changing drawings), but we QE’s continued to keep them in line.

  • JV

    Roger, thanks for the post. The “silent upgrades” are done on almost every product in every industry – cars, laptops, cameras, microprocessors.

    It takes time for the manufacturing to stabilize. As with software, there will always be bugs when manufacturing ramps. Some changes fix the bugs while others address cost reduction, yield, reliability, supplier changes, etc. Depending on the change they can be an upgrade or a downgrade.

    Some people believe that there is an optimal time to purchase a product. If you buy too early you don’t get the bug fixes. If you buy too late you get potential downgrades when the manufacturer tries to reduce costs.

  • Engineering sense says that these changes (for better or worse) are often because a part that the old design relied on is going out of production (“end of life”) but the lens company wants to keep making the lens.

    For mechanical changes the QA/production engineers/support staff have noticed that particular parts may fail in a particular way fail or are more difficult to adjust than they could be and so need a minor redesign.

    The effort behind these maintainace changes is not trivial. You need a good reason (and a better one that subbing a 10c part for a 5c part) to make these changes. The effort in doing a minor redesign and verifying the design and putting it into production then training support staff to maintain the new hardware are considerable.

    People who haven’t shipped a product (either software or hardware) rarely consider the process of making and supporting a product is more than a single person designing and building a prototype.

    I don’t mean Roger here. Clearly LensRentals has excellent processes in place to maintain their product quality that are similar to production engineering processes. I’m talking about the forum authors who write in CAKWAF and AFIDAWAB.

  • Peter

    Common sense says that these changes (for better or worse) are all for cost reasons.

  • Karl

    How soon do you think Rosetta Stone will offer courses in CAKWAF and AFIDAWAB?

    These lenses sure are prettier on the outside than the inside.

  • A 6-month old Canon 855mm f/1.8 (left) and an 18-month old copy (right).

    …Wow, an _855_mm f/1.8 lens? Where can I get one? 😉

Follow on Feedly