Repair: Nikon SP/S3/S4/F Shutter Speed Calibration

Hello, Everybody! How are you guys today? I’m stuck at home today to take care of baby. It was a very tiring day because my toddler is full of energy! Cameras are like humans in a way in that they come out of the factory working fine but as they age and wear it will begin to show and the performance will deteriorate. I am in my mid-life and I feel like an old man now as the years of abuse is finally taking it’s toll on my health. The good thing with cameras is that you can fix them to a certain extent or change the parts to make it work closer to factory specifications and today, I am going to show you how to perform a simple maintenance routine for your 60 year-old Nikon SP/S3/F cameras!

IMG_4329Look at all the yummy food! This sushi place has an all-girl staff. I would rather prefer to eat one prepared by a pretty young woman than a middle-aged Japanese chef obviously.

I performed a partial overhaul on my Nikon SP. I got it as junk so I had to spend plenty of time reviving this thing to at least get it to a decent operating condition. The viewfinder took the most time because it is the most complicated thing on the camera and the finder of the Nikon SP is legendary for being ahead of it’s time and equally legendary for being a very difficult instrument to clean! Of course, the helicoid had to be cleaned as well but I left the serrated wheel pretty much intact because it requires me to tear the rubber skin off from the front (right side) of the camera.

The shutter speed was also tested using my shutter tester and it proved to be accurate on the slower speeds below 1/60s but it is firing too fast on 1/1000s and 1/500s. If the speed is just off by 1/3 of a stop then I can still live with that but at times 1/1000s gives me around 1/1750s to 1/2700s and that is way more than what I can consider to be acceptable! This is something that had to be fixed and so I did not waste any time and quickly went to work!

Now, you may be wondering why I wrote Nikon SP/S3/S4/F in the title of the article but I am only showing you the Nikon SP here. The reason behind this is because the Nikon SP chassis is the basis for the Nikon S3, F and S4! The basic schematics should be similar on these 4 cameras so having knowledge on one is also applicable to the rest.

WARNING!!! Please read the following!!!

This is a VERY DELICATE operation that requires specialised equipment and experience. I will admit that this task is way beyond my skills but I did it anyway. Follow this at your risk and I will not be held responsible for any damage done to your camera! This is only for your education/entertainment so you will know how things work or how it is fixed. If your camera’s shutter speed needs to be calibrated then send it to the people who do this professionally such as these people in the list below.

You can also try asking the local camera repair guy but be aware that there are plenty of people with mediocre skills selling their services! They are probably just as skilled as me or even worse! I only do this for my own benefit so the only person I harm is myself if I made a mistake.

Before We Begin:

If this is the first attempt at opening a lens then I suggest that you read my previous posts regarding screws & driversgrease and other things. Also read regarding the tools that you will need in order to fix your Nikkors.

I highly 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 beginner. Also before opening up any lens, always look for other people who have done so in Youtube and 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 also 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 here and there and it will be beneficial for you to read this.

About Me:

I am a photographer based in Tokyo who scours the junk section of the camera shops here on a regular basis. I started this hobby of fixing old lenses and cameras because I kept on getting scammed before when I purchase online. This turned out to be a blessing because I now buy junk lenses for a fraction of the price and then fix them to add to my growing now collection. This allowed me to buy gear that were otherwise off-limits to me if I were to get them in better condition.

I was a scale modeller before who built models for other collectors for a very longtime, got an education as a dental prosthodontist (but didn’t pursue dentistry) and growing up in a watch repair shop gave me the useful skills that would help me in this craft. Fixing my car also contributed some know-how.

Having mentioned the above, I will tell you now that I am not a professional repairman! So please take what I do with a grain of salt and I will never be held responsible for anything wrong that will happen to you and your project. I hope that the pros would guide and teach us but nobody is writing anything.

As my collection of repair notes grew, I get requests from people with similar interests and from professionals who just needed some notes just in case. Now, I am sharing my library with you for your entertainment and reference. I hope that you find my work useful.

Testing:

What is the point of showing you how to calibrate your shutter speeds if I wouldn’t show you how to test it? Here are the methods that are easily accessible to you. These methods are old-school but seem to be reliable enough for our purpose.

 

Here is a video of me testing my Nikon S3’s shutter speed and you can see from the video above that the speeds are spot-on! This is what I was expecting from my Nikon SP but it was unfortunate that it had to be fixed.

There are many ways to test your camera’s shutter speeds at home. One is to close all the lights on your room and with the camera (without lens) facing a CRT monitor TV, press the shutter and take note of how wide the slit is (between the curtains) as you actuate the shutter. For example, if 1/250s gives you a slit of 1cm then 1/125s should give you a slit as wide as 2cm and 1/500s should give you a slit that is around 5mm wide. Do you get what I am trying to say? Now, if the distances between the speeds are not even then you have a defective camera. Of course, this is not accurate but it is a quick way to see wether you have a good working camera or not.

Another way is to simply listen by ear and by cross-checking it with another camera that you have that is known to have an accurate shutter speed. A digital camera is a good one for this because they are electronically controlled and they are made in the past decade to the present, very young compared to our old junkers. A recent film camera is also fine for this job. For this, simply test each speed with both cameras and then make a mental note as to which speeds sounds off. I do this while on camera shops because I don’t have access to my equipment and I can make a quick judgement on-the-spot.

The best way available for the amateur is to buy shutter speed testers online. There are plenty of sellers and they come in a variety of form and prices. I recommend that you get those that are activated by light and not sound as these are more accurate. There are also apps that you can download for your smart devices that do not require special hardware to operate. I will not recommend a certain manufacturer or brand at the moment yet. I’m currently using something that is activated by light and for what it is worth, it seems to be fairly accurate for my purpose.

Calibration:

Before you begin, protect the shutter first by taping a card over it or setting the shutter to T and then press on the shutter so the aperture (gate) is left open. Both ways will ensure that your finger will not poke on the shutter by accident while you do the first few steps in this exercise. You should also remove any lens that is attached to the camera so that it will not be damaged accidentally as you work on the camera.

IMG_4350First, remove the camera’s back and then unscrew these 4 screws to remove the bottom plate. This plate protects the delicate parts underneath it so go about it carefully. Be sure to use a driver that fits properly or else you will ruin the screws’ slots!

IMG_4351Notice the encircled part. These two worm gears are connected to the little cogs that are responsible for the curtain springs’ tension. Loosening or tightening these will make the shutter curtains travel faster or slower.

IMG_4352I marked them with dots so I will know which gear is in charge of which curtain. Usually, you will only need to calibrate the rear curtain’s travel only so do not touch anything that is related to the front curtain or you will get an ugly black bar in your exposures!

wormgearPlease study the diagram above carefully. The worm gears drives the tensioning gears. It (worm gear) is being secured by a set screw that you need to loosen first. The worm gear is hidden underneath the casing but the head is accessible and this part is what you want to adjust. The little set screw is usually secured by lacquer or something else so use some alcohol or acetone to soften it up first before you loosen the set screw. Make sure that its clean before you proceed! There is no excuse for sloppiness in this part of the camera!

Below are the steps (ordered) that you need to do:

  1. Carefully loosen the set screw but do not remove it from the casing/housing.
  2. Loosen (CCW) or tighten (CW) the the worm gear depending on what you need.
  3. Check all speeds with your shutter tester.
  4. Repeat steps 2 and 3 until you are satisfied.
  5. Tighten the set screw and apply nail polish or lacquer paint to secure it.
  6. Put the base plate back in place.

There are no set guidelines in adjusting the worm gears apart from not turning them too much. Usually, a quarter-turn is enough but cases vary. I also learned that there are cases when tightening the screw will retard the shutter. This is totally opposite to conventional wisdom but this was the case with this particular Nikon SP. Just see what is working with you and just follow your common sense. This can be tedious and may take you an hour  or so to do as you go back from steps 2 and 3 but it is all worth it!

My Nikon SP’s shutter speed is still a bit off but it is much more accurate than before. Its not as accurate as my Nikon S3 but at least it is within my accepted tolerance. Now, all I have to do is shoot a test roll with camera and look at the index print. I used an expired Kodak film for this that I got for less than $1. Sure, it is going to be less consistent but for my purpose, it is more than enough.

IMG_4354The moment of truth! Look at the index print and see for yourself! frames 1-5 were shot with the same aperture but the speed is different. It looks OK to me! The rest were shot with different speeds and aperture changes that correspond to the speed difference of a stop in succession. The exposure looks even so this means that 1/1000s is firing properly up to 1/60s! These speeds matter to me the most so I was more than happy to see this!

Prevention:

What causes this problem? leaving the shutter cocked is what is causing these springs to store tension longer than they was designed to. It was also specified in the Nikon camera manuals so this is something that you should never do! Leaving it this way (cocked) over-night is long enough and when done regularly or left in that state for too long, the spring will wear out over time and cause this to happen.

I make it a point that I do not leave the shutter cocked for too long on all of my cameras with horizontal-travelling curtains like this one to prevent this from happening. While there are other sources that can cause this like gummed-up grease inside each spring’s housing or the curtain getting in contact with something else inside and those will have to be repaired in differently, this is the first thing that you should attempt and see wether it will work or not.

Conclusion:

Overall, I am happy with the job I did with the Nikon SP. Again, I advise that you just give this to a professional to work on specially if it is an expensive camera like a Nikon SP. It will be the wiser thing to do as they should have the spare parts or know-how to revive a bad spring/drum back to it’s factory tolerances. I have ran a couple of rolls with this one now and the negatives all came out predictably as expected. Success!

IMG_4355My Nikon SP keeping me company while I finish this bowl of Japanese-style Chinese food. All that MSG makes my sight fuzzy and “bokelicious“.

Here we are again at the end of another blog post! Wow, all this blogging business is very tiring so I hope that you are enjoying my blog. If you love my blog, please share this with your friends or help support it. I am using the fund to pay for the upkeep like paying for the domain,etc. I am also using it to buy me a few rolls of film from a big Jewish business that I will not name unless they support me 😉 Thank you very much! Keep shining, 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 upkeep of this site, you can simple make a small donation to my paypal.com account (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.

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 and other information so that the donations will totally be anonymous it is at all possible. This is a labor of love and I intend to keep it that way for as long as I can. Ric.

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