Liberty Bell Ranger

He was standing on the side, patiently looking at people moving through the exposition leading to the bell. Philadelphia, 2016.

Cleaning a Canon LTM 50mm f1.8 Lens

Sometime ago I bought a Canon 50mm f1.8 LTM lens, also known as Serenar. It had some haze on the internal elements, but between one thing and another it took me a while to get to it and clean it. I managed to remove the haze from all the optical surfaces but one.

One of the internal elements has some haze that doesn’t come off with anything I’ve thrown at it. I tried H2O2, H2O2 with windex (for the ammonia), windex, alcohol, acetone, lighter fluid. None of these worked. My guess is that it is either a coating damage, in which case there is nothing to do, or perhaps it is the doublet that is separating (though it looks to me the haze is on the outside surface, not in between the elements).

I took some pictures of the steps to take the lens apart, since I couldn’t find much online. To take this lens apart you will need a rubber tool. Also, I didn’t lubricate the aperture blades at all after cleaning them. I’m not sure if that’s the way to go, but even the smallest amount of oil was migrating on the blades so I decided not to do it.

 

Use a rubber tool to unscrew the front ring

Use the same rubber tool to unscrew the front element

As you can see, there was haze and what appears to be fungus on the inside of the front element. I used Hydrogen peroxide mixed with ammonia to clear the lens. After that, I used lighter fluid and a cotton swab to remove any residues. I also used a clean microfiber cloth to wipe the lens clean. After that, I used an air blower to get rid of the lint left behind. The front element came out perfect, nothing could be seen with the flashlight test.

With the spanner wrench, remove the outmost ring that keeps the mount attached

The mount part of the lens can be slid off

The mount, with the helicoid, was working fine, so I didn’t take it apart any further

Remove the spacing ring and don’t loose it

You can now unscrew the rear element

Remove the three screws just like the one in the red square in this picture

Remove the pin that controls the aperture

Now the front element mount can come out of the aperture ring

If you want to clean the aperture blades (They were very oily in my lens), remove the brass retaining ring

Now you can remove the slotted ring that controls the aperture

With the aperture controlling ring off (on the left) we can now remove the blades

It might be easier to remove the blades when they are in this configuration. Don’t worry, it looks scary but it is not that hard to remove the blades and put them back in. Just use a good set of tweezers and take your time

One of the blades

You can also, if you haven’t done it already, remove the last doublet. this is the one that has marks on the coating

The blades cleaned and ready to be reassembled

The blades reassembled. Compare this picture with the one before cleaning, and you’ll see how much oil was on them

The aperture ring (the one you move to change aperture once the lens is fully assembled) was stiff, so i decided to take it apart. Remove the screw with the red arrow.

Remove these two screws. The brass spring comes off and be careful not to loose the metal ball that the spring keeps in place. Be sure to scribe the screw position before removing them.

Remove these 4 screws. As before, scribe the position of the screws on the brackets they are holding, so you will be able to put them back in the right position when reassembling.

Remove the last two screws and remove the slotted piece

Remove the brass retaining ring

Now the two pieces come off. Clean them and lubricate them slightly with some grease.

 

Olympus XA2 Meter Adjustment

Despite the similar name, opening and adjusting the meter for the Olympus XA2 is fairly different than doing it for the Olympus XA. Here are a few pictures on how to do it correctly for an Olympus XA2.

Remove the two screws under the rewind crank.

The small potentiometer in the red box controls the light meter of the XA2. Move it around till you get the correct exposure.

Another view of the pesky metal cylinder. Also, note how the previous owner tried to remove the shutter button. In the XA2 that red button doesn’t need to be pried away, but it is screwed in from the bottom.

Remove the central screw in the rewind crank and lift the assembly up.

Put the bottom plate back on with a couple of screws, so you can put the battery in place and power up the camera to check the light meter.

Remove the dust cover, also known as that sliding piece of plastic. Be careful not to loose the small metal cylinder that you see in the middle of the picture.

Remove the bottom plate

Remove the black screw on the side of the top plate. You can now remove the top plate. Be careful not to damage the thin wires that are attached to it (shutter button and beeper)

Remove the 5 bottom screws

Olympus XA Meter Adjustment

As always, I pick up cameras that are for parts on eBay and then I try to fix them. This time I got a cute Olympus XA, a little rangefinder film camera with a 35mm lens. The listing said that it was not turning on at all. After randomly pushing levers inside the camera, I managed to unlock it and after that it started working again. The one problem was the meter that needed adjustment. You can find the service manual here, but it’s not very clear how to regulate the light meter. The following pictures will hopefully help you.

Remove the 5 screws that keep the bottom plate in place

Be careful not to damage the delicate battery contact

Remove the dust dover, in other words that sliding piece of plastic that covers the lens when the camera is not in use. Be careful not to loose that metal rod right next to the film rewind lever.

Replace the bottom plate, since we will need to fit the battery back in and check the meter

Remove the one silver screw

Remove the black screw next to the film spool

Remove the front plate

That potentiometer you see is the one used to adjust the meter

Fix Loose Aperture in a Tele-Elmarit 90mm

I recently bought a Leica Tele-Elmarit 90mm on ebay, in as is condition. It had haze, some cleaning marks on the front element, and the aperture ring had two problems:

1. a lot of radial play,
2. the ring would not stop properly and go slightly past the f16 mark.

While the first problem shouldn’t affect performance, it made the lens feel sloppier and it bothered me a lot. Both these issues were solved with shims.

 

Remove the front ring. In this picture you can also see the damage to the anti-reflective coating of the front element.

With a suction cup, remove the front element

Remove the three set-screws on the aperture ring

Lift up the aperture ring and remove it. Be careful not to loose the spring and the ball underneath it. The ball is pushed by the spring in some grooves under the inner aperture ring. If the aperture ring is not snappy enough, gently bend the spring till you get the result that you want.

Remove the six screws and the mount

Remove the pieces under the mount, and take note of how they go back together. Unscrew to lens from its focusing ring.

The arrows show the radial play of the inner aperture ring. Align the inner aperture ring as shown, and remove the set screw.

Once the set screw is removed, you can unscrew the front element

You can disassemble the front element even further if you want to clean it

Slide off the inner aperture ring

This screw is dragged by the inner aperture ring that was just removed. It travels in a slot, and that limits its movement. The ring travels past f16 because that slot is a little too long. We will place a small shim on the right side later. Remove the screw and gently lift the inner piece (the metal ring to which the screw is attached, and that holds and moves the aperture blades).

Carefully remove the aperture blades

Now it’s a good time to clean them if you want to

Remove the set screw

Unscrew both sides of the outer shell. The lower part is the helicoid that goes in the focus mount, while the top part is where we will do all our work.

here you can see the inner part of the lens, with the focus helicoid next to it. The top part that we just removed is not shown here. You can further dismantle the lens if you want to clean the glass.

Here is the top part from Picture 16, with the shim fitted. Every time you make a new shim or you modify it, put the inner aperture ring on and check the radial play.

I started from a paper dummy shim

Then I used an X-acto knife to cut the actual shims from brass sheet. I used the thinnest I could find, I think it was 1 or 5 thousand of an inch.

The final shim, after a first fitting and with a hole for the set-screw

The ends of the shim are folded and anchored to the end grooves (those are not used by the steel ball of Picture 5). A small amount of glue in those grooves makes sure the shim won’t move.

The shim on the other side

I oiled the shim, and put new grease on the grooves, so the steel ball of Picture 5 will slide easily from one aperture stop to another.

Lastly, I used thicker brass sheet and cut out a few tiny shims to stop the aperture from going past f16

These are small!

Trial and error, two of those shims perfectly stop the aperture at f16. A spot of glue and we are good to go!

Replace the film take-up spool of a Leica CL

Leica CLs have a plastic take-up spool that is prone to breaking. The following pictures guide you through removing the white part of the spool, the one that usually breaks, so you can replace it with a new one. The following images start with the bottom plate already removed.

Unscrew the top-left screw a couple of turns, without removing it. Remove the bottom-right screw.

Lift the battery compartment and put it to the side, no need to desolder the wires.

Lift and move to the side, do not remove.

Remove the eccentric disc

Unscrew using a spanner or other tool. In some cameras this screw is very tight, so you will need to make yourself a tool.

I ground this spanner tip to dimension, so that it’d be easier to remove the screw without damaging it.

Remove the axis

Remove the axis

Now you can carefully extract the take-up spool

Some version of the cameras have an additional screw that needs to be removed before the white plastic part (the one that usually breaks apart) from the black part.

I’ve seen two versions so far: the one on the left has the additional screw shown in the previous picture, while the one on the right doesn’t. The black part of the take-up spools are not interchangable, and they ahve to be the right one to match the white part.

Modify a Pentax Spotmeter 1º/21º (II)

I recently bought an old Honeywell Pentax Spotmeter 1º/21º, version II, also known as the Ashai.

This very old meter, introduced around 1965 according to this, had corrosion in the battery compartment and was sold as is. After a good cleaning of the corrosion with white vinegar, I tried it and realized two things:

1. The needle movement was erratic, often going from the reading to zero and back again
2. This model needs two batteries, a classic 9V and a defunct mercury 1.35V.

A good cleaning of all the internal sliding contacts, quite a lot and definitely the weak point of an otherwise excellent design, solved the first problem, while I took a more complicated route for the battery issue.

The reason why the meter uses two batteries is because there are two separate circuits, one for high-light reading and one for low-light reading. The first one uses the 1.35V mercury battery while the second one the 9V battery. The battery test button on the meter checks the 9V battery, since the 1.35V mercury has a very stable voltage.

Initially I wanted to use a regular hearing aid battery to replace the mercury one, re-calibrate the meter, and be done with it. Unfortunately, this earlier version of the meter does not have potentiometers but fixed resistors, making a recalibration impossible.

Since the use of two batteries for one meter was already bothering me a lot, I decided to design a small voltage regulator that gives exactly 1.35V when connected to the 9V battery. This way, a regular 9V battery can be used to power the meter and there is no need for a second battery. I used a micro-power LDO, TPS72301, two resistors and a capacitor. I wanted to make this modification seamless and reversible, so I used SMD component everywhere to keep the PCB dimensions to a minimum.

The final circuit is on a square PCB with a 1cm per side. It is small enough to be hidden next to the main PCB board of the meter, so that once the modification is done the meter looks just like it did before.

 

12/12/17 Update:

You can find the PCB at this link, where you can order it or download the .brd file for it. Unfortunately, I lost some data when I changed my computer, and I don’t have the schematic anymore, but this regulator uses the classic resistive feedback topology, so it shouldn’t be hard for you to figure out where each component goes. Refer to the LDO datasheet here.

 

You can see the main board, with the fixed resistors, and the sliding contact that connected to the low-light button

Detail of the connection to the CdS cell

The optics removed, so to access the battery test button contacts, and the clean them

the small PCB with the voltage regulator, connected to the 9V

The regulator connected where the 1.35V mercury battery used to be connected

The regulator wrapped with electrical tape to avoid shorts, and put where there is some room

The meter is closed, and a small red paint dot is now on the tag, just to remind me that this unit was modified

Inside a Leica CL Metering Device

The meter needle of my Leica CL wasn’t moving at all, so I decided to take it apart and see what the problem was.

As it turns out the metering device, a galvanometer, is broken. When measuring the resistance of the coil, which should be around 3.8kΩ, I get an open circuit. This means that somewhere inside there is a wire that is disconnected, and I decided to take the galvanometer apart and try to repair it. Here are some pictures of the disassembling process and of what’s inside the galvanometer.

 

We want to remove the linkage for the shutter speed indicator. Put the shutter dial on the B position and unscrew that top screw that holds the spring in place.

Before you remove the arm, loosen the screw in the red box, till you can move the metal piece on the right. Then gently remove the arm.

Remove the two screws that keep the metering device arm in place

Notice that there are two metal pieces that come off

Gently remove the arm

Unscrew the two screws that you see on the left of where the galvanometer was, and gently remove that device (you will need to desolder the wires from it)

If you unscrew one of the screws on the side of the galvanometer, you can pop the lid off

Before you can remove the coil from its inner housing (that C shaped brass piece with the silver magnet in the middle) you will have to desolder the two hairsprings

This hairspring, and the other on the other side of the coil, provide the spring action for the coil, while also functioning as the electrical contact between the ends of the coil and the outside contacts

As you can see, the hairspring is very small, you will need tweezers, a loupe (or better a microscope), a good soldering iron and a lot of patience

The red arrow points to one of the ends of the coil that attaches to the contact. In my case, both the ends of the coil had to be re-soldered to their contact. It’s a painful and slow process, and if like me you don’t have a microscope and a good SMD soldering iron, it is very much a difficult and trial-and-error process. You will need time and patience.

After several attempts, the coil is connected to both contacts, and the contacts are connected to the hairsprings. As you can see, that soldering spot where the hairspring connects is NOT a good joint, but that’s as good as it gets with my limited tools. To have a nicer and more secure joint you will need a microscope, good tin, flux, and a SMD iron.

The coil back in its frame! After hours of work the galvanometer is finally working again, and can be reassembled and reinstalled on the camera.

The whole process is a delicate and painful one, unless you own a stereo microscope and a good SMD soldering iron. If you contact Leica they can send you the spare part, but it takes 3 weeks to come from Germany (they don’t repair Leica CLs in  USA) and it costs more than $80.

1.35V Mercury Battery Replacement

There are a lot of articles out there about what kind of battery you can use instead of the defunct 1.35V PX625.

I have tried the Wein PX625 and I like it, but as every Zinc-Air battery it doesn’t last long, and at roughly $6, that’s a problem. The alternative is to use a Silver oxide battery, but those are expensive too.

The solution I found is to use Zinc-Air 675 hearing-aid batteries, for example from Duracell, with a ring adapter. These batteries run at 1.4-1.45V, which means you will have to calibrate your camera for that voltage, but they are very cheap, around $1 each.

Where to find the perfect ring adapter? Buy a Wein PX625 and when that battery is dead remove the ring and use it on the 675, it fits perfectly.

Wein battery

Wein battery with the ring removed

Wein battery next to the hearing-aid 675 battery, exactly the same size

The 675 battery with the Wein ring

Taking a Leica M3 apart

I got a used M3 off ebay a few months ago and I fixed it. There are a few websites and youtube videos that show how to open an M3 and fix some issues it may have, and there is also a service manual for the Leica M2 (which is very similar to the M3) .

Here are some pictures that walks you through taking a Leica M3 apart, with some comments on the tricky steps.

Remove the bottom

Remove the hinged back

Remove the eye ring with a flexi-clamp

Remove the lens with a spanner wrench or other tool that fits in those two slots

You can see the removed lens, washer, and rubber seal

Remove the flash sockets with a flexi-clamp

If you want to remove the preview lever, you’ll need a tool that fits in those two slots (you can file a slotted screw driver to make one)

Remove the reverse lever (left), the top screw on the mount flange (center), and the preview lever (right)

Remove the screw holding the rewind knob. Again, you’ll need a specific tool that you can file out of a slotted screwdriver.

The screw holding the rewind knob spins around, unless you block the gear that engages the film spool

I use my caliper to block it, but you can use anything that works.

Remove the retaining ring, use a flexi-clamp

Remove the retaining ring of film transport lever

You will remove the retaining ring, washer, and film transport lever, in that order.

Remove the hot shoe and the speed dial with a screwdriver.

Remove the retaining ring with a spanner wrench or other tool that fits in the slots.

Now, gently rock the top cover up.

Be careful and gente, you might have to push the rangefinder roller toward the inside, to avoid damage. The top cover has a snug fit, so work slowly and make sure the flash sockets on the back aren’t getting stuck.

If you want to access the rangefinder roller arm settings, or if you want to remove the outer sleeve, you’ll have to remove the bottom plate.

Before removing these 5 screws, make sure you load the self-timer lever

Gently rock the camera out of the outer sleeve. this is a snug fit too, so take your time and don’t force it. You might have to push on the mount flange spring at some point to make let the camera out, and you have to make sure not to stress the rangefinder roller arm.

Don’t forget that this little guy goes right there, it always pops out when removing the outer sleeve and it’s cumbersome to figure out where it goes.

This cover plate gives you access to the rangefinder settings

From the bottom of the camera, you can see that the cover plate has two small slots. Use a tools that fit to twist the plate 90 degrees in order to release it.

I used my tweezers

Now that the cover plate is removed, you can access all the rangefinder settings (you don’t need to remove the top plate and the outer sleeve to do that)

If you want to remove the viewfinder/rangefinder assembly, remove the roller arm and the eccentric nut (still screwed in in the picture). Be aware that if you remove these components, you will have to adjust the rangefinder for distance measurement when you put the camera back together.

At this point, with the rangefinder arm and eccentric nut out of the way, you can remove the main light baffle if you so desire.

Remove also these two screws in order to release the viewfinder/rangefinder assembly