Sunday, September 22, 2013

Long Beach

I went today with Johnny Murphy to Long Beach and the So-Cal Cycle Swap Meet.  There were quite a few bikes parked in the lot next to the swap meet.  I spent quite a bit of the day wandering in amongst them and took photos of the ones I liked.

I took my Nikon D7000 with an 18-55 vr zoom lens which is handicapped by not having an aperture mechanism.  Notice I didn't say that it was broken, I said it doesn't have one.  I bought the lens (actually, I'm pretty sure I traded something for it) at the Pasadena Camera Show a few years ago and noticed that it behaved a bit oddly.  Opening it up I was astonished to discover that it had no aperture blades at all!  I disassembled it completely and it sat for two years in my junk box.  Yesterday I decided to see if I could get it back together (minus the empty aperture assembly) and, after a few fits and starts, I did, so I tossed it in the bag (along with my OM1, the photos from which are yet to be developed) and took it along.

My thanks to Johnny for driving,  Advil and the company and conversation.

The bikes (in no particular order...)

Sunday, September 15, 2013

Simi Valley Car Show

We went to a car show a while back.  I took the Yashica-mat LM.  I bought this camera super cheap because it was pretty dirty and the meter didn't work.  As it turns out, the meter DOES work; someone had glued a piece of flat plastic over it and the needle was stuck against it.  I cut a section out of an old filter case and replaced the flat plastic with it.  Ugly, but it works.  Someday perhaps I'll come up with a more elegant solution but for now... meh.

Yashica-mat LM - Nikon D7000 microNikkor 55mm f3.5

The Yashica-mat is a Twin Lens Reflex camera where the viewfinder is on the top.  The image from the top lens is reflected up through the focus screen with a 45 degree fixed mirror.  The film is behind the bottom lens.  Both lenses move in and out together when the focus knob is turned.  It works very well but things are reversed left and right in the finder so framing is a tiny bit challenging.  Also, since the lens is fixed and a near normal 80mm the view in close quarters is tight.  I like the way it works for cars, however, since it allows me to shoot tight framed details which I prefer anyway.  The f3.5 lens is super sharp on the large 6cm square negatives.

A few shots from the show:

Saturday, June 1, 2013

Nikkor 35mm f1.4 pre-AI

As I showed in my last couple of posts, I've been doing some camera and lens servicing for my friend Ben.  There were four lenses in the old Halliburton case.  Two of them needed some pretty serious help.  The last of the lenses that needs disassembly is the Nikkor 35mm f1.4 pre-AI.  This is an absolutely beautiful lens.  Serious lens envy.  Unfortunately the aperture blades have become oily and because of the proximity of the inner rear element to the blades, it too has become oily in streaks that match the aperture blade travel.

Screws on the mount this time.  Looks simple.  Looks, however, can be deceiving. That rear element could use a good cleaning.

That is a dirty filter.  This is one good argument for putting filters in front of lenses.  I usually don't, unless I'm going somewhere really dirty like the beach.  This one has managed to keep the front element fairly clean, though.

The front element under that filter needs a good, gentle scrubbing.

The mount came off easily.  I needed to focus the lens at its limit in order to free the aperture linkage though.  There is a little stop for the aperture ring, but the ring comes off with it in place.

Aperture ring removed and ready for cleaning.  I pulled off the long screw at 5 o'clock on the lens in this picture.  It is the link between the ring and the aperture mechanism.  Finally I removed the aperture index stop which is held on with two small slotted screws.

The index ring is interesting on this lens.  It looks like two separate pieces but it isn't.  I'd love to know how they chromed part and painted part and still got the quality of finish that they did.  This is a JIS screw (Japanese Industrial Standard).  As I pointed out in the last blog entry while they look like Phillips heads, they aren't.  Phillips screw heads and screwdrivers have an angled slot which is designed to prevent over-torquing the fastener.  JIS slots have parallel sides and a Phillips will actually cam out of the screw, ruining it quickly.  You've been warned.

The index ring removed.   This is where things get complicated.  I've removed the mount, I've pulled off the aperture ring and the index ring.  I spent the next hour or so trying to figure out how to open up the lens further.  I knew that the lens had to open somehow, yet I couldn't figure it out.  On some lenses the logo ring unscrews opening from the front.  Not on this one.  Also sometimes the rear element ring can unscrew, allowing access from the back.  Nope, not this one. 

Finally, I spot it.  A tiny grub screw in the focus ring.  I unscrew it carefully with one of my tiny jeweler's screwdrivers.  It serves no obvious purpose.  I turn the lens over and over in my hands, twisting and pulling and pushing on parts.  Finally, I grab the rubber jar opener and twist on the focus ring, figuring that screw must do something.  I feel it give.  The front angled portion is separate!!!  It unscrews from the front of the focus ring, revealing the structure beneath.

Hiding beneath that angled part is another ring fastened with another grub screw.

Removing it allows the entire lens body to be pulled out of the focus ring/lens mount unit.

The lens body out of the mechanism portion.  Lots of oil on the outside explains the oily aperture.

Because this lens uses a kind of construction which Nikon calls "close range correction" the rear elements are in their own module which rides on its own helical which moves at a different rate from the main lens body when the focus ring is rotated.  This means that the front and rear element packages are a different distances from the focal plane as the focal distance changes.

For my purposes that means that the rear element package unthreads from the main module, revealing the aperture blades.  I first marked the location of the package on the main body so that I would be able to replace it in the correct index.  The threaded section is actually four complete helicoids so it is possible to put it together three incorrect ways and one right way.

The aperture blades sit VERY close to the rear element of the front module.  The grease them was thick enough that it had made little grease pathways on the glass.  I used cotton swabs and paper towel strips soaked in lighter fluid to gradually get the grease off the glass and off of the aperture blades.   This took a while but eventually the were clean, dry and snappy.

The main body was just a little grimy, so it got a good scrubbing with vinegar.  The focus action was still smooth so I didn't need to pull it all apart and regrease like I did the 105 f2.5.  This cut a couple of hours off the time required to service this lens.

Reassembly.  This is the out angled section threading back on.  Also, note the tiny hole near the front of the focus ring.  That is the hold for the grub screw.  There was enough dirt packed on top of it that it was really hard to see.

The aperture click stop mechanism being replaced.

All back together.

Nice clean front element and filter.

The rear element cleaned.  Nice shiny mount, too.

While I was at it, I cleaned the dirt off the Halliburton case with a Brillo pad and Windex.  This was really dirty, having lived in a garage for the last 20  years or so and probably hasn't been cleaned ever.

Top is clean, bottom is not (duh).


Re-loaded, ready to give back.  I now want to see film put through this beautiful system.

Monday, May 27, 2013

Nikkor 105mm f2.5 gets clean

The second of my camera cleaning posts is about the Nikkor 105mm f2.5 pre-AI lens.  This was one the great lenses of the seventies.  It is a longish portrait length or a short telephoto and is pretty fast.  The out of focus renders beautifully with this lens.

This particular example has sat in a camera case for the last 20 years.  It was grimy, gritty and stiff but the glass was clear, without any fungus.  The aperture was stiff and appeared to be sticky as if it had oily blades except they didn't actually look oily.  I was pretty sure I was going to have to get inside it and clean them.

The first thing I realized as I looked this lens over was that the mount has no screws!

On the left is a Nikon Series E 50mm f1.8.  On the right, the 105.  Note the lack of screws on the silver lens mount.  Ordinarily the mount can be unscrewed from the lens revealing the back end of the lens allowing access to the aperture mechanism.  Not so this lens.  I was going to have to go in from the front.

The focus ring is secured to the center helicoid by three small, black, round head slotted screws.  These early Nikkors use slotted screws throughout.  The later AI and AIS lenses tend to use more JIS (which resemble a Phillips or cross point) screws.  As a caution to the adventurous, JIS and Phillips are NOT the same.  Phillips screwdrivers will quickly strip and ruin JIS screws.  Guess how I know that.  JIS screwdrivers are available (after some searching) and are the only safe tool for JIS screws.

Slotted screws require attention as well in that the size of the screwdriver is important.  It should be carefully selected to match the width of the screw head as closely as possible in order to avoid stripping the heads.  I have a fairly wide selection of screwdrivers which I've accumulated over the years and can usually find a good match.

Removing the focus ring revealed the first bit of evidence that I am not the first person to open up this lens.  Carefully scribed straight lines matching the inner and center helicoids to the outer helicoid (and mount).  These were not here when the lens was new.  This is one of the tricks that techs use to ensure that they can reassemble the helicoids properly.  I've done this myself.  I've also NOT done it and learned the hard way that there are about a dozen ways to fit helicoids together that are incorrect and only ONE right way.  These are a good thing, as now I know that I can strip the lens down completely and have a pretty good chance of getting it back together again, working.

Next to come off was this chrome index ring.  It is secured by three chrome slotted screws.  

Removing that revealed a great deal of oil.  This is not a good sign.  This paint is NOT glossy, that is a solid layer of oil which has seeped out the the helicoid.  This is bad because it can migrate into the aperture mechanism which is supposed to stay dry AND it attracts dirt.

At this point I've wiped down the main lens body with paper towel moistened with lighter fluid.  This shot shows a couple of interesting things.  One is that dirt I was talking about in the slot above the aperture ring.  Yuck.  Another is the continued scribe line.  More evidence. Also in this shot you can see the three helicoids (visible in that vertical slot) and the key (in the same slot).  The way the mechanism works is that the focus ring turns the center helicoid (the small ring almost to the top of the lens in this view.  The mount is attached to the camera body so the force of the center ring turning pushes against the key in the slot (the small chrome rectangle at the bottom of the slot).  This forces the inner helicoid to rotate within the center at the same time the center rotates within the outer.  Since the threads are opposite the inner helicoid moves out, away from the lens mount and presto!   Focusing.

This is the same area as above except the focus ring (center helicoid) has been rotated.  It has moved away from the mount while at the same time the inner helicoid (with the chrome part attached) has rotated within the center, also moving forward, away from the mount.  You can see that the key has reached the top of the slot.  These helicoids are full of old, dirty grease and grit and really need to be completely flushed and re-greased for this lens to work correctly.

At this point I've removed the key by means of screws hiding in the holes near the base of the slot and I've unscrewed the center helicoid (and the entire lens assembly) from the mount assembly.  Point of no return here, as now I've disengaged the helicoids.   Also of note is that little, chrome screw to the right of the inner helicoid.  It and two like it hold the aperture mechanism in place.  That narrow part of the lens body actually unscrews from the main lens body now, giving access to the aperture mechanism.

Now comes the scary part, and the part of which I have no photos because I was concentrating so hard on not screwing it up, I forgot to take any.  That black ring with the silver nut on it slides out the top.  The black slotted ring underneath it also slides up, freeing nine tiny, thin, metal aperture blades from each other and the remainder of the mechanism.  They all need to be cleaned with lighter fluid, along with both of the rings, then dried and carefully re-assembled, one atop the other, delicately so as not bend the extremely thin metal, then carefully slid back into place in the lens body.  Exciting stuff.

These two photos show the focus ring (left), index ring(right) and...

the main lens body without the lens mount (top left), inner aperture linkage ring (top right), center helicoid (bottom left), inner helicoid (center) and aperture ring (bottom right).

These are all aluminum and therefore safe to wash in hot, soapy water in the sink.  The toothbrush is used to ensure that all the old grease and grit is removed from every thread and every slot.  It is really convenient that all the moving parts can come apart like this and allow a complete refresh of the lens.  Great design.

In the immortal words of every shop manual ever written, assembly proceeds in the opposite order of disassembly.  Really, though, with the markings already on the lens and a couple of scribbled notes (like the aperture ring is 9 rotations, the inner aperture linkage is 10 rotations) re-assembly was pretty painless.  I re-lubed the helicoids with my own special mixture of greases.

The lens mount is nice and clean, as is the rear element.

That beautiful piece of glass now resides in a smoothly functioning refreshed lens body.

As you can see, all the dirt has been flushed from every crevice.  The lens mounts and focuses easily and is nicely damped.  Beautiful.

All told I spent about five hours disassembling, cleaning and re-assembling this lens.  At my normal hourly rate that is about 5 times what the lens is worth.  Obviously, I do it for love, not money.