Category Archives: Lenses

Collimating … collimating … hello?

At some point in time you will need to collimate a lens/camera.

I recently serviced a Frank Six TKS shutter, and I had to unscrew the front cell. As the camera not a through the lens viewfinder, I am not sure if the lens has been correctly set for infinity focusing … how do I know I screwed it back on the correct starting thread ?

This is where you need to check with a lens callimator … well I do not have such a dedicated machine, so lets go with a DIY solution … so I checked the web. There are many online docs about this (I noted some below) … so here is what I did.

First you need to have a camera to mount the lens on … unless the lens is part of the camera … then you need to put something on the film plane for the calibrator to focus on, then you need a second camera with a (preferably) telephoto lens to be the calibrator, and lastly some light.

  • I cut down the clear plastic from an old CD case (a Dremel is really handy for this) to about 61.5mm x 63mm (in this case the camera was Frank Six 6×6 format). I roughly sanded one side to make it a ground screen, and used a Sharpie to make some marks on it.
  • Sony NEX-6 with an adapted Minolta MD 135mm f/2.8 lens
  • USB LED light

I taped the “ground screen”, ground side inside, to the back of the camera. I pointed the LED light to shine on the screen. The Frank Six lens was set to infinity.

The Sony NEX was positioned right up to the Frank Six lens as close as possible but left enough room for me to turn the front lens cell, and the Minolta lens set to infinity.

Using the Sony live view and flip up rear screen, I was able to see if the marks on the ground screen were in focus, or not. First try it was not, so I back out the front cell and tried a different starting thread … until the Sony showed an in-focus marking. Done.

Callibrator Camera+Lens — infinity — Lens+Camera+target

As I mentioned … more detailed info can be read below:

Rick Oleson – collimator options

Mike Elek – collimating your lens

Addicted2Light – collimator

Feuerbacher – infinity lens calibrator

FD lock … not lock?

Thought I would put this up since I looked into the back of my Canon FD 50mm f/1.8 to see how the lock button worked … as I have never paid much attention to how this actually worked.

Looking at the back of your typical FD lens, and not the breech lock ones ..

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The metal securing ring can be taken out after removing the three black screws on the outside of the barrel

 

 

 

 

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You can pull it off

 

 

 

 

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You will probably see that there is a mixture of grease and dirt on that part.

 

 

 

 

The middle rear cap can be removed by revolving it clockwise until the lump lines up with the release button.

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The back of this shows the ring that couples with the aperture arm … than inverted U.

When the lens turns (when you lock it on the body) the U sits in front of the release button … until it lens reaches the end when the release button slips behind it, thus locking.

 

DSC00795Make sure the release button is not gummed up.

 

Olympus 50mm clean out

Since I just acquired an Olympus SLR, I needed a lens to go along with it. I was able to pick up an Olympus F.Zuiko Auto-S 50mm f/1.8 that needed a cleaning.

fZuiko50mmElementsThe F means the lens has … hmm, ABCDEF … 6 elements. It’s always handy to hunt down an illustration of the elements and groups, cause if you put them in the wrong order or flip one of them around, you ain’t got much of a good lens.

With this particular lens there was black flakes littered between most of the elements, so this means I need to take it apart.

DSC00683From the back first … just to be different.

Ok, remove the three screws.

You can now lift the entire mounting ring off.

 

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The rear element group is encased as a complete unit.

Unscrew it.

Hmm, in my case I could not get this to move … the last element is secured on by a threaded ring … unscrew this to get into there.

Since I could not get this group removed, I could not get to the inner element to clean it … so now I have to go in from the front.

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The name plate ring has two notches … so unscrew that using a spanning wrench.

 

 

 

 

DSC00692The inner ring pulls off.

Be aware of the ball bearing on the aperture ring below it … you don’t want to loose that.

DSC00691You can see the holes where the bearing will sit.

These are the click stops for the aperture ring.

Note the little lip … it sits in a slot. Remember that when you put it back on.

 

 

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Pull off the aperture ring … watch the bearing (not pop out and bounce around on your table).

DSC00689Note the arm sticking out of one side … that arm couples with the aperture ring.

 

 

 

The front lens group is also encased as a complete unit … but, it is not so easy to get them out as one.

Use a rubber grippy tool to unscrew the group … do not grasp the outside as this will not move.

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What might happen is that you unscrew the top part.

Then you have to unscrew the rest of it.

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DSC00684Here is where you should remember to look back at the first image in this post.

Warning: the middle element is not secured so it will fall out with a spacer. Best to loosen then flip over so everything doesn’t just fall out all over the table.

Note how the elements are arranged.

Now you can get to the front of the rear group.

Check out the aperture and mechanisms.

 

Dirt, dust, ding, and … fungus.

This lens was in bad shape … though I expected that based on the sellers images.

s-l1600 - CopyIt needed a body cleaning, and also the built in metal lens hood has a dent. The previous owner did not try to fix the dent so continued to retract it as seen by the scrapped of black paint on the inside.

… those things are doable … the fungus, well that will be this story.

I searched the web and it appears nobody has posted an attempt to take this lens apart … not being sure if I could get inside the element groups (sometimes they are encased) I took a chance on purchasing this lens.

You will need a wide spanner wrench as the front element is huge.

First I needed to get the built in hood off. First pull off the rubber ring. Remove the black tape. Then finally pull off the black metal top ring.

Now you can slide the hood off … in my case some bending had to start first.

You can use a filter ring vise, wood dowels and a hammer, etc … to put the hood back into shape.

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The front lens label ring is notched to allow a spanning tool to unscrew the entire front lens group … there are four large elements in this.

Be nice, and don’t slip … this group is very secure.

Once unscrewed. When you hear it pop out of the last thread, cup the end and turn the lens over … it should just fall out.

 

DSC00669You can split the top group in half to get into it.

There is more tape … remove it, then you can unscrew the top part.

The rear section has some “lock tight” type substance to keep it from unscrewing … I did not have to go there.

Clean up the elements.

DSC00674Under that front group you can get to the

If you open the aperture you can get at the front of the internal element group to clean it up.

Now to clean your backside … sorry the back of the lens.

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Take out those four screws.

The pull off the mounting ring.

 

 

 

 

 

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I missed taking a picture of the cap … remove the screws that hold that on.

Pull it off, while watching out for the wires.

At the bottom of the wires there is the distance switch set. Take the two screws off that hold it.

Take one end of the spring off the hook.

Remove the four screws that hold the collar on. Remove the collar.

 

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Remove the screws that hold the rear element ring on.

Pull off.

Now you can use the spanner to unscrew the rear element group.

 

 

 

DSC00673You can clean the rear of the internal group.

There, that wasn’t all that difficult eh?

Now put it back together … make sure the aperture lever and focus moves before tightening each part.

Tip: as I suspect the lens hood is the last part you will put on … the top lip should be tight enough so that when the hood is retracted it has contact enough to keep the hood from easily falling forward when you tilt the lens downward. I did a little light bending before I put the black metal ring on.

I was lucky that the fungus was only on the surface of the coatings, so it cleaned off easily. Not much I can do about the body paint … it ain’t white, but I was able to scrape off the green brass erosion on the nameplate.

Legendary … 200

I remember long ago when white lenses started appearing. These lenses were mostly long focal length, very wide aperture, and very expensive. I’m not sure who really started it, but I know Canon has become synonymous with the colour.

Sometime starting in 1985 Minolta started marking their high end telephoto lenses with a white finish. This started with the introduction of their revolutionary Maxxum Auto Focus cameras … 5000, 7000, and 9000.

In ’86 a short little white lens was made, the Maxxum AF 200mm f/2.8 APO (a higher gear speed version replaced it in 1988 … same optics, and possibly upgraded IC).

ElementsGroups20030+ years later these lenses are still sought after and has become legendary … supposed-to-be-legendary lens … ,some have stated that this is one of the the top 5 greatest lenses ever made.

Ehhhh, I am not sure if they are right but pretty much well everyone on the Inter-Web have stated the lens is is one of the best.

Sadly, the white finish (paint) does not tend to survive well after all these years, especially the original, so many of them have the flaked off fugly paint look.

Any whooo, I finally landed one and it is in bad shape !!! As noted above, the white finish is kinda beige now, bubbling and flaking off in places.

It is quite small … 13.4cm tall and only weighing 795g … but it has high resolving power. My quick tests, it appears to be better than my Maxxum 80-200mm f/2.8, and also the SAL70400G @ 400mm compared to a cropped 200mm image. Don’t judge a book by its cover.

200_Sony