ZorkiKat ЗоркиКат Фотографий » Rangefinder and Focus Adjustments

Industar-69 28mm

admin — Thu, 29 Oct 2009 15:24:34 +0000

This lens was made for the half-frame Belarussian “Chaika” (”Чайка” = “Seagull”) half-frame cameras. The 2nd and 3rd models of the Chaika were designed to have removable lenses. No one is sure why this was done -the first Chaika model had a fixed, non-detachable lens-, but I think it was to allow the lens to be used in an Enlarger for printing.

The lens has the standard Leica M39 thread (LTM39) mount, but the working distance (the focal plane to lens mount flange distance the lens is positioned which allows infinity focus) is not the the same. Leica’s is 28,8mm. Chaika used something like 29 or so mm. This extra millimetre or so prevents infinity focusing when the I-69 28mm lens is mounted on the Leica.

the “Индустар-69″ 2,8/28mm mounted on a Leica IIIc

As the reader will note later, infinity focus is not the only, nor is it the greatest concern here. Coverage, or the ability to focus an image large enough to fill the frame. “Frame” here is relative- the standard 24 X 36mm, ‘half-frame’(a.k.a. “single frame”) 18 X 24mm, and the 23.7 x 15.6 mm APS-C size CCD of the Epson whose 1,5X factor makes it ’see’ like a 42mm on standard 35.

The lens was modified by altering its focus movement. Portions of the inner barrel were filed away to make the lens move further in to allow infinity focus. The focusing scale on the barrel was also reset to synchronise it with the lens’ focus. The aperture mark no longer coincided at the new positions, so a new mark was made by putting a drop of red paint on the aperture adjusting ring.

The lens too, being originally meant for a non-RF coupled camera, will focus only by scale since it has no means of engaging with the RF cams of the camera. Scale focusing with a 28mm isn’t that hard- its greater DOF more than compensates for focusing errors. Plus, the I-69 has three “snapshot” focus settings on its barrel: “Portrait”, “Group”, and Landscape”. How is this used? Look through the finder and set the focus against the figure which resembles closest what was seen through the finder:

Just line up the figure against the pink triangle which corresponds to “how much” is seen in the viewfinder.

Focusing is often a trivial matter. In many instances, leaving the scale at the “group shot” mark (the 3 metre mark) and using f/8 will deliver DOF with a range of 1,6 metres to infinity.

Since the I-69 was designed to cover the 18X24 frame, the IMAGE CIRCLE it produces will be much smaller- smaller than what ‘full frame’ needs, but sufficient for the smaller ‘half-frame’.

On an APS frame, the corners already vignette. Aside from losing coverage, the edges of the image circle also dims. Here is what it does with the Epson R-D1s digital rangefinder camera:

Scale-focused/distance ‘guess-timated’ at 0,9 metre. Full 2,8 aperture.
The I-69 is a Tessar type lens, and produces a swirly blur when used at full aperture, for closeups.
The corners of the picture show significant vignetting.

If the smaller APS-C frame already shows vignetting, a full 35mm frame shows TOTAL DARKENING at the corners of the frame. This, as well as the significant loss of definition at the threshold areas indicate that its image circle is too small for the 35mm format, but more than sufficient for the half-frame picture.

Same subject as above, but on a 24X36mm Leica frame.
The blue tinge stems from the unfiltered exposure of tungsten movie film in daylight.

Conclusions: The significant vignetting prevents further use of the lens for ’serious’ work on full frame 35. However, it can be useful for experimental or whimsical applications.

On the Epson R-D1s, it can be used as a scale-focus snapshot lens, with a 42mm view. Using it at f/8, the vignetting is not to apparent in many situations.

The lens would be a perfect “normal” focal length for the micro 4/3s cameras. No modification is even necessary to adjust the focus.

The “Zorkikat Wrench”

admin — Wed, 02 Sep 2009 07:45:27 +0000

Removing viewfinder and rangefinder bezels from Leica, Canon, FED, Zorki, FED, and other similar Barnack-copies can be difficult. It is required to adjust the vertical alignment of the rangefinder patch image. And necessary when disassembling the camera for major repair.

A special wrench made from fibre or soft metal like copper or aluminium was made for that purpose. The wrench can be quite expensive for one-off jobs. It can also be made, if you have access to a machine shop.

Substitute procedures like using long-nosed pliers lined with rubber tape or heat shrink tubes have been proposed, and worked. Often though, it lead to the deformation of the bezel from the heavy grip of the plier jaws. Using rubber pads to remove the bezels have been proposed too. This worked only if the bezel has not siezed on its threads yet. But old bezels tend to be stuck. And in the factory, the workers made sure that it would remain in place by really tightening it in place.

There is a simple and inexpensive alternative to all methods described above: The “Zorkikat Wrench”. It’s a DIY tool made from thick aluminium or copper wire. Single strand copper wire with insulation removed or aluminum wire 2-3mm thick is needed. Cut a 6-8cm [edited] length. Then bend it around a metal pen or whatever object which has a diameter slightly smaller than the bezel or retainer nut (it can also be used for removing retainers from advance levers, eyepiece rings, etc). The two ends serve as the handle and the grip.

The tool can easily lose its shape. But it can easily be reshaped. However too much bending can cause fatigue to the metal and cause it to break at the bends. Nothing to worry about really since a new one can always be easily made when the old tool breaks.

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HOW NOT TO DESTROY YOUR FED AND ZORKI (A Basic Primer)

admin — Fri, 10 Jul 2009 12:01:26 +0000

For newbies, applicable to most FED and Zorki cameras.

1. Do not force anything. Despite their price or appearance, any FED or Zorki is a true precision machine that requires careful and proper handling.

2. Do not remove the lens unless necessary. Most FED and Zorki are Leica type RFs whose lens can be removed. Some exceptions are found though, like the Zorki 10/11 or the FED Boy, Atlas, or 50.

The instruction manuals for the older FED do not even recommend lens removal, adding a warning that doing so can damage the camera’s rf cam:

If the lens has to be removed, MAKE SURE THAT ITS SET TO 1 METRE. Do the same when mounting it back. The cam at the rear of the lens retracts at 1 metre, making the mount clear of any obstruction.

The camera RF cam (the sloped part shown in the picture) has to be at a specific angle. If this moves, the RF’s focusing accuracy is compromised. It will no longer focus accurately at close distances.

FED and Zorki rangefinders are adjusted for both infinity and close distances separately.

3. All FED and Zorki Leica types have rotating shutter dials. Keep fingers or other objects off the dial when firing the shutter. At best, this will cause erratic exposures. At worst, it can make the shutter hang.

4. The speeds on the shutters on these camera are set by lifting and shifting the dials. Lift first, then set turning the dial.
THIS MUST BE DONE ONLY WHEN THE SHUTTER IS COCKED.

Rotating dials can only be set when the shutter is cocked. With some models, this would not permit correct shutter speed setting. On models with SLOW SHUTTER SPEEDS (ZORKI 3, 4, and 4K; FED 3, 4, and 5), turning the shutter dial without cocking WILL DESTROY THE MECHANISM.

Some models do allow changing speeds before or after cocking. These are models without slow speeds. Their shutter dials are of the the “double dial” type- an outer dial which can be set, and an inner dial which does not move, and marked with an index arrow. FED-2 (on some versions only), Zorki-5, Zorki-6 and Zenit 3/3M/E/EM/B have this type of dials.

Single and Double speed dials found on two variants of the FED-2. This dual-dial design was also used by Zorki-5 and -6, Zenit -E, -B, -3, and -3M.

BUT ITS BETTER TO ERR ON THE SAFE SIDE. ALWAYS COCK BEFORE CHANGING SPEEDS.

5. On some models, do not shift or turn the dial between B and 1/500. On cameras with slow speeds. the dial turns two ways- one towards 30 and another towards B. Try to feel where the dial’s movement stops, and do not force it beyond that.

6. With bottom loading cameras (FED-1, Zorki-1/S/2/2S/5), the film leader must be trimmed properly. The modern short tongues of today’s films must be recut. Not a difficult thing to do, but the cut must be correct- tongue is 10- 11cm long, gently tapering, and no cuts between perforations:

There is ONLY ONE WAY TO LOAD A BOTTOM LOADING CAMERA- THE CORRECT WAY:

Some have suggested tricks like inserting cards in the film channel. THIS IS A STUPID WAY TO LOAD THE CAMERA. It can damage the mechanism, scratch the pressure plate, and generally slower than the correct method. Forget about these tricks or claims about them being ‘more efficient’ or ‘easier’. The inventors who first designed these cameras knew what worked best- how can anyone else say otherwise? And if the method requires lens removal, insertion of cards, holding shutters open, etc- how could that be faster than the ‘original’ procedure which requires only the removal of the baseplate and take-up spool?

A crazy, dubious, purportedly ‘better’ way to load film in a bottom loader…

NB: The long leader cut is not needed to load other FED or Zorki whose backs slide off or open for loading.

7. The Zorki-5 shutter MUST NOT BE FIRED without a lens on the camera. This Zorki has a quirk in the layout of its parts. Without the lens in place, a part of the RF cam goes in the shutter speed control dial and can mesh with the parts.

8. The Shutters on these cameras have cloth blinds/curtains. Do not touch them. Also, do not point the camera towards the sun for extended lengths of time. When lens is focused at infinity (or close to it) a tiny image of the sun is focused on the blind. This can cause a pinhole to burn on the shutter.

9.DO NOT DISASSEMBLE THE CAMERA. The temptation is there to make some adjustments. But unless you know what you are doing, do not go beyond the usual minor cleaning and adjustment procedures. FED and Zorki can be more difficult to calibrate than a Leica.

10. Do not leave the shutter tensed for long periods of time. When storing the camera, make sure that the shutter is released.

The above do not apply to Kiev rangefinders. They are a different breed of animal.