Sunday, June 24, 2012

Beam splitter mirror replacement in Barnacks and clones

[From the Archives, ca. 2005]



Replacing beam splitter mirrors on Barnacks and clones
is relatively easy....


Leica II beam splitter mirror


Tools


Compressed air, lens cleaner [or windex], spanner wrench, jeweller's screwdriver [1.4mm and 2.5mm], ring wrench [micro-tools 50D] sharpening stone, glass cutter, tweezers, air blower, lens tissues, cotton swabs and needle nose pliers. A digital camera may come in handy too.


To the left is a mirror type beam splitter from Edmund Scientific catalog no. 3043359 with 50/50 reflectivity/transmission. This size is good enough to service a number of Barnacks and clones. To the right are two corroded samples of 8 mm x 10 mm beam splitters taken out a Leica II and Fed 1d. The one at the bottom is a replacement I carved out from the larger mirror. I used a cheap glass cutter from Home Depot and the cuts where not clean so I had to shave it down to size with a sharpening stone with flowing water in the kitchen. I would welcome glass cutting tips from people who have experience working with glass.


To remove the rangefinder cover or top plate set the shutter speed dial to Z [or B] or any speed to gain convenient access to the set screw. It may be wise to write it down for reference in reassembly. If the dial only has one set screw chances are it is threaded [Leica, Feds and earlier Zorkis]. Loosen the set screw and turn the dial counter clockwise for removal. On later Zorkis like a 1d the dial is not threaded and will come off once the the two set screws are loosened.

The next step is to remove the three screws securing the accessory shoe and lift it off.


Then remove the screw covering the infinity adjustment [right beside the VF bezel].

Using the ring wrench from micro tools, remove the bezel around the optical wedge and also the RF window. Then using a spanner wrench or needle nose pliers, carefully turn the optical wedge counter clockwise to remove it.



Turn the camera around and remove the screw in between the RF and VF eyepieces and using the ring wrench remove the eyepieces. Carefully remove the RF cover making sure it does not scratch against the rewind knob.

If you encounter difficulty in removing the bezels, optical wedge and RF/VF eyepieces try dropping tiny amounts of thin oil [watch maker's or Radio Shack 64-2301] or even lighter fluid and let it sit for a couple of hours.

Two links with better illustrations on how to dismantle a Barnack clone:

Zorki 1d with the RF cover off. The eyepiece tunnels on this late Zorki is one piece and detachable, soldered on most Feds and threaded in Leicas. For proper reassembly take note of the difference between RF and VF eyepieces since they have similar threads, the RF is 1:1 and you can "see through it", while the VF is convex and will be blurred.


Pry off the cover on the side of the beam splitter mirror with a small screw driver.


You will find a "leaf spring" securing the beam splitter mirror wedge. Pry this off very carefully with tweezers and/or a screwdriver because it can fly off.


Front

Now is a good time to clean and dust away dirt from the RF/VF housing using lens tissues and cotton swabs moistened with lens cleaner or windex. Use compressed air to accelerate drying.
You will also notice in this picture that there is a single screw cover directly above the infinity adjustment worm screw. If you encounter difficulty in turning the infinity adjust, remove the cover and loosen the set screw inside for the worm screw to turn freely. Many infinity screw heads have been stripped due to tight adjustment.


Back


The wedge came out fully in this Fed 1d however on other models, it may not be possible for the wedge to slide out completely if the tip of the screw that holds the RF housing is in the way. In this case you have to carefully shake out or maneuver the wedge with tweezers to slide out or install the beam splitter mirror.
In this picture I just inserted a new mirror and is ready for reassembly. Take note of the assembly sequence - wedge, leaf spring and cover.

Reassembly is done in reverse order.

Before you use the camera you need to recalibrate the vertical and horizontal RF adjustment, if you need information on this procedure go to Jay's Fed/Zorki survival site.


If contrast between moving and stationary image is an issue you can try cutting a small piece out of an enlarger contrast filter just big enough to be wedged in the RF tunnel when the RF eyepiece is screwed back on.

Leica IIIc and IIIf

Good luck and good light!

Sunday, June 17, 2012

JE Labs Open Baffle redux

Original article



G. A. Briggs

Wharfedale SFB3

Stereo Sound "Tube Kingdom"
1996 Volume 3

JE Labs (cheap 😉) DIY version inspired by Stereo Sound
as featured
in Sound Practices issue 17 "JE Homebrewer"

JEL OB for Altec 755 built from
3/4" Birch plywood ca. 1997

Built using Tanguile 'tongue in groove'
 flooring planks for an Altec 605B 

November 2008 Hi-Fi Show

Mondrian 2011 edition
for a 12" driver 

Have fun and happy listening!




Saturday, June 16, 2012

Classic Light Meters

Light reading gadgets


Selenium - batteries not required
Clockwise: Weston Master IV (accurate, serviced by Quality Light Metric), Leningrad 2 (?), Weston Master II (seems to match the IV) and Zeiss Ikophot (?)


Battery dependent
Clockwise: Voigtlander VCII (almost as sensitive in low light as the built in meter in the M6), Gossen Luna Pro F (very sensitive) and Sekonic L-208 (not for low light)


When I like to travel light I go back to my roots and shoot Sunny 16 with this gizmo. It's just as good as (if not better than) any of the other toys above since it exercises my mind.

Thursday, May 31, 2012

Listening Room - Minimalist



A music lover's system based on a CD transport + DAC as source, JEL 76/6SN7GTB line stage preamp with remote volume control, JEL SE10 mono block amps driving PHY-HP 2-way 12" co-axial speakers housed in Hans Kortenbach enclosures.

Tuesday, May 29, 2012

Leica M3 + Summicron 35 and 50



Despite my fondness for Leica screw mount (LTM), it was this M outfit I received in trade for a SE300B amp I built that got me hooked to cameras and photography - a '61 M3 with '61 rigid 'cron + '66 8-element 35 'cron which I was using with an external VF until I acquired an M6.

This well used single stroke M3 as received was working but in dire need of a CLA and a new vulcanite so I sent it to Sherry Krauter. Upon return, Sherry noted separation in the viewfinder and highly recommended TLC in handling. That was in '97 and so far, have not noticed further deterioration.


When I visited Shanghai in 2010, I bought this half-case from Mr. Zhou. I would like to believe the padded leather is providing added protection aside from a spruced up look. The .91 (almost 1:1- life size) viewfinder magnification of the M3 is its greatest asset. It is so much easier to frame and focus a 50mm, 90 mnn or 135mm lens on this model compared to the M6's .72 VF.

Leica M3 + Summicron 50/2 rigid
Kodak TX400 in Diafine


Leica M6 + Summicron 35/2 8-element
Kodak TX400 in Diafine


So far I have not been compelled to upgrade to later Summicron versions as these two lenses far exceed my picture taking abilities. 😊





Saturday, May 26, 2012

Listening Room - Monaural Hi-Fi

Why mono?




The JEL SE2A3 and SE10 integrated mono amplifiers were built for this installation.


Idler driven turntables from Rek O Kut, Garrard, Presto, Bogen/Lenco, Neat and...


...viscous damped tone arms equipped with variable reluctance cartridges from GE > Tannoy.


Altec 802 + 416 drivers converted to field coil powered by a 12VDC power supply.





Jensen M10 field coil was featured in the 2009 November Hi-Fi Show.






another project....but just as significant ;)   







Wednesday, May 16, 2012

Voigtlander: Vito II + Vito B

Scale focus cameras from the original German factory.

Late 40s-early 50s - folding
Voigtlander Vito II  with Prontor S - B, 1s - 1/300
Mid 50s - rigid
Voigtlander Vito B with Prontor SVS - B, 1s - 1/300
Both cameras are equipped with the coated Color-Skopar 50mm, f3.5 Tessar type lens but there's a difference in performance under strong direct or side light situations....

Vito II + Agfa APX100 in Rodinal





Earlier Vito II is more prone to flare...







Vito B + Agfa APX100 in Rodinal




... it seems, coating technology made a leap within a couple of years.








Vito II + Agfa APX100 in Rodinal 
Vito B + Agfa APX100 in Rodinal
more pics


TIPS


The shutter on both cameras will not work unless loaded with film. Got the Vito B for $10 because it was advertised with a non-functioning shutter. A dummy film roll fixed the shutter ;)















Back in the 40s and 50s, most entry level cameras were scale focus only. With the addition of an accessory rangefinder like this Prazisa, it becomes a rangefinder camera ala early Barnack.