TomB_tx Posted November 4, 2011 Share #1 Posted November 4, 2011 Advertisement (gone after registration) I inherited this setup many years ago, and remember my uncle using it for nature photography. It seems to be pre-war era. Going to give it a try this fall. Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/165560-astro-berlin-400/?do=findComment&comment=1834725'>More sharing options...
Advertisement Posted November 4, 2011 Posted November 4, 2011 Hi TomB_tx, Take a look here Astro-Berlin 400. I'm sure you'll find what you were looking for!
jc_braconi Posted November 4, 2011 Share #2 Posted November 4, 2011 Beautiful set ! Link to post Share on other sites More sharing options...
zeitz Posted November 5, 2011 Share #3 Posted November 5, 2011 It looks post-war to me. Pre-war serial numbers ended at less than 39999. Post-war serial numbers started at greater than 50000. I have never seen an Astro product with a serial number between 40000 and 49999. If it is coated, it will have a red C on the rim with the lettering. Some post-war lenses were not coated. Link to post Share on other sites More sharing options...
TomB_tx Posted November 5, 2011 Author Share #4 Posted November 5, 2011 Serial number does place it post-war. Curious, as it only gives "Germany" for country of origin. Makes some sense though, as my aunt taught children of US army there in the late 40s, and her IIIc was 1948. Perhaps the lens was hers also. Link to post Share on other sites More sharing options...
zeitz Posted November 5, 2011 Share #5 Posted November 5, 2011 Tom, is your lens coated? This lens is an achromate so coating is not as important; two glass pieces cemented into a single element resulting in just two air to glass surfaces. It should have high contrast. Achromates tend to have flield curvature so that the edges may be out of focus when the center is in focus. Achromates remained popular for a long time and can give excellent performance. The Leica 400 & 560 f5.6 and f6.8 lenses are achromates. Link to post Share on other sites More sharing options...
luigi bertolotti Posted November 5, 2011 Share #6 Posted November 5, 2011 Nice set indeed !!! Is the mirror housing correctly working ? It looks a finely engineered item, probably more practical than the Viso I, at least for such long focals... Link to post Share on other sites More sharing options...
jc_braconi Posted November 5, 2011 Share #7 Posted November 5, 2011 Advertisement (gone after registration) . The Leica 400 & 560 f5.6 and f6.8 lenses are achromates. Absolutely ! Link to post Share on other sites More sharing options...
lars_bergquist Posted November 8, 2011 Share #8 Posted November 8, 2011 I have never seen and handled that mirror housing and know nothing about its internal optics. Is the finder image laterally reversed? A full pentaprism in those days absorbed quite a lot of light. And it looks as if the lens has aperture preselection. Is that so? The old man from the Age of Flintstone Optics Link to post Share on other sites More sharing options...
luigi bertolotti Posted November 8, 2011 Share #9 Posted November 8, 2011 I think is the version of Identoskop with right-way image... there had been a thread about time ago... http://www.l-camera-forum.com/leica-forum/leica-collectors-historica/129390-astro-berlin-identoskop.html (see Zeitz' post, #5) Link to post Share on other sites More sharing options...
TomB_tx Posted November 8, 2011 Author Share #10 Posted November 8, 2011 OK - some updates: The mirror housing works fine. Some dust on the screen, but not bad. Aperture control has "dry-grease" feel, generally stiff but frees up as moved. Clearly this is dried lube on the control ring, and the blades are fine. The special cable-release is also pretty stiff acting. It is NOT a pre-set diaphragm setup - just set the fstop and its done. The lenses are coated, so clearly post-war. The mirror housing is NOT pentaprism, and the image is reversed in both left-right & top-bottom. (Don't think I'll use it for sports!) I'm going to try a roll of film shortly, as the matching IIIc is in decent shape. I had Leitz NY service it just before they stopped working on the Barnack models. That was many years ago, but at well after 1948! After that... I'd like to clean & re-lube the lens. I've worked on a lot of SLRs and lenses, but wouldn't want to mess this up. I may send it to the repairman who is restoring my Zunow. (He's had it well over a year, but he does great work!) Link to post Share on other sites More sharing options...
zeitz Posted November 8, 2011 Share #11 Posted November 8, 2011 There are two eyepieces for Identoskops. The short finder, which you have, is 5x and is reversed and upside down. The long finder is 2x and is correct up/down & right/left. It is about twice as long as the short eyepiece. I theory the eyepieces are interchangeable, but in practice those from different eras are not interchangeable. There was also a 45 degree eyepiece. It is very rare and I don't know its characteristics. A pre-war lens could have been coated after the war. If the lens has a red C, it left the factory coated. The lens is easily disassembled and recoated. It think all Fernbildtlinses are all single helical mounts. Link to post Share on other sites More sharing options...
zeitz Posted November 8, 2011 Share #12 Posted November 8, 2011 I mean the lens is easily disassembled and relubricated. Sorry for the" inadvertent recoated". Link to post Share on other sites More sharing options...
TomB_tx Posted November 9, 2011 Author Share #13 Posted November 9, 2011 Thanks for the info. This is marked with a red "C" - so is factory coated. I can see where a long reversing finder would work in place of a pentaprism. The carrying case has two compartments for accessories, where this finder and the cable release fit for storage, but they look too short to fit a longer finder - so I'm sure none came with this. It is certainly single helicoid, which should be easy to work on. Not as sure about the diaphragm controls. Link to post Share on other sites More sharing options...
zeitz Posted November 9, 2011 Share #14 Posted November 9, 2011 The diaphragm is actually easy to work on if there is no rust or corrosion on the blades.. If the lubricant is dry, use these instructions. Here is how mine comes apart; it is post-war, but earlier serial #. The lens element section (front section) is about 4 inches long and contains the aperture. This should easily unscrew; just look to see if a set screw needs to loose first. Mine does not have a set screw. A regular lens spanner will remove the lens element retaining ring. The lens element will then push out from behind. Make sure to know the front of the element from the back of the element. Whey you put it back in, only one way is right. Wear vinyl gloves when you handle the lens element. Now set to min aperture; f50 in my case. Flush the aperture mechanism with lighter fluid to remove the old lubricant. Work the aperture to help. Now put in a minimum amount of light oil. Comes in the little one drop at a time dispensor. A couple of drops are all that is needed. It now should work like new. If it does not, you may be dealing with rust or corrosion. If so, no amount of lub will totally solve the problem. The aperture can be diassembled removing the ring with the same wrench at the other end, the aperture end. You just have take notes on what pins go where and how the blades overlap. You may not want to get into the lens this much. Link to post Share on other sites More sharing options...
TomB_tx Posted November 9, 2011 Author Share #15 Posted November 9, 2011 Thanks - sounds very reasonable. I have the tools, and compared to the automatic diaphragm SLR lenses I've figured out, shouldn't be bad. Link to post Share on other sites More sharing options...
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