Camera detective: Bizarre shutter behaviour on a Konica Autoreflex TC needs explaining.

<p>Hi all!<br>

I recently shot my first roll with a Konica Autoreflex TC that I got off eBay mainly for the AR Hexanon 1.8/40 it came with. When I got the roll back from development, most of the shots (3 out of 4) were completely blank, as if the shutter didn't open at all. Successful shots were randomly spread throughout the roll and were perfectly exposed. Furthermore, the spacing seems correct, i.e. blank segments between good frames correspond to either single or multiple frames, as indicated by 8 sprocket holes per frame. The Autoreflex TC has a mechanical shutter and while shooting the roll, everything sounded OK, the relatively loud thud of the metallic curtains was there for every shot, without any audible difference from the previous or the next one. Frame counter worked OK and the rewind lever turned OK while advancing the film, The first and last shot registered OK and there were no exposure problems in the successful shots, nor did anything register on the blank frames (no bands, dark corners, half frames, etc) they are just completely blank. Here comes the spooky stuff: While dry testing the shutter in manual mode with the film door open both before and after shooting the roll in question, everything seems OK: I tripped the shutter on every single speed in manual mode for more than 50 times for each speed and it fired correctly every single time. I repeated the same with the lens in AE mode (shutter priority) and every single time the shutter opened correctly with the lens aperture varying as expected between shots, corresponding to what the needle showed in the viewfinder. I shot a second roll with it, taking care to shoot each photo both in AE and manual mode, and the same thing happened: Some shots are completely blank in random order, sometimes both AE and manual versions of the same shot registered OK, sometimes one is missing, sometimes both are missing. I'm really baffled by this, as was my camera repair guy when I described the problem to him on the phone. Any ideas? Is it possible that the presence of film somehow causes the shutter to fail randomly?</p>

<p>I too faced the same problem but with Canon EF-M film camera! Most frames were exposed fine, a small number of random frames were completely blank. When I checked without the film, shutter worked as it should be.</p>

<p>Lens cap left on? Sorry I couldn't resist. My only thought was when you tested it dry, did you actually see the light through the shutter curtain slit? Try this in front of a bright light. If you do see the light I have no other explanation. </p>

<p>Would this happen if the mirror fails to rise? </p>

<p>@Daniel Deary: I own dozens of SLRs, light came through the shutter just fine every single time, on every single speed from 1/8-1/1000, both in full manual and AE mode.<br>

@Matthew Currie: The mirror seemed like a possible culprit, but I could see the whole circle of light coming through the lens and the shutter every single time of the hundreds I tripped the shutter both in AE and Manual with the film door open. If the mirror failed to rise at all, I wouldn't be able to see any light coming through. If it rose only half-way, some of the shots would be cut in half or underexposed, but at least something would have registered on film. It is either perfectly exposed images or total blanks, nothing inbetween. For the second roll, I deliberately shot some pictures at 1/1000 and while a couple of them failed to register at all, most came out just fine...</p>

<p>Christos, I had three TC bodies that did exactly the same thing. You don't see it without film, because there is no tension on the take up spool. It is a fault with the gearing in the film advance/shutter cocking mechanism. Take a roll of film, put it in the camera, and for the first 10 frames, very carefully and methodically actuate the advance lever, smoothly and completely, at the same speed each time. You will occasionally feel very small "tugs", this is the damaged gearing. The shutter is not FULLY wound when this happens, resulting in one curtain never opening. I never bothered with fixing these cameras, I simply threw them away. I have two TC bodies right now that work perfectly, so I am content.</p>

<p>Michael is quite correct, and the shutter will still make a normal sound when it miss fires.</p>

<p>@Michael Howard: Thanks for the feedback, this makes total sense. Film advance resistance is noticeably increased when film is loaded, so increased tension is a plausible culprit. This is also supported by the fact that most missed shots occured in the beginning of the roll where tension is greater. It's a pity really, because the TC is almost the only affordable compact, fully mechanical Konica body to use the Hexanon 1.8/40 with. A T/T3 body negates the size/weight advantage of the lens and the T4 is just too expensive on the european eBay sites. Electronic Konicas (FC/FT/FS) are out of the question due to reliability issues, plus I have made a conscious decision to stick to mechanical cameras only. Funny thing is that although only 9 out of 36 frames got exposed in the first roll, I got 27 exposed frames on the second one. Perhaps I advanced the film more calmly the second time?. Anyway, off to get another TC body!</p>

<p>The later TC-X is also mechanical and uses one AAA battery just for the meter.</p>

<p>I wonder who repairs Konica Autoreflex TC cameras? I guess parts might be an issue, but maybe a CLA would set thing right?</p>

<p>@Jeff Adler: I wasn't aware a Konica TC-X existed, I looked it up and it seems like it's another Cosina CT-1 spin-off. It's not as good-looking, but it seems like a good alternative, esp. with the AAA-powered meter instead of the two 675 cells required for the TC.</p>

<p>@Anthony Oresteen: |I guess the TC is common (and cheap) enough to just get another one hoping it will work, instead of trying to get it fixed. Getting spare parts must also be a problem.</p>

<p>My Konica Automatic T shutter had similar problem, it seems the exposure meter and the shutter<br>

coupling not reliable, finally I sold it with three lenses.</p>