Praktica super TL: Shutter - diaphragm not synchronized with auto lens on

<p>Hi!<br /><br />I recently bought a nice praktica Super TL with an Oreston 1.8/50. What i've noticed is that when the shutter is depressed, the lens diaphragm closes and opens at a fast speed which seems constant, unrelated to the shutter speed. For example, with a shutter speed selected at 1/4 sec or slower where the problem is easiest to observe, the diaphragm will stop down to the selected aperture when the shutter is depressed, but it will open again BEFORE the shutter closes, i.e. the shutter is still open when the lens aperture goes wide open again. Looks like there is no synchronization between the shutter and the diaphragm. This happened with every auto lens i tried, the Oreston behaved normally on my Yashica TL Super. However if you press the shutter release and keep it pressed, the diaphragm stays stopped down throughout the exposure. Is this normal? Certainly, if the diaphragm opens up before the shutter closes, the picture will be overexposed? If the lens has a manual setting this can be avoided, but what if there's no manual switch? Thanks.</p>

<p>Sounds like a linkage problem in the camera body. Observe the action without a lens in place. The little paddle at the bottom of the lens mount moves forward to push a pin inward on a M42 auto lens. That paddle should stay extended throughout the shutter cycle. If it does not then what ever pushes on it must be slipping off at the end of the stroke. On some simple screw mount cameras the action of pressing down on the shutter release was directly mechanically linked to the stop down paddle. In that type of set up the shutter button would have to be held down through out the whole shutter cycle. I don't know how your Praktica works but a simple test will tell if holding the shutter button down is required on this model</p>

<p>As john says. Look at the paddle and see what it does. This should work on this model exactly as it does on your Yashica.</p>

<p>Yes <strong>Christos</strong>; in the Super TL <strong>one must keep the shutter button pressed down</strong> until the exposure is over. It is <strong>critical in slower/longer</strong> exposures with <strong>automatic lenses</strong>. It may not be necessary at 1/8 sec and shorter exposures. I have a few Super TLs [and other Novas] of this nature. I have also verified the same with others and have posted my findings on PN in some earlier posts.<br /> The peculiarity is true of the <strong>entire Nova</strong> series, including the Praktica MAT [i verified again just now]. Most people do not seem to notice it, mainly, because the finger press and release on the shutter button takes more than 1/8 sec. Thus, the problem would arise only in speeds 1/4, 1/2 and 1 second. It is an excellent camera despite the peculiarity. <strong>John, JDM</strong>, I think these cameras were designed, thusly. sp.</p>

<p>Thanks! In any case, i have cultivated the habit of squeezing the shutter release and hold still until the exposure is over, so i don't think it would cause any problems in real life, who goes slower than 1/16 handheld anyway.</p>

<p>Yep! It's right there in the manual. It specifically emphasizes that the shutter release button must stay pressed throufhout the shutter cycle, ESP. at the lower speeds. I should have looked for the menual before posting. Thanks!</p>

<p>You learn something every day. :)</p>

<p>So few of my nova series cameras work at all that I had little opportunity to notice this.</p>