shutter speed with back open in T-series cameras

[h_s1]

<p>Do all the T-series cameras default to a fixed shutter speed when the back is open? It appears that my T-50 is defaulting to 1/60, no matter where I point it (dark or bright scenes). Is it true for T-series cameras with Tv and M modes as well?</p>

<p>Does this have something to do with the film counter remaining at "S"? IIRC, the AE system in the cameras starts working only from frame number "1".</p>

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[User_4136860]

<p>I have three T90s and I can't imagine why anyone would need to fire the shutter with the back open ?</p>

[h_s1]

<p>People who are used to doing basic checks with their equipment use the method for various diagnostics.</p>

[Farkle-Mpls]

<p>Testing shutter speeds requires the back be open.</p>

[Farkle-Mpls]

<p>I just tested my two T90s and they shoot actual programmed shutter speeds with the back open. I had fun testing them both out to 30s and they are EXACT with respect to each other, but they both run a bit long: almost 32 seconds. However, that represents <1/10 stop error so no biggy with an exposure that long.</p>

<p>I'm curious if someone else wants to time their T90 shutters set at 30s and see what elapsed time they actually get. Is it more like 31.5s - 31.75s?</p>

[User_4136860]

<p>Since I don't have the knowledge, skill,test equipment, or tools to remedy any inaccuracy s in the shutter speeds or indeed know the margin of error + or - that's acceptable, I leave it to the camera repair technician I use to adjust them.</p>

[h_s1]

<p>Ben, I think you hit the nail on the head with the first two points. As to the rest:<br>

Equipment: the camera, a flash that works on it.<br>

Tools: a person who has even a rudimentary insights in how a camera functions basically.</p>

<p>As I wrote earlier, it is a diagnostic method, not a remedy. Remedy comes after a diagnosis.</p>

<p>Example, with the back open and with a flash, it is almost trivial to diagnose if flash sync is working properly or not. One can also easily find out if there is shutter capping occurring. If one is careful, one can also get a good idea if shutter speeds are changing with every change in the Tv setting. Quite simple, really, and a neat way to narrow down common problems.</p>

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[User_4136860]

<p>Sorry Duplicated</p>

[h_s1]

<p>I just got a chance to confirm this on a T-90 as well. With a lens attached and the back open, the shutter opens according to the Tv value set. T-50 is a different story. The T-50 appears to release the shutter at a fixed 1/60 s value if the back is open.</p>

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[philip_wilson]

<p>Carl</p>

<p>IO just tested my pair of T90s and while my timing was limited by just using a stopwatch and thus subject to error I made one 30.5 seconds, the other 31 seconds. I tested twice and they were both very consistant.</p>