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Mamiya 7ii - How Long Will Shutter Stay Open


baisao

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<p>I tried to take a 1.5 hour night photo last year during the holidays and the shutter closed after about 18 minutes, judging by the star trails. I wound on a frame and it fired right away, so the battery wasn't dead. The holidays are nearing and I want to attempt this shot again with the Mamiya. </p>

<p>The temp never got below 40° but there was condensation enough on the lens that the shot would have been spoiled anyway. Neither should have effected the shutter.</p>

<p>With a fresh battery and temps above 40°, how long should I expect the Mamiya 7ii shutter to remain open?</p>

<p> </p>

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<p>Quoting from the manual is probably not much practical help to you, but it says:<br>

"At "B" the shutter will remain open as long as the release is pressed down."<br>

and<br>

"A new alkaline manganese battery is durable for about 3 hours, silver oxide battery and lithium battery for about 7 hours. When the battery is fully consumed, the shutter will be closed automatically."</p>

 

<p>I suppose it's possible that a weak battery will work fine for short exposures, but may not have enough power for bulb exposures, particularly in cold conditions when batteries are less efficient.</p>

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<p>I bought a Mamiya 645 in 1974 when they first came out.........it ate batterys in cold weather.<br />I would go out to shoot a mill in the snow, when I got there the battery was dead.<br />In 1980 I dumped all my 645 gear and bought a Hasselblad CM set......never had a battery problem again.<br />Maybe you could rig up an external power supply of sorts for long exposures?<br />It would probably be your only solution, good luck Jim.</p>
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<blockquote>

<p>I bought a Mamiya 645 in 1974 when they first came out.........it ate batterys in cold weather.<br />I would go out to shoot a mill in the snow, when I got there the battery was dead.</p>

</blockquote>

<p>That's strange. I've had over a year of usage with some of my M645 batteries, and that includes shooting long astro exposures on cold winter nights. You must have had a defective camera...maybe an early test model, as they officially came out in 1975, not 1974. </p>

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<p>Robin, that's a good idea for a test. I may just try to borrow a camera with a mechanical shutter for this one outing since the needed exposure is well in excess of 15 minutes. Perhaps it's an undocumented auto-off feature.</p>

<p>I don't think that 40° is all that cold. I have regularly used it for exposures in the 2-8 minute range in temps in the 20s.</p>

<p> </p>

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  • 2 weeks later...
<p>Okay Ray I was off by one year, bought it in 1975..........but yes I had to always carry spare battery's when in the cold with that camera.<br />When the battery's warmed they would often work again.<br /><br />Any way the point I was trying to make was with an electronic shutter you may need an external power supply?<br /><br />But you did not pick that point apart.......<br />Glad to have experts on board.</p>
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<p>Russ, I merely took you at your word - I'm sorry if that annoyed you.<br /><br />I'm not here to pick points apart, I'm here to help the diagnosis. The M645 does not have a reputation for cold weather issues, and certainly your M645 experience does not tally with mine, so the most likely reason is that there was something defective, either in your camera or the batteries you were using.<br /><br />Mamiya did/do offer external power sockets/supplies for their more battery-dependent cameras and accessories...such as the RZ67's power winder, the WG401 winder/grip for the 645 Pro, and the 645AF(D) bodies. But not for the original M645 series. I think that is telling us something...</p>
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