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mary ellen
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, October 22, 2004 - 04:39 am: | 
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I have a child very interested in photography.who is taking a her first photo class...her uncle gave her his Fujica st701 ...it takes a epx 400 battery...what can we substitute or where can we buy these ? I would apreciate any input as we can't afford another camera and I do not want to disappoint child on way to life long hobby..Thanks |
M Currie
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Votes: 0 (Vote!) | | Posted on Friday, October 22, 2004 - 08:26 am: |
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A quick web search shows that there are silver-oxide and zinc-air "wein cell" replacements for this battery. Try Google for sources. If at all possible, I'd see if the silver-oxide one will work with either a recalibration of the meter (probably too expensive in this case), or compensating with the ASA(now ISO) setting. The Wein cell replacements, though they require no recalibration, are more expensive and not as long-lasting, so if you can make a silver-oxide cell work, you're better off.
For compensating with the ASA dial, what you would need to do is either experiment with settings until you get good exposures, or find another, known accurate meter or camera-with-meter, and adjust until they agree. You could start with the "sunny 16" rule: in bright sun, exposure should be about f16 and the reciprocal of the film speed. so for example, using ISO 100 film, F16 at 1/125 would be about right. If, with your new batteries, you fudge the ASA dial until the meter shows that setting, you'll at least be close. If the camera has an older averaging type meter, your child will soon learn that she has to second-guess the reading in difficult lighting situations anyway, and a ball-park figure may be all she needs from it.
There might be a third possibility depending on how and whether there's a battery test function on the camera. On some cameras, such as the Konica T3, the battery test function itself is dependent on the ASA setting, and it is easy to calibrate the meter for other batteries simply by adjusting the setting during the test. Some other cameras do not do it this way, though, so you'll probably have to experiment a bit.
Another possibility, if you can't get the built-in meter to work well, is just to find a relatively inexpensive hand-held meter (not too hard to find on ebay, etc.). Less convenient, of course, but versatile, allows use with any camera, including meterless or broken ones. |
Berk Sirman
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, October 22, 2004 - 09:56 am: |
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Original mercury batteries' output is 1.35 V. The silveroxide and alkaline batteries give 1.5V. The difference of 0.15V may cause faulty readings. I say "may" because I do not know whether the camera is question has a bridge circuit to rectify the difference in battery voltage.
Your best bet is to get zinc-air hearing aid batteries. They are very cheap. The voltage on those is 1.4V which very soon after putting it in the camera drops to 1.35V. The 0.05V diference does not cause any faulty readings anyway. The zinc-air batteries last only 1-2 months but again they are very cheap and available everywhere. The battery will not fit the camera perfectly, you will need some plastic O ring-paper whatever to hold it in place. Also watch the polarity when putting the battery in since the original px400's had the positive polarity on the opposite side of what one might expect. You will need to put the new zinc air battery "upside down" The zinc-air batteries take about 30min to stabilize voltage after the tag is removed.
Of course you may do it the more "proper" way and get weincells but if you do not have a pro photo store near where you live you may have to order it online. Good luck |
Kiron Kid
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, October 28, 2004 - 07:39 pm: |
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The hearing aid, zinc-air cells work fine, and are about $1.00 per battery. The "Wein" zinc-air cells last considerably longer, but cost a few dollars more. If you use a Silver Oxide 1.5v cell, you can cut the film speed in half (½), and that will give you accurate meter readings and exposures.
Kiron Kid |
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