View Full Version : Bttery Replacement of Pentax V Spotmeter
Michael Heald
28-Jan-2006, 06:13
Hello! I just purchasesd a used Asahi Pentax V spotmeter to use with my 4x5 Tachihara. I need to purchase batteries, since it used mercury batteries, and I see from previous posts that the LR44 batteries should work.
Have members found other replacement batteries also work with this spotmeter?
Should I check the accuracy of the meter with the new batteries, since the voltage is slightly different from the old mercury cell? Would a step wedge work, if the meter needs to be checked? Thank you and best regards.
Mike
Leonard Evens
28-Jan-2006, 08:52
I don't have any experience with that particular meter, but I do have an old Honeywell/Pentax spotmeter made by Asahi. My meter used a 9 v battery for low level light and a mercury cell for high light. There is a 1.5 alkaline battery which fits in the space for the mercury battery, but the voltage is considerably different. I found that I could not use a 1.5 v battery in my meter. The problem is that the scale is not linear so the errors are different in different parts of the range. You would have to do a careful calibration against a reliable meter for the entire range of high values and compile a correction table. In practice, it would be awkward to use, I think. My best choice for this camera was a Wein Cell MRB625, which is a 1.35 v battery. It doesn't fill the space, but I improvised a conducting filler from coper wire. Also, the voltage was still not quite right, but the maximum error was something like 1/2 to 2/3 stop. The main problem was that when it failed, it still passed the check mechanism which was to compare 10 in both the high and low readings. The only way I knew the battery had failed was that the high readings were far off. I finally gave up and got myself a Pentax Digital Spotmeter, and I've been happy with it ever since.
If you want to do a careful calibration, I would suggest finding large uniformly lit surfaces at different intensities and measure both with the spotmeter and with the other reliable meter, using the spotmeter to check the uniformity of the lighting. I wouldn't try to do it with step wedges.
Doug Pollock
28-Jan-2006, 10:03
I purchased a PX640 BATTERY ADAPTER off that auction site for $21.00 It fills up the battery compartment after inserting commonly available button batteries. Accurate. Simple. Reliable, so far.
tim atherton
28-Jan-2006, 10:33
I thought the Spotemeter V took three (G-13 type) 1.5 Mercury batteries.
I've always just used three 1.5 silver oxide batteries with no problem....
Keith Fleming
28-Jan-2006, 12:53
You might check with your local Radio Shack store. As I remember, there is a battery that is equivalent in size to three of the 1.5 volt batteries--and the voltage is 4.5 volts. I don't know if that's the PX640 mentioned earlier.
My Pentax V manual is about 20 years old, and it specifies G-13 silver batteries
ronald moravec
28-Jan-2006, 14:58
The older meters did not use the 3 - 1.5v battery pack.
Bite the bullet and get the digital spot meter.
Tom Westbrook
28-Jan-2006, 15:06
Mine has 3 Energizer 357's in it now and work fine. Those are silver oxide. I've also used A76 or D76A's (same as G13), too, but those are the alkaline version and won't last as long and don't do as well in the cold. Here's a handy conversion chart: http://www.kassoy.com/watch05.html.
Michael Heald
28-Jan-2006, 15:40
Hello! I put in three LR44 1.5 volt batteries, and it has powered up fine. Now to run some tests, and to check it for consant signal as the batteries wear down. Best regards.
Mike
tim atherton
28-Jan-2006, 15:49
you may have to wait a bit - I think I've had the same set in for at least 2 1/2 years....
Paul Wallis
29-Jan-2006, 12:12
HAve a look at http://www.smallbattery.company.org.uk/index.htm?http://www.smallbattery.company.org.uk/sbc_home_page.htm , they sorted me out a replacement for mine.
Michael Heald
30-Jan-2006, 13:04
Hello! I tested the meter against my camera meter in my Canon, and they agree. Interestingly, I tried the EI test described in the current Large Format Magazine using the spot meter, and I've been giving about a stop over exposure! I was wondering why the negatives were looking off.
the battery guy at b+h told me i was out of luck; the batteries aren't made anymore. but the guy at radio shack around the corner had a modern substitute that works just fine. i don't know what the battery number is for the replacement, so i'd suggest just taking the old batteries to a radio shack.
tillari
26-Feb-2009, 06:26
Hello, a fiend gave me a Pentax Spotmeter V, but it only has two A76 batteries. Is there something wrong?
Thanks,
Ariel
John Armbrust
18-Mar-2009, 11:03
Mine takes the 3XLR44 (equivalent to the 354). Works fine, batteries available at my local grocery store (Publix). FWIW.....
G 13 is equivalent to the following according to BatteryMart.com
I use the Energizer 357 or 303 with no problems
* Duracell: LR44
* Eveready: A76
* IEC: LR44
* Maxell/Toshiba: LR44, LR44H
* Renata: LR44
* Varta: V13GA
* Vinnic: L1154
* Other: SG13, GP76, AG13, GPA76, 5244, A01, A200, A76LR44, FM28F, G13,G13-A, G13A, GP76A, KA, KA76, L1154, RW82
Kirk Fry
19-Mar-2009, 23:47
I use 3 EPX76 in mine, seem to work fine. Analog Pentax V. I just had it calibrated at Quality Light-Metric and they used those. Fine outfit by the way.
7095 Hollywood BLVD #550
Hollywood, CA, 90028
323-467-2265.
The circuit board in mine died and they replaced it for $88.
They do light meters, not web sites.
Call them the old fashioned way. Very friendly.
K
Powered by vBulletin® Version 4.2.5 Copyright © 2025 vBulletin Solutions Inc. All rights reserved.