Pentax Spotmatic (SPII) Light Meter Repair

NorwichCameraMan · 11-23-2021, 02:54 AM

Hi Guys,

I have found a really decent deal on a spotmatic without a working light meter however I would ideally want to get this light meter working.
The sale describes the light meter as:

The light meter is not working although it the needle does move when I put in an L44

So I am wondering if this is a common problem that someone could spot and it may be an easy/cheap fix. The rest of the camera is described as in perfefct working condition and the photos suggest the same. If it is an easy fix, this camera will definitely be worth me buying so if anyone can help me out it would be greatly appreactiated!

NorwichCameraMan

lotech · 11-23-2021, 07:04 PM

Originally posted by NorwichCameraMan

Hi Guys,

I have found a really decent deal on a spotmatic without a working light meter however I would ideally want to get this light meter working.
The sale describes the light meter as:

The light meter is not working although it the needle does move when I put in an L44

So I am wondering if this is a common problem that someone could spot and it may be an easy/cheap fix. The rest of the camera is described as in perfefct working condition and the photos suggest the same. If it is an easy fix, this camera will definitely be worth me buying so if anyone can help me out it would be greatly appreactiated!

NorwichCameraMan

A camera that old but uses LR44 cell are you sure ? I've not touched the Spotmatic but wonder what type of light sensor it uses. As far as I know old camera uses Selenium cell that generates electricity need no battery, has a large window on the camera body to capture the light, commonly used on old Russian camera, can also be used to control the current flow thru' the meter with added battery. Other type being CDS Cadmium Sulfide which is a light sensitive resistor and very small size, also control the current flow to the meter. The last type we used today is SPD Silicon Photo Diode, this type is very reliable and accurate. Since the light sensor of the Spotmatic is very small put inside the camera (?) I believe it is CDS ? if you put in battery and the needle moved, you could replace the light sensor if possible, or try to find the trimming pot to calibrate with another meter. But if I were you I would simply buy a hotshoe mount meter instead, but does the Spotmatic have a hot/cold shoe ?

beemac · 11-23-2021, 07:32 PM

It has a CdS light meter and originally used a PX400 cell. These are NLA but I'm told there is an alkaline cell equivalent.

lotech · 11-23-2021, 07:41 PM

Originally posted by beemac

It has a CdS light meter and originally used a PX400 cell. These are NLA but I'm told there is an alkaline cell equivalent.

Thanks for the tips, I read that Pentax uses balanced circuit in the light meter, so that battery voltage variation will not affect the reading, but new battery will need adapter to fit in.

MarkJerling · 11-23-2021, 08:11 PM

Originally posted by NorwichCameraMan

Hi Guys,

I have found a really decent deal on a spotmatic without a working light meter however I would ideally want to get this light meter working.
The sale describes the light meter as:

The light meter is not working although it the needle does move when I put in an L44

So I am wondering if this is a common problem that someone could spot and it may be an easy/cheap fix. The rest of the camera is described as in perfefct working condition and the photos suggest the same. If it is an easy fix, this camera will definitely be worth me buying so if anyone can help me out it would be greatly appreactiated!

NorwichCameraMan

Hi.
This thread may be useful to you:
Replacement battery for Spotmatic SPII - PentaxForums.com

11-23-2021, 02:54 AM	#1
NorwichCameraMan New Member Join Date: Jun 2021 Posts: 3	Pentax Spotmatic (SPII) Light Meter Repair Hi Guys, I have found a really decent deal on a spotmatic without a working light meter however I would ideally want to get this light meter working. The sale describes the light meter as: The light meter is not working although it the needle does move when I put in an L44 So I am wondering if this is a common problem that someone could spot and it may be an easy/cheap fix. The rest of the camera is described as in perfefct working condition and the photos suggest the same. If it is an easy fix, this camera will definitely be worth me buying so if anyone can help me out it would be greatly appreactiated! NorwichCameraMan

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Spotmatic SPII Shutter & Mirror Stick at 1/15th of a Second	tsoybeans	Troubleshooting and Beginner Help	4	12-06-2020 02:28 PM
Shutter Speed Tolerances Spotmatic SPII	Nick Rowland	Film SLRs and Compact Film Cameras	5	02-29-2020 12:29 AM
K1000 Light Meter Calibration - Aperture has no effect on light meter?	appalachian1	Film SLRs and Compact Film Cameras	5	03-14-2017 07:08 PM
Repair Asahi SPII My Light Meter	3RiC	Film SLRs and Compact Film Cameras	3	11-02-2009 12:14 AM
Asahi SPII My Light Meter Isn't Working.	Cameron030293	Film SLRs and Compact Film Cameras	7	10-13-2009 06:46 AM

11-23-2021, 07:04 PM	#2
lotech Pentaxian Join Date: Apr 2012 Posts: 1,312	Originally posted by NorwichCameraMan Hi Guys, I have found a really decent deal on a spotmatic without a working light meter however I would ideally want to get this light meter working. The sale describes the light meter as: The light meter is not working although it the needle does move when I put in an L44 So I am wondering if this is a common problem that someone could spot and it may be an easy/cheap fix. The rest of the camera is described as in perfefct working condition and the photos suggest the same. If it is an easy fix, this camera will definitely be worth me buying so if anyone can help me out it would be greatly appreactiated! NorwichCameraMan A camera that old but uses LR44 cell are you sure ? I've not touched the Spotmatic but wonder what type of light sensor it uses. As far as I know old camera uses Selenium cell that generates electricity need no battery, has a large window on the camera body to capture the light, commonly used on old Russian camera, can also be used to control the current flow thru' the meter with added battery. Other type being CDS Cadmium Sulfide which is a light sensitive resistor and very small size, also control the current flow to the meter. The last type we used today is SPD Silicon Photo Diode, this type is very reliable and accurate. Since the light sensor of the Spotmatic is very small put inside the camera (?) I believe it is CDS ? if you put in battery and the needle moved, you could replace the light sensor if possible, or try to find the trimming pot to calibrate with another meter. But if I were you I would simply buy a hotshoe mount meter instead, but does the Spotmatic have a hot/cold shoe ?

11-23-2021, 07:32 PM	#3
beemac New Member Join Date: Jun 2014 Posts: 17	It has a CdS light meter and originally used a PX400 cell. These are NLA but I'm told there is an alkaline cell equivalent.

11-23-2021, 07:41 PM	#4
lotech Pentaxian Join Date: Apr 2012 Posts: 1,312	Originally posted by beemac It has a CdS light meter and originally used a PX400 cell. These are NLA but I'm told there is an alkaline cell equivalent. Thanks for the tips, I read that Pentax uses balanced circuit in the light meter, so that battery voltage variation will not affect the reading, but new battery will need adapter to fit in.

11-23-2021, 08:11 PM	#5
MarkJerling Moderator Site Supporter Join Date: May 2012 Location: Wairarapa, New Zealand Photos: Gallery \| Albums Posts: 20,423	Originally posted by NorwichCameraMan Hi Guys, I have found a really decent deal on a spotmatic without a working light meter however I would ideally want to get this light meter working. The sale describes the light meter as: The light meter is not working although it the needle does move when I put in an L44 So I am wondering if this is a common problem that someone could spot and it may be an easy/cheap fix. The rest of the camera is described as in perfefct working condition and the photos suggest the same. If it is an easy fix, this camera will definitely be worth me buying so if anyone can help me out it would be greatly appreactiated! NorwichCameraMan Hi. This thread may be useful to you: Replacement battery for Spotmatic SPII - PentaxForums.com