As an old Spotmatic user (shot professionally in the ‘70’s) I can attest the light meter was a guide at most. Shooting Tri-X for sports was easy as it was extremely forgiving. We relied on knowledge of the film and how we would develop it. We relied heavily on experience and hand held light meters. for most situations. For event photography we relied on using the flash for light and again knowledge of guide numbers, film, and later flashes such as the Sunpak 511 & 611 that had built in thyristors. I always took the Spotmatic meter as a starting point to get in the ballpark. Phenomenal, rugged cameras and lenses.
My Spotmatic was rescued from a bin and now is looking brand new. It's underrated for sure. Sturdy and solid. I just need some screw mount M24 lenses now. I'll be damned if I'm paying prices for a new one though. I'll fix up an old mouldy one instead.
I really like my Spotmatics and have always wondered why so many people seem to be obsessed with the light meters on old cameras. Very few of them are accurate to begin with and following the sunny 16 rule works incredibly well for obtaining proper exposure. Maybe it’s just an assumption or attitude of “it’s a feature of the camera, so if it doesn’t work then the camera sould be avoided” kind of thing, but that’s a shame because the Spotmatic cameras, well cared for, will probably outlive us all.
I got my SPF in 1974 and liked it very much. First failure was a broken "klick spring" for the time settlings. After removing it it works until 2002, when I switched to K. Fun fact on the batteries: I still use a Gossen Lunasix3 wohl 2 PX625 Mercury Batteries and still work with a small remaining stock of old batteries bought end of the ,80s
I have a Honeywell Spotmatic (same as the Asahi Spotmatic except distributed in the U.S. by Honeywell). Mine's circa about 1970 it's the version without the flash mount on the pentaprism. Bought it a couple of years ago with a Pentax Super Takumar 50mm f/1.8 lens, Tokina 28mm f2.8 lens, case and Sunpak flash for $45.00. Great camera it's a well made solid camera I enjoy using it. I don't mind the match needle 'stop down' metering at all. The Super Takumar 50mm lens is easily the best 'normal' focal length lens I have.
This is the biggest reason I've borrowed and tinkered with spotties over the years but never owned one. I have two S series earlier (S1a and H3v) which are lighter, smaller, slightly prettier and much simpler mechanically... and a few K and M series following later which have reliable, better metering and early creature comforts. Always felt like Spotties are (today anyhow) stuck between those eras.
While I use 1.5 volt silver oxide batteries on my Spotmatics, which are accurate due to the Wheatstone bridge circuitry, I never buy Wein cells anymore for my vintage cameras lacking that compensation. Hearing aid zinc-air batteries are so cheap that their short lifespan is not problematic, and you can use a metal washer from the hardware store of a brass adaptor with good success. Just don't remove the tab until you're ready to use them. You can also get MR9 adaptors that will accept the silver oxide button cells and reduce the voltage enough for accuracy.
You probably know this already...but for anyone else reading this, soak the bottom plate in white viegar for a few hours it eats away at he corrosion, then the battery cover should come off for cleaning. Also always tighten battery cover first then loosen it helps to break any crustiness in threads. I have saved many Spotmatics this way.
I had a very stubborn battery cover with a slightly stripped turn slot- in the freezer for 1/2 hour in ice (thermal shock) did the trick! - cleaned up with some vinegar and she is working like a champ!
The Spotmatic (not the F) has a balanced bridge circuit that is supposed to deliver 1.35v to the meter circuit regardless of variations in input voltage. I imagine they designed it like that to make the meter immune to voltage drop as the battery loses capacity. You can see the circuit diagram in the service manual, figure 9, the bridge circuit is the arrangement of four resistors. That being said not a single one of my Spotmatics had an accurate meter. Even the ones I sent to Eric for servicing came back with meters that were only accurate around a narrow part of the EV range (probably around whatever EV is set on his tester). I suspect that either the resistors in the bridge go wonky with age or the galvometer driving the meter needle becomes less linear with age and wear. I no longer own any Spotmatics; my M42 camera of choice is a Pentax SV. Small, light (for an all metal camera), no grafted on hotshoe messing up the lines. You can pretty much service it by giving it a good smack on the bottom with your palm.
I do love the SV, significantly better focus screen than the H3 but I mostly shoot with the H3 for the same reason as the light meter just never really works as well as I'd like in other spotmatics and for that size I'd almost prefer shooting with a K1000 instead. I was looking into the photo resistors for a while because I was noticing those were failing but it could have also been the resistors on the board. Regardless I appreciate the input and maybe one day someone will get some better metering system in there.
There is a bridge circuit in the Pentax Spotmatic 1 and 2 that regulates somewhat the current going through the galvanometer. It is called a Wheatstone bridge. It does not regulate the battery voltage per se, but when the bridge ( consisting of the variable resistors and photoresistors) is on equilibrium, it gives a reading of zero, that in voltage insensitive. Only the zero is accurate. That's the theory. In practice, Pentax has made it so (and calibrated the circuit) in such a way that the galvanometer is indicating good exposure (zero) when the current flowing through it is 3 µ Amperes, not zero A (source = the repair manual). Therefore, the Spotmatic is not completely voltage insensitive. Furthermore add the problem that these early cadmium sulfide photoresistors have sometimes aged badly over the decades, and you have a bit wonky lightmeter. For good measure, the photocells should be replaced by new ones, (when they are still obtainable !) and the circuit should be recalibrated.
Watching this prompt me to pull out my first Spotmatic and a KX that some how I ended up with. Fortunately both battery chambers were clean!. Half way through watching, I thought about battery replacements in case I wanted to do film again and came to the same conclusion as you did, just use my external light meter.
I have five Spotmatics. Four are chrome and one is black. None of the cameras have batteries because I choose to not use the built-in light meter. I use six lenses (28/35/50/105/200/300). The 8-element 50mm f/1.4 and the 105mm f/2.8 are my personal favorites. My Spotmatic system serves as a backup to my Nikon F SLR system.
I've heard that Spotmatics utilize a Wheatstone Bridge in the metering circuit so you can use standard 1.5V LR44s rather than a Wein Cell or 1.5V battery with resistive adapter. That said, the meter still needs to be in decent condition to provide a reasonable reading.
The Spotmatic and SV are probs the most beautiful Pentax cameras and also generally very good cameras in terms of simplicity and reliability, much prefer them to what came after. Saying that the K mount KX is probs the best version of the Spotmatic. If I'm not mistaken the mechanical bits are the same as the Spotmatic (It shares the same bits in the service manual) but the light meter is highly improved; it uses standard alkaline batteries and also uses silicone photo diodes instead of the cadmium type used on the older cameras which degrade.
I just bought one from Japan in immaculate condition. I have the same battery problem but was able to get the Wein battery. It will go with my Helios. Otherwise I use micro four thirds (x4).
This is a good presentation of the problems that occur with the venerable Spotmatic lightmeter and circuitery. I will add this : There is a bridge circuit in the Pentax Spotmatic 1 and 2 that regulates somewhat the current going through the galvanometer. It is called a Wheatstone bridge. It does not regulate the battery voltage per se, but when the bridge ( consisting of the variable resistors and photoresistors) is on equilibrium, it gives a reading of zero, that in voltage insensitive. Only the zero is accurate. That's the theory. In practice, Pentax has made it so (and calibrated the circuit) in such a way that the galvanometer is indicating good exposure (zero) when the current flowing through it is 3 µ Amperes, not zero A (source = the repair manual). Therefore, the Spotmatic is not completely voltage insensitive. Furthermore add the problem that these early cadmium sulfide photoresistors have sometimes aged badly over the decades, and you have a bit wonky lightmeter. For good measure, the photocells should be replaced by new ones, (when they are still obtainable !) and the circuit should be recalibrated.
I came here to say this - I have two Spotties, and both meters function fine (checked against meters known to be accurate) with 1.5 volt silver oxide cells. It's a little bit fussy getting the meter centered as it jumps (due to the point you cite above) but the needle centered position is within 1/3 stop at all light levels.
People whom have the K1000 and K* cameras... Why does the winder not sound like the spotmatic... The winder in the K1000 is spongey and not as tactile... Anyone agree?
No other Pentax is better than the MX I’m sorry. The best 35mm cameras ever made are the Olympus OM-1 and the Pentax MX, period. We could talk about Nikons and Leicas but these cameras being expensive doesn’t make them the best ever made, because you need to pay a lot for them whereas Olympus and Pentax managed to make compact, very bright viewfinders, very affordable and reliable cameras. I was recently given a Spotmatic Sp F, and although it’s a great camera, the m42 screw ring is awkward, the viewfinder is dim and it’s kind of a heavy 35mm. Being a fully mechanical camera makes it worthy for sure, but my Pentax MX is better having a brighter viewfinder, smaller, lighter, fully mechanical, Pentax K mount for quick lens switch and it has and does everything better than all previous Pentax models. Pentax MX I’m telling you
A simple, inexpensive light meter that can fit in a shirt pocket is my answer! If you can't grasp the utter simplicity of the "Sunny 16" rule, just take a meter reading! I've used these old Gems for years! Always getting great pictures 📸 and confusing the young folks, who just can't grasp the concept of a "Non-AUTOMATIC" picture-taking-thingie!!!
Spotmatic is pure joy! Oh the meter is poor? Really 40 years later.. My Leica Meter with battery was Fluffed 18 months after purchase! I used them profesioinaly..Useless video.
As an old Spotmatic user (shot professionally in the ‘70’s) I can attest the light meter was a guide at most. Shooting Tri-X for sports was easy as it was extremely forgiving. We relied on knowledge of the film and how we would develop it. We relied heavily on experience and hand held light meters. for most situations. For event photography we relied on using the flash for light and again knowledge of guide numbers, film, and later flashes such as the Sunpak 511 & 611 that had built in thyristors. I always took the Spotmatic meter as a starting point to get in the ballpark. Phenomenal, rugged cameras and lenses.
My Spotmatic was rescued from a bin and now is looking brand new. It's underrated for sure. Sturdy and solid. I just need some screw mount M24 lenses now. I'll be damned if I'm paying prices for a new one though. I'll fix up an old mouldy one instead.
I really like my Spotmatics and have always wondered why so many people seem to be obsessed with the light meters on old cameras. Very few of them are accurate to begin with and following the sunny 16 rule works incredibly well for obtaining proper exposure. Maybe it’s just an assumption or attitude of “it’s a feature of the camera, so if it doesn’t work then the camera sould be avoided” kind of thing, but that’s a shame because the Spotmatic cameras, well cared for, will probably outlive us all.
I got my SPF in 1974 and liked it very much. First failure was a broken "klick spring" for the time settlings. After removing it it works until 2002, when I switched to K.
Fun fact on the batteries: I still use a Gossen Lunasix3 wohl 2 PX625 Mercury Batteries and still work with a small remaining stock of old batteries bought end of the ,80s
I have a Honeywell Spotmatic (same as the Asahi Spotmatic except distributed in the U.S. by Honeywell). Mine's circa about 1970 it's the version without the flash mount on the pentaprism. Bought it a couple of years ago with a Pentax Super Takumar 50mm f/1.8 lens, Tokina 28mm f2.8 lens, case and Sunpak flash for $45.00. Great camera it's a well made solid camera I enjoy using it. I don't mind the match needle 'stop down' metering at all. The Super Takumar 50mm lens is easily the best 'normal' focal length lens I have.
This is the biggest reason I've borrowed and tinkered with spotties over the years but never owned one. I have two S series earlier (S1a and H3v) which are lighter, smaller, slightly prettier and much simpler mechanically... and a few K and M series following later which have reliable, better metering and early creature comforts. Always felt like Spotties are (today anyhow) stuck between those eras.
While I use 1.5 volt silver oxide batteries on my Spotmatics, which are accurate due to the Wheatstone bridge circuitry, I never buy Wein cells anymore for my vintage cameras lacking that compensation. Hearing aid zinc-air batteries are so cheap that their short lifespan is not problematic, and you can use a metal washer from the hardware store of a brass adaptor with good success. Just don't remove the tab until you're ready to use them. You can also get MR9 adaptors that will accept the silver oxide button cells and reduce the voltage enough for accuracy.
Excellent video. I once had a Spotmatic. Beautiful camera.
That black Spotmatic is gorgeous!
You probably know this already...but for anyone else reading this, soak the bottom plate in white viegar for a few hours it eats away at he corrosion, then the battery cover should come off for cleaning. Also always tighten battery cover first then loosen it helps to break any crustiness in threads. I have saved many Spotmatics this way.
I had a very stubborn battery cover with a slightly stripped turn slot- in the freezer for 1/2 hour in ice (thermal shock) did the trick! - cleaned up with some vinegar and she is working like a champ!
I was able to get the old mercury battery out of my dads Olympus 35 EC with vinegar, it still works great.
The Spotmatic (not the F) has a balanced bridge circuit that is supposed to deliver 1.35v to the meter circuit regardless of variations in input voltage. I imagine they designed it like that to make the meter immune to voltage drop as the battery loses capacity. You can see the circuit diagram in the service manual, figure 9, the bridge circuit is the arrangement of four resistors.
That being said not a single one of my Spotmatics had an accurate meter. Even the ones I sent to Eric for servicing came back with meters that were only accurate around a narrow part of the EV range (probably around whatever EV is set on his tester). I suspect that either the resistors in the bridge go wonky with age or the galvometer driving the meter needle becomes less linear with age and wear.
I no longer own any Spotmatics; my M42 camera of choice is a Pentax SV. Small, light (for an all metal camera), no grafted on hotshoe messing up the lines. You can pretty much service it by giving it a good smack on the bottom with your palm.
I do love the SV, significantly better focus screen than the H3 but I mostly shoot with the H3 for the same reason as the light meter just never really works as well as I'd like in other spotmatics and for that size I'd almost prefer shooting with a K1000 instead. I was looking into the photo resistors for a while because I was noticing those were failing but it could have also been the resistors on the board. Regardless I appreciate the input and maybe one day someone will get some better metering system in there.
There is a bridge circuit in the Pentax Spotmatic 1 and 2 that regulates somewhat the current going through the galvanometer. It is called a Wheatstone bridge. It does not regulate the battery voltage per se, but when the bridge ( consisting of the variable resistors and photoresistors) is on equilibrium, it gives a reading of zero, that in voltage insensitive. Only the zero is accurate. That's the theory. In practice, Pentax has made it so (and calibrated the circuit) in such a way that the galvanometer is indicating good exposure (zero) when the current flowing through it is 3 µ Amperes, not zero A (source = the repair manual). Therefore, the Spotmatic is not completely voltage insensitive. Furthermore add the problem that these early cadmium sulfide photoresistors have sometimes aged badly over the decades, and you have a bit wonky lightmeter. For good measure, the photocells should be replaced by new ones, (when they are still obtainable !) and the circuit should be recalibrated.
LOL @ "You can pretty much service it by giving it a good smack on the bottom with your palm."
I have my pentax spotmatic since 1967 the light meter still works and I use it all the time it's a great Camera
Watching this prompt me to pull out my first Spotmatic and a KX that some how I ended up with. Fortunately both battery chambers were clean!. Half way through watching, I thought about battery replacements in case I wanted to do film again and came to the same conclusion as you did, just use my external light meter.
I have five Spotmatics. Four are chrome and one is black. None of the cameras have batteries because I choose to not use the built-in light meter.
I use six lenses (28/35/50/105/200/300). The 8-element 50mm f/1.4 and the 105mm f/2.8 are my personal favorites.
My Spotmatic system serves as a backup to my Nikon F SLR system.
I've heard that Spotmatics utilize a Wheatstone Bridge in the metering circuit so you can use standard 1.5V LR44s rather than a Wein Cell or 1.5V battery with resistive adapter. That said, the meter still needs to be in decent condition to provide a reasonable reading.
The Spotmatic and SV are probs the most beautiful Pentax cameras and also generally very good cameras in terms of simplicity and reliability, much prefer them to what came after. Saying that the K mount KX is probs the best version of the Spotmatic. If I'm not mistaken the mechanical bits are the same as the Spotmatic (It shares the same bits in the service manual) but the light meter is highly improved; it uses standard alkaline batteries and also uses silicone photo diodes instead of the cadmium type used on the older cameras which degrade.
what do you think about ES II?
You can get the SP SL which is a version with no light meter.
I did. Mine has a sporadic mirror return issue (should be an easy fix) otherwise a nice simple camera. I like the bright, clean viewfinder.
I just bought one from Japan in immaculate condition. I have the same battery problem but was able to get the Wein battery. It will go with my Helios. Otherwise I use micro four thirds (x4).
Thanks for the video. What about the prism? My spot matic has a black line across the viewfinder. It doesn't affect the photo but it is annoying.
It’s the desilvering of the prism, there’s not much I’ve found that can fix that aside from just replacing the prism
This is a good presentation of the problems that occur with the venerable Spotmatic lightmeter and circuitery. I will add this :
There is a bridge circuit in the Pentax Spotmatic 1 and 2 that regulates somewhat the current going through the galvanometer. It is called a Wheatstone bridge. It does not regulate the battery voltage per se, but when the bridge ( consisting of the variable resistors and photoresistors) is on equilibrium, it gives a reading of zero, that in voltage insensitive. Only the zero is accurate. That's the theory. In practice, Pentax has made it so (and calibrated the circuit) in such a way that the galvanometer is indicating good exposure (zero) when the current flowing through it is 3 µ Amperes, not zero A (source = the repair manual). Therefore, the Spotmatic is not completely voltage insensitive. Furthermore add the problem that these early cadmium sulfide photoresistors have sometimes aged badly over the decades, and you have a bit wonky lightmeter. For good measure, the photocells should be replaced by new ones, (when they are still obtainable !) and the circuit should be recalibrated.
I came here to say this - I have two Spotties, and both meters function fine (checked against meters known to be accurate) with 1.5 volt silver oxide cells. It's a little bit fussy getting the meter centered as it jumps (due to the point you cite above) but the needle centered position is within 1/3 stop at all light levels.
There is a company that overhaul the spotmatic with a new board and led meter in the prism
Who
@@robwhite461yep... Who
Same question: Which company?
and what about the diode modification? Is just one time operation of 30 min and forget about it.
That thumbnail tho😂
People whom have the K1000 and K* cameras... Why does the winder not sound like the spotmatic... The winder in the K1000 is spongey and not as tactile... Anyone agree?
No other Pentax is better than the MX I’m sorry.
The best 35mm cameras ever made are the Olympus OM-1 and the Pentax MX, period.
We could talk about Nikons and Leicas but these cameras being expensive doesn’t make them the best ever made, because you need to pay a lot for them whereas Olympus and Pentax managed to make compact, very bright viewfinders, very affordable and reliable cameras.
I was recently given a Spotmatic Sp F, and although it’s a great camera, the m42 screw ring is awkward, the viewfinder is dim and it’s kind of a heavy 35mm.
Being a fully mechanical camera makes it worthy for sure, but my Pentax MX is better having a brighter viewfinder, smaller, lighter, fully mechanical, Pentax K mount for quick lens switch and it has and does everything better than all previous Pentax models.
Pentax MX I’m telling you
A simple, inexpensive light meter that can fit in a shirt pocket is my answer!
If you can't grasp the utter simplicity of the "Sunny 16" rule, just take a meter reading! I've used these old Gems for years! Always getting great pictures 📸 and confusing the young folks, who just can't grasp the concept of a "Non-AUTOMATIC" picture-taking-thingie!!!
Spotmatic is pure joy! Oh the meter is poor? Really 40 years later.. My Leica Meter with battery was Fluffed 18 months after purchase! I used them profesioinaly..Useless video.