Cortexturizer
Member
Continuation of my other thread - so I am puzzled as to why my Olympus 35RD, Hi-Matic 7S II and Auto S3 would all measure absolutely the same with either a fresh 1.55v alcaline and a steady 1.35v.
The lightmeter indicated exposure values (F stops in these cases) of all 3 just don't seem to differ between the two voltages at all. What gives? How can that be?
All 3 cameras are in pristine condition, innards are clean, etc.
Any thoughts?
The lightmeter indicated exposure values (F stops in these cases) of all 3 just don't seem to differ between the two voltages at all. What gives? How can that be?
All 3 cameras are in pristine condition, innards are clean, etc.
Any thoughts?
Ko.Fe.
Lenses 35/21 Gears 46/20
I’m lost in translation.
They show the same or they don’t change at all?
They show the same or they don’t change at all?
Cortexturizer
Member
all 3 cameras show the same values in the viewfinder with both voltages
CharlesDAMorgan
Veteran
Is that the same in varying light conditions (dark, normal, bright)?
Cortexturizer
Member
Yes, tried it in various light
CharlesDAMorgan
Veteran
Interesting!
I swapped the 1.5v battery in my Leica M5 for a 1.35v and the result was a different value at that time.
It's all magic anyway.
I swapped the 1.5v battery in my Leica M5 for a 1.35v and the result was a different value at that time.
It's all magic anyway.
Cortexturizer
Member
I would SO appreciate it if maybe someone who has these cameras could do a test in theirs. Pretty please? :angel:
Phil_F_NM
Camera hacker
Sounds like the meter cells themselves are dead. I get this problem once in a while in a camera I'm tinkering with. The battery will send current so the meter will look active but even if I shine a light right at the meter cell, nothing happens. I think 2 out of 3 Konica T3 & T4 SLRs I've worked on have this problem. Strangely enough I had a Konica Auto-Reflex with a meter that worked perfectly.
I've owned all the cameras you mentioned and the needles all reacted to changes in light.
Try cleaning your battery contacts with a pencil eraser and recheck.
Phil Forrest
I've owned all the cameras you mentioned and the needles all reacted to changes in light.
Try cleaning your battery contacts with a pencil eraser and recheck.
Phil Forrest
Ko.Fe.
Lenses 35/21 Gears 46/20
Compare it with reference meter. If all four are the same, here is no problem.
Cortexturizer
Member
All 3 cameras take great pictures, the meter cells are fine. I just like them so much that I am aiming for perfection, or as perfect as metering can go with these primitive old meters.
All over the internet I've read that 1.5v makes a two stop underexposure difference. Seems like it makes no difference in my case.
I also tried just before today on my 35 RC. Absolutely no difference.
So at this point, after 4 cameras, I am challenging the internet-wide spread assertion that the new modern alcaline batteries make a difference.
Of course, their discharge curve is very different, but on full charge, I see no difference at all.
All over the internet I've read that 1.5v makes a two stop underexposure difference. Seems like it makes no difference in my case.
I also tried just before today on my 35 RC. Absolutely no difference.
So at this point, after 4 cameras, I am challenging the internet-wide spread assertion that the new modern alcaline batteries make a difference.
Of course, their discharge curve is very different, but on full charge, I see no difference at all.
Cortexturizer
Member
I also edited my start of the convo post as upon repeated reading I realized that it may had sounded as the meters were dead.
Ricoh
Well-known
Maybe there's an excess potential being regulated to a lower operating voltage, making the result independent of terminal voltage, eg both the 1.5 and 1.35 are regulated down to 1.0V. To some degree it makes sense if you study the discharge curves of batteries.
What's the voltage of the various cells under load? How did you ensure the light value remained constant between tests? Did you rest the cells after bright light readings? Etc. Your four camera sample hasn't sold me, yet.
Rob-F
Likes Leicas
This pretty much has to be the case. The cameras that show the same with either voltage, must have internal voltage regulation. Are they more recent than the Leica M5? If so, they probably use technology that wasn't available yet for the M5. A zener diode, maybe.
Ricoh
Well-known
There's various ways of playing the voltage regulation tune, eg use of a Schottky diode, a silicon p-n junction, or a simple resistive-bridge across the cell. However, without knowledge of the load, ie the light cell and beyond, it's difficult to reverse engineer the solution.
Cortexturizer
Member
Used several scenes all with constant lighting, no TVs in the background, no cars passing buy throwing lights at certain moments, none of that stuff.
I am telling you the 1.35v it makes no difference at all.
And according to the I N T E R N E T Z it should be a mild difference at all, it should be straight visible as soon as the lower voltage is in.
Cortexturizer
Member
The cameras were not tinkered with prior. There are no diodes or anything, and I would know as I used to build guitar pedals so I know what one looks like
The only camera I haven't tried the mr44 1.35v thing in is my Yashica Minister 700, that is a very old camera so THERE it might make a difference. I'll try it later in the day and post findings.
Ronald M
Veteran
When the 1.35 mercury cells were banned, some cameras had bridge circuits so they could use silver oxide 1.5 volt cells.
The Schokky Diode is in the CRIS adapter and I had 5 at one time. They worked in some cameras, not in others as they do not pass enough current. Sometimes they worked in bright or dim light , forget which, and not the other. Depends on current draw of meter.
1.55 Alkaline battery has lower voltage as it ages. The banned mercury cells always put out 1.35 until it dies rapidly.
Hearing aid battery and O ring are cheapest solution.
Some cameras can be recalibrated to 1.5 V.
Bad news is your cameras probably have cds cells which are at or near their expected life . SBC cells have longer life.
The Schokky Diode is in the CRIS adapter and I had 5 at one time. They worked in some cameras, not in others as they do not pass enough current. Sometimes they worked in bright or dim light , forget which, and not the other. Depends on current draw of meter.
1.55 Alkaline battery has lower voltage as it ages. The banned mercury cells always put out 1.35 until it dies rapidly.
Hearing aid battery and O ring are cheapest solution.
Some cameras can be recalibrated to 1.5 V.
Bad news is your cameras probably have cds cells which are at or near their expected life . SBC cells have longer life.
Beemermark
Veteran
I've posted this before (as others have) many camera have circuits that compensate for voltage / resistance changes. They may read a stop or so off with a silver oxide battery but if you compensate for that (by changing the iso setting) the meter will read correctly. How do think camera technicians calibrate a camera that took mercury batteries for a silver oxide battery? They aren't changing out the meter circuitry, they simply adjust the resistor pots to get the correct high and low readings with the new battery.
Phil_F_NM
Camera hacker
In all Konica Autoreflex T series cameras, the difference is obvious and profound. There is no way I would substitute a 1.5v battery, silver oxide or alkaline, in one of those cameras because they are very sensitive to voltage changes. Also remember that the light value is on a log scale so just adjusting the ISO won't be good enough if you're using slide film. Negative film, go for it. With a Konica T3 or T4 though, for example, I wouldn't even expose negative film without the proper voltage because I have seen a full two stop difference between 1.35v and 1.5v. Then again, I usually shoot meterless anyway so it doesn't matter. But the voltage has always made a difference in meters which require 1.35v. This is the whole reason Gossen makes the battery adapter for the LunaPro.
Phil Forrest
Phil Forrest