Pentax LX Exposure Meter Problem

[gabri.guido]

Hi!

I finally found this great camera for a great price!
BUT, it has a problem: the seller says that the meter was "reset" in a camera shop, but then they calibrated it not in the proper way, so now it underexpose some stops (don't know how many). (everything else works properly).

What I would like to know is if there is someone here who have experienced the same problem, or, at least can tell me if this can be fixed.
If there is someone who can explain to me how to do, I would be really grateful!

P.S. do you think it's worthed to buy this camera with this problem or not?

 

[Arvee]

Easy solution: Set ISO to 125. Pick and average subject on a bright sunny day and check the meter's recommended exposure. Adjust the ISO setting until the camera's meter recommends an exposure of f16 @ 1/125. Record the difference from the original ISO setting of 125 and incorporate that delta in future settings. Shoot several test films at different ISO and observe whether the exposures are okay and the offset is linear. Done!

Or, pony up some Euros and get it re-calibrated.

 

[GRHazelton]

If you don't have the manual for the LX, visit this site http://www.butkus.org/chinon/ where you will find one you can download. And send Brother Butkus a little money so he can continue his valuable work!

Now. The LX has an exposure compensation dial concentric with the rewind crank. Check that it is on "0". If it is miss set that could be the problem. Otherwise follow the advice of Fred Aspen above. If the offset is linear you could use the compensation dial to accommodate it and set the ASA in the usual fashion. BTW, I assume you know the sunny f16 rule? If not a usable exposure approximation for any camera is to set f16 and the shutter at the reciprocal of the film speed. Thus for ASA 400, set f16 and 1/500 for a sunny day. If the meter indicates close to this all is good. This is what Fred suggested.

The LX is a magnificent machine. It has perhaps the best metering system ever made. If you can deal with the possible cost of a possible CLA - Clean, Lubricate, Adjust - you will find it delightful to use. Watch for a flash which will work with its TTL system. Enjoy!!

 

[gabri.guido]

Sorry for this late post, but I thought I had posted this a long time ago. I also have found the solution, so I post here if someone will have the same problem.
The problem to focus to infinity that LXs have, is related to the so called "sticky mirror": the foam pads which set the mirror in a rest position will eventually deteriorate during the time and become sticky. This means the mirror stays down when the shutter speed is pressed, resulting in dark or half exposed images.
The problem is that those pads, when becoming sticky, also becomes thinner:this means that the mirror change the resting angle, resulting in an inappropriate "infinity".
The solution is then to bring to a repair shop which: a) change the mirror pads; b) calibrate the focus (by moving 2 screws near the shutter curtains)

 

[trendland]

If you don't have the manual for the LX, visit this site http://www.butkus.org/chinon/ where you will find one you can download. And send Brother Butkus a little money so he can continue his valuable work!

Now. The LX has an exposure compensation dial concentric with the rewind crank. Check that it is on "0". If it is miss set that could be the problem. Otherwise follow the advice of Fred Aspen above. If the offset is linear you could use the compensation dial to accommodate it and set the ASA in the usual fashion. BTW, I assume you know the sunny f16 rule? If not a usable exposure approximation for any camera is to set f16 and the shutter at the reciprocal of the film speed. Thus for ASA 400, set f16 and 1/500 for a sunny day. If the meter indicates close to this all is good. This is what Fred suggested.

The LX is a magnificent machine. It has perhaps the best metering system ever made. If you can deal with the possible cost of a possible CLA - Clean, Lubricate, Adjust - you will find it delightful to use. Watch for a flash which will work with its TTL system. Enjoy!!

I can imagine GRHazelton that OP's problem should be solved from your recomandation. If not we might think on alternate reasons with wrong exposure of LX.
From my point the LX is very reliable. Some state the NikonF3 comming out the nearly same period is much more reliable ! I don't feel that way.
But there are lots problems with Pentax LX today. The main reason isn't its age. It is far behind caused from pricing of Pentax find comfortable for LX.(Nikon F3 was 100 bucks cheaper from the body in comparison to Pentax).
So you may find lots of F3 in good used condition - but Pentax LX is beside the Pentax MX " rare" today.
The reason is very simple. Nikon produced much much more F3 than Pentax was able to sell LX to professional photographers.
That is the problem : the majority of LX was used from professionals. If you might have the idea that isn't correct because : " F3 was THE PROFESSIONAL SYSTEM OF THE EARLY 80th". you are right.
But then you forget : F3 was also "everybodys darling from amatheuric photograpers!
And 85% of F3 photographers wasn't professionals.

The next issue is : you simply are able to notice if a used F3 was professional used (in most cases)
because the type of professional photographers was different to professionals with LX.
(press photograpers)! They gave their F3 cameras no chance to survive the first 3 years... !

I realy remember just a single situation were I noticed a professional with LX on a press shooting.
His F3 colleagues were laughing about the Pentax LX photographer.

So the percentage of LX cameras bought from amatheuric photograpers was less in comparison to Nikon. The condition of professional used LX cameras is (in most cases) better in comparison to professional used Nikons.

But that is hard to find out with today's Pentax LX : You don't notice much difference via optical inspection.(professional used or amatheuric used).
Some amatheuric LX are looking more worst than professional used ones.
That is also caused from its age. (Pentax LX came out 1981) the last ones were sold 1997 !
(2000 this Y2k edition was presented) :

If you spend that money a Y2K cost today you definitivly will see no technical problems for many many years.

The same is on a LX in unused condition wich looks like this here :

But this LX (unused) is also rare and still expensive! The produced LX before 1990 are too old -
remember its age > 28 years. A service to change a couple of parts is allways necessary!
( Mirror dampers).

Conclusion : Electronic failures with used LX is possible but much more possible is incorect shutter speed with professional used cameras due to mechanical wear.

If a LX is at the end of its best days the x- synchroner 1/125 is a last option. A service repair is possible for some hundred bucks. And that is the actual danger with cheap LX today.

I saw a used LX 1991 !!!!!! for a cheap pricing ! The LX was much exausted. Today (17 years later )
it should make the intention to buy a good LX to a special kind of challenge - it is a "lottery" !

Buy the time does anyone own a Y2K ? There is still a guy in Malaysia who deals with Y2K boddies!

with regards

 

[trendland]

Sorry for this late post, but I thought I had posted this a long time ago. I also have found the solution, so I post here if someone will have the same problem.
The problem to focus to infinity that LXs have, is related to the so called "sticky mirror": the foam pads which set the mirror in a rest position will eventually deteriorate during the time and become sticky. This means the mirror stays down when the shutter speed is pressed, resulting in dark or half exposed images.
The problem is that those pads, when becoming sticky, also becomes thinner:this means that the mirror change the resting angle, resulting in an inappropriate "infinity".
The solution is then to bring to a repair shop which: a) change the mirror pads; b) calibrate the focus (by moving 2 screws near the shutter curtains)

Yes " sticky Mirror " is the same kind of mechanical wear I noticed more and more the last years with
Pentax LX! So it should be necessary to give a "rare" LX in good conditions (from optical inspection) to a "second view" to an expert before buying one on high pricing!
With low priced Pentax LX the temptation is allways to gamblers !

with regards

PS : I gamble and bought one at about 250 bucks in good condition - much more expensive today!

 

[trendland]

Sorry - here is a much better detailed picture to express what "good condition" should be with Pentax LX (just from optical side ) often mentioned as "mint" :

with regards

 

[gabri.guido]

Yes " sticky Mirror " is the same kind of mechanical wear I noticed more and more the last years with
Pentax LX! So it should be necessary to give a "rare" LX in good conditions (from optical inspection) to a "second view" to an expert before buying one on high pricing!
With low priced Pentax LX the temptation is allways to gamblers !

with regards

PS : I gamble and bought one at about 250 bucks in good condition - much more expensive today!

I agree with you! I've just bought one in "bad" conditions for 100€. But since I like to repair them, that was more something to make experience on. I think I'll sell once I have repaired the sticky mirror and the MLU button.
PS: it's nice to see another Pentax user around here!

 

[GRHazelton]

I agree with you! I've just bought one in "bad" conditions for 100€. But since I like to repair them, that was more something to make experience on. I think I'll sell once I have repaired the sticky mirror and the MLU button.
PS: it's nice to see another Pentax user around here!

I now own THREE! My first one has the sticky mirror problem, or some such, if used in Auto mode. In manual all seems well. When switched from AUTO to a marked shutter speed the mirror descends. The other two, one with dark blue "leather," are fine. I scored one for about $160 in BGN from KEH. Ir was a little dusty and showed some brassing, but works perfectly. BTW, Advance Camera brought my AsahiFlex IIa back to life. Not really cheap - they had to fabricate some parts, but excellent work. Of course if the electronics in the LX go bad......