Buying Praktica MTL 5 - what to look for?

[cdzombak]

I plan to apply a correction factor when I expose each photo...it's kind of guesswork, but I think it'll work fine.

 

I'm actually a college student in my first year. I'm probably going to specialize in chemical engineering, but I'm not quite sure yet.

[steve_sheppard]

Hello again Chris, Have just come back to your thread after a day offline. In answer to your questions of a few posts back, the information that the metering should be operative over the whole range at ASA 80 came from the instructions for an MTL3, which is an identical metering system. It has been valid for all cameras of this type I've checked (MTL3, MTL5B, Super TL1000). Pentacon presumably worked out that arranging things this way gave the most useful range of metering.

 

I'm not sure what you mean in your second question! If the potentiometer slider is correctly positioned at opposite ends of the track at 1 sec and 1/1000 sec speeds (at 20 DIN/80 ASA) then you have got the gearing back into the same position as when you found it. There is only a single linkage between the shutter-speed/film-speed controls and the metering. In other words if you change the shutter speed from 1/1000 to 1/500 and the film speed from 200 ASA to 100 ASA the gears will be in the same position, and the metering will indicate zero at the same aperture.

[cdzombak]

Steve: thank you for the explanation; that makes sense.

<br><br>

I'm back, everyone! I finally have a film scanner, meaning I can show you photos from the Praktica (with only minor retouching): <a href="http://photo.chrisdzombak.net/temp/Praktica">here</a>. Sorry about the bg file sizes; I'm still playing with the settings on my scanner and export settings in Lightroom.<br><br>

 

Full size photos are in <a href="http://photo.chrisdzombak.net/temp/praktica.zip">this zip file</a>.<br><br>The meter is reasonably accurate in light that's "in-between" bright and very dim, but outside or in a dark room it's always off. Print film is forgiving enough, though, that I can estimate the proper exposure.<br><br>This is a fun little camera. Thank you, Subbarayan and Steve, for all your help!!

[c_locke]

I have an MTL 5 that I got from eBay. My dad gave me an LTL to learn photography when I was in college, and I've

been sentimental about getting antother Praktica, so I got the MTL to replace it.

 

Alas, when I got it, the meter was several stops off. So, I started tinkering with the potentiometers underneath

and REALLY screwed it up good. I'd used it a few times without the meter, but was never totally comfortable with

it. I was always afraid I was going to miss a good shot.

 

So, then I was directed to this article from a Flickr page. Following these instructions written by Subbarayan

Prasanna, I set out to fix it:

 

"Try and keep VR2 and VR3 as low as possible. Then check if the needle moves faster and gets more sensitive. You

should be able arrive at a reasonable level of indication...Since your needle is moving freely now keep VR2 and

VR3 equal [or near equal] and try adjust VR1 to get the needle to zero. In the absence any instrumentation and

specifications from the factory this seems to be the way to do it."

 

This is exactly the method that worked for me. And, I've been looking for this all over the internet ever since

I got this camera almost two years ago.

 

I compared meter readings to a known working Nikon FM2 and the MTL-5 was within + or - 1/2 stop at every

shutter/film/aperture combination I could throw at it. I could probably make it more accurate, and I might at

some point, but right now I'm just tickled to have it working well enough to use!

 

Thanks so much for your posts. I'm gonna have some fun with this camera in the next few weeks!

[subbarayan_prasanna]

C.Locke! hi! I am glad the notes worked for you and your meter on the go now. All the best. Thanks for acknowledging. It is a small world. Regards, sp.

[zolt_n_kelemen]

Hi!

 

I've got an MTL-3, but my meter is completely busted. It's not only offset by something, but the needle goes all

the way down every time I try to use it.

 

Based on the posts in this thread, and on the light meter circuit (original here:

http://alspix.blog.co.uk/2007/08/24/praktica_light_meter_circuit~2860252 ) I think I've narrowed it down to the

LDR not working (most probably). Measuring it's connections show no change whatsoever while the lens are exposed

to light or covered. Shorting the two contacts does flip the meter's needle completely to +

 

My question is: do you have any idea, where is the LDR located? Is it reachable/changeable/etc?

 

I also tried removing the top, but I can't figure out how can I remove the wind lever ... I'm stuck with that and

I don't want to force it.

 

any ideas appreciated.

 

thanks,

Zoltan

[subbarayan_prasanna]

<p>Hi Zoltan,<br>

I came across your query just now. Sorry I did not look at it earlier.<br>

From your description I guess that your CdS cell has lost its sensitivity to light or has lost its connectivity internally. Yes, if you short the two contacts on either side of the LDR then you are by-passing the resistance, completley. So the current flow would be high and show positive on the Galvanometer.<br>

Please, also verify if the sliding contact on the resistor connected to the shutter speed selector moves properly along its circular range and is not stuck at high resistance end. It would be a rare event. But would be good to eliminate that possibility.<br>

It may be better to use a good hand held meter rather than trying to replace this CdS cell. Usually, one can buy a very good hand held meter for a much smaller price than the repair/replacement costs and labor for this type of effort.<br>

The Praktica L-series camera are excellent machines, with very accurate shutters and working mechanical components. Some 40 years later the meter may fail to perform. But that is a very small part. So please do cherish the rest and have great time with your camera. Regards, sp</p>

 

[zolt_n_kelemen]

<p>Subbarayan, thanks for your response. <br /> <br /> Indeed I'm using the Praktica right now, without any light meter, using a simple chart ( http://www.fredparker.com/ultexp1.htm ) and relying on color films relative insensibility to over-exposure. Considering that I get reasonably good results, I'm quite content with that. <br /> <br /> I just like to fix things if I can, but trying to fix the Praktica probably will have to wait, until I might move on to another camera to shoot with :)</p>

[al_wateen]

<p>Hello,<br>

I know it is not the thread I should post - but it will attract genius people from here - sorry for the inconvenience and thanks for understanding.<br>

I have seen some of your posts and came to know that you have some experience with shutter of MTL-3 Practicka I just have got this camera and did a test roll everything was fine, I went to the lab gave them the roll - came back home and tried to do a non-sense - putting the speed to 1 from 30 (1 in Orange Colour on Speed Dial) - Instantly the shutter got opened and won't closed I tried to push the shutter release a lot of time but it never worked - I tried to do the corked it but it wont go further - I tried manupulating with speed dial - it is jammed.<br /> Everything including selftimer is jammed except the shutter release which can be pushed how many times you would like to push it but won't work as it should do.<br /> Now at this time I can't find any help - I have put it in fourm of Pracktica Users but they are not responding - so I think you might help me with this - this is my first camera and I don't want to ruin my experience.<br /> <br /> I am sure you will give some solution.<br /> <br /> Thanks in Advance,<br /> <br /> Ali</p>

[subbarayan_prasanna]

<p>Al Hi!; I suggest saw your post; sorry I could not respond earlier. One of the "accidents" that happens to Praktica and other similar cameras is that the mirror operating spring gets weak or stuck out of alignment. After removing the lens reach in to the mirror chamber on to a lever to your left that operates the mirror. Wiggle it a little and the mirror will come down and the shutter will fire. This is a common "accident."<br>

However, if this is not the case then you may have some thing more serious. And you may have to delve deeper into the mechanism. Please check with Steve Shepherd; he is the authority on the Praktica L-series. Regards, sp. </p>

[ken_weeks]

<p>Hi all, have been reading your contributions and have been fascinated by the depth of knowledge and amount of information flowing!!! <br>

I recently repaired my old (circa 1972) Praktica LTL, the PCB had battery corrosion. I managed to repair it with Araldite epoxy adhesive so its now back in one piece, although I had to solder a small `jumper` wire to reconnect the <strong>centre</strong> battery terminal (<strong>negative</strong> side) to the circuit board.<br>

I`m now having a problem in reconnecting the PCB to the camera wires. My PCB is different to that shown in `ALSPIX`s PHOTOS`, in that it appears older; it doesn`t have the printed circuit strips.<br>

The camera wire colours are also different; on the <strong>Light Sensor</strong> side 3 wires go off through a black sheath; these are coloured black, red, and a much thinner black (which I know connects to the centre potentiometer as you look at the PCB, with the printed number `5659` reading the right way up.)<br>

I`m not sure where the thicker black and the red wires connect to, as the PCB soldering points are also different to those shown in ALSPIX`s PHOTOS PCB.<br>

On the <strong>Speed Selector</strong> side the camera has yellow, green and blue wires. I know that the yellow wire connects to the left hand side potentiometer, and the blue wire connects to the right hand side potentiometer,again as viewed with the printed number `5659` reading the right way up.<br>

<strong>Does anyone out there have photos of both sides (top and bottom) of my type of PCB? If so could they send me copies? And can anyone advise me of the correct attachment points for the wires?</strong><br>

At this stage I can`t tell if the light meter works, so I need to correctly connect up the wires in order to test the meter. <br>

The rest of the camera, lens etc appears to be OK, except for a lot of debris on the inside of the fresnel lens etc which I can see through the viewfinder. <strong>Can anyone recommend the best method of cleaning the internal parts please?</strong><br>

Thanks everyone, Ken Weeks.</p>

[ken_weeks]

<p><strong>OOPS! </strong>regarding my previous post (27.11.09)- as regards the correct wiring connections for the circuit board of my Praktika LTL, I should have also mentioned that I need to know where the <strong>green</strong> wire from the <strong>Speed Selector</strong> connects to the circuit board.<br>

I know that it connects somewhere to the left side of the circuit board when viewed with the printed number `5659` reading the right way up.<br>

As mentioned before, my LTL circuit board is older than the PCB shown in `ALSPIX`s PHOTOS`; it doesn`t have the printed circuit strips but is of the `hard wired`type - the soldering connection points are different to ALSPIX`s and the wires pass below the circuit board on their way to their connection points. <br>

Again, if anyone knows could they please send me photo/s or a simple drawing, wiring diagram or what have you?<br>

Many thanks, Ken Weeks.</p>

[subbarayan_prasanna]

<p><em>"The rest of the camera, lens etc appears to be OK, except for a lot of debris on the inside of the fresnel lens etc which I can see through the viewfinder. </em><strong><em>Can anyone recommend the best method of cleaning the internal parts please?"</em></strong></p>

 

<p>Ken Hi! the safe method to cleaning is a hair drier/blower. Try blowing the dust off with just cold air; no heat at all! It should remove most of the dust from the mirror chamber and other optical glass. Cleaning the fresnel separately is a delicate job, as the fresnel is made of plastic and stuck to the glass lens. The grooves in the fresnel will leak any liquid and the grime to surfaces between the plastic rings and the glass; that might ruin the optical quality. Some people remove the fresnel screen and wash it in soap water and rinse in warm water generously, then blow dry the same. I have not tried such a technique. <br>

 <br>

On the other internal mechanical metal parts you could use ethyl alcohol with a cotton bud; for joints, pivots hinges and bushes [if they do need any cleaning you may use the same alcohol or equivalent with a syringe or dropper and blow dry the same. After they dry out you may use watch oil or light grease to lubricate the joints again. Be very conservative in applying the lubricant; in temperate climate use only half a drop or less. In the tropics you would need a full drop or more!<br>

 <br>

On the other part of the question I shall try and get the pictures of the PCB. I don't have any ready. i hope this helps. Best regards, sp.</p>

[ken_weeks]

<p>Hi Subbarayan, Greetings from Wales, UK!<br>

Thankyou so much for your kind help re: cleaning of my LTL, It seems most of the debris I can see in the viewfinder is up inside the camera on the prism in the vicinity of the lightmeter needle, I`ll persevere but will probably need to dismantle the camera in order to gain access.<br>

I`m not sure if the lightmeter still works, but if I can get it all wired up correctly I can test it; if everything works then my final task will be to clean and lubricate it before final assembly. Fingers crossed!<br>

Thankyou also for looking for the circuit board connections for me.<br>

Kind Regards, Ken Weeks. </p>

[david_robinson7]

<p>I thought that I might help others having PraktikaTL/SUPER TL metering problems with the following.<br>

Thanks to Subbarayan (and his good Smaritan) for supplying the Praktica Meter Circuit, it helped me to trace and correct an annoying exposure problem on my Super TL1000. This proved to be due to the change in type from the original (now banned) mercury cell (PX625) to its alkaline replacement (PX625A). The original PX625 provided a 1.2V bridge supply source whereas its replacement provides 1.5V. In a perfectly balanced bridge, the actual bridge supply voltage is irrelevant because the algebraic sum of the currents flowing in the meter arm of the bridge matrix is zero. The battery voltage problem occurs because zero current flow in the Praktica meter will not result in a zero visual indication on the needle display. There is a mechanical offset on the meter pointer which requires that a positive standing current has to flow in the meter arm in order to achieve a visual indication of zero. This means that there needs to be a deliberate impedance imbalance in the bridge and it is this imbalance that renders the bridge susceptible to variation in supply voltage. Performing a Kirchoff analysis (I am an Electronics Design Engineer by profession) of the circuit provided revealed that the displayed error would be multiplied by the delta-V change in the supply voltage, hence a supply voltage difference of only 0.3V would result in a significant metering error. This was the root cause of my problem (and of anyone else using the PX625A). In the circuit supplied, VR2 and VR3 control the effective 'span' of the ASA/DIN potentiometer and VR1 is responsible for balancing the impedance of the LDR. From my circuit analysis, I reasoned that the (factory set) span impedance would not need readjustment and that all that would be required to accommodate a different supply voltage would be a simple readjustment of VR1. From the information supplied by SP and so many other contributors (my thanks to you all) I removed the camera base plate, selected 100ASA and 1/125 S, chose a suitably neutral evenly illuminated background and adjusted VR1 to achieve indicated f-stop/speed correspondence of the camera with a hand-held meter. It was a bit fiddly (the camera base plate is used to complete the battery circuit) but after about 3 iterations I had it spot on. Checking the metering at both ends of the speed scale showed 100% conformance with the hand-held meter which confirmed my reasoning regarding VR2/VR3 not requiring readjustment. What of the future? The PX625A is probably not the best choice for the metering battery as the voltage discharge characteristics of an alkaline cell are not particularly stable but as the meter is only switched on for short periods it is likely that in normal use, a standard cell will stay in range for years. Use of a S625PX (1.55V) silver oxide cell will eliminate any uncertainty with battery voltage, as the voltage discharge characteristics of this type of cell are very stable in use but it should be fitted before any readjustments are made. At least all the nonsense of zinc-air (Wein cell) batteries and hot carrier diode adaptors are simply avoided!<br>

I hope that others will find this of use and thanks again SP!</p>