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Post by Stuart Walker on Jan 16, 2009 16:37:42 GMT -5
Interesting. Unfortunately there is a fundamental problem in that the remote doesn't operate the shutter at all. From studying the inside of the remote switch and the T90 service manual it seems the longer pin in the camera socket is an earth pin, and when this is connected to one of the other two it switches the meter on, and then when all three are connected it fires the shutter. Is this how you have your home made wired remote? I assume, but it is never safe to assume, that the remote switch parallels the camera mounted shutter switch. Therefore if there are connections from the remote switch all the way up to the camera switch it should work, and if it doesn't work there must be a lack of connection somewhere. Am I correct. And if so where is the break in the connection? Am I likely to do more damage poking around inside this camera than leaving it alone?
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Post by Stuart Walker on Jan 16, 2009 11:54:01 GMT -5
Thanks for looking. Unfortunately from responses I have had elsewhere it seems the fault lies in the camera. My brother in law gave me the camera and he has told me that he never used the remote socket, (I recently bought the remote switch), so I guess it's probably had the fault from new. I don't suppose Canon would repair it under warranty now though!
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Post by Stuart Walker on Jan 15, 2009 16:00:09 GMT -5
I have a Canon T90 that seems to work alright except for the remote shutter control. I am using a 60T3 remote switch, and I asssume that it is supposed to switch the light meter on with the first part of the button movement and then fire the shutter when pushed all the way down, similar to the button on the camera. I've dismantled the switch, cleaned the terminals, but they didn't seem bad anyway, and checked continuity with the plug with a multimeter. I've also tried shorting the terminals in the remote socket on the camera with a paper clip, to no avail. So does this mean that the remote socket on the camera is faulty, or is there some setting on the camera to disable the socket, and so it just needs activating?
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Post by Stuart Walker on Jan 15, 2009 15:56:48 GMT -5
I have a Canon T90 that seems to work alright except for the remote shutter control. I am using a 60T3 remote switch, and I asssume that it is supposed to switch the light meter on with the first part of the button movement and then fire the shutter when pushed all the way down, similar to the button on the camera. I've dismantled the switch, cleaned the terminals, but they didn't seem bad anyway, and checked continuity with the plug with a multimeter. I've also tried shorting the terminals in the remote socket on the camera with a paper clip, to no avail. So does this mean that the remote socket on the camera is faulty, or is there some setting on the camera to disable the socket, and so it just needs activating?
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Post by Stuart Walker on May 2, 2008 14:13:52 GMT -5
I've recently obtained a Praktica EE2, (not I believe, the most reliable of the L series Prakticas), and it seems to work OK except at speeds less than aboout 1/8 sec. I'm using 3 LR44 button cells in a home made adapter, which I originally made for my LLC camera. With old batteries which didn't have enough voltage to raise the needle to the 250 check mark, only the manual speeds worked, (but the LLC light meter still worked fine, but some of these LLC meters will still work at 1.5V, which is why you can sometimes get away with an AA battery; of 3 LLC cameras I have, 2 will work at 1.5V but one doesn't). I then tried some fresh batteries and the light meter works OK and as mentioned the shutter works down to about 1/8 sec. I then thought that these button cells may not not have enough current capacity, so I checked the voltage drop when using the light meter and the voltage dropped below 4V. Is this enough voltage drop to cause the shutter to stay open below 1/8 sec? If anyone has any knowledge or experience I would like to know before I have to spend more on a new PX21 battery than the camera cost me!
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Post by Stuart Walker on Dec 20, 2007 15:35:54 GMT -5
It seems so. If anyone is interested there is a Fujica ST705 repair manual here: www.pentax-manuals.com/fujica/fujica.htmand you can indeed see that there is an aperture variable resistor inside the camera, p22, which is adjusted by the lens aperture ring. Presumably other manufacturers, (except Praktica who put the resistor in the lens, but same principle), had something similar, but there was no standard. Hm, could this be an excuse to collect all the different types?
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Post by Stuart Walker on Dec 20, 2007 8:16:36 GMT -5
I have a Fujica AZ-1 which came with a Sigma zoom lens to suit the open aperture metering. It has the notch to engage with a stop pin in the camera mount and a lug on the aperture ring which engages a pin on the ouside of the mount which is sprung to a stop in the anticlockwise direction. The aperture ring moves this pin in a clockwise direction as you stop down. I ssume this is connected to a potentiometer inside the camera, similar to the Praktica, except that theirs is in the lens. I have another Sigma zoom which has the aperture lug on the inside of the mount and a locating lug instead of a notch, sounds a bit like the Pentax ES mount mentioned above. I was considering modifying this to mate with the Fujica mount, but it's probably not worth the effort. Anyway one would need to check that the aperture ring moves the same amount from stop to stop first. It sounds like the Mamiya and Fujica must be similar but the start points are different, thereby giving you the couple of stops offset. One would need both types of lens and check if the lug is in different places for the same aperture setting.
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Post by Stuart Walker on Dec 6, 2007 15:07:03 GMT -5
Thanks for replies. I must admit that I prefer the mechanical ones, and this Cosina probably isn't worth the trouble, but it's become a sort of challenge! It's tantalisingly close to working, but so much for electronics being more reliable than mechanisms. Anyway the strange thing is that the shutter works better with a low voltage. I had bought five new batteries, two for this camera and three for a Fujica thinking this would give a bit extra oomph but it was actually worse! However one of the five batteries was faulty only showing about 0.2V instead of 1.55V on the multimeter which the Fujica didn't like at all, but strangely the shutter on the Cosina seemed to work betterusing one good battery and one bad one, albeit not perfectly, and the voltage was so low that the light meter LEDs didn't even work. Strange. If anyone has access to a service manual and could let me have a copy then I would be grateful and I could check out the voltages. Of course it could be some irrepaceable component that has gone down. You can't make electronic bits with a hacksaw file.
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Post by Stuart Walker on Dec 5, 2007 15:44:03 GMT -5
Well I've come back to this camera and after reading about Fujica cameras being fixed by changing the capacitors I thought I would give it a go. It didn't make any difference! So I tried some new batteries and lo and behold one of the batteries was faulty and only produced about 0.2V but the shutter now almost works on the faster speeds. The battery voltage is so low the light meter doesn't even work, so what does this mean? Is there some sort of voltage regulator thats supposed to drop the voltage to the electromagnets?
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Post by Stuart Walker on Oct 6, 2007 5:03:18 GMT -5
With a bit more fiddling around with adjusting the position of the electromagnet I can sort of get 1/125 and 1/250 speeds working. If you have the electromagnet pushed up hard against the release arm then all the fast speeds seem to be 1/60, if you have it barely touching the blinds don't open. Somewhere in between you can sort of get a few faster speeds, albeit they don't seem very consistent. It seems to be rather sensitive, the mechanical timers seem more consistent. Anyone know if this means their is some critical adjustment of the release arm and the electromagnet, or is there some electrical/electronic adjustment, or am I wasting my time? I don't really like to give up on something, especially when it's almost working.
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Post by Stuart Walker on Oct 5, 2007 16:44:54 GMT -5
Shooting it sounds a bit drastic! Anyway I was wondering if we have any electronics experts, to help with these later cameras? I can manage the mechanical ones, but it's difficult to figure out electronics without circuit diagrams. I did e-mail Cosina on the hope they might dig out a bit of technical info. They did have the courtesy to reply but not much help;
Dear Mr. Walker,
Thank you for using our camera. Sorry but we can not supply spare parts directly consumers. Please contact where you bought the camera, and ask them to check and repair it.
Best regards., Goda
I can see some external capacitors which I hope might be where the problem is, otherwise if it's the main IC then there's probably not much hope. However the meter and slow speeds all work OK, so it's tantalisingly almost working!
Regards
Stuart
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Post by Stuart Walker on Oct 5, 2007 4:07:26 GMT -5
I have a Cosina CSL, (similar to CSM, and maybe others) which has a horizontal cloth shutter controlled by an electromagnet. With a bit of bending and and adjusting of the magnet and the operating arm, (accessed from the bottom of the camera) I can get all the slow speeds up to 1/60 to work alright, but the speeds above that either don't work at all, that is the blinds travel across together with no gap, or all the higher speeds seem to be about 1/60, checked by viewing the computer monitor through the shutter a la Rick Oleson. Other cameras I have give results similar to those on Rick's site, so there is a problem with this particular camera. I've had the top cover off but I can't see anything obvious. Is the problem in the electronics, or elsewhere, any ideas? (It's quite a neat little M42 camera, which it would be nice to get working properly, or would it be quicker to just buy another one?)
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Post by Stuart Walker on Oct 5, 2007 12:07:20 GMT -5
Ok, I've got one of them in front of me. It does come apart as Kim Coxon describes for the first silver finish one. Remember to grip just the very front of the lens where the filter thread is, (mine has a serrated edge to it). You may have to grip it with a rubber cloth, and hold the focus ring on the other end. It can be very tight, some Zenit Helios lenses I've disassembled have been. Make a note of how the aperure ring aligns with its index mark so that you can be sure you have tightened it together in the same place. If you remove the rings mark their position before you remove them! I seem to remember that you can reorientate the aperture ring by loosening the three screws. The points of the screws go into drilled depressions in the mating part, so you have to unscrew them enough to clear these depressions, or remove them altogether, but then they are fiddly to get back in, especially when ones eyes are getting older! I hope this helps.
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