Minolta Hi-Matic 11

[irvine.short]

<p>Hi All,</p>

<p>I was tidying up and found one of these in a box I had forgotten about. Last time I tried it the shutter would not fire so I forgot about it.</p>

<p>Somehow 6 months in a box had cured the shutter so I fitted a little alkaline cell with the help of a ball of tinfoil and some cardboard and to my delight it came alive and apparently works perfectly.</p>

<p>If I move the thingummy on the lens to "battery check" the needle moves to the right place.</p>

<p>This is a fairly specific place, it is not a range of "OK-ness"</p>

<p>Which makes me wonder - does this meter use a bridge circuit like the Yashica Electro 35, making it immune to input voltage changes?</p>

<p>Also, the viewfinder is quite yellow and hazy. There seems to be a lot of gunk on the inside of the front window.</p>

<p>Any hints and tips for opening this up and cleaning it? What should I avoid touching?</p>

<p>And what is the right tool to unscrew the collar around the rewind handle spindle, and the top of the wind crank?<br>

What else would need to come loose to get the top off?</p>

<p>Cheers,</p>

<p>--Irvine</p>

 

[rick_drawbridge]

<p><strong>Irvine</strong>, in view of the current ferment on the Forum regarding the definition of "Classic Manual Camera" could I suggest that a query regarding a non-manual camera such as the Hi-Matic 11 might be better posted on a forum such as the Classic Camera Repair Forum? They're nice helpful people, over there.</p>

<p>http://www.kyphoto.com/cgi-bin/forum/discus.cgi</p>

[irvine.short]

<p>Thanks Rick - I will ask over there as well.</p>

<p>As for those fermenting on this list, they can pretend it was a typo and I had meant to type "Hi-Matic 9" :-)</p>

<p>The thing is over 40 years old, it's hardly a modern film camera. </p>

[CoryAmmerman]

<p>Don't know how well this applies to the Hi-Matic 11, but I recently disassembled a Hi-Matic 7. If the 11 is similar, all you have to do is unscrew the shutter button and wind lever and 3 phillips head screws and the top plate should come off. A spanner wrench was necessary to remove the wind lever. On my Hi-Matic 7 the viewfinder was easily accessible once the top plate was off. Like I said, I don't know how different the 11 is from the 7.</p>

<p>Here's a pic with the top plate off.</p><div></div>

[maderik]

<blockquote>

<p><strong>Irvine</strong>, in view of the current ferment on the Forum regarding the definition of "Classic Manual Camera"</p>

</blockquote>

<p>Current ferment? I know it pops up every now and then but I've missed this round.</p>

<blockquote>

<p>The thing is over 40 years old, it's hardly a modern film camera.</p>

</blockquote>

<p>Exactly. The "<strong>About this Forum</strong>" for CMC says: </p>

<blockquote>

<p>The Canonete [sic] QL17 GIII requires batteries to run. And yet we all would agree that this 30+ year old camera would qualify as a classic and be fine for discussion here. </p>

</blockquote>

<p>So we can tell anyone who complains to take a hike over to the main forum page and read. (Or to complain to the moderators to change the definition.)</p>

[zane1664879013]

<p><em>The Canonete [sic] QL17 GIII requires batteries to run.</em></p>

<p>There's one problem with the Forum Definition right there. The Canonet GIII works just fine without a battery as a fully manual camera. You only need a battery to enable metered, shutter-priority shooting.</p>

[JDMvW]

<p>Ferment is welcome in the right place.</p>

<p>But sometimes things just go 'bad' like that Chinese food from two weeks ago.</p>

<p>I wouldn't worry about it, it's just the "usual suspects" going at it again. Little will change, for better or for worse, and most of us will welcome your input and questions here on CMC.</p>

<p>For the record. <em>modern</em> is an era, not a statement of contemporaneity. Modern music starts in the 1<strong>8</strong>90s as does Modern architecture and a host of other things. So no one would object if you had posted on Modern Film Cameras either.</p>

<p>Edit, well never say "no one".....</p>

[greg_nixon2]

<p>Neither the Electro 35 or the Minolta 7 use a bridge circuit. Not sure about the 9 but I think its just an autoflash system, similar to The first Konica C35. Don't know about the 11. All of these Konicas still only use a battery for metering. They do some clever mechanical things to make them seem auto, like trap meter aperture and/or flash setting, relative to shutter speed and light. Its still one done from a single metering circiut.<br>

The Electro 35 is different approach, but it is still essentially a metering circuit. You never actually get to see the readout, but it controls the shutter speed relative to aperture and light. Interestly it must be one of the first aperture priority cameras around.<br>

Cheers</p>

 

[irvine.short]

<p>Thanks Greg! I have been told the Electro 35 uses a bridge circuit, but without a circuit diagram we will never know.</p>

<p>My camera guy checked my Hi-Matic 11 on his calibrated light source at 1/60th / f8 ISO100 and it was spot on.<br /><br />I put a roll of FP4+ through last weekend and got a lovely set of sharp fairly dense consistently negatives so if anything it is slightly over exposing in brighter lights. Since higher voltage pushes the needle further and towards higher f-stops the increased battery voltage should make the thing under expose.</p>

<p>Only way to nail this problem for sure would be to put the camera on a bench power supply and vary the voltage between 1.2 and 1.6V and see if the exposure changed at all.</p>

<p>Does anyone know where I might find service and circuit diagrams for these cameras? In a previous life I was an electronics technician and I would like to know how the engineers of old solved this problem with, as Spock put it, stone knives and bearskins.</p>

<p> </p>

[greg_nixon2]

<p>Double Post. D'oh!</p>

[greg_nixon2]

<p>Hi Irvine.<br>

There are copies of the electro 35 cct around. Just google for it. If U have no luck I'll mail you the ones I have. I'll be out of town for a few days , so when I come back.<br>

Essentially, its an RC time constant cct. The CDS cell forming part of the R of the cct. The output drives the shutter hold in solenoid, as well as the over/under lamps.<br>

The other circuits I trace out the hard way. Most are just a cell, battery and meter in series. The meter is R shunted in both parallel and series. Its just a matter of doing the maths on the shunts to see how much to change them.<br>

I'll mail a few samples of what I have.</p>

 

[irvine.short]

<p>Having had a chance to look up the Electro 35 circuit diagram, that all makes sense.</p>

<p>The RC time constant will not care much about what voltage it is driven by.<br /><br />The Minolta Hi-Matic however has a mechanical shutter, not electro-mechanical and the Aperture is controlled by the trapped needle.</p>

<p>In the "lid off" view posted earlier of the Hi-Matic 7 there are two little preset pots.<br /><br />My Hi-Matic 11 has 3 even tinier ones.<br /><br />This would suggest there is something slightly more complicated than a cell, battery and meter in series.<br>

My curiosity is piqued - anyone have any further ideas?<br>

Cheers,</p>

<p>--Irvine</p>