Canonet Aperture Spoilt?

[hoppinghippos]

Dear all, I have just received my canonet QL17 GIII from ebay. And I would like to check with those who own this camera if my aperture is spoilt, when you turn the aperture to F1.7, how big is the aperture opening? my opening is like 1/4 to 1/2 of the entire lens width, but is this supposed to be or is it supposed to open up totally (as with all my other lens)? When I close it down to the smallest it does stop down correctly to a very small aperture, but when I open it up again, it doesn't open up immediately, and I have to fire the shutter a few times to "jolt" it open. stuck aperture syndrome?

I have tried taking out the front of the lens, but the outer most ring is easy to take out, which exposes the metering cell, and the next inner ring which holds the lens elements is simply a devil to take out, can anyone share any advice on this ring? is it a counter clockwise twist to unscrew it or am I doing it wrong?

Any help would be greatly appreciated!! :angel:

 

[Sonnar Brian]

The aperture is probably stuck from oil and needs to be "flood-cleaned". I just successfully flood-cleaned two non-working Canonets. The Front Lens Assembly screws out counter-clockwise. The bad news is that the obvious slots unscrew the front element only. The hard-to-see slot down into the assembly are the ones you want. I used a very firm set of needle-nose pliers to reach inside, get into the slots, and unscrew it. After that I used Ronsonol and let the aperture air dry for a couple of hours before re-assembling

 

[hoppinghippos]

Thanks Brian, did you have to file down the front of the pliers or could it fit the small notch in the ring already? I'm currently using a pair of tweezers, and its a devil to use!!

 

[Sonnar Brian]

This particular pair of needle-nose pliers was long and thin; I did not file them down but did turn the last 1/2inch or so inward. When the pliers were spread apart to the appropriate diameter the "bent-inward" tips went down in parallel to reach nicely into those hard to reach slots. Filing other pairs would also work, I have done that with several retaining ring pliers before.

 

[hoppinghippos]

I say that's a really good idea brian! must try that out! thanks!