Lens repair help needed

Nick Siebers · 10-03-2009, 07:40 PM

I have admired the acumen of several of the lens hack artists on this site, and now I am hoping to benefit from it. A year or two ago I acquired a nice Ricoh XR zoom which unfortunately was missing its diaphragm release as well as an internal light baffle. I was able to replace the latter part and use the lens on a K100d (lacking a stop-down coupler?) without difficulty as a manual diaphragm lens. However on any film body, the stop down coupler would push the aperture ring closed. Between the focus, the zoom and holding that ring in place it just couldn't be used.

So, I opened up the lens and cut the stop-down indicator off. Then the lens would stay open or wherever I put it, but unfortunately the meter read it as stopped down fully. So I glued a little piece of wood into the spot, and now it seems to work but meters about 1-1.5 stops less exposure than a similar non-repaired lens at the same aperture setting (1/20 instead of 1/6). Is this because I put the wood stop too far towards the open side? I eyeballed it with a similar lens, but it may not be in exactly the same place. Or am I leaving some other step out?

Thanks very much! Nick

ryan s · 10-03-2009, 09:40 PM

It could very well be that it's a little off. After all, you can make the meter read differently without a lens on the camera just by turning the coupler.

The stop down lever and the coupler are technically independant of each other, but may share a mounting point for the spring controlling both. It sounds like that spring was binding up. Make sure that they operate independantly of the other.

I think

I only deal with fixing primes as of yet.

10-03-2009, 07:40 PM	#1
Nick Siebers Veteran Member Join Date: Jun 2008 Location: Madison, WI Photos: Gallery \| Albums Posts: 2,165	Lens repair help needed I have admired the acumen of several of the lens hack artists on this site, and now I am hoping to benefit from it. A year or two ago I acquired a nice Ricoh XR zoom which unfortunately was missing its diaphragm release as well as an internal light baffle. I was able to replace the latter part and use the lens on a K100d (lacking a stop-down coupler?) without difficulty as a manual diaphragm lens. However on any film body, the stop down coupler would push the aperture ring closed. Between the focus, the zoom and holding that ring in place it just couldn't be used. So, I opened up the lens and cut the stop-down indicator off. Then the lens would stay open or wherever I put it, but unfortunately the meter read it as stopped down fully. So I glued a little piece of wood into the spot, and now it seems to work but meters about 1-1.5 stops less exposure than a similar non-repaired lens at the same aperture setting (1/20 instead of 1/6). Is this because I put the wood stop too far towards the open side? I eyeballed it with a similar lens, but it may not be in exactly the same place. Or am I leaving some other step out? Thanks very much! Nick

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10-03-2009, 09:40 PM	#2
ryan s Veteran Member Join Date: Jan 2008 Location: Madison, WI Photos: Gallery Posts: 2,383	It could very well be that it's a little off. After all, you can make the meter read differently without a lens on the camera just by turning the coupler. The stop down lever and the coupler are technically independant of each other, but may share a mounting point for the spring controlling both. It sounds like that spring was binding up. Make sure that they operate independantly of the other. I think I only deal with fixing primes as of yet.