SMC Pentax-M 28mm 2.8 on Canon 60d

strangeboy · 01-23-2014, 02:56 PM

I sold this lens to a buyer who claims that the lens blades are slipping AND sticking. He's attempting to use it on a Canon 60d, though it appears he is clearly unfamiliar with this lens. He says there should be a manual/auto mode button... but as we all know, there is no such thing on this lens.

On Pentax DSLRs, this lens must be used with the "green button" function. I have no idea how this would work on a Canon body.

I sold it for $50 because I simply wasn't using it. All of my lenses are stored in a case, cool, clean and dry. He say's he's going to send me a video of the problem, if that happens, I will share it here. I don't need the headache and am considering just getting the lens back and refunding the loot. Any thoughts on this? Doesn't sound right.

Thanks.

causey · 01-23-2014, 03:55 PM

Manual/Auto button? He's probably confused about mounts. M42 lenses have M/A switch. (Some of them.)

stevebrot · 01-23-2014, 04:29 PM

Originally posted by strangeboy

On Pentax DSLRs, this lens must be used with the "green button" function. I have no idea how this would work on a Canon body.

On a Canon body the lens would be adapted and the diaphragm would be fully manual (always stopped down). There is no coupling between the lens and body. I would refer the buyer to the 60D manual in regards to how to do stop-down metering with his camera.

As for the blades "slipping and sticking"...slipping is a good thing. Sticking is not. It is possible that the lens has a sticky diaphragm. It happens and is one of the first things I check when I take delivery of a lens. Conditions of storage can be a contributing factor due to migration of oil on to the blades with elevated temperatures, though not always. Sometimes the lubricants just simply get gummy. Physical damage to the mechanism is another possible cause.

Along with the video, you may want to have him give you a detailed written description of what constitutes a "slip" and what constitutes a "stick".

Steve

fuent104 · 01-23-2014, 09:59 PM

I'd ask him about his adapter, too. My M28 f2.8 does not give me problems on my 60D.

strangeboy · 01-29-2014, 12:21 AM

Hello all...
Sorryfor the slow response...life.

Anyway, he asked that I refund $45 (90% of the selling price) and allow him to keep it and he'd deal with it. This dude has lost his mind, and seems quite unethical. Now he wants to return it after having it since last Thursday... not happening.

I spoke with eBay customer service and they agree with me. They were surprisingly nice, BTW. They're handling it, so, I'm done.
Thanks for your feedback on this.
Cheers!

01-23-2014, 02:56 PM	#1
strangeboy Senior Member Join Date: Nov 2011 Location: Chicago Posts: 126	SMC Pentax-M 28mm 2.8 on Canon 60d I sold this lens to a buyer who claims that the lens blades are slipping AND sticking. He's attempting to use it on a Canon 60d, though it appears he is clearly unfamiliar with this lens. He says there should be a manual/auto mode button... but as we all know, there is no such thing on this lens. On Pentax DSLRs, this lens must be used with the "green button" function. I have no idea how this would work on a Canon body. I sold it for $50 because I simply wasn't using it. All of my lenses are stored in a case, cool, clean and dry. He say's he's going to send me a video of the problem, if that happens, I will share it here. I don't need the headache and am considering just getting the lens back and refunding the loot. Any thoughts on this? Doesn't sound right. Thanks.

01-23-2014, 04:29 PM	#3
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by strangeboy On Pentax DSLRs, this lens must be used with the "green button" function. I have no idea how this would work on a Canon body. On a Canon body the lens would be adapted and the diaphragm would be fully manual (always stopped down). There is no coupling between the lens and body. I would refer the buyer to the 60D manual in regards to how to do stop-down metering with his camera. As for the blades "slipping and sticking"...slipping is a good thing. Sticking is not. It is possible that the lens has a sticky diaphragm. It happens and is one of the first things I check when I take delivery of a lens. Conditions of storage can be a contributing factor due to migration of oil on to the blades with elevated temperatures, though not always. Sometimes the lubricants just simply get gummy. Physical damage to the mechanism is another possible cause. Along with the video, you may want to have him give you a detailed written description of what constitutes a "slip" and what constitutes a "stick". Steve Last edited by stevebrot; 01-23-2014 at 04:36 PM.

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01-23-2014, 03:55 PM	#2
causey Veteran Member Join Date: Feb 2009 Location: Arlington, VA Photos: Albums Posts: 3,757	Manual/Auto button? He's probably confused about mounts. M42 lenses have M/A switch. (Some of them.)

01-23-2014, 09:59 PM	#4
fuent104 Veteran Member Join Date: Apr 2011 Location: California Photos: Gallery Posts: 1,356	I'd ask him about his adapter, too. My M28 f2.8 does not give me problems on my 60D.

01-29-2014, 12:21 AM	#5
strangeboy Senior Member Join Date: Nov 2011 Location: Chicago Posts: 126 Original Poster	Hello all... Sorryfor the slow response...life. Anyway, he asked that I refund $45 (90% of the selling price) and allow him to keep it and he'd deal with it. This dude has lost his mind, and seems quite unethical. Now he wants to return it after having it since last Thursday... not happening. I spoke with eBay customer service and they agree with me. They were surprisingly nice, BTW. They're handling it, so, I'm done. Thanks for your feedback on this. Cheers!