[Kieron]

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I've just signed up and have always needed to because of numerous problems I've encountered with my K-r but I've always found a way to overcome my problem. This time I have no clue what to do.

I bought a lens off of eBay (Well my mum did) hoping to get a bargain. It was a tenner and I needed a zoom lens, my kit only containing the standard 18-55 kit lens and also a 50mm f/2. I thought what a steal. I ordered the lens and waited over a week for delivery, Finally got home with the lens and attempted to mount it onto my K-r. It fits into the mount, but it doesn't lock or click at all. I will make a video if you need further proof that'd help.

I'll attach some picture which will help because I need help to identify if this is a K mount lens (which it was promised in the ad, (Centon Pentax Mount Zoom Lens 70-210 F4-5.6 Pentax K Mount)

My 50 on the left and the Centon on the right.


50mm Mount


Centon 70-210 Mount


Bits of broken plastic above the mount, could this affect it?


Size comparison? (Idk why haha)


Thanks in advance, Kieron!

[jatrax]

Not Pentax. Clearly says "MD" which is Minolta. Look here. And here for a good picture.

Will not work on Pentax, send it back for refund as it was "not as described".

I think these can be used on Sony Alpha cameras but not sure, maybe someone else more familiar with the mount will jump in.

[boriscleto]

Not Pentax. Clearly says "MD" which is Minolta. Look here. And here for a good picture.

Will not work on Pentax, send it back for refund as it was "not as described".

I think these can be used on Sony Alpha cameras but not sure, maybe someone else more familiar with the mount will jump in.

You can use them on NEX but not Alpha. Minolta, like Canon, screwed their legacy manual focus users when the released the Maxxum.

[Kieron]

Never knew that, thanks for the heads up, looks like I'll search for another lens because the adapters are expensive in comparison to the lens and I have no clue whether the adapter will mess around with the 'flange' distance.

[boriscleto]

Never knew that, thanks for the heads up, looks like I'll search for another lens because the adapters are expensive in comparison to the lens and I have no clue whether the adapter will mess around with the 'flange' distance.

MD to K adapters have to be optically corrected to have infinity focus. They act like a short teleconverter and degrade image quality, especially wide open.

[Kieron]

Which lens would you advise purchasing?

eBay - The UK's Online Marketplace
(I have heard a problem with the Ricoh PK mount which causes a pin to get stuck in the AF pin area or something along the lines)

Rikenon 35-70mm 1:3.5-4.5

or

Vivitar 28-70mm f3.4-4.8

I've become bored of my 50 and am looking to explore zoom/macro.

[jatrax]

Try:
Pentax F 35-70

More money but quality glass and AF. Can be had for $50usd if you shop careful. I know budget is important but quality glass is forever.

[Kieron]

Try:
Pentax F 35-70

More money but quality glass and AF. Can be had for $50usd if you shop careful. I know budget is important but quality glass is forever.

I've found two on eBay at my luck! Sample images on google look sweet but I guess I'll have to find out, thanks for the info on this!

[jatrax]

Here is a link to the lens review section on this forum for that lens Pentax F 35-70 in case you have not found that yet. I would recommend to never buy a lens without looking here first. All of the Pentax and many third party lenses are listed.

[Don Little]

Looks like I just made the same mistake. Picked the same lens up at the local thrift store (no refunds allowed) but for some reason, it seems to work - not too well so far, but it does work. Clicks in the same as a Pentax lens, then, as long as I'm in "Auto" mode on the lens, the camera asks for the focal length, and once set, it becomes useable. I do have to use manual focus (you have to pull the barrel back and forth). I kind of got fooled because it has a Pentax lens cap on the back.

[sterretje]

I do have to use manual focus (you have to pull the barrel back and forth).

I always thought that that would be the zoom function, not the focus. That was the case on my old Minolta MD lenses.

[Don Little]

You're right. I was mixing functions up. After a bunch of reading, I discovered that the one I just happened to buy was the right one for the Pentax, which is why it worked at all. It said "KR" on the barrel, so I figured that was a good sign, but the engraving at the lens said "MC", so I was confused. There is some clouding inside on the outer lens, just to one side, but the few photos I've been able to take so far don't show it. I'll take it out tomorrow and give it a good try.
Early times. Still getting used to Pentax.

[sterretje]

MC stands for multi-coated in this case.

KR might be a bit of a concern, but I might be wrong; it might indicate the Ricoh pin. If you can remove the lens from the camera, there is no issue.

[Don Little]

I took the camera out with the lens today, and I must say, I'm not impressed. I'll stick with it to see if maybe I haven't done something with setting I should have, but I'm not expecting much.