Faulty FA 80-320

*EsBee* · 06-20-2009, 08:23 PM

Just got a used smc PENTAX-FA 80-320mm f4.5-5.6 in Black but utterly disappointed that its faulty. No chance of return or refund.

No matter what the aperture setting is, including "A", the K20D and *ist DS show the "f" number blank so aperture cannot be controlled from the camera. I took a few shots mounted on the *ist DS and the camera shoots the lens either at f4.5 or f5.6 depending on the focal length. It is as if the aperture ring has no effect. Also, the K20D requests the focal length suggesting the contacts aren't communicating the lens information. However, pictures taken with *ist DS contain correct EXIF information about the lens.

I didn't really pay an arm and a leg for this so its not worth sending it in for repairs. Does anyone know of any tricks or have suggestions as to what might be wrong?

Thanks much.

*Andi Lo* · 06-20-2009, 09:36 PM

Try cleaning out the contacts on the lens first, then if it still doesn't work, maybe the contacts on the camera.

*billhardie* · 06-20-2009, 10:00 PM

I had the same problem with mine a year ago. Sent it into KEH and they replaced some electronic for $125. It has worked great ever since. I tried the contact cleaning route prior to with no success.

*EsBee* · 06-20-2009, 11:38 PM

I did clean the contacts, quite thoroughly in fact. The camera started to focus afterward but didn't do much else. The camera doesn't seem to recognize the lens, yet PhotoME reads the lens information accurately from pictures taken (all at the widest aperture).

*billhardie* · 06-21-2009, 11:50 AM

You might want to contact "Eric". He has done repairs for lots of people on this forum including me and is very well respected.

*EsBee* · 07-01-2009, 10:20 PM

Thanks for the advice, but since I didn't pay too much for this lens, I am wondering if its even worth paying shipping and the repair costs.

But I can't get myself to throw away this big point-and-shoot lens, either. Even though I don't like not having any control over the aperture, its not impossible to get a few keepers.

octavmandru · 07-01-2009, 11:13 PM

Repair it.

Just1MoreDave · 07-01-2009, 11:42 PM

Originally Posted by EsBee

Thanks for the advice, but since I didn't pay too much for this lens, I am wondering if its even worth paying shipping and the repair costs.

But I can't get myself to throw away this big point-and-shoot lens, either. Even though I don't like not having any control over the aperture, its not impossible to get a few keepers.

I would see if it works as a non-A lens. Try setting the aperture ring to f11, the camera to M mode, use the green or AE-L button to meter and see if the shot is properly exposed. That would verify that the mechanical aperture functions work.

What is broken is most likely to be some electrical contact in the lens mount. Unfortunately there are a lot of electrical contacts in the lens mount. Most (as many as 6) tell the camera what the lens's aperture range is. They usually are brass or steel pins, with rounded ends that you see at the rear of the lens, insulated from the mount with plastic. On the inside, the pins get a lot smaller and have tiny springs loosely fitted on the small ends. Those springs rest on contacts when the mount is installed.

The probably broken one is unlike those, possibly just a spring that contacts the inside of the mount and an interior contact. It is mixed among the other contacts, but you can usually tell where it goes because the plastic insulator takes a jog to leave a spot where the spring can touch the mount.

You might be able to take the mount off, work out where this spring should go, get it back in place and reinstall the mount. The mount holds a lot of parts together, so you want to do it carefully in a clean, well lighted, controlled space to keep those parts in place. I have sometimes taped the contacts to the mount to keep them from moving, and taped the aperture ring to the lens to keep it from lifting off. I can do it now without those precautions but as long as the tape doesn't leave residue it won't hurt.

*stl09* · 07-02-2009, 12:23 AM

EsBee,

I too purchased a used version of this lens and it's a wonderful lens, I think you would be really pleased with it if you did get it repaired. On another note I know you said you didn't pay much and their is no return. Have you stated your case to the person who sold it to you. I recently purchased a lens off ebay which clearly stated no return. I went ahead and contacted the seller and stated my case the seller ended up offering to refund everything except shipping. If you by chance did purchase from ebay you could contact paypal and ask them to help you with your problem. They have helped me more than once to my satisfaction.

Good Luck to you....

Kevin

Originally Posted by EsBee

Just got a used smc PENTAX-FA 80-320mm f4.5-5.6 in Black but utterly disappointed that its faulty. No chance of return or refund.

No matter what the aperture setting is, including "A", the K20D and *ist DS show the "f" number blank so aperture cannot be controlled from the camera. I took a few shots mounted on the *ist DS and the camera shoots the lens either at f4.5 or f5.6 depending on the focal length. It is as if the aperture ring has no effect. Also, the K20D requests the focal length suggesting the contacts aren't communicating the lens information. However, pictures taken with *ist DS contain correct EXIF information about the lens.

I didn't really pay an arm and a leg for this so its not worth sending it in for repairs. Does anyone know of any tricks or have suggestions as to what might be wrong?

Thanks much.

*EsBee* · 07-03-2009, 02:40 PM

I tried it in non-A mode on my K20D, and it constantly overexposed regardless of the aperture. The following pictures were taken in M mode after increasing the shutter speeds until the exposure seemed about right.

I don't think the aperture ring is functional

But in Av mode the metering seems accurate for the widest aperture, except the pictures are a bit soft.

I did buy the lens on evilBay but returning is not an option as the seller clearly stated that it was never tested. And as for trying to fix it, I opened up the mount and looked at the gazillion tiny parts inside for a lens this old. The tiny brass springs (5 of them) on the inside of the contacts seemed to be intact.

A small chrome spring attached to the ring off the aperture lever, however, was loose. I am not sure if it came off when I opened the mount. I was able to screw it back in place with a lot of difficulty and help from my significant other, who wondered why taking pictures had to be so complicated (she uses my G-9, which takes phenomenal pictures for a point-and-shoot, BTW).

The lens works exactly as it did before and I am back to where I was. A nice big, black and old chunk of metal, glass and plastic that always shoots wide open. I think this lens has some serious potential when stopped-down so as a last resort, I emailed Eric as suggested by forum members to see if he'd fix it, and will decide what to do when I get a reply.

Thanks Octav, Dave and Kevin for all the advice and help!

*EsBee* · 08-28-2009, 07:49 PM

Okay, the lens is with Eric right now being fixed as I type.

I got a few surprisingly sharp photos at the long end on a recent trip to the park, which prompted me to send it into Eric in hopes of getting even better results once the lens can be stopped-down.

Thanks for the advice to send it to Eric. I was hesitant at first but I think it will definitely be worth it now.