N65 - Lens issue or meter problem?

[mike_cusack]

I have been using a recently purchased N65. I put an older Quantaray 70-210mm

lens on it and was shooting in bright sunlight. I had the camera set in auto-

program sports mode. I would take a few shots and all of a sudden the

viewfinder went much darker, the meter would indicate flash was required, the

shutter speed would drop down to 1/90=1/60th range, and the aperture set as if

it were dark. The first few times this happened I turned the camera off, took

the lens off and put it back on and it was fixed. The next few times I simply

turned the aperture ring of the lens from f/22 to f/6 and then back to f/22.

Problem fixed. Take a few more shots, same issue. Replaced lens with my

Nikkor 50mm. No problems. Am I correct in guessing that the aperture

mechanism in the lens may be sticking from time to time? Or is there some

sort of metering issue with the camera. If it is a camera body issue I can

send this camera back to KEH, so I would like to diagnose soon.

 

Thanks,

 

Mike

[michaelkh]

If the viewfinder is going dark, I'd say you're correct.

[photojim]

Your theory is a good one, and it will be easy to verify. If the viewfinder is dark, look in the front of the lens. You should clearly see the aperture blades of the lens. Normally, if the lens is operating correctly, you will not see the blades while the lens is mounted because they will be fully open. (They only close when the camera is shooting an image, or if you use the depth-of-field preview lever, which your camera doesn't have.) When you remove the lens from the camera, the aperture blades will stop down so if you have trouble seeing them, dismount the lens and you will see what I mean.

 

Quantaray lenses aren't very good so if the lens is broken, it likely isn't worth the cost to repair. You can get a decent Nikon 70-210/4.5-5.6 autofocus lens for around $100 used. It's not a fast lens (although likely no worse than what you have), but it will be distinctly superior optically.

 

There is a chance that it is a problem with the camera, though. There is a lever in the camera that opens and closes the diaphragm. However, since the camera works fine with your 50, that makes this theory unlikely. Can you mount your Quantaray lens on another Nikon to see if the same problem happens? That way you can be certain.

[ShunCheung]

It indeed sounds like the aperture diaphragm in your Quantaray lens is sometimes not opening and closing smoothly. It shouldn't be all that hard to verify whether that is indeed the problem.

[mike_cusack]

Thanks for the responses. I did notice that I could see the aperture blades in the lens when I looked into it when this problem occurred. (BTW - the N65 does have depth of field preview button). I will continue to try shooting with my 50mm to see if it has the problem. So far it has not. I may shoot the lens on my N70 tomorrow and see if the problem happens there. I had used the lens the week before on my N70 with no issues, so I'm a bit worried that it may be the camera and not the lens. I guess I need to hurry up and figure this out as I recently purchased this body from KEH, and would return it if I think it is not functioning properly.

 

-Mike