Nikon D600 with one lens overexposure

<p>Hi all,<br>

I had used a Nikon D600 with a Nikkor AF 35/2 lens in A mode almost exclusively, and then I a few months ago I tried a Tokina 19-35mm AF lens but recently decided to go back to my Nikkor 35 lens, that's when the overexposure occurs, I mean it blows the pictures to no use. I did tried different metering.<br>

I initially thought it is the camera, but then it works pretty much spot on with the Tokina lens in Aperture priority mode (and other modes too). So can I say it doesn't seem to be the fault of the camera?<br>

Then I thought the Nikkor lens must have gone bad on me while sitting, especially the overexposure seems to occur more consistently when I use the smaller apertures (f8 and smaller). I thought could it be that the lens blades stopped communicating with the camera to close down when needed? On surface, the lens seems to communicate with the camera fine with changing aperture and metering, etc. If I switched to manual exposure mode, it works just fine. So it seems that the lens aperture blades do open and close fine.<br>

I am seriously confused. Any idea what might be wrong?<br>

Thanks!</p>

 

Check whether the aperture diaphragm on the lens is closing down properly. E.g. Check depth of field preview. Also

whether there is overexposure when the lens is wide open at f2.

<p>Hi Shun, I just tried depth of field preview and it does close down nicely. Any other thoughts?</p>

<p>No overexposure at f2, but the smaller aperture, say f16, is way overexposed.</p>

<p>Oh, I should mention, with this lens, when at f2, the speed is 1/320, but at 16 with the same scene, the speed drops to 1/5. </p>

<p>So it appears on surface all is correct. The only thing I can think of then is the lens has "fooled" the camera but never close down the aperture when taking the shot? But why then when I use manual mode, it does close down. Could that be possible?</p>

Aperture blades can get "sticky" and be slow to

close down. So using the preview stop-down button is no guarantee of correct operation.

 

Best test is to flick the aperture actuator on the lens very quickly with your finger or thumb so that it snaps into the closed position. Look through the lens and see if it rapidly changes between open aperture and closed. If you flick the lever 3 or 4 times a second, any stop-down lag becomes obvious.

 

With a film camera you can remove the back and see directly what the aperture is doing through the shutter. Not possible on a DSLR unfortunately.

 

BTW; 1/320th at f/2 gives exactly the same exposure as 1/5th at f/16. So it looks as if the camera meter is working properly.

<blockquote>

<p>No overexposure at f2, but the smaller aperture, say f16, is way overexposed.</p>

</blockquote>

<p>That is your answer. When a lens is used wide open, the aperture diaphragm doesn't need to close down, hence no overexposure.</p>

<p>Although I tried to snap the aperture ring and the blades open and close nicely and adequately, I guess the lens won't communicate with the camera at this pint. So I am declare the defect of the lens...Thanks!</p>

<p>Flick the aperture open/closed one-hundred times. Then see if it's still a problem.</p>

<p>I had a lens with this problem: OK wide open, grossly overexposed at smaller apertures. Removed the rear mount, was discouraged, could see anything to fix. Replace the rear lens mount and all was well. ??? So, try fiddling with things till it's right.</p>

<p>Best regards to all!</p>

 

The only aperture "communication" between a D

type lens and camera IS the mechanical stop-down lever. Non G lenses (ones with a manual aperture ring) use only the mechanical lever to set the working aperture. The electrical contacts simply communicate distance, focal length and maximum/minimum aperture information. They

play no part in setting the aperture, which is done

by the camera limiting the travel of the stop down

lever.

 

It's possible that if the aperture lever is bent slightly sideways that it will stick against part of the camera or lens, and so prevent it working properly.

<p>I had the same issue about 10 years ago with my 35mm f2 D lens. The problem is a small amount of oil causing the diaphragm blades to become sticky. This was a known issue with the 35mm f2D and I had to have the lens repaired.</p>

Thanks, Sebastian. I will see

how much I would want to play

with the lens then. ;)

Rodeo, I will further check.

Ronald, I see not sign of oil

though.

<p>The oil or dirt can cause problems even one cannot see oily aperture blades. One week ago I had to open my nice Nikkor 180 ED. Some dirt had accumulated to the moving parts of the aperture mechanism. Aperture blades were ok.<br>

This - now corrected - problem came apparent when I was shooting with very small apertures below freezing point.<br>

When testing the aperture mechanism by flipping the aperture lever at the lens, I thought first that it is ok. Only after a carefull inspection it came apparent, that there was a small amount of delay in the closing phase. This delay can make things to go wrong.</p>

<p>M if you use the photo.net search engine at the top of this page you will see numerous post for this issue. If you google this issue you will see post on other sites with this over exposure issue including you tube videos. When I sold my 35mm f2D last year to one of the large NYC camera stores they spent 20 mins checking out the lens to insure that lens was working properly before making an offer.</p>

<p>A while back I bought a set of Vello Tubes. I used a 50mm f/1.4 with one of the tubes. It was doing the same thing, over-exposing every shot. Sure enough the blades were sticking. A couple months later I used the tubes with my 28mm lens. It started over-exposing again. I took the lens off and looked down in the tube and the freaking aperture control arm was badly bent. Luckily, it did not ruin my 28mm like it did my 50mm. I was able to swap (and pay the difference) the Vellos for some Kenkos. Nobody was willing to fix the damaged 50mm lens. I learned a couple of lessons! BTW, the bent aperture control arm bent the aperture control on the lens which is what caused the stuck blades. Believe me I spent a lot of time on that lens trying to bend the thing back to normal to free up the blades. It is one of three lenses that sit in my closet waiting for parts that are no longer sold!</p>

<p>Anyway, like everyone said, it is the aperture blades. They are getting stuck some how. </p>