Nikon D50 with Nikkor 50mm 1.8AF

[bozmillar]

quick question. I have a D50 and just got a 50mm f/1.8 AF lens. It's not the "D" one, it's the older made in japan lens. It works great except for one thing. I tend to use my camera in aperture priority mode. When I open it up to f/1.8, it works as expected, but when I close the iris up a bit, it seems the camera overcompensates and the pictures come out way overexposed.

Anybody know the reason for this and if there is any sort of remedy that doesn't involve buying a new camera?

 

[Mike_E]

Take notes and compensate accordingly. Or just shoot in manual.

Welcome to the forum BTW.

 

[g-fi]

Pictures? It's hard to tell what you mean without an example and your EXIF. I'm not sure why you would be getting way too much overexposure in AP mode unless you've changed your EC settings or something. Show us what you mean with your camera settings.

 

[bozmillar]

Maybe this is a good excuse for me to start shooting in manual. although if I keep the autoISO on, it still boosts the ISO too much. I guess I can keep that in manual as well, but usually my kids aren't eating worms long enough for me to get all the setting right if I have to manually adjust everything.

I'll post pictures tonight when I get home with all my settings.

 

[bozmillar]

ok, here's what happens. I took the same picture a few times in aperture priority mode. AutoISO is on. the only thing I'm adjusting from picture to picture is the aperture.

A: f/1.8
S: 1/125
ISO: 200

A: f/2.0
S: 1/125
ISO: 280

A: f/2.8
S: 1/125
ISO: 400

A: f/4.0
S: 1/125
ISO: 900

A: f/5.6
S: 1/90
ISO: 1600

A: f/8.0
S: 1/60
ISO: 1600

A: f/13.0
S: 1/15
ISO: 1600

I think by this point the pattern is pretty obvious. I can't figure out why it's doing this. It doesn't happen with any of my other lenses.

 

[bozmillar]

holy crap, I think I figured out the issue. when I change the aperture on the camera, it doesn't actually change the aperture on the lens. In full manual mode, changing the aperture from f/1.8 to f/22 makes no difference to the exposure or depth of field. From what I can tell, when it's taking the picture, the iris is open all the way no matter what I have it set to, but it's adjusting the speed and sensativity as if it was adjusting the iris.

So then I did a long exposure at 4 seconds and looked at the lens, but it is small. Is it possible that the iris just isn't getting to it's position fast enough to take the picture? Is that my lens being busted or is it my lens just not working with this camera. I guess I'll have to test it out on another camera to see if it does the same thing.

 

[bozmillar]

Resolved: I took the lens off and put it back on, and now it works fine. Must have had a bad connection on there or something. At least that's a relief.

 

[djacobox372]

Glad you figured it out. It sounds like the aperture probably wasn't fully locked at the highest setting. If the problem comes back, check for a setting in your camera to use the aperture ring instead of the dial (my d700 has that setting, not sure about a d50) that may make it more reliable.

As for it not being a "d" lens, that should have no affect on non-flash photos. "D" photos send distance information to the camera which is useful only in flash photography. Everything about the lenses optical design is identical to the "D" version.

 

[bozmillar]

yeah, I'm not sure exactly what was causing it, but at least I know how to get it to work again if it gets messed up again. As far as I can tell, on my camera, I have to lock it up at 22 and control it from the dial on the camera. When I try using the ring, it just gives me an error message. I'll have to check if there is a setting on the camera that will let me use the ring instead.

 

[NJLoons49]

On the rear of the lens there is a little lever which is the mechanical linkage for the stop-down mechanism. The lens iris is normally fully open and is stopped-down to the aperture setting when the shutter is actuated. If the linkage on the lens is stiff then the camera actuator will not be able to achieve the required stop down. I have seen this happen on a lens or also if the camera body actuator was not fully engaging the lever which may have been the case as you said it worked correctly after removing and re-mounting the lens.