# Need to set minium lens aperature to attach lens?



## greenlion (Sep 4, 2009)

The aperature of my camera does not open up as I change the aperature settings on the camera. What do I need to do? (Sorry for the newbie question.)

I am using an old camera, a Nikon D100. I have type D lenses. The instructions for attaching lenses to the camera say that I need to lock the aperature of the lens at the minimum setting (highest f-stop number). 

When I try to set a wider aperature using the camera settings, the camera display says I am working with a smaller f-stop number, but I still can barely see out out the viewfinder. If I set a wider aperature using the lens aperature ring, it looks great through the viewfinder, but then the camera does not let me take pictures. 

It works the same with different types of lenses (e.g., a Nikon AF NIKKOR 20-35mm lens, and a Nikon AF Micro 60 mm lens).

Can someone explain what is happening here? Shouldn't the lens open up as I change the aperature setting using the camera controls? How can I get it to do that? I wonder if 1) the camera is broken or 2) there is some obscure setting I need to change.

Thanks.


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## KmH (Sep 4, 2009)

The aperture won't actually change until you release the shutter. The lens is kept all the way open so the viewfinder stays nice and bright. If you had your aperture set to F/22 the viewfinder would be very dark.

Many cameras have a DOF preview button you can push that will set the lens to the selected aperture so you can see the DOF, if the viewfinder image is not to dark from a small lens opening.

On Nikon cameras, lenses that have their own CPU have to be locked at the smallest aperture to enable the camera to control the lens aperature. Otherwise, the lens aperture has to be controlled manually by turning the aperture ring.


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## Dwig (Sep 4, 2009)

greenlion said:


> ...Can someone explain what is happening here? Shouldn't the lens open up as I change the aperature setting using the camera controls?...



The f/stop ring itself doesn't change. The f/stop that will be used for the exposure will change when you change the setting using the camera body's controls. The aperture you see when looking through the camera will stay as maximum aperture (widest f/stop, lowest f/ number) until the the picture is taken when it will close briefly to the chosen f/stop and then reopen after the picture when the mirror returns.

BTW, there's no need to set and lock the minimum aperture before mounting. You just need to set it. and preferably lock it, before you use the camera.


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## Derrel (Sep 4, 2009)

A clue might be when you say, "but I still can barely see out out the viewfinder". This makes me think that the aperture actuator mechanism in the D100 body is damaged. The Nikon system holds the lens aperture open when viewing through the lens mounted on the body, and then the diaphragm actuator in the body allows the lens to stop down to taking aperture when the shutter is pressed.

To determine if the diaphragm actuator lever in the camera body is indeed broken, simply mount a Nikkor lens, set it to the minimum aperture size (f/16 or f/22 on most lenses), turn the camera on, and then using the front control wheel on the body, set the lens to its widest aperture, or something like f/4.5 or f/3.5 or f/2.8 and turn the camera around and look through the lens front....what do you see??? Is the aperture extremely small? If the aperture you are seeing is very small, then the diaphragm actuator in the camera body is broken or damaged.

You do have a charged battery in the camera,right? The viewfinder screen in older Nikon and Fuji-branded, N80-based d-slr cameras is artificially illuminated,and viewfinder brightness crops wayyyy down when no battery is inserted in the camera, at least on the Fuji S2, which is similar to the D100 in its underlying components (basically a N80 body).

Hold onto your hat--I had a Nikon D1 with a damaged aperture actuator problem, and the Nikon Torrance,California repair cost was over $700....a D100 with this problem might not be worth fixing if the repair estimate is very high.


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## greenlion (Sep 5, 2009)

Yes, thanks, I think you are right, it is a damaged aperture actuator problem, as you say.

When I try to open up the aperature settings using the control on the camera body, the aperature doesn't appear to change; it just remains fixed admitting barely a tiny pinhole of light. The view through the viewfinder remains very dark. This happens with different lenses and with different camera modes (both aperature priority and manual settings). 

The camera body does seem, however, to be communicating with the lenses. For example, the lens adjusts itself for auto-focus.

The camera had been sitting around unused in a camera bag for a long time. So now I guess I need to figure if I can get it fixed, or if I should simply toss it away. It used to be a nice camera, but it is pretty old now.


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## Garbz (Sep 7, 2009)

Nikons use a lever to push ... a lever on the lens to open / close the aperture blades. Remove the lens and check the lever in the lens mount on the camera body. Give it a little nudge, it may just be jammed.


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