So a guy at work is looking to get a digital SLR. I have done a fine job locking him into a better Nikon. When he told me of his love of his Olympus SLR and how he knows it is worthless I told him, "Not so fast" and told him to google up converts. Success, he has found converts to F mount. I told him, you are good to go in manual mode. I do that with my D90. I am prepared to tell him the camera will verify focus with the green focus dot. I assume both 7000 and 7100 will do that as well. I thought I read somewhere, more than likely on one of our forums that these cameras can meter a manual lens. I guess that means you set the aperture and the camera will select a shutter speed. Any info on this would be great. I don't want to mis-inform him. I have also sent him our link to sign up himself and join the group. Thanks in advance. JB
With the F, the lenses were labeled, "Auto," in reference to the fact that the lens will meter and allow you to compose at full aperture, but then stop down to the set aperture immediately before the picture is taken. It's one of the features that made the F so unique. However, this means that unless you were shooting wide open, the meter would receive far more light than the film would, so the meter would have to compensate for this in its readings.
Before 1977, lenses coupled to the meter using a set of forks that stuck out of it and engaged a pin on the camera. Post 1977, Nikon introduced AI lenses, which skipped this and communicated via a feeler that engaged the aperture ring. Either way, however, the camera's meter must know the set aperture in order for the meter to work properly.
When you cross-mount like that, the camera has no way of knowing what aperture the lens is set to. To get around this, you have to meter the way it was done before the F: by setting the lens to the taking aperture to meter. This is done by actuating the depth of field preview.
In short: those lenses will only meter properly when the depth of field button is depressed.
>When you cross-mount like that, the camera has no way of >knowing what aperture the lens is set to. To get around this, >you have to meter the way it was done before the F: by setting >the lens to the taking aperture to meter. This is done by >actuating the depth of field preview. > >In short: those lenses will only meter properly when the depth >of field button is depressed.
You were OK up to this point. First prior to the F, Nikon cameras were rangefinder models that did not view through the lens except when using add on reflex mirror adapters and telephoto lenses. There was no DOF feature. The lenses were just preset to the desired aperture. Nothing was automatically stopped down. Other camera makers, like Exakta, were making reflex models long before Nikon and they did have ways to stop down the lens prior to fully pressing the shutter release. In the case of non-Nikon compatible lenses that used an adapter on a Nikon body, there is no linkage to the DOF preview lever so you had to manually stop down the lens to take the photo. Since this would darken the view making focusing difficult, you would focus with the lens wide open and then stop down the lens.
However I'm not aware of any Olympus to F adapters and if there was it would probably need a built in element to focus to ∞.
In simple terms, to focus the Aperture ring must be rotated to the maximum aperture (smallest f/#) to make the viewfinder as bright as possible to make focusing easier or even possible.
Then after focusing the lens you must rotate the Aperture ring on the lens to the desired f/stop setting, then take a meter reading and adjust the shutter speed, and ISO accordingly based on the meter reading. Then release the shutter and capture the image.
Then start the process over again to capture the next image.
Given that there is no way for the camera to determine the aperture setting on a Zuiko lens, or for the camera to stop-down the lens for that matter, you will be limited to Manual exposure mode.