Fisheye Lens Troubles...

[wfooshee]

Unchipped doesn't mean unmetered. It just means the camera and lens don't communicate electronically. The camera doesn't know the f-stop unless it has a non-CPU menu listing and reads the aperture ring (which my D7000 has - it knows when I've mounted my 85-1.8 and reads the aperture ring) and it doesn't know the distance being focused so there is no 3D zone metering. The camera can still measure light through it, and it would work in aperture-priority, just like the old Nikon cameras used.

 

[jake337]

Unchipped doesn't mean unmetered. It just means the camera and lens don't communicate electronically. The camera doesn't know the f-stop unless it has a non-CPU menu listing and reads the aperture ring (which my D7000 has - it knows when I've mounted my 85-1.8 and reads the aperture ring) and it doesn't know the distance being focused so there is no 3D zone metering. The camera can still measure light through it, and it would work in aperture-priority, just like the old Nikon cameras used.

But the D3200 will not meter ais lenses. I don't believe they added that feature to prosumer dx models till the d7000. At least my D90 was completely manual with ais lenses except for focus confirmation.

 

[pez]

I love this lens. I have one for my Pentax k-mount, and it came with auto aperture setting- works great.

 

[wfooshee]

Unchipped doesn't mean unmetered. It just means the camera and lens don't communicate electronically. The camera doesn't know the f-stop unless it has a non-CPU menu listing and reads the aperture ring (which my D7000 has - it knows when I've mounted my 85-1.8 and reads the aperture ring) and it doesn't know the distance being focused so there is no 3D zone metering. The camera can still measure light through it, and it would work in aperture-priority, just like the old Nikon cameras used.

But the D3200 will not meter ais lenses. I don't believe they added that feature to prosumer dx models till the d7000. At least my D90 was completely manual with ais lenses except for focus confirmation.

You're right with that, and I'd forgotten the link to metering only "smart" lenses in the consumer cameras. I stand corrected.

 

[jake337]

Unchipped doesn't mean unmetered. It just means the camera and lens don't communicate electronically. The camera doesn't know the f-stop unless it has a non-CPU menu listing and reads the aperture ring (which my D7000 has - it knows when I've mounted my 85-1.8 and reads the aperture ring) and it doesn't know the distance being focused so there is no 3D zone metering. The camera can still measure light through it, and it would work in aperture-priority, just like the old Nikon cameras used.

But the D3200 will not meter ais lenses. I don't believe they added that feature to prosumer dx models till the d7000. At least my D90 was completely manual with ais lenses except for focus confirmation.

You're right with that, and I'd forgotten the link to metering only "smart" lenses in the consumer cameras. I stand corrected.

But that still leaves the question as to what your camera will do if left in auto ISO with a non-PCU lens on a camera that doesn't meter.

Does it just go with the highest ISO you have selected?

 

[wfooshee]

If it's not metering, it probably does nothing. But still, I don't like auto-ISO, generally.

 

[TCampbell]

Cameras in full auto mode tend to use something called the "program line". The camera attempts to use a middle/safe exposure. In very low light you force it's hand and it has to max the ISO and max the aperture size in an effort to not have an extremely slow shutter speed. But once the shutter speed is fast enough for handheld photography based on the focal length of the lens, the camera will start backing off on the aperture and ISO.

If the camera can get back to base ISO and the shutter speed is fast enough for hand-held photography, it will start using a faster shutter speed AND using a smaller aperture and it will do this in roughly equal parts.

You can do a Google search for "program line" and should be able to find articles that explain how it works. It will be different for every lens.

For a manual lens, however, it can't read or control anything about the lens. I don't know what it will try to do.

 

[Derrel]

This is a non-CPU lens in F-mount, so on a baby Nikon both ambient light exposures AND flash exposures can be made ****ONLY**** in manual modes. The pop-up flash must be set to manual flash power control; there is no automatic flash metering. Since the baby Nikons (D40,D40x,D60,D3000-series, and D5000-series) also have no AI-indexing system (located at 1 o'clock around the mount) AND they ALSO LACK the minimum aperture sensing tab (located at 7 o'clock, outside of the lens mount), this type of lens has absolutely ZERO automated functions on the baby Nikons and ZERO communication with the metering systems. This non-CPU lens design allows a really basic lens like this Samyang to adapt to a number of generations of Nikon cameras.

On a D3200, the user must set the lens aperture on the lens; do not set the lens aperture to minimum aperture on any of the baby Nikon models, unless you wish to shoot at that aperture. Set the desired lens aperture on the lens's f/stop ring, and set the shutter in manual mode to the right speed value for the exposure, and set the ISO by hand, as desired.

 

[jake337]

This is a non-CPU lens in F-mount, so on a baby Nikon both ambient light exposures AND flash exposures can be made ****ONLY**** in manual modes. The pop-up flash must be set to manual flash power control; there is no automatic flash metering. Since the baby Nikons (D40,D40x,D60,D3000-series, and D5000-series) also have no AI-indexing system (located at 1 o'clock around the mount) AND they ALSO LACK the minimum aperture sensing tab (located at 7 o'clock, outside of the lens mount), this type of lens has absolutely ZERO automated functions on the baby Nikons and ZERO communication with the metering systems. This non-CPU lens design allows a really basic lens like this Samyang to adapt to a number of generations of Nikon cameras.

On a D3200, the user must set the lens aperture on the lens; do not set the lens aperture to minimum aperture on any of the baby Nikon models, unless you wish to shoot at that aperture. Set the desired lens aperture on the lens's f/stop ring, and set the shutter in manual mode to the right speed value for the exposure, and set the ISO by hand, as desired.

All this I knew and understand. But the question is if the user had the camera set to auto ISO and switched to this, non-cpu, lens what does the camera do with ISO? In this case it used the highest setting @6400. Does the camera use the highest ISO in auto or revert back to whatever ISO the camera was set to in non-auto ISO mode?

 

[wfooshee]

If you're referring to my comment about seeing "max sensitivity" in the EXIF data, it did not use 6400, it used 100, but it showed max at 6400. That implied that auto-ISO was on, but I'd forgotten about the lack of metering on that camera with a non-CPU lens, so in this case, nothing I said about auto-ISO was actually relevant.

It will change your expected results with a chipped lens if you set exposure manually but leave auto-ISO on, or on higher cameras with an un-chipped lens (that can still meter.)