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View Full Version : Canon 70-200 F2.8L IS II and Nodal Ninja M2 - Nodal point?



Ryan0751
06-18-2013, 09:48 AM
I set up a very cool little box, with a screwdriver poking out the top of the box, with a slit cut into a piece of cardboard that was placed behind the screwdriver. Using this setup I was very easily able to find the nodal points of my shorter lenses.

With my Canon 70-200, however, I found it next to impossible to figure it out at the long (135-200) end. Even looking through the viewfinder, as you move your head slightly (without moving the camera) you can see some parallax. I ended up just sort of "guessing" a value.

Any pointers for this lens? I have it mounted up using the tripod collar.

Hugh
06-18-2013, 10:26 AM
Ryan,

With your long lens use points that are much further apart.
See:
http://www.johnhpanos.com/epcalib.htm
http://hugha.co.uk/NodalPoint/Index.htm#A_simple_method_...

Hugh.

nick fan
06-19-2013, 01:07 AM
I set up a very cool little box, with a screwdriver poking out the top of the box, with a slit cut into a piece of cardboard that was placed behind the screwdriver. Using this setup I was very easily able to find the nodal points of my shorter lenses.

With my Canon 70-200, however, I found it next to impossible to figure it out at the long (135-200) end. Even looking through the viewfinder, as you move your head slightly (without moving the camera) you can see some parallax. I ended up just sort of "guessing" a value.

Any pointers for this lens? I have it mounted up using the tripod collar.

Some tele lenses have NPP/ entrance pupil behind the sensor. If you set the lens at NPP, it will be very unstable. You have to decide whether it is necessary. If you are shooting far away scenes with no near objects, you can neglect NPP. Set the lens where the whole rig is more stable.


NIck

chesty
01-04-2015, 10:54 PM
After having ensured being level and centered left to right on the rotator I setup a plumb bob hanging from my ceiling and stopped down the aperature to f8 to f16 and centered it on the string. Then it was a matter of setting desired focal length, rotating left or right a set amount of degrees. If the center moved left or right all I had to do was move the lens forward or back till stopped down opening was again centered on string while in the rotated position. This of course requires you to site down string from directly in front of camera at all times. This worked for all of my lenses.

With the 70-200 (using the lens collar and adapter) I found at 135 and beyond I had to position lense as far forward on upper rail as possible and at 200 the upper rail had to be moved as far forward as possible putting the npp behind the camera more or less (this nakes me a bit nervous and wondering how I would do this for say 300f2.8). I have verified all my settings using this technique except for the 70-200. I shoot a 5DMKIII. Hope this helps

John Houghton
01-05-2015, 10:46 AM
With the 70-200 (using the lens collar and adapter) I found at 135 and beyond I had to position lense as far forward on upper rail as possible and at 200 the upper rail had to be moved as far forward as possible putting the npp behind the camera more or less (this nakes me a bit nervous and wondering how I would do this for say 300f2.8).
It's quite common for the NPP to positioned inside or behind the camera body for focal length settings at the maximum extent. It all depends on the optical design of each lens.

John

chesty
01-05-2015, 10:09 PM
It's quite common for the NPP to positioned inside or behind the camera body for focal length settings at the maximum extent. It all depends on the optical design of each lens.

John

It is a strange optical quality. I just get worried about stability. The longer focal lengths almost require more than 1 row for pano shots.

nick fan
01-06-2015, 06:50 PM
unless one is making pano with close subjects, it is better to place the lens near the center of gravity. Parallax effect decreases with subject distance. Also the movement of lens is very small with the small shooting interval. Distant scenes are almost flat and can be optimized with view point correction.

NIck