Cannot find nodal points for tele lenses

This is driving me insane. I have tried everything but I cannot find the nodal point on my 70-200 and 200 f2. I have rrs 192 precision package with a nodal slide. It doesnt matter where I move the slide I get the same results which is little or no parallax.

Because there is little to no parallax with tele lenses.
With the narrow angle of view of a tele, all the subject matter you can practically shoot will be situated far away, and thus not shift very much

It may vary with different versions of the 70-200 but I have notes from my 70-200 IS MkII (long since departed) that I calculated it to be 34mm from the sensor plane (ie, completely behind the lens). This is the "no parallax point" and not specifically the "nodal point".

Worth a try and see what results you get.

Bob

The nodal points are marked on every lens - on L series it's red ring, on the other ones - gold/silver strap. Clever

I have spent several hours today and all nodal points turned out to be ahead of the ball head. In fact, for 200mm (both the zoom and the prime), I had to place the nodal slider all the way ahead (around 16mm mark) and on top of that I had to move the clamp to the position 2mm. As I zoomed out, from 135 to 100 and to 70, I had to get closer to the ballhead.

For the wide angles (24-70, 35L, etc), it was the complete opposite, they had to be further back from the ballhead.

Humble Photographer wrote in post #16256759
I have spent several hours today and all nodal points turned out to be ahead of the ball head. In fact, for 200mm (both the zoom and the prime), I had to place the nodal slider all the way ahead (around 16mm mark) and on top of that I had to move the clamp to the position 2mm. As I zoomed out, from 135 to 100 and to 70, I had to get closer to the ballhead.

For the wide angles (24-70, 35L, etc), it was the complete opposite, they had to be further back from the ballhead.

This is a little meaningless without knowing the relationship between your ball head and the sensor. The NPP (or NP) is usually specified from the sensor/film plane.

Bob

Canon Bob wrote in post #16256781
This is a little meaningless without knowing the relationship between your ball head and the sensor. The NPP (or NP) is usually specified from the sensor/film plane.

Bob

Sensor plane is well ahead of the rotation axis (ballhead) for the teles and behind for wide angles.

I'd shoot an email to canon. It probably isn't a secret.

Humble Photographer wrote in post #16256936
Sensor plane is well ahead of the rotation axis (ballhead) for the teles and behind for wide angles.

Hmmm, I can't get my head around that concept. I'll have to hope somebody drops in to explain how and why it can occur.

Bob

there's quite a reasonable description here: http://archive.bigben.​id.au …ials/360/photo/​nodal.html

and a lot of actual measurements here: http://wiki.panotools.​org/Entrance_Pupil_Dat​abase

Canon Bob wrote in post #16257810
Hmmm, I can't get my head around that concept. I'll have to hope somebody drops in to explain how and why it can occur.

Bob

Moving the camera behind the rotation axis made parallax much worse. I have spent hours on these two tele lenses (all my wide angles literally took 5 minutes).

Quick question, does camera orientation matter when it comes to determining nodal points? I'm guessing not but still wanted to check.

Humble Photographer wrote in post #16258418
Quick question, does camera orientation matter when it comes to determining nodal points? I'm guessing not but still wanted to check.

In one respect, yes. The lens' axis must run right over the pivot point for things to work just right. When the camera is rotated, there's quite a difference in the orientation of the camera's tripod mount screw and the lens' axis. Thus, your mounting method may have to be very different.

If you're using a lens tripod mount that rotates around the lens to support the camera/lens rig, then camera orientation won't make any difference.

I just tried rotating my camera and all measurements came out same.

As for the tele lenses having a negative nodal point, that website linked couple posts back does have a lot of tele lenses, mostly nikkor or sigma, which have negative nodal points.

Humble Photographer wrote in post #16258837
As for the tele lenses having a negative nodal point, that website linked couple posts back does have a lot of tele lenses, mostly nikkor or sigma, which have negative nodal points.

Yes, I see that but I still can't get my head around it.

Bob