Nodal Point

Started Aug 5, 2007 | Discussions
Rudi2K5
Contributing MemberPosts: 714
Like?
Nodal Point
Aug 5, 2007

I have a question to those panorama freaks:

Is there any source in the web where they list lenses with information about the physical location of their nodal points?
--
http://www.pbase.com/rudiknust

John Kim
Senior MemberPosts: 1,256
Like?
Doug Kerr wrote up how to find the pivot point
In reply to Rudi2K5, Aug 5, 2007
Reply   Reply with quote   Complain
fredlord
Senior MemberPosts: 2,315
Like?
Re: Nodal Point
In reply to Rudi2K5, Aug 5, 2007

Rudi2K5 wrote:

I have a question to those panorama freaks:

Is there any source in the web where they list lenses with
information about the physical location of their nodal points?

Although we are not "those panorama freaks," a few photographers have listed them. It is so absurdly simple to find them that most have not bothered to make a list. Zoom lens nodal/pivot points vary with focal length anyway.

Reply   Reply with quote   Complain
Vernon D Rainwater
Forum ProPosts: 11,867
Like?
Re: Nodal Point
In reply to fredlord, Aug 5, 2007

fredlord wrote:

Rudi2K5 wrote:

I have a question to those panorama freaks:

Is there any source in the web where they list lenses with
information about the physical location of their nodal points?

Although we are not "those panorama freaks," a few photographers have
listed them. It is so absurdly simple to find them that most have not
bothered to make a list. Zoom lens nodal/pivot points vary with focal
length anyway.

I agree with your comment about NOT freaks. Also, I think it would be very helpful if there was a site where the "so called" Nodal Point information could be accessed. Yes, it may be east, however; it is somewhat like "re-inventing the wheel".
This would be good if included with lens specifications
--
Vernon...

Reply   Reply with quote   Complain
GaborSch
Veteran MemberPosts: 7,203
Like?
Entrance Pupil Database
In reply to Rudi2K5, Aug 5, 2007

(it is not the nodal point but the entrance pupil)

http://wiki.panotools.org/Entrance_Pupil_Database

There are only a few Canon lenses listed.

No, it is not true, that it is easy to find the exact location. It requires a series of shootings and comparison on computer.

The location varies not only with zooming, but in case of some (most) lenses, with focusing as well, although this becomes relevant only indoor.

There are three lenses we both have (four, but the Tamron 17-35mm is not good enough for panos). The distances in the following chart are measured from the mounting screw of the 20D. No idea, if and how much the 400D differs from that.

Canon 50mm f/1.4: 49mm @ infinity, 50mm @ 4m

Tamron 28-75mm: 102mm @ 28mm, 97mm @ 35mm, 92mm @ 50mm, 85mm @ 60mm, 79mm @ 75mm

Canon 85mm f/1.8: 73mm @ infinity

For the others: you can get a good approximation, if you stop down to f/10 or smaller, look into the lens from the front and actuate the aperture (on-off-on-off). The location you see the aperture is the entrance pupil. This is good enough in most cases, but not indoor.

Reply   Reply with quote   Complain
rpcrowe
Contributing MemberPosts: 859
Like?
Nodal Point - sites
In reply to Rudi2K5, Aug 5, 2007

I hope these help...

http://www.path.unimelb.edu.au/~bernardk/tutorials/360/index.html

http://www.zenadsl5251.zen.co.uk/photos/panos.html
see Tutorial 5 for above

http://forums.dpreview.com/forums/read.asp?forum=1029&message=16638706

http://gregwired.com/pano/Pano.htm
Relatively inexpensive pano mount the Panosaurus

http://www.vrphotography.com/data/pages/techtutorials/technotes/nodalptalign-tn.html

-- hide signature --

Retired Navy Master Chief Photographer's Mate. I was a Combat Cameraman, Motion Picture Director, and a Naval Aircrewman. I also had experience in reconnaissance and intelligence photography. I have had considerable commercial photo experience in weddings and advertising photography. I am fully retired now although I dabble occasionally in dog portraiture. I presently use Canon DSLR cameras.

Reply   Reply with quote   Complain
peppino
Regular MemberPosts: 444
Like?
Re: Doug Kerr wrote up how to find the pivot point
In reply to John Kim, Aug 5, 2007

thanks a great article!

Reply   Reply with quote   Complain
Rudi2K5
Contributing MemberPosts: 714
Like?
Thanks a lot,
In reply to GaborSch, Aug 5, 2007

Hi Gabor, thanks for your detailed information.

I am right now in the process of selling about 1/3 of my lenses to buy some better stuff. Among them are the Tamron 17-35 mm, Canon EF-S 10-22mm, Canon 24mm f/2.8 and the Sigma Fish-eye, too. I am going to Germany on Sept. 2, and I will sell them all through ebay. I am also selling my Manfrotto pano head 303, because it is way to heavy to carry around. I bought already a Nodal Ninja 3, which I will pick up in Berlin next month.

But I will have also some new purchases in September:

Canon 5D
EF f/2.8 16-35mm L II
EF f/4 70-200 L IS

Besides that in my sons house in Berlin are some manual zuiko lenses for me to be picked up and bring back to China (bought them all on ebay recently):

f/3.5 18mm
f/2 21mm , f3.5 21mm
f/2.8 24 mm
f/2 28mm
f/2 35mm
f/1.4 50mm , f/1.8 50mm

I will purchase adapters here in Guangzhou, China. I am also looking at those manual Zeiss ZF lenses, since they are much cheaper here.

So, when coming back to Guangzhou on October 5, I will have a lot of "lens testing" and "nodal point finding" work to do.

Thanks also for the critics on my panos. I am taking it with a positive attitude. I have taken a closer look and found some more issues. I am learning constantly.

Reply   Reply with quote   Complain
Rudi2K5
Contributing MemberPosts: 714
Like?
Re: Nodal Point - sites
In reply to rpcrowe, Aug 5, 2007

Thanks for the links.
--
http://www.pbase.com/rudiknust

Reply   Reply with quote   Complain
GaborSch
Veteran MemberPosts: 7,203
Like?
Addendum
In reply to Rudi2K5, Aug 5, 2007

I forgot to mention: the conversion of the distances from the 20D to your camera should be easy. The Entrance Pupil Database contains the distances from the mounting screw to the lens base, in case of the 20D this is 36.5mm. The 400D is not listed there, so you have to measure that distance yourself and add/substract the difference to the distances I listed. The values measured from the lens base are the inherent characteristics of the lenses, but that is useless, as in the practice you need the distance from the mounting screw.

Reply   Reply with quote   Complain
netmare
New MemberPosts: 12
Like?
Re: Nodal Point
In reply to Rudi2K5, Aug 17, 2007

I'm wondering

Did you measure the distance from the mounting screw to the lens base?

Reply   Reply with quote   Complain
netmare
New MemberPosts: 12
Like?
Re: Addendum
In reply to GaborSch, Aug 17, 2007

If I understand Gabor correctly, that means

Canon 50mm f/1.4: mount-to-lens-base-distance + 12,5 @ infinity
Canon 50mm f/1.4: mount-to-lens-base-distance + 13,5 @ 4m

Is this correct?

Reply   Reply with quote   Complain
GaborSch
Veteran MemberPosts: 7,203
Like?
Right (nt)
In reply to netmare, Aug 17, 2007
Reply   Reply with quote   Complain
Vernon D Rainwater
Forum ProPosts: 11,867
Like?
Re: Addendum
In reply to netmare, Aug 17, 2007

netmare wrote:

If I understand Gabor correctly, that means

Canon 50mm f/1.4: mount-to-lens-base-distance + 12,5 @ infinity
Canon 50mm f/1.4: mount-to-lens-base-distance + 13,5 @ 4m

Is this correct?

Below is a copy of the explanation provided by the other poster:
*******

There are three lenses we both have (four, but the Tamron 17-35mm is not good enough for panos). The distances in the following chart are measured from the mounting screw of the 20D. No idea, if and how much the 400D differs from that.
Canon 50mm f/1.4: 49mm @ infinity, 50mm @ 4m
Tamron 28-75mm: 102mm @ 28mm, 97mm @ 35mm, 92mm @ 50mm, 85mm @ 60mm, 79mm @ 75mm
Canon 85mm f/1.8: 73mm @ infinity
*******

The "so called" lens Nodal point should be DIRECTLY above and in line with the center of the tripod.

Before and alignment and with the camera mounted directly on the tripod; the "Nodal Point" will normally be in FRONT of the center of the tripod. Therefore, to align the Nodal point with the center of the tripod; it usually is necessary to have some type of a bracket to allow moving the Camera backward (the proper distance) to have the lens nodal point directly over the center of the tripod.

The measurements provided by the other poster evidently is the distance to move the camera and lens backward for the alignment.

The normal (and preferred) method is to use the tripod "connection hole) in the Camera to express how much to move to make the proper alignment.

Just think of when the camera is mounted directly on the tripod (before any adjusting for nodal point) that the distance from center of the tripod to the camera tripod mount "hole" is 0 (ZERO). Then, how far do we need to move the Camera+Lens to have the nodal point aligned properly. This distance is based on the lens setting for MM, etc....

Canon 50mm f/1.4: 49mm @ infinity, 50mm @ 4m

The (copied from the other post) 49mm and the 50mm above are the distance to set the camera tripod mount hole on the camera backward from the center of the tripod in order to properly align the lens nodal point.

I have NOT used the 50mm f:1.4 lens to know the proper settings, however; the other poster obviously has.

The reason (of course) to have the nodal point "directly" over and aligned with the center of the tripod is so when the camera is rotated for the pano exposures, there will be NO change because the nodal point is centered directly in line with the tripod.

I hope this is at least as clear as "mud" [Grin]... I do hope this helpful for you.
--
Vernon...

Reply   Reply with quote   Complain
netmare
New MemberPosts: 12
Like?
Re: Addendum
In reply to Vernon D Rainwater, Aug 17, 2007

I understand it. I think:-).

Gabor uses a different camera but does use the same lens (the 50mm 1.4).

I'm just trying to find out if I understand his hints of "translating" his measurements to my situation ...

Thanks

Reply   Reply with quote   Complain
Keyboard shortcuts:
FForum MMy threads