Marvin wrote: »
Hi there sorry I don't know your name but I notice other thanks to you mentioned the name Dave so I assume it is Dave. I just recently joined Digital Grin and Smugrug and was browsing the forum and found your entry on finding the nodal point of a lens etc.
It sure is a good tutorial. I was wondering could you let me have an address where the MPR-CL11 nodal slide can be purchased, I live in Northern Ireland and have been looking for this particular one for some time now.
I would appreciate the address if you have it.
David_S85 wrote: »
Easy enough to find the middle and mark it with a line, no?
Ascherjim wrote: »
My camera is mounted on a nodal slide in portrait mode with a generic L-bracket without a lens center line marked on the L-bracket. Aside from positioning the camera on the slide so the vertical center of the lens seems by eyesight to be aligned with the center line of the slide, is there not a more precise way to do this? Or doesn't that level of precision really matter? If the camera were positioned on the slide in landscape mode, without an L-bracket involved, there would likely not be a problem, as in that instance the tripod socket is usually positioned at the vertical center line of the lens. Thanks, Jim
David_S85 wrote: »
Initial trial and error is the best way for each lens and focal length. With the advent of live view, you might not even need to take a real shot to set things up. Sure wish I had that option back in my 20D days. But guessing where the center point may be is difficult in many lenses. My Canon 10-22's center pivot points are very odd. One would think that notation marks on a nodal slide would correspond and progress in order up and down the slide. They don't. There are some lenses that the center pivot point might not be physically within the lens' length. I have learned not to guess.
Exact lens centering matters less when all objects are far away; so in many landscape pano's, you might very well get decent results without calibrating for your camera/lens/focal length combo.
Stitching programs have more difficulty when objects are nearer. Those are situations where you are best to spend time calibrating first, and somehow marking the slider, or doing whatever is necessary to repeat good results.
I recently shot an eight image 360 VR pano at 10mm of a small kitchen for a real estate listing. The corner of a doorway was a couple of feet away from the pano head, and with the natural lens distortions at extreme wide angle, I would have had a jumbled mess on my hands with even the best stitching software had I not calibrated the rig those several years ago. Since I had the marks on my slide for my lens, the setup was easy, and I just swung the thing around and shot every 45 degrees. I had no worries that it wouldn't work.
pathfinder wrote: »
The newer L brackets from Really Right Stuff have lines machined into them that display the exact center of your sensor, so that you CAN center your camera body on the center of the shooting axis of your rotating pano head.
Some camera bodies have marks showing the center of the sensor plane, and some the central axes of the sensor itself.
Otherwise, you just have to eyeball getting the lens axis centered on your planned shooting axis...