The lens node is a very important basic concept for collage and panoramic photography. In fact, it is easy to understand. Baidu encyclopedia explanation node is the lens of the optical center...... What is the optical center, really a bit obscure, forget it, take a few figure to speak.

Figure 1

We used to fight when the camera will do for the screw fixed center of rotation of the camera, the fact is that the rotation of the high precision pieces demand is insufficient, as shown above, if we are on the front of the two chopsticks at different angles to shoot three photos, this may be because the rotation of the shooting angle in three photos of objects are different, so the photos could not achieve high precision splicing.

Figure two

Now we put into rotation position of lens lens nodes, then rotate the camera, three photos on the performance of objects is consistent, and this point is the node, "optical center lens", it is sometimes called "light", to rotate the camera optical center, and object perspective will not change. The lens will not happen before and after the object displacement, so as to ensure the accuracy of our photo mosaic.

Figure three

In fact, the node is a point, it is located in the optical axis of the lens if we can fix the node, whether in horizontal or vertical or any direction to rotate the camera, it can ensure the object in the picture is unified, when we fight wide rotary shaft only to rotate the camera node in just take a few pictures of a full 360 degrees, the last one can pick up first.

(Figure three: wide strip camera installation way)

This is a node centered rotating camera wide TAB example, put the camera with the extension board is arranged in the head, and not directly to the fast loading plate is fixed on the head. The special handle of the rotary head with dividing it only to the level of rotation, the benefit of not having to see disk or scene scale, rotate to the position after it has Carlton, so you can take the breadth of the blind. As long as there is a long time, taking one hundred as a ring shot line ah.

For the lens, it is only one node, and the focusing distance and aperture size, the zoom lens will become more complex in different focal segment node position of it might be in a different place, the prime example would be easier.

The key now is how to find the node, some nodes to find on the Internet, in fact, generally are similar, and we step by step, will be more simple, here we introduce the ring shot way to find the node level.

For the horizontal ring shot, it would be easier to find, first, I see the SLR camera for a fixed screw in the lens axis (note here that most of the fixed screw card machine or DC a bit is very casual), if we fixed on the SLR level on the head it is, in the lens axis, now only need to find the node in the axis.

In front of the lens at a distance of two hanging line, or insert two toothpicks or what, on a tripod fixed camera with median two overlapping vertical view, left and right rotating camera, let the objects stay to the left and right of the screen, carefully observe the objects overlapping situation:

If the foreground is in the side, we show that our rotation is too far ahead. (see Figure four below).

If the future is biased toward the outer side, we show that our rotation position is too close to the rear; (see Figure 1).

After adjusting to the rotation of the camera, whether the object on the left or right side of the screen overlap, the node was found.

(Figure four: rotation too front screen performance)

Of course, accidentally broke character perhaps a camera you can just stand shelves to node position, if so, the luck is not blowing, will not take panoramic or breadth of his character was sorry.

A few pictures above spent some time, don't waste, now we will further understand the relationship between the node importance and distance.

Suppose, if the two end of the pencil, are stuck in front and rear balcony opposite upstairs, then we use one eye to observe the overlap of two pencils, move around a few centimeters observing them, overlapping their performance is also very good. And if we were sitting on the table and observing two of the two pencils standing up on the table, we would find that we should hold our breath and make our eyes can not move.

The fact is this: in an open space on the panoramic photography or wide pieces, it is much lower. Sometimes take wide scenery is not even considering node or hand to see about a few pictures taken back later found to fight...... Outdoors, if you feel the lens is not wide enough, can be used as ordinary equipment pieces to get the broader picture, the general landscape, we don't need a lot of close range performance.

The panoramic photography was not so pleasant love, at least the picture will be extended to our feet, the surrounding environment can not leave anything, if you do not have a basic understanding of the node, if ignored node control, the last patch results will let oneself very headache.

In addition, it is difficult for me to draw a graph to show, in general, long requirement on the nodes is low, wide requirements will be higher, and the big frame machine of nodes can be a little tolerance.