HiHarry,
I've written a long post before logging in and lost all the information - I'll try to summarize:
I believe your scene size is large. Your System Unit is inches and Display Units is Generic which -to my experience- means your units are in Inches. The tubes are about 6600 inches. Almost at a height of a skyscraper.
Max -just like the programs of its category- has a limitation of precision. Large scales may cause problems in many areas.
I've switched to Corona Renderer at first. Your Camera renders fine in Corona Renderer. Switching back to Arnold, your camera was again rendering the tip of the tubes out of the view. At first I thought it has something to do with Arnold. (May be a post effect) but I've placed a new camera just over your camera and saw that the new camera renders fine, only needs perspective adjustments.
That is when I noticed that your camera shape is distorted. I believe you've added some sort of perspective correction.
To see the distortion in detail, I zoomed in the camera in the Front Viewport and to my surprise, your objects get distorted in the viewports as I get close to them. Look at the below Front Viewport.
What you see in the image is your Camera zoomed in. Upon zooming in more, it eventually disappears after a few more garbled versions.
Max has a limited Decimal Places of Accuracy. You need to keep your scenes in the intermediate scale to have enough space for Precision. In a scene with extents of around 16.777.216 inches, the smallest distance you can move is 1 inch. This is a shortcoming of all Single Precision software. This extent concept is the distance of objects from the origin. Even if you have your objects around the origin, at an acceptable size, when you have a single object placed at such a distance from the origin, you'll have precision issues. These range from jagged motion of objects to black stripes with jagged edges over entire objects. (Clipping issues) Clipping also shows in the form of disappearing objects when getting close to or farther away from the objects.
This precision will even manifest itself as severely as corrupting your objects, when you change your System Unit Scale so that the precision required to display the details of your object is way smaller than your newly set System Scale and the object's distance is far from the origin.
Consider adjusting the scale of your scene and re-create a new camera for that scene.
Hope this helps.
