When is alignment required?

[Penthode]

Originally Posted by old_tv_nut

There never was a specific dot filter in a B&W chassis - unnecessary expense.
Also, manufacturers learned that a picture with less than full resolution, but reduced noise, was preferable to many people. The classic flat-topped response was replaced by a "haystack" IF curve, which attenuated high frequency noise and added mid-frequency peaking to restore apparent picture sharpness.

It is interesting to note that with the evolution of NTSC color television, that the loss of luma resolution was seen as a tradeoff to the benefit of full color. Artificial crispening of video has become the norm to offset lower resolution. Even HD images are now currently subject to this. However, when a comparison is made between lower bandwidth with artificial sharpening, the wider bandwidth hence higher resolution is noticably better.

The later trend (after 1953) to lower resolution images is akin to the abandonment of DC restoration: the tradeoff is cost of manufacture against minor picture improvements. It was all about economics and it was just too expensive to continue to build a better set.