Anonymous ID: 7eceef Feb. 9, 2020, 11:12 p.m. No.8089645   🗄️.is 🔗kun   >>9741

LB

 

>>8089106

 

Video astronomy requires much more equipment than traditional eyepiece viewing. It helps to understand what is going on between the camera lens and the video screen.

 

Most important is the conversion of the cameras analog signal to the computer digital format. This is usually done with a frame grabber and its associated drivers. The cameras typically have 700 ish lines of resolution which are usually translated into 640 by 480 digital signal. The camera analog signal is 60 cycle interlaced. The computer display frequency is whatever the PC is set to. I'll let the Math people tell us how the drivers fit all those numbers together and make a nice picture. I think the answer is PI or at least within a decimal place or two. The numbers get rounded and every once in a while the computer screen hiccups. National Enquirer sort of news.

 

The frame grabbers come in a wide range of cost and reliability. There's no rhyme or reason to their reliability. They depend on the computers operating system which is not identical on every computer. The frame grabber and driver will work well on one PC but not another similarly equipped PC.

 

Typically the astro video cameras two output connectors, a coax and an S-Video. The person making the video could have proven the "Waves" were and artifact of the PC by simply connecting one of the cameras outputs to an analog video screen, a television with a composite input for example and the other output to the computers frame grabber. Provided the camera and analog video are functioning properly he could have shown us a rock steady image on the analog screen and the waves on the Computer screen. With a little skill he could have shown us an alien or two surfing on the waves.

 

Smoke, mirrors and snake oil. Suckers are said to be born at the rate of one per minute. I have a feeling the con artist birth rate is up there as well.

 

It is a bit of a shame, Video or near live viewing as many of us call it, is gaining in popularity. Having someone use what is not unusual for a Video astronomer to see just for a bit of sensationalism serves no useful purpose.

 

Another point to edit in. The uTube is a video of a video. The image we see is taken by a second video cameras pointed at a video image being displayed on a computer screen. Crunch the computer screen frequency and resolution with the frequency and resolution of the second camera. You end up with images of airplane propellers that appear to stand still or move very slowly. I wonder how much adverting revenue that sort of video would bring into uTube.

 

https://astronomy.stackexchange.com/questions/27597/what-phenomenon-causes-lunar-waves