Ganesh Ujwal Posted December 30, 2014 Share Posted December 30, 2014 why most of space videos are CGI? i never saw how Mar's Curiosity lands, maximum all space images & videos in google & youtube are CGI. why so? why NASA hiding real videos? see most of space images are artistic. Link to comment Share on other sites More sharing options...
Mordred Posted December 30, 2014 Share Posted December 30, 2014 The majority of research does not use visual based telescopes. How can it, take a star for example that is emitting light in the visual frequencies. Then redshift that light till it's just barely detectable in the infra red spectrum. Redshift is merely one aspect of visual limitation. We also have the limitation of sheer distance. Those stars and planets we find are mere dots in some cases. For that matter some galaxies are barely detectable. So we don't rely on the visible frequencies. Instead we look for signals in the entire range of the electronagnetic spectrum. Then when a signal is found you need to determine its distance (Google cosmic distance ladder for a variety of methods as no one method works at all distance scales). Once the distance is known then you need to compensate for the redshift and possible blueshift to those detected frequencies. Rarely will those frequencies fall into the visual spectrum of light. More oft than not they will fall into the infrared spectrum. Particularly the further away said object is. The majority of research does not use visual based telescopes. How can it, take a star for example that is emitting light in the visual frequencies. Then redshift that light till it's just barely detectable in the infra red spectrum. Redshift is merely one aspect of visual limitation. We also have the limitation of sheer distance. Those stars and planets we find are mere dots in some cases. For that matter some galaxies are barely detectable. So we don't rely on the visible frequencies. Instead we look for signals in the entire range of the electronagnetic spectrum. Then when a signal is found you need to determine its distance (Google cosmic distance ladder for a variety of methods as no one method works at all distance scales). Once the distance is known then you need to compensate for the redshift and possible blueshift to those detected frequencies. Rarely will those frequencies fall into the visual spectrum of light. More oft than not they will fall into the infrared spectrum. Particularly the further away said object is. Here is one of the better articles on the cosmic distance ladder http://terrytao.files.wordpress.com/2009/09/cosmic-distance-ladder1.pdf Forgot to mention you also have to filter out all the gas and plasma interferance in order to find objects. Our galaxy has lots of plasma that prevent visual spotting of objects Let's look at the Hubble satellite for example its sensors detect ultra violet visual and near infra red light. However not at the same time. See link below http://hubblesite.org/the_telescope/hubble_essentials/ 1 Link to comment Share on other sites More sharing options...
Ganesh Ujwal Posted December 30, 2014 Author Share Posted December 30, 2014 (edited) The majority of research does not use visual based telescopes. How can it, take a star for example that is emitting light in the visual frequencies. Then redshift that light till it's just barely detectable in the infra red spectrum. Redshift is merely one aspect of visual limitation. We also have the limitation of sheer distance. Those stars and planets we find are mere dots in some cases. Thanks, but i am not asking what is Red Shift, once again i repeat the question for you: why most of space videos are CGI? i never saw how Mar's Curiosity lands, maximum all space images & videos in google & youtube are CGI. why so? Edited December 30, 2014 by Ganesh Ujwal Link to comment Share on other sites More sharing options...
Mordred Posted December 30, 2014 Share Posted December 30, 2014 You can infer from this article even the data is computer processed You asked why computer graphics are needed I didn't explain redshift it is simply one of the reasons. Look at the types of sensors used. Link to comment Share on other sites More sharing options...
Ganesh Ujwal Posted December 30, 2014 Author Share Posted December 30, 2014 Anyway i asked the similar question to my friend, he replied like this: while landing curiosity, there is no camera device for recording the incident. but you Mordred, you never mentioned camera device anywhere in your reply, why? i am confused. Link to comment Share on other sites More sharing options...
Mordred Posted December 30, 2014 Share Posted December 30, 2014 I didn't take your question as specific to the mars rover Obviously there is no camera watching the rover land or on the surface. However looking at the wiki link below it took color images at a rate of 4 frames per second during its descent. Using the Mardi camera http://en.m.wikipedia.org/wiki/Curiosity_(rover) 4 frames per sec would be rather blocky so I would imagine some CGI was used to add intermediate images Link to comment Share on other sites More sharing options...
Ganesh Ujwal Posted December 30, 2014 Author Share Posted December 30, 2014 (edited) 4 frames per sec would be rather blocky so I would imagine some CGI was used to add intermediate images why 4 frames per sec would look blocky?, see frames per sec is related to video, resolution is needed for images, not frames per sec for example: if you have JPEG file it contains resolution not frames per sec as you said. Edited December 30, 2014 by Ganesh Ujwal Link to comment Share on other sites More sharing options...
Mordred Posted December 30, 2014 Share Posted December 30, 2014 Blocky is the wrong word but 4 frames per second is rather slow in video. I'm no video expert but formats I'm familiar with are 24 to 75 frames per second Flickering is the more apropriate word. Link to comment Share on other sites More sharing options...
Endy0816 Posted December 30, 2014 Share Posted December 30, 2014 If you go to the 4 second mark, the dog jumping and then the girl swinging are in 4 fps. I'm honestly surprised they didn't just use false color imagery again. Link to comment Share on other sites More sharing options...
Strange Posted December 30, 2014 Share Posted December 30, 2014 (edited) Anyway i asked the similar question to my friend, he replied like this: while landing curiosity, there is no camera device for recording the incident.. Exactly. Why would that confuse you. It sounds like most of the videos you have seen are made for publicity purposes, often in advance of the mission. There are others. Including, of course, real photos and video clips. From space probes, the Mars rovers and many other missions. The recent Rossetta / Philae landing, for example. Why would you think NASA (who are not responsible for all these missions anyway) would hide things? What would they be hiding? Edited December 30, 2014 by Strange Link to comment Share on other sites More sharing options...
Airbrush Posted January 1, 2015 Share Posted January 1, 2015 (edited) why most of space videos are CGI? i never saw how Mar's Curiosity lands, maximum all space images & videos in google & youtube are CGI. why so? why NASA hiding real videos? see most of space images are artistic. Most space videos are CGI because they can illustrate for the viewer better than the data we get from cameras. Yet the CGI is totally based upon photographic evidence. It's all about catering to our eyes and imagination. Also, CGI can be manipulated so you can see an object from different angles, where the actual camera cannot. Edited January 1, 2015 by Airbrush Link to comment Share on other sites More sharing options...
Moozy Posted January 1, 2015 Share Posted January 1, 2015 Very often for copyright considerations, they publish artist's view, or 3D images instead of received real images. Link to comment Share on other sites More sharing options...
StringJunky Posted January 1, 2015 Share Posted January 1, 2015 Extra-terrestrial exploration is a fine balance between available energy, weight, resources and the limitations of communicating with something so far away. Having tools in situ that can give us the experience to the level that CGI gives is not feasible to do 'live'. Link to comment Share on other sites More sharing options...
Acme Posted January 1, 2015 Share Posted January 1, 2015 why most of space videos are CGI? i never saw how Mar's Curiosity lands, maximum all space images & videos in google & youtube are CGI. why so? why NASA hiding real videos? see most of space images are artistic. Curiosity can take video but usually doesn't because of the limited transfer rate and because little to nothing is moving on Mars. See this: >> Video: NASA Gives a Tour of the Cameras on the Mars Curiosity Rover And this: >> Why does the $2.5 billion Curiosity use a 2-megapixel camera? NASA doesn't hide raw images; you can see them here: >> Curiosity raw images Link to comment Share on other sites More sharing options...
MigL Posted January 2, 2015 Share Posted January 2, 2015 NASA only releases CGImages to the general public, since the 'real' photographs show the aliens and their spaceships. Link to comment Share on other sites More sharing options...
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