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Posted

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.

Posted

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/

Posted (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 by Ganesh Ujwal
Posted

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.

Posted

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.

Posted

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

Posted (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 by Ganesh Ujwal
Posted

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.

Posted

 

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.

Posted (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 by Strange
Posted (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 by Airbrush
Posted

Very often for copyright considerations, they publish artist's view, or 3D images instead of received real images.

Posted

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'.

Posted

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

Posted

NASA only releases CGImages to the general public, since the 'real' photographs show the aliens and their spaceships.

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