Exposure Query for 5x video mode

[Cotts]

I took my first 5x planetary mode videos with BYE this evening.  I shot Polaris at the following shutter speeds, all at ISO 3200 and 200 frames:  1/50 sec, 1/10 sec., 1 sec, and 2.5 sec as tests.

 

Although the 1/50 and 1/10 videos look different from one another, the 1 sec and 2.5 sec vids look exactly like the 1/10 vid in terms of exposure.  They don't seem to go any deeper.  

 

  If I'm shooting 200 2.5 second frames shouldn't it take 500 seconds to do so? i.e. isn't the frame rate tied to the exposure length?  Well it seems not.  The vids are all just a few seconds long....  The 2.5 second frames are most certainly not 2.5 seconds long....

 

So, when I adjust the exposure in 5x video mode what am I really adjusting?  Is the frame rate tied to shutter speed?  If not, why not?  etc. etc.

 

Thanks,

 

Dave

[admin]

I took my first 5x planetary mode videos with BYE this evening.  I shot Polaris at the following shutter speeds, all at ISO 3200 and 200 frames:  1/50 sec, 1/10 sec., 1 sec, and 2.5 sec as tests.

 

Although the 1/50 and 1/10 videos look different from one another, the 1 sec and 2.5 sec vids look exactly like the 1/10 vid in terms of exposure.  They don't seem to go any deeper.  

 

  If I'm shooting 200 2.5 second frames shouldn't it take 500 seconds to do so? i.e. isn't the frame rate tied to the exposure length?  Well it seems not.  The vids are all just a few seconds long....  The 2.5 second frames are most certainly not 2.5 seconds long....

 

So, when I adjust the exposure in 5x video mode what am I really adjusting?  Is the frame rate tied to shutter speed?  If not, why not?  etc. etc.

 

Thanks,

 

Dave

 

Live view exposure length with Canon DSLR is not true exposure length, it is was Canon calls Exposure Simulation.  Depending on your ISO (and lens if any)  it is very possible that the exposure simulation has maxed out a 1 second and this is why you see difference beyond that.

 

When you are taking 5x zoom images you are ensuring a 1:1 pixel resolution; meaning 1 pixel on the sensor = 1 pixel on the image.  This is the best image quality you can get because no image transformation occurs, no resize.

 

Hope this helps,

 

 

 

[Cotts]

Thanks, Guylain, for the quick response.  I know about the 1:1 pixel thing.  I've been getting 1:1 in camera (60Da) by using the 640x480 pixel movie crop mode.  BYE gives me no improvement in resolution.

 

However, there is an exposure limitation when using the movie crop mode:  there is a fixed frame rate of 60 f.p.s. which means the longest exposure I can use is 1/60 second.   By using BYE I was hoping to get longer exposures, as long as 2.5 seconds, in order to get fainter double stars within my reach.

 

 But you say that these longer exposures are 'simulated' and that the simulation is related to the ISO setting..  Considering that I am shooting almost always @ 6400 ISO are the exposure lengths longer than 1/60 sec offered by BYE all 'simulated'?  

 

Thanks,

 

Dave in Toronto

[admin]

Thanks, Guylain, for the quick response.  I know about the 1:1 pixel thing.  I've been getting 1:1 in camera (60Da) by using the 640x480 pixel movie crop mode.  BYE gives me no improvement in resolution.

 

However, there is an exposure limitation when using the movie crop mode:  there is a fixed frame rate of 60 f.p.s. which means the longest exposure I can use is 1/60 second.   By using BYE I was hoping to get longer exposures, as long as 2.5 seconds, in order to get fainter double stars within my reach.

 

 But you say that these longer exposures are 'simulated' and that the simulation is related to the ISO setting..  Considering that I am shooting almost always @ 6400 ISO are the exposure lengths longer than 1/60 sec offered by BYE all 'simulated'?  

 

Thanks,

 

Dave in Toronto

 

All live view exposures -ARE- simulated, not just the longer ones. 

 

This is a camera limitation/implementation, it is not a software limitation.  I have to take whatever the camera gives me.  There comes a point where the exposure simulation can't go further and when this happens you see no difference even if you change your values to a higher value/limit.

 

Hope this helps,

 

 

[PoppaChris]

 

When you are taking 5x zoom images you are ensuring a 1:1 pixel resolution; meaning 1 pixel on the sensor = 1 pixel on the image.  This is the best image quality you can get because no image transformation occurs, no resize.

 

Hope this helps,

 

 

 

Guylain:  Can you also please let us know what the pixel resolution ratio is for Standard and 10X?

 

I have noticed that in recent images of Saturn, 10X is a lot "softer" than 5X and Standard is just too small an image to deal with.

[admin]

 

When you are taking 5x zoom images you are ensuring a 1:1 pixel resolution; meaning 1 pixel on the sensor = 1 pixel on the image.  This is the best image quality you can get because no image transformation occurs, no resize.

 

Hope this helps,

 

 

 

Guylain:  Can you also please let us know what the pixel resolution ratio is for Standard and 10X?

 

I have noticed that in recent images of Saturn, 10X is a lot "softer" than 5X and Standard is just too small an image to deal with.

 

10x is a 2x digital zoom against the 5x zoom... so 10x will be 1 pixel on the sensor = 4 pixels on the image... it is enlarged by a factor of 2 in both width and height.

 

Regards,

[astroman133]

I would suggest putting a Barlow lens or Powermate ahead of the camera to increase your focal length and enlarge your target as an alternative to using the 10X Zoom capability.