Single shot CCD vs Tri color CCD
Single shot CCD vs Tri color CCD
I was reading on ccd imaging. i would like to find out if its true that single shot ccd is actually much user friendly than Tri-color ccd and it take lesser imaging time. Do we still need to consider the RGB Ratios for single shot CCD since everything is done by the ccd chip. How does the image color change be if i use the same exposure time between single shot CCD and Tri-color CCD. Ex- 3 mins on Single shot CCD and 1 min Red, 1 min Green and 1 min Blue on the same image. Or maybe my thinking of ccd imaging is wrong. It seems that single shot ccd is gaining popularity. Thanks
Hi,
This has always been the dilemma of imagers as we always hoped to get a nice colour image with lesser effort, but too bad, there is no shortcut.
Let me just give you some points and I hope things will be there from there.
1) Lower resolution than RGB taken from mono-imagers of the same pixel number. This is because of the the Bayer array. So when you are taking a picture, 1/4 pixels are taking red, 1/4 taking blue, 1/2 taking green. Whereas for a mono-imager, all pixel are taking red when you are at the red filter and so on. If you just want to try astrophotography for fun, then 1-shot is ok. If you are after high res pictures, then mono is the way to go. This is the most important reason why you should avoid 1-shot colour cameras.
2) Colour balancing actually becomes a bigger problem with 1-shot cameras. Imagine the skyglow is an ugly red dome in the sky, as you can't control the length of exposure of each of the colour channels, you may end up red channel overexposed and blue and green channels slightly underexposed.
By the way, the 3 min 1-shot colour camera will show more than 1min R + 1min G + 1 min B, given the same optical system and QE of the sensors.
Hope this has helped.
This has always been the dilemma of imagers as we always hoped to get a nice colour image with lesser effort, but too bad, there is no shortcut.
Let me just give you some points and I hope things will be there from there.
1) Lower resolution than RGB taken from mono-imagers of the same pixel number. This is because of the the Bayer array. So when you are taking a picture, 1/4 pixels are taking red, 1/4 taking blue, 1/2 taking green. Whereas for a mono-imager, all pixel are taking red when you are at the red filter and so on. If you just want to try astrophotography for fun, then 1-shot is ok. If you are after high res pictures, then mono is the way to go. This is the most important reason why you should avoid 1-shot colour cameras.
2) Colour balancing actually becomes a bigger problem with 1-shot cameras. Imagine the skyglow is an ugly red dome in the sky, as you can't control the length of exposure of each of the colour channels, you may end up red channel overexposed and blue and green channels slightly underexposed.
By the way, the 3 min 1-shot colour camera will show more than 1min R + 1min G + 1 min B, given the same optical system and QE of the sensors.
Hope this has helped.
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