suggestion for canon guy for 7D update

M

mel4tonin

Member
what about a digital zoom using the sensor in smaller section and having a digital zoom 5x using the central part of the sensor without any loss in quality?
that would be a wonderful feature and very easy to add
 
mel4tonin said:
what about a digital zoom using the sensor in smaller section and having a digital zoom 5x using the central part of the sensor without any loss in quality?
that would be a wonderful feature and very easy to add
Click to expand...

Despite the fact that the sensor size is larger than 1080p (obviously), this is actually not a good idea.

Why do you think vDSLRs look so good? It's because they're cramming lots of data from over-sized sensors down into 1080 or 720p. Have you ever taken a crappy looking photo and scaled it down to like 320 by 240 and it looked pretty good? Similar principal. Not saying the cameras put out crappy images, far from it, I'm saying that the main reason you get such an excellent image from these cameras is by using the entire sensor.

Therefore, I reject your assertion that this is possible without a loss in quality...you're basing that statement based on the fact that the sensor size is larger than 1080p...and that is exactly the reason you will lose quality. There's a reason why little 1/4" 1-CCD cameras put out a much poorer image @ 640 or 720 x 480 than did their 3-CCD counterparts, and the same holds here.

Also I feel like cropping the sensor to that extent would aggravate rolling shutter as the "roll" would be much more perceptible in a smaller area....but it might be balanced out by the fact that it takes less time to roll through the smaller refreshing sensor area...maybe it all cancels out....I have no data to support this, it's just a thought.
 
Ben_B said:
Despite the fact that the sensor size is larger than 1080p (obviously), this is actually not a good idea.

Why do you think vDSLRs look so good? It's because they're cramming lots of data from over-sized sensors down into 1080 or 720p. Have you ever taken a crappy looking photo and scaled it down to like 320 by 240 and it looked pretty good? Similar principal. Not saying the cameras put out crappy images, far from it, I'm saying that the main reason you get such an excellent image from these cameras is by using the entire sensor.

Therefore, I reject your assertion that this is possible without a loss in quality...you're basing that statement based on the fact that the sensor size is larger than 1080p...and that is exactly the reason you will lose quality. There's a reason why little 1/4" 1-CCD cameras put out a much poorer image @ 640 or 720 x 480 than did their 3-CCD counterparts, and the same holds here.

Also I feel like cropping the sensor to that extent would aggravate rolling shutter as the "roll" would be much more perceptible in a smaller area....but it might be balanced out by the fact that it takes less time to roll through the smaller refreshing sensor area...maybe it all cancels out....I have no data to support this, it's just a thought.
Click to expand...
i'm sorry but your assertion of the downscaling is wrong, since the vdslr don't downscale (that would pump up the quality) but they simply select 1 pixel every 3 and 1 line every 3 (more or less) that's why images don't look perfect, especially diagonal lines. a 5x digital zoom is techically possible and would be a very nice picture to use, just a nice bonus when you need extra zooming, but don't have a lens to do it.
 
According to Canon rep, Tim Smith, 5D doesn't skip lines. It 'bins' pixels in groups of 6 and processes them that way for video. I'm sure the 7D is doing something similar.
 
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