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Need help in calculating digital camera's MP
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#12
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Need help in calculating digital camera's MP
On Fri, 02 Jan 2009 12:45:07 -0800, aniramca wrote:
On Jan 2, 2:04Â*pm, "David J Taylor" - this-part.nor-this-bit.co.uk wrote: John Navas wrote: [] Most current TV electronics aren't capable of that kind of pixel level resolution -- put the HD input on pause and look closely -- and your eyes couldn't see it in a moving image even if. I don't know if any tests have been done to check what the actual ratio is, but I recall that the Foveon sensor is reckoned by some to be equivalent to something like twice the number of pixels. That's not directly comparable. I therefore revise my estimate to, for a 4:3 aspect ratio camera 2 * 1920 * 1440, i.e. about 5-6Mpix, resampled and cropped to a 16:9 1920 x 1080 ready-to-display image. Cropping a movie is usually impractical. 2-3 MP is really enough. The LCD TVs I've seen are quite capable of pixel-level resolution, John. Recall that the OP wants stills, not movies. David Thanks for all of the info and discussions. However, I just simply could not get sharp, crisp photos from my cameras. I tried some photos using a 3MP Lumix digital camera and they show excellent colour and sharpness under my 21 in. LCD computer screen. They are close-ups of a red flower, and showing its extremely focused and sharp filaments. I used the flower (no flash and under bright light) as it usually gives the best resolution and colour. I also shot a couple of photos using a Canon G7 (10 MP). The results have also been disappointing in my TV. These JPG files are all over 2MP that all of you indicated. So, what's wrong? I just copied the JPG files into a CD and use a DVD player attached to the TV. They just do not show sharp photos that I always see at the TV stores when they display the TVs. Are they using high MP photos? Thanks any way for the information. It appears that every one agrees that you only need a 2MP JPG file to produce excellent photos in a 46 in. TV screen. I am just not happy for what I got so far and perhaps I will keep trying. Perhaps I should try to download one of the best and sharp , over 2MB photos from the internet and try that on my TV. Does the process to download to the TV matter? or it does not matter as long as they are a JPG files? It sounds to me like you are basically displaying in TV mode - probably analog TV mode - which is simply not high resolution. Suggest you use a high def or computer monitor interface. You may not be able to do any better. |
#13
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Need help in calculating digital camera's MP
ray wrote:
On Fri, 02 Jan 2009 12:45:07 -0800, aniramca wrote: On Jan 2, 2:04 pm, "David J Taylor" - this-part.nor-this-bit.co.uk wrote: John Navas wrote: [] Most current TV electronics aren't capable of that kind of pixel level resolution -- put the HD input on pause and look closely -- and your eyes couldn't see it in a moving image even if. I don't know if any tests have been done to check what the actual ratio is, but I recall that the Foveon sensor is reckoned by some to be equivalent to something like twice the number of pixels. That's not directly comparable. I therefore revise my estimate to, for a 4:3 aspect ratio camera 2 * 1920 * 1440, i.e. about 5-6Mpix, resampled and cropped to a 16:9 1920 x 1080 ready-to-display image. Cropping a movie is usually impractical. 2-3 MP is really enough. The LCD TVs I've seen are quite capable of pixel-level resolution, John. Recall that the OP wants stills, not movies. David Thanks for all of the info and discussions. However, I just simply could not get sharp, crisp photos from my cameras. I tried some photos using a 3MP Lumix digital camera and they show excellent colour and sharpness under my 21 in. LCD computer screen. They are close-ups of a red flower, and showing its extremely focused and sharp filaments. I used the flower (no flash and under bright light) as it usually gives the best resolution and colour. I also shot a couple of photos using a Canon G7 (10 MP). The results have also been disappointing in my TV. These JPG files are all over 2MP that all of you indicated. So, what's wrong? I just copied the JPG files into a CD and use a DVD player attached to the TV. They just do not show sharp photos that I always see at the TV stores when they display the TVs. Are they using high MP photos? Thanks any way for the information. It appears that every one agrees that you only need a 2MP JPG file to produce excellent photos in a 46 in. TV screen. I am just not happy for what I got so far and perhaps I will keep trying. Perhaps I should try to download one of the best and sharp , over 2MB photos from the internet and try that on my TV. Does the process to download to the TV matter? or it does not matter as long as they are a JPG files? It sounds to me like you are basically displaying in TV mode - probably analog TV mode - which is simply not high resolution. Suggest you use a high def or computer monitor interface. You may not be able to do any better. The key here is "I just copied the JPG files into a CD and use a DVD player attached to the TV." If that is not a Blu-Ray DVD player attached via HDCP then it is likely not capable of sending more than standard analog broadcast resolution to the TV. With regard to "They just do not show sharp photos that I always see at the TV stores when they display the TVs. Are they using high MP photos? ", they'll either be using a DVI/HDMI input from a PC or an HDCP input from a blu-ray player or HDTivo or the like. -- -- --John to email, dial "usenet" and validate (was jclarke at eye bee em dot net) |
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Need help in calculating digital camera's MP
On Fri, 2 Jan 2009 16:41:40 -0500, "J. Clarke"
wrote in : The key here is "I just copied the JPG files into a CD and use a DVD player attached to the TV." If that is not a Blu-Ray DVD player attached via HDCP then it is likely not capable of sending more than standard analog broadcast resolution to the TV. DVD resolution is quite a bit higher than analog broadcast resolution -- many DVD players have progressive scan component output, quite a few with scan doubling, and some are capable of upscaling to HD resolution. -- Very best wishes for the holiday season and for the coming new year, John |
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Need help in calculating digital camera's MP
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#16
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Need help in calculating digital camera's MP
David J Taylor added these comments in the current discussion du
jour ... .. although a "normal" 4:3 aspect ratio camera needs to be 1920 x 1440 pixels to at least match the display resolution horizontally (i.e. 2.76 Mpix), and it would be helpful to have some crop margin for those times when your framing isn't perfect , so say 5-6Mpix. Leaving the question, are any current cameras less than 5-6Mpix? David, we've had this discussion ad nauseum, namely is "more mega pixels better images" or not. You are obviously correct that few cameras other than toys are less than about 6 MP but that hardly means they are all created equal. -- Jerry, aka HP "If you are out of work and hungry, eat an environmentalist" - Florida billboard |
#17
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Need help in calculating digital camera's MP
David J Taylor added these comments in the current discussion du
jour ... There's another reason for using more pixels. In the display, each of the pixels is an RGB triple, i.e. a full colour pixel, whereas in the camera each pixel is either red, green or blue. So to match the display resolution, you may need more pixels in the (Bayer) camera than are on the display. I don't know if any tests have been done to check what the actual ratio is, but I recall that the Foveon sensor is reckoned by some to be equivalent to something like twice the number of pixels. Huh?! How does the way a camera "sees" a pixel translate into how a TV sees one? Or, a PC monitor? 16 million color requires 3 bytes per pixel, of course, but how does this matter to a TV? Isn't it far more important how the TV system that reads digital images from, say, it's memory card slot, depend on how well it fills the screen from whatever it is provided? I therefore revise my estimate to, for a 4:3 aspect ratio camera 2 * 1920 * 1440, i.e. about 5-6Mpix, resampled and cropped to a 16:9 1920 x 1080 ready-to-display image. True enough but my Canon DSLR creates 3:2 images. But, whether a camera is 4:3 or 3:2 or something else, to get all the way to a 16:9/16:10 aspect ratio also requires the photographer to be VERY aware of how they must crop their images or something important will likely be lost. -- Jerry, aka HP "If you are out of work and hungry, eat an environmentalist" - Florida billboard |
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Need help in calculating digital camera's MP
John Navas wrote:
On Fri, 02 Jan 2009 20:04:19 GMT, "David J Taylor" [] The LCD TVs I've seen are quite capable of pixel-level resolution, John. Brand and model please. All I have tested, when fed from the computer input. Examples: Logik L19LID648 Samsung LE26R74BD David |
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Need help in calculating digital camera's MP
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#20
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Need help in calculating digital camera's MP
nospam wrote:
In article , David J Taylor wrote: There's another reason for using more pixels. In the display, each of the pixels is an RGB triple, i.e. a full colour pixel, whereas in the camera each pixel is either red, green or blue. So to match the display resolution, you may need more pixels in the (Bayer) camera than are on the display. I don't know if any tests have been done to check what the actual ratio is, but I recall that the Foveon sensor is reckoned by some to be equivalent to something like twice the number of pixels. the foveon fans come up with their own math to justify the sensor's existence. it's often hilarious. i've seen everything from 1.4x to over 3x, with some even claiming infinite resolution, depending on how creative the (misinformed) zealot is. the main difference is not the co-located layers, but rather the false detail from the lack of an anti-alias filter and heavy sharpening in the raw processing. Yes, it was the only closely related comparison I could think of at the time, and has unfortunate connotations for the photographic community! Perhaps the 3-CCD video camera would have been a better comparison, but there you have alignment issues between R, G & B which are not issues for a LCD screen. I'll accept a factor of two until I see a more reasoned (and perhaps empirically-tested) value. David |
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