|GG| Need help in calculating digital camera's MP

wrote:
For a 46 in high definition TV (1920x1080 Panel resolution) - 1080p
Full HD definition, the screen size of the TV is 40 in. x 23 in. ( 102
cm x 58 cm). How many MP digital camera that I need to have JPG
photos, so that I can watch clear, sharp, crisp JPG photos on the TV?

Common aspect ratios:
16:9 = 1.77 HD video
8:6 = 1.6 Widescreen LCD
3:2 = 1.5 DSLR
4:3 = 1.33 Compact digital
10:8 = 1.25 8x10" print

Computer wide screen monitors are taller than they need to be:
1200x1920 1:1.6
1080x1920 1:1.7
Compact digitals are a 1:1.3 aspect ratio (4:3)
If you aren't going to crop to fit the screen and it's only 1080 high,
there will be considerable wasted space on the sides:
1080x1404 = 1.5MP
If you do crop and the screen is 1200 pixels high:
1476x1920 = 2.8MP

Digital cameras have an anti-aliasing filter which blurs the image some
to avoid moire patterns on striped detail so you can get a considerably
sharper image by reducing to around 50% so:
2952x3840 = 11.3MP

Maybe that's overkill but not far off. If you are just turning down the
capture size for your camera, you will get this advantage. Full size
pixels are definitely less sharp than if you reduce some. A 3MP native
image will be noticeably softer than a 10MP image reduced to fit.


I must admit that I don't have much knowledge about the pixels in
digital cameras,etc. and how that translates into the high definition
TV. Therefore, I do need practical, layman terms answers for info or
links to specific discussion to any websites.
What about for the 52 in. TV, 56 in. TV, etc?. Is there a chart
available somewhere?. I recall a table showing how MP is connected to
photo print sizes (at the photo printing stores). But this screen size
is much larger than those listed - perhaps more for poster sizes.
Someone may ask on how close you are watching the TV screen... and I
am thinking about relatively close range, say 5 ft distance.
Thanks for the info!

--
Paul Furman
www.edgehill.net
www.baynatives.com

all google groups messages filtered due to spam

On Fri, 02 Jan 2009 13:14:05 -0800, Paul Furman
wrote in :

Compact digitals are a 1:1.3 aspect ratio (4:3)

Many, but not all.

Maybe that's overkill but not far off. If you are just turning down the
capture size for your camera, you will get this advantage. Full size
pixels are definitely less sharp than if you reduce some. A 3MP native
image will be noticeably softer than a 10MP image reduced to fit.

Depends on the cameras. There are 3 MP cameras that are noticeably
sharper than some 10 MP cameras.

"All generalizations are false."

--
Very best wishes for the holiday season and for the coming new year,
John