Exporting images for TV viewing

Swatcher

Swatcher

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Evenin' all!

I am new to the world of digital photography and have been wondering how best to "print" my RAW images. If I export without resizing, my images end up around 10MB each from an original of 21MB. This is pretty big so I don't really want to make a habit of it if I don't have to. All they need to be is big enough to display on large computer monitors (1600 high seems the largest around at the moment) but also on TVs. This is the bit I'm not sure about.

Has anyone any experience of what dimensions would provide tolerable quality on both a CRT and plasma TV?

Thanks for any suggestions.

Regards,
Swatcher
 
Swatcher said:
Evenin' all!

I am new to the world of digital photography and have been wondering how best to "print" my RAW images. If I export without resizing, my images end up around 10MB each from an original of 21MB. This is pretty big so I don't really want to make a habit of it if I don't have to. All they need to be is big enough to display on large computer monitors (1600 high seems the largest around at the moment) but also on TVs. This is the bit I'm not sure about.

Has anyone any experience of what dimensions would provide tolerable quality on both a CRT and plasma TV?

Thanks for any suggestions.

Regards,
Swatcher
Click to expand...

Resolution for a CRT TV is 720 x 576 for PAL and 720 x 480 for NTSC. Not very high res at all!

1080p TVs need 1900 pixels x 1080 pixels. (2Mp images)

Some HD TVs are 1368 x 720

So depends on the TV you are looking at displaying the images on.
 
Thanks, people, that's exactly the kind of info I was after. Much obliged to you. All the best, Swatcher
 
I've been round a couple of manufacturers' sites and have some follow-up you may find interesting. This is not at all comprehensive so there may be exceptions or further developments.

The largest 16:9 monitor I've found is 27W (31" equiv). Being HDTV-ready its pixel height is still only 1080.

Compare this with 1600 on 30" 16:10 monitors. 60% more pixels! Worth the cropping.

If nothing else it has made me think twice about buying a 16:9 PC monitor - or a big one at any rate. I wonder which way the market is going and whether 16:10 monitors will get even bigger.

So I suppose the answer to my question is that there is no need to store any image for on-screen viewing greater than 1600 pixels high. At the moment.

Thanks again for the contributions and pointers.

Swatcher
 
Oh really?! I hadn't thought of that but it makes perfect sense now you mention it.

I wanted to avoid stretching when displaying but I suppose this is okay for small differences and, as you say, you'll be viewing from well back.

Thanks, Chaz,
Swatcher
 
The issue about image size and viewing distance extends to prints too.

The optimal viewing distance for prints gets larger as the prints get larger. It's quite easy to show that, no matter how big you want to print, you never need more than about 6 Megapixels to make a print which will always look sharp when viewed from the optimal distance.
 
Hi Stewart. Oddly enough, we were discussing the very same thing last night, that there must be a maximum dpi per "apparent" inch, i.e. that whether you're looking at a big or a small image, you will always prefer to stand at a distance that reduces them to the same apparent size. We tried this and, of course, it is impossible to take it all in when you're constantly having to flick your eyes about. Being of a technical and theoretical bent (as well as artistic, I hope!), I wouldn't mind finding out a bit more about the details you refer to. Is there a link to anything that demonstrates how this works, like a diagram?

In the meantime, thanks for the figure of 6Mpx. The picture is becoming clearer (sorry...)

Swatcher
 
Swatcher said:
Hi Stewart. Oddly enough, we were discussing the very same thing last night, that there must be a maximum dpi per "apparent" inch, i.e. that whether you're looking at a big or a small image, you will always prefer to stand at a distance that reduces them to the same apparent size. We tried this and, of course, it is impossible to take it all in when you're constantly having to flick your eyes about. Being of a technical and theoretical bent (as well as artistic, I hope!), I wouldn't mind finding out a bit more about the details you refer to. Is there a link to anything that demonstrates how this works, like a diagram?

In the meantime, thanks for the figure of 6Mpx. The picture is becoming clearer (sorry...)

Swatcher
Click to expand...

Just remember that dpi (actually it should be ppi as images are measured in pixels per inch) is only used for the resolution of a print at any given size.

If you output the images to the maximum screen resolution (1920 x 1080 for a high def TV) then pixels are mapped 1:1

The ppi value means nothing. PPI is ONLY used to measure the resolution of your final print.

For prints, look at huge bilboards - many are printed at VERY low ppi values but because viewing distance is great, you don't see the dots in the final print unless you look up close. I print my A3 images at around 150-180 ppi and most smaller images at 240-300ppi.
 
I've just had my calculator out and both sets of figures you quote, EOS_JD, give pictures containing around the 6Mpx mentioned by StewartR. Confirmation doesn't get any more independent than that! Seems that our perceptions are more in common than we're sometimes led to believe, although beauty will remain strictly in the eye of the beholder.

Right, that's enough philosophising for now. And maths.

Just speculating here at the risk of taking the point too far, but would having too great a resolution give you that lack of "sharpness" that I sometimes feel HDTV pictures have? At at any rate, a less hard image and not so satisfactory in some way. Not sure I'm explaining this well but it's maybe like the difference between CD and vinyl.

Gotta go, F1's on!
 
Swatcher said:
I've just had my calculator out and both sets of figures you quote, EOS_JD, give pictures containing around the 6Mpx mentioned by StewartR. Confirmation doesn't get any more independent than that! Seems that our perceptions are more in common than we're sometimes led to believe, although beauty will remain strictly in the eye of the beholder.

Right, that's enough philosophising for now. And maths.

Just speculating here at the risk of taking the point too far, but would having too great a resolution give you that lack of "sharpness" that I sometimes feel HDTV pictures have? At at any rate, a less hard image and not so satisfactory in some way. Not sure I'm explaining this well but it's maybe like the difference between CD and vinyl.

Gotta go, F1's on!
Click to expand...

Yes I'm watching the f1 here too :) Even although I'm a Scot I want Jensen to do well - C'mon Button!!!


Anyway you should not see any less quality with more pixels? Will be down to the individual panel you use.

To view images on an HDTV, you only require 2Mp images - 1920x1080 = just over 2 million.

For print though yes around 6-8Mp will allow you to print pretty much anything at great quality. Higher MP cameras though allow a lot of cropping :)
 
Great drive, Jensen. What a race!

Regarding the matter in hand: 2Mp for HDTV, thanks, I see that now. I'm surprised how low some of these figures are but, as I now know, it's in the distance.

I really appreciate all this help and advice I've had from all of you so I'm telling everyone how great you are. All I need to do now it get on with it myself!

Cheers,
Swatcher
 
Swatcher said:
Great drive, Jensen. What a race!

Regarding the matter in hand: 2Mp for HDTV, thanks, I see that now. I'm surprised how low some of these figures are but, as I now know, it's in the distance.

I really appreciate all this help and advice I've had from all of you so I'm telling everyone how great you are. All I need to do now it get on with it myself!

Cheers,
Swatcher
Click to expand...

Once you understand it, creating your images for output is much easier :) Good luck

Yes well done JB What a race :)
 
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