Digital image size for local and regional camera clubs

1024x768 images are fine for computer screen, though we know that even then some sharpness and detail can be lost. It seems hopelessly small for projection to screen in halls etc, as equivalents or alongside colour slides.

Newent camera club, which I prefer of our 2 local ones allows one to submit at 1600x1200, the max resolution of the projector used (and calibrated etc with considerable trouble). Images end up 700-1100kb and show well, and as everyone comments, making the slides look a touch on the dull side when shown just after.

Beacon, the other club only allows 1024x768, apparently because the Midlands whatever it is likewise does.

It strikes me we are heading towards poor use of the available technology.

Does anyone else have experience of local rules and the results, or any way influence can be directed?

[Joe]

Industry standard for newsprint photos is 300dpi....With a max data size of around 1mb. Any greater, all that happens is FTP transfer takes more time for "no great benefit".
Is a shame when technology is capable of far greater.

1024x768 images are fine for computer screen, though we know that even then some sharpness and detail can be lost.

Are they keeping the size requirements low to encourage more people to enter? By reducing the photo sizes some photos can be made to look sharper and smooth over digi noise....Has been a while since attending a local camera club. Can remember at the one I once went to, they had two print competitions running side by side. One was for 'professional' prints ie done by a lab, the other was for 'home done' prints......colour accuracy and rendering was judged differently for the two.
Maybe a similar principle can be applied here, perhaps?

[Derekb]

Up here in Yorkshire the rules stipulate 1024x768 maximum for most of the club/interclub and county competitions. Never had a problem other than our clubs crappy projector will sometimes render the images too dark.

[Gidders]

Our club specified 1024 x 768... because thats the resolution of our projector so anything greated has to be downsampled somehwere to project.

Untill higher resolutions projectors become universally available, there seems little point

[robski]

1024 x 768 ( XGA 4:3 screen aspect ratio ) appears to be a common native resolution for many of the digital projectors. Most will re-sync and re-sample to other display standards. There are also some 1280 x 720 ( 16:9 screen aspect ratio ) intended for wide screen format images.

This link is quite informative on the workings of Digital projectors.

http://www.christiedigital.com/AMEN/...Resolution.htm

So Chris I doubt you are truly seeing the full resolution of 1600 x 1200

On the subject of photos for Newsprint, a field in which I am currently employed. The photos are not printed at 300 dpi. A printing press cannot print continuous tone images that you see on the computer screen. The images are re-sampled to produce what is called a halftone. A complex subject but in essence a range of different size dots to represent the different levels of colour.

The limits of the human vision system is said to be about 7 lines per mm or 180 lines per inch. To avoid beat frequencies and moire in the halftone re-sampling the input dpi needs to be at least double the output dpi (in halftoning the term lpi (lines per inch) is used instead of dpi) dpi is reserved for the resolution of the laser scanner that produces the printing plates.

So a 300 dpi photo you submit could be printed using a 150 lpi halftone typically used in high quality glossy magazines. Halftones typically around 100 lpi are used for your newspaper depending on the grade of newsprint paper and press used.

Originally Posted by robski

1024 x 768 ( XGA 4:3 screen aspect ratio ) appears to be a common native resolution for many of the digital projectors. Most will re-sync and re-sample to other display standards.
So Chris I doubt you are truly seeing the full resolution of 1600 x 1200

thanks Robert - I am sure you are on top of the technics. Just 2 observations
(a) it is a small friendly club and we did quite a bit of experimentation last season before putting 'projected digital' as acceptable alternative to slides and judged along side them. The 1st few trials showed some weak colour, which the Spyder calibration seems to have cured.
(b)The software/projector happily seems to munch whatever is thrown at from some folks who put in full size .jpgs of 2500k ±

I settled for 1600w x 1200max h as that is the nominal projector resolution probably UXGA on your site (thanks for that too) AND the image size of 1000k ± seems a reasonable one to get enough info onto a big screen. I doubt that the 700k maximum for a 1024x768 reduction does?

The previous 'king' of the slide section is now doing some rapid homework on digital!