High resolution pics on web.. how??

[Eyad]

Hi All,

Many photography websites I've seen contains Hi-Res photos with -somehow- quick loading time.

Would that be achieved by lowering the dpi of the pic to 72 or simply by resizing the image and lowering the quality?

Thanks..

[wulf]

The factors to consider are firstly the size of the file and secondly the size of the "pipes" it must pass through.

The first is in your control. File size depends on file dimensions and the type and amount of compression used. You can save copies using different settings and decide on what is an acceptable compromise for your application.

The second is much harder to control. You may have paid for a hosting service that guarantees to quickly serve up the images but there are other bottlenecks - the visitor's ISP, their networking and computer hardware and the random factors of what else is going on round the Internet.

Wulf

[private]

I can tell you what zenfolio does - when you upload your high res file, they make a copy of it and that is what you see on the web. If you want to buy the high res file or print a photo they use the "stroed" version of the original file - at least that is how I understand it.

[fletch]

In some ways the two are a bit at odds. The bigger the size of the file the slower it will be to download. Higher resolution pictures are normally larger files.

Therefore the sites that display 'high resolution' files very quickly either are actually loading more slowly, just not so much that you will notice, or they will not actually being showing high res files, just stating they are available (as private says Zenfolio do)

[OsmosisStudios]

Preloading.

It's possible to have the page load an image in cache in the background while youre viewing the page. You click on the link, all the browser has to do is read the (local) cache and TADAA! High res in a second or so

[Eyad]

Ok, so basically these files are not so Hi-Res.

I agree on the caching technique, but it depends on the website if it's programmed to cache the pics before you view it.

Anyway, I'll just try on different sizes/ resolutions and see.

Thanks for all who contributed

[wulf]

Preloading a lot of large images is a dubious tactic. It forces people to receive data they may not even look at. From a development point of view, it makes some sense when the visitor only has a choice of a couple of pictures (eg. next and previous... and previous may already be cached on the client side) but not when presenting a gallery of thumbnails. If the visitor has a generous enough connection that it won't bother them it won't take long to load the images directly; meanwhile it will make a big saving on your hosting bandwidth.

Wulf