The pics you click on? You could start with pictures with better resolution, what dpi are they?

yes, its the image you can click on, the DPI is correct 72 for monitors, if you click on the image its ok, the problem isn't the resolution, but the compression that Wordpress makes on the images, do you know how can I solve this? thanks.

Did you try to edit the css for the fancy box?

What should I change in the css to make my images more clear? thanks.

You will need to upload a larger image. Your current images are too small and being stretched to fit the size.

Hi, i have put a much bigger image (1500 x 560 px.) but it keeps happening the same, tha image from the "fancy box" is still not clear, any other ideas? thanks.

The full-size image looks perfect. The problem is the image size for the thumbnail is in-correct and stretching it (Not your fault).

Edit your portfolio-1.php file:
Remove this specific area of code and it should fix the problem:
width="696" height="220"

This will ensure your image isn't stretched but renders correctly like so:
http://www.merida360.es/wp-content/uploads/2012/05/puente-lusitania-slider-638x200.jpg

Your full-size image looks fine as well:
http://www.merida360.es/wp-content/uploads/2012/05/puente-lusitania-slider.jpg

Ok, it works, thanks
if the previous problem didnt have a solution (http://support.progressionstudios.com/discussion/502/full-width-slider-with-link) , what theme you sell have that option
(Head with external link)?

Our Adora theme has a full width slider and allows linking by the featured image. The only time we limit this is if the slider on-click function sends to the next slide. You could create a work-around positing a block div over the slider, but it's not something we bundled in our the theme as it's not ideal.

hi, i deleted the labes you said to me and the problem was solved during some time but now it has come back and its all like before, any other idea? thanks

The width and height are still there. Just view source after making changes to see if they are working. The theme won't reset itself, so the change was not made. Make sure you are using an FTP program to update this as some hosting providers block the use of the WordPress Editor.

Just view source on the page after making the changes to ensure the width/height have been removed.

Ok, it works, thanks ;)