Yes we do understand the issue that you are trying to explain, and actually the code we have provided works for the resolution of the issue itself.

The theme has registered different range of image sizes that is used in the theme in different places, With the layout you have selected for the Work section the default “business-page-plus-work” image size pulls smaller image size, hence making it blurry.

To resolve the issue you can try using the code we have provided that will; pull the “full” size image for the section and resolve the blur issue.

You can also replace the “full” parameter in the wp_get_attachment_image_src( get_post_thumbnail_id( $post->ID ), 'full' ); function in Line : 162 of the code we have provided to any registered image size in the theme of your choice.

If you have any queries further, please feel free to write back to us.

Hope this Helps,

Best Regards !!

The issue is the image being resized to a bigger size than its original size so it blurs to avoid pixelation.

In the page I sent, the images are all 275×175 (http://www.appy.co.ao/wp/wp-content/uploads/2017/08/Banner-RECOLHA-275×175.jpg) but they are resized to around 360×229, thats 30% the original which is a lot.

Browsing the files I see there are many more different thumbnail sizes including 360×270. How can these be used instead?

The work section crops the image . So if you want to display the full image size you have to activate the child theme .

You can even activate the child theme using the plugin given below :

https://wordpress.org/plugins/wp-child-theme-generator/

After activating the child theme in your child theme create the folder sections . Then create the file section-work.php inside the folder sections. Finally paste below given code in your section-work.php file .

https://gist.github.com/anonymous/256f12b3eabafd4f531efc4362011a4a

Hope this helps .

Best Regards!!

Can I change the thumbnail image so that its size is the same or at least reduced so the images are sharp?

Refer to this page:
http://www.appy.co.ao/wp/#work

Glad we could help you !!

If you have any issues further, please feel free to post your queries and we will happily help you further.

We will really appreciate if you could help us too by rating our theme in WordPress repo here:-

https://wordpress.org/support/theme/business-page/reviews/

Best Regards !!

To remove the top filter in our work section use below given CSS.

For this go to Admin Panel > Appearance > Customize > Additional CSS and paste below given CSS.

.work-section .portfolio-gallery-menu {
    display: none;
}

Hope this helps .

Let us know if you have any confusion further .

Best Regards!!