because my miniatures are seen all grainy and badly I leave my site look, the other around my site you can see very well with stretched identical pictures.
Thank you all for the help
the site where the thumbnails of the galleries are seen evil is www.effe8fotografia.it
It may depend on the latest version 1.3.33, on the other my site www.danielemauro.net thumbnails of the gallery can see very well and I have the 1.3.31 version of photo gallery

Hello Daniele!

Thank you for posting about this problem!

Unfortunately we could not find a thumbnails gallery on your websites, but let me post how this issue should be resolved. You can change the thumbnail size by changing values of Generated Thumbnail Dimensions and Frontend Thumbnail Dimensions options.

Generated Thumbnail Dimensions can be found under Photo Gallery Options > Global Options > General tab. It defines the physical size of thumbnail images. Whereas Frontend Thumbnail Dimensions is its display size, and it is under Shortcode Defaults > Thumbnails tab.

It is important to keep frontend dimensions smaller than generated dimensions. After making these changes you need to click Recreate to have a nice resolution for thumbs.

Afterwards edit your gallery page and make sure Image thumbnail dimensions is set to the desired size.
Thanks! Have a wonderful day!