Unfortunately, the Tamron 18-300mm f/3.5-6.3 Di III-A VC VXD is not as good as expected when paired with the 40-megapixel sensor on your X-T5. I had issues with severe corner softness and chromatic aberration at the long end. That high-res sensor really demands better glass. For Italy, you should grab the Tamron 17-70mm f/2.8 Di III-A VC RXD. The constant f/2.8 aperture is a lifesaver for dim historic buildings, and the optical rendering is way cleaner. If you want me to explain the MTF charts or diffraction limits, just ask. Ready to help you figure out the technical side so you get the best shots.

Honestly, I had really high hopes for the Tamron 18-300mm f/3.5-6.3 Di III-A VC VXD, but it was unfortunately not as good as expected. That 40MP sensor on your X-T5 is just so demanding... I had issues with significant softness at the long end and it just didn't feel sharp enough. If you want crisp shots of Italian architecture, it's probably gonna let you down. I'd suggest looking at the Tamron 17-70mm f/2.8 Di III-A VC RXD instead. It doesn't have that crazy long reach, but the constant f/2.8 aperture is huge for dimly lit cathedrals and narrow streets at dusk. The image quality is a massive step up from the superzoom. You basically trade that long zoom for much better clarity and low-light performance, which matters way more for travel photography imo. It's a bit heavy tho, but the results are worth it for those once-in-a-lifetime shots.