A photography website should give the pictures room to breathe without asking every visitor to download the original files. I start with how each image is displayed: a thumbnail, a wide introduction and a full-screen viewer have different jobs.
The useful target is a convincing picture at the size somebody is viewing it. The smallest possible file is not automatically the best result, and a larger hosting plan will not fix a page that sends needlessly large images.
Keep the original separate from the web versions
Retain a recoverable original and generate web-sized versions from it. That gives you a way to change compression, crop or format later without repeatedly editing an already compressed file. Check that your backup actually includes whichever storage location holds those originals.
Use a few purposeful sizes rather than generating dozens without a display requirement. A gallery grid needs a suitable thumbnail; an opened photograph may need a larger version. Match the output to the layout and check portrait as well as landscape images.
For commercial work, decide separately whether visitors should be able to obtain original files. A public portfolio preview and a client delivery area are different products.
Send the right size for the layout
Responsive image markup lets the browser choose between available files. The layout information must describe the real rendered size: otherwise the browser can choose a larger download than the design needs.
Check the chosen image in the browser’s network tools at a narrow viewport and on a larger screen. Look at the downloaded file, not just the dimensions shown in your media library. A small thumbnail on screen may still be loading a very large source.
Preserve width and height information so the page can reserve space before the image arrives. Then inspect faces, fine branches, text and gradients at realistic viewing sizes. These reveal quality problems that a quick glance at a reduced preview can miss.
Prioritise the opening image
Images far down a long gallery can usually wait until the visitor approaches them. The main image already visible on arrival should not be held back by lazy loading. Browser performance guidance specifically warns against delaying an image that determines the page’s Largest Contentful Paint.
Do not give every photograph high priority. Identify the image that matters for the opening view, then measure what happens. Loading a lightbox’s full-size collection before anybody opens it can undo the saving from carefully prepared thumbnails.
Test a fresh visit with a slower connection profile, and then test a return visit. A warm cache can make an inefficient first visit look healthy.
Make image changes recoverable
Before regenerating a large library, try a small representative set. Check that pages use the new versions, older links still behave as expected and the originals remain available. Record the settings so another batch can be reproduced.
If you use a CDN, verify the delivered file and its cache behaviour after a change. A successful upload does not establish that visitors are receiving the new version. Use the normal invalidation or versioning process rather than repeatedly uploading the same file and guessing.
My final check is visual as well as technical: does the page open promptly, stay steady while loading and still show the detail the photograph needs? Good delivery supports the work instead of becoming the thing the visitor notices.
Further reading: responsive images and Largest Contentful Paint guidance.