Exporting a hundred photos with one preset does not give them identical file sizes or visual quality. A clear sky may look clean with little data, while fabric, foliage, and dark texture need more detail. Start with a small trial set that spans the files you expect to export.

Include easy and difficult images

Choose a landscape, a portrait, a dark frame, fine line art, and a saturated photo. Include a small source if the dimensions vary widely. Note what you will look at in each image. Eyes, shadows, and skies reveal different kinds of problems.

Keep output separate from the source

Use a trial folder away from the originals. Record dimensions, format, and quality. Check that small files are not enlarged unintentionally, vertical photos have the correct orientation, and transparent images have the intended background. Change one setting at a time.

Read the extremes as well as the average

Sort the results by file size and open the largest. If one file approaches a limit, handle it as an exception instead of compressing the entire set more aggressively. Look for artefacts at 100% and readability at the intended display size.

Sample the full output

After the job finishes, match the number of outputs to the number of inputs. Check for naming collisions and open a few files from the beginning, middle, and end. Keep a short note with the trial settings and exceptions so you can repeat the decisions on the next batch.

Group the images by content before comparing averages

A batch of fifty product photos might contain forty plain backgrounds and ten close-ups shot in darker conditions. The plain images may compress well enough to hit the overall size target, while the darker pictures lose fine marks. An average cannot show which group suffered. Sort a sample by intended use and difficult content. Include lettering, hair, grass, transparent edges, dark material and smooth gradients where they exist. Open each sample beside its master in the same viewer. If one group has a problem, test a separate export for that group before increasing the settings for the entire batch. This keeps files that need to stay light from growing unnecessarily. Organise the output so the file and the settings used to produce it can be identified together. Let reviewers see samples at the intended size. If a difference only appears at extreme zoom, consider the delivery purpose. It may be irrelevant for a tiny card and significant in a print or a detail view.

Inspect the output folder before delivery

Compare the source and destination counts when the export ends. Equal counts can hide a repeated file and an omission. Look at the names and at the smallest and largest file sizes. Open the first and last images, then a sample from both size extremes. If several formats are present, open one of each, including a file that must preserve transparency. An unusually small file may be simple, but it could also have been resized too far, cropped or replaced by the wrong item. Open it before deciding. If you find a defect, identify the group that shares the same setting. Check those files and export a replacement from the master. Keep the new delivery in a separate version folder so the recipient can tell which set to use. Decide how long you need the previous set for comparison. In the final notes, record the most demanding sample, the chosen settings and the accepted output. That gives the next batch a useful benchmark.