If the images in your Batch are too dim, you can open them in the main editor and lighten them using the Light on feature. You access the main editor from the Batch Editor and when you exit, you can choose whether to apply the improved lighting to all images in your batch.
Steps (Web App)
Create a new batch or work with the batch you already have open.
Open a dim image in the main editor:
Select the image
Select its context menu and then Edit.
Select the foreground layer and activate Light on to improve the light in the image.
Exit the editor to return to your batch.
Choose whether to apply the changes to all images in your batch.
Learn how to use Light on
Light on for batch images works the same way as editing individual images outside of a batch. Learn how it works in Improve the lighting of a design (Web App) . The important difference in Batch is that that when you exit the main editor, Photoroom asks whether you want to apply your changes to all images.