Product images sizing fix

[atomicshinji]

Is there a way to set a fixed size for the main product images and the sub-images on my Shopify store (dawn theme) without losing image quality? I want to ensure that all images have a uniform appearance but still retain high resolution.

here's the link - https://1bc201-61.myshopify.com/products/knife-kniz6-retractable-hd-trimming-w-holster-blue
password: eashal

Thank you for your assistance!