Thumbnail problems

[Miff]

I have been uploading all product images at 500px as my biggest length. The image looks great when i click larger image but the thumbnails look fuzzy. What is realy stranging me out is that when i use google chrome browser the images are fine, its just when i use IE9 or Firefox ...
I used a 15" laptop with IE8 installed and this also looked fine. This is obviously nothing to do with the images themselves but something to do with how the browser is rendering the image.
I tried creating differently sized images with _LGE prefix and shrunk my main image to thumnail size and they look great on all browsers then but when customers click larger image the same thumbnail sized image appears? Instead of my larger image appearing when this is clicked it appears underneath my advert in the same position as when you add similarly named images.
I would prefer to use zens automatic image sizing from a larger image if possible but this seems as though it will not work correctly with all browsers. If creating thumbnail sized main images and then adding the larger version with the _lge prefix is the only option to completely fix this could anyone offer any help as I cannot get this lkarger image to appear when the thumnail is clicked rather than displaying underneath as a poor quality thumnail (again) but looking great when clicked and the large image is displayed.

[kobra]

If creating thumbnail sized main images and then adding the larger version with the _lge prefix

That is a sufix and should be _LRG
Note capitalization and you can & should create a _MED

Tutorial should assist
https://www.zen-cart.com/tutorials/i...hp?article=224

I would prefer to use zens automatic image sizing from a larger image if possible

ZenCart does not have this facility by default
There is a 3rd party module for this "Image Handler II" in the free software add ons area