Recomended image specification/size for product images

[baggeler]

Our photographer is right now photographing all products and in the process of editing the images.

Whats the optimal/recomended size/format/configuration(s) he should process and save all the images so they are all ready to upload for virtuemart shop and need no further editing?

[jenkinhill]

Ideally for VM images uploaded should be at the largest size required on the site, as this uses less bandwidth. This will be dictated by he image used in the product details litebox, or as required by an image zoom plugin if used. The largest I normally use is 600px wide (or 600px high) jpg.

I hope you are not using those old J/VM versions listed in your sig!  http://forum.virtuemart.net/index.php?topic=118683

[AH]

Larege banners and scrolling modules will have a big impact on your page load times, the singel product image will often be a small aspect of a page laod speed.

Of course optimise the size and compression method - but not at the cost of displaying your product and making it easy for a customer to know what they are getting.  Poor quality and small images will kill your sales!

It really depends on your product range.

Type and visual complexity of item may lead to more than a single image images per item

JPEG's are smaller in size when optimised for web, but your background has to be solid.  550 x 550 max for me. I use a mouse over zoom for product detail page to allow for a sensible image size and placement.
The compression technique will depend on the software utilised (I use photoshop and the imageready component)
Transparent PNG's are much larger in size and give longer load times.

Your big hit will come on large category pages, where lots of images are loaded.  So watch out for the size on such pages.

You may be able to use google's lazyload script to manage images out of the web viewing port (but I have not used this so cannot commment on the benefits/negatives)

[baggeler]

I am still a little confused about image sizes. So let me sumarize what I understand by now and where I need clarification:

If I upload the images all 600 px wide (seems pretty large picture to me) will Virtuemart create/handle all the smaller picture sizes for thumbnails, etc. based on them or do I need to upload separate pictures?

600 px seems very large to me and would be completely overloading the product details image (which I am forcing to a size of 350px acording to another thread here). Is that really the product detail image size you are recomending to use or can Virtuemart downsize the image to a more convenient size on the product detail page (Is 350 px apropriate, too big or too small for that?).

I think in fact there are 2 questions, one is about ideal UPLOAD size (from the answers I got until now I assume this to be around 600 px wide) and the second one which to be the ideal PRODUCT DETAIL IMAGE SIZE (and how to best configure this if not = upload size)? 

Thanks in advance