I would say that it all depends on the size of the picture files, and whether you are showing them one at a time or not. Basically, a computer screen is a low resolution device. So a decently quality JPEG or PNG, sized and optimized by a graphic application to be the correct height and width looks just fine. If you try and show a big high resolution graphic on the screen, expecting the browser to downsize it, then you're just wasting people's time. If you show anything except properly converted and sized thumbnails in a list type view, then same.
In other words, it's not really the number of pictures that slow things down. It's that they have not been properly prepared for screen viewing.
I have read that storing the pictures as files, then allowing the web server to reference them, as it would normally in an HTML page (common in Custom Web Publishing), is likely faster than embedding in FileMaker (most common in IWP). I don't really know. But if you size the pictures appropriately, I think either is OK.
I have a similar situation. I have about 5,000 labels.
What I did is create a website that is accessed through the webviewer to upload and show images.
This is the most simple way, as this will allow any user to see the images without having to worry about mapping drives to the folder with the images.
While I hate to "plug" plug-ins.... the company I work for had a similar issue with images and other documents.
Using the SuperContainer plug-in (360 works) has solved all our issues, works great, is easy to manage and was easy incorporate into our solution. We currently have 9,046 images/documents in our system. Prior to supercontainer they were stored in container fields (because only linking them has other issues i.e.. broken links) and this was slowing down our solution and creating an HUGE file size (they were stored in their own file... but it was massive).
SuperContainer was a lifesaver - we've been using it for 2 years now. :) And no, I don't work for 360 works.
I want to thank you all for your sejestions, I tried a few options first creating folders to store them in the server and some times people decided for some odd reasons to rename the folders and that created broken links. Then I tried to store them in the FM by creating 8 diffrent files and linking them with container fields, a file for pic 1, pic 2 ects, I thought this way I could spread them out, but they all still needed to uplode in the record that combined them. Supercontainer is my last solution, I just got it and it does help out big time.