I recently replaced a ten year old photography site with about 4,000 pages with a new wordpress site. The new site consolidated a lot of duplicate pages and also I removed old content that really wasn't being requested. The new site shrank to about 1,500 pages...so 4,000+ pages redirected to a smaller number of pages. The overall effect was a fairly big drop in organic search traffic of around 13% due to the amount of pages that were removed. They may have been dupes, but they were all effectively made to look different with varying titles and descriptions. The smaller overall amount of content and internal links in the site had a big effect, with some landing pages losing up to 80% of their traffic...others shot upward though.
An even worse effect was a massive drop in image traffic. I did not redirect another 4,000+ images as my .htaccess file was already huge with the list of 301 redirected html pages. Also, all of the images changed and were made newer, larger, watermarked with new branding and had a different file name. From everything I read Google will simply not see the new file as the same image and will just drop the old image from the index anyway. Because of the way the old CMS handled image urls with dynamic url strings it was impossible to copy the old iimages with the exact same filename to the new site. So I simply wrote one rewrite rule to grab the referral string and rewrite it to the new filename and then the old image could be found on the new site. This didn't really work and I have lost about 85% of my image traffic, which contributed to another 25% decline to my total traffic. On top of this Google's update around the 1st of October seemed to hit the new site hard and it took another big drop down and has stayed there this entire month.
As far as I can tell, the old images had a lot of links coming in and this has dropped my positioning dramatically. I am wondering how to recover those links to images and forward them to new pages or images? It's been a month and a half, is it too late already? Thanks for any advice!