Importance of Image URL Length in Google

I have a question for the community and my experience to share about the image url length and how G treats it.

One of my sites is a News publisher for Google News. Almost all the articles had images with them and followed Google's guidelines for including images in News. However, none of the image was indexed by Google News (although some of these images were indexed by Google Images).

The images on the site have 'breadcrumb' like URLs, sometimes about 4-5 directories deep. Some of the URLs are about 150 characters long. I tested a news article by adding a shorter image URL and GNews grabbed that image. If you are facing a similar problem, try shortening your image urls. I learned it the hard way, it took me 6 months of experimentation.

The site also has a photo gallery (thats where the Image URLs were from) with close to 50K images (same amount of thumbnails). All the links to the 'image pages' are sitemapped and most of them show up in Google web results. Out of about 50K images, only 3.5K images (at this time) are indexed by Google Images. I do see some of the images with long URLs (about 150 chars) in Google Image's index.

My concern is - could google be missing/penalizing most of the images for having long URL or was the bug (I'd call it a bug) in the News only isolated to News as the crawler follows stricter rules?

Links for all the images were changed about a 6 months ago and more images are added every week. So, at most the images are 6 months old. Is it enough time for Google Image bot to crawl and index all the images?

Thank you in advance.

Google will not be penalizing those long URL's. What is important is:\

a. Concentrate your effort in shortening those URLs if you can by mod rewrite.
b. Make them easy to remember, so that people can increase chances of remembering it.
c. Put some keywords in your URL, so that your visitors can associate content with it.