Philip writes I ordered PRs from the 16C for Hitchin at my local LDS Family History Centre. They were so blurred as to be virtually unreadable. The images of same PRS at HALS were crisp.
I have photographed Kings Walden PRs and found several pages to be so faint as to be almost blank. On Thursday, I viewed a new film of K Walden PRs at the LDS Centre and ALL the images were easily read.
My point is that if the quality of films of PRs is patchy, it may be worth trying another source.
I rarely use microfilm now but I have come across variable quality in census images both from CD and online. For this reason it is often worth trying a different source if you get a very faded image. Of course there are some pages which, in the original, are so faded that they are difficult to read. I suspect that images made in the last few years using digital techniques are likely to be far better than some of the early microfilm copies,
Comment below if you know of other cases of this problem.