So far as I know, all parish registers that were sent to Chester Record Office have been microfilmed by the LDS. (There's probably a privacy cut-off, of course). Some English county record offices had other people in to do filming or fiching but Chester seems to be all LDS.

There are just a tiny handful of parishes excluded - mostly because they retain their own registers. Astbury is one, but the Bishops' Transcripts (copies made for the Bishop of Chester) for Astbury are held at Chester and they *have* been filmed by the LDS.

All the films done by the LDS, have been indexed by FamilySearch and the *indexes* are on FamilySearch. The indexes *and* the images are available on FindMyPast (a subscription site, though I think it may do pay-per-view also).

The above applies to all registers regardless of date. If you go to https://familysearch.org/learn/wiki/en/Cheshire_Parishes you will find many articles - hopefully there's one for each parish. The Prestbury article (e.g.) says that the registers began in 1560. It also gives you the LDS film numbers and tells you what info can be found where, online. (Though I emphasise that very few images of Cheshire registers can be found online except for those on FindMyPast).

For events post-1837, marriages could also take place in a register office or in a chapel without its own register, in which latter case the registrar from the register office had to attend to do the legal bits. To find out where a marriage took place ***post-1837***, if you can't find it in FamilySearch, you need to go to http://www.cheshirebmd.org.uk/cgi/marrind.cgi?county=cheshir...

That will tell you where the marriage took place. If it says something like "Northwich, Civil Marriage" then that was a register office wedding or chapel without a register and the ONLY way to see the certificate is to order one. These are not at the Record Office.

If it is a church marriage, then consult the Wiki to see if the register has got through to Chester and been filmed.

Have a look at http://www.cheshirebmd.org.uk/marrcov.php where it tells you about the post-1837 indexing of marriages covered by the CheshireBMD site.

Basically, if you can order FS microfilms, then if something is in FamilySearch, you can order the film. If it isn't in FamilySearch (if it's post-1837) then it's almost certainly a register office only marriage for which you need to order a certificate if you want the detail.