As you've filtered out the red end of the spectrum it's hard to see how it can be put back. I would suggest lateral thinking and converting them all to monochrome. It will of course be mono shot with a blue filter and that will give you an effect similar to using "ordinary film" that was only sensitive to blue. You might get a nice vintage effect on suitable shots. Skies will be more or less pure white and the tonal values will be different. Sometimes it works really well, depending on subject.

Down at Arley Hall today for the Mushroom walk with Fungalpunk Dave. Here's an example:


The rest of the images are on my EPZ blog here: https://www.ephotozine.com/user/johnriley1uk-22471/blog

David, you are clearly a man of your word!

Quite right, I wasn't suggesting posting, just phoning, but I think it does go to show that it's useful to put a location with the user name. Especially as we are now gathering in more worldwide members.

JPS are the official repair house for Pentax - http://www.johnsons-photopia.co.uk/JP%20Service%20Solutions_17.php

When the aperture ring is not set to A, the camera will only operate in Av mode, unless set to M, B or X. So all other modes will only give you Av (aperture priority) regardless of setting TAV or any other auto mode.

Normally, the latest version will update all the previous versions without any problem, all previous updates having been included in it. However, to be absolutely sure in the light of a version not being mentioned, an enquiry to JPS would perhaps be the absolutely safest way to go.

Why not give them a ring and ask?

As long as using aperture ring is set to permitted, the f/8 fixed aperture is simply open aperture. The camera will work fine in manual and Av. I have a feeling IIRC that whatever other mode is set the camera will still operate only in Av unless set to M.

Perhaps another consideration is the versatility of a zoom against a fairly wide prime lens?

There's an increase in fine detail and I think you would notice it.