Why not put the items in a small waterproof Billingham bag? Surely in the waterproof box they can be carried about but it's hardly useful when using the cameras. There's also no padding so the lenses and camera will get rubbed.

The bit that was missing for me was the answer to why we would do this? What am I misssing?

Probably the Nikon VR lens is just a better lens than the Tamron one.

The SMC Pentax-DA 55-300mm lens would seem the probable best choice for you.

Yes, the distance that the subject is in focus, which presumably is where you are!

Fair enough, but it does depend on the sort of photography you are doing. I love the rich colours in the rain and find the opposite is true for me.

Guide no is 26 (m) so from that you can work out the correct aperture for any distance. So if you were 5m away, the the aperture to use would be 26/5 = f5.2 (f5.6 in practice).

There is a mains adapter for this unit as well.

Yes, it does work. Just allow time for the hand symbol in the viewfinder to stabilise.

What lens are you using on your Pentax?

Ah, does the camera read the DX code by preference or was it pre-DX? It's a long time ago since I used one of these. If it does read DX coding then why does it have an ASA dial?

There's a misunderstanding here. Film canisters have a series of DX coding squares on them - these are a combination of conductive and non-conductive squares. Inside the film chamber of the camera is a strip of contacts that reads this and sets the ISO (ASA) accordingly.

If you want to change the setting of the meter, for example to under-expose slide film and make the slides darker, then you can buy stickers to replace the DX coding on the film, or indeed scratch out the appropriate squares if you know the layout.

The other reason for increasing say the ISO value is to use in lower light. But usually development time is increased to compansate for this.

Glad to hear it's resolved.

This is a potential weakness and a good wiggling, a really great technical term , can do the trick.