I've been thinking about expanding my lens collection to add a new fixed focal lens to the list

If I go for a standard prime I'm looking around £60 for a Minolta 50mm F1.7 lens (highly rated from what I can see)
If I go for a macro lens I'm looking at quite a bit more

I was hoping to do close up shots of plants and animals, are there things to adapt a prime lens so I gain (even partially) a macro zoom?

You can get macro extension rings that will turn a lens into a macro, and a macro into a super-macro. There are a few limiting factors that can mean taking shots of anything moving faster than a snail are nigh on impossible though. Basically, everything will require manual control if you choose basic and cheap rings. If there is a more expensive option available then they will probably be quite costly and still may not be compatible with certain lenses.

Another option is to get a lens mount that allows a lens to be mounted onto the body in reverse. I'm not familiar with these but I guess you would again lose all of the automatic functions.

I haven't seen anything that will turn a prime lens into a zoom though.

Could you get the 50mm prime and add some close-up filters when you want to do some macro work?

Something like this: http://www.microglobe.co.uk/catalog/pro ... s-filters&

Get a dedicated macro if macro photography is what you want to do. Filters, adapters etc. will affect the quality of the image you get and you may lose f-stops.

This is what can be done with such a lens:
http://www.clairedunning.co.uk
(this is my sister’s web site)

I can’t remember what macro lens she uses - but I’ll ask if you are interested. She tells me that even your heart beat can affect very close macro focussing, so you’ll need some kind of tripod or support, and a lot of patience.

Those are the kind of photos I want to be able to take, got a few tripods so that isnt an issue, money for the lens probably will be as I don't get paid sick leave so this gastro bug has meant almost a week unpaid atm

I'll agree with what Paul said there.
Forget about tubes and converters, if you know you want to do macro stuff then get a proper macro lens, even hire one for a week (or even a weekend) and see how you get on with it.

Mark

They ake a lot of patience to do. Insects react to noises off, the camera, even your smell. You'll need to read up on what as known as "field craft". The results are, as you can see, very rewarding.