Can anyone explain the pro and cons of the two systems regards to macro photography?

The biggest difference is that all modern high end objectives are infinite. So, if you want the advantages of modern optical designs -- higher resolution, longer working distance, bigger image circles, better color correction -- you will eventually have to go infinite.

However, this is not to say that

*every* infinite objective is better than

*every* finite objective, or that you absolutely need an infinite objective to do good work. Some of the older finite objectives give excellent image quality. Many Nikon Small World awards have been won using finite objectives.

Finite objectives can be a good place to start, because:

- in addition to the objective, all you need is some empty space such as bellows or extension tubes, and
- there are some very good low cost finite objectives, both used and new.

But if you want to keep going, then eventually you'll end up infinite, for the reasons noted above. And as Adi notes, infinite objectives can play nicely with some forms of in-camera focus bracketing, which finite objectives do not.

You asked:

If we take two similar objectives with similar quality one is finite and the other is infinite which one will perform better?

I do not know how to answer this question.

As Adi points out, we usually judge the quality of a lens by the quality of the image that it makes. But by that criterion, it is essentially a truism that two objectives of similar quality will perform equally well.

So, I presume that you mean something else by "similar quality". Can you clarify?

--Rik