Is this the best decision?

I have pretty much decided that I will sell my EF 55-200 and put that money towards a 70-200 F4. I've decided this because I think that the image quality will be a huge improvement, but I also think that a 70-200 is a more useful lens than a 100mm macro or waiting and saving for a 100-400 (which could take a while) or some other expensive option. Am I making the right move?

CRAP - I forgot to add this:

Somebody mentioned an option for macro that involved screwing on a filter-type of thing that would connect two lenses end-to-end and would give you a macro effect. Is this for real? Is this any good?

That 55-200 costs like $190 new, so would could you get used? $150? $100? The 70-200 new is $570 or so, so whatever you get for the 55-200 would only be a drop in the bucket towards it. The question is would you rather have the $100-$150 or the lens?

Yes.

So it's a done deal then. I'm going to sell this thing and get a nicer lens.

And regarding the second question?

I'm not sure if the device you mention exists, but other options include:

(1) close up lenses - which you would use with a 67 to 77mm step-up ring on the 70-200/4

(2) extension tubes

Jay,

Thanks for the answer, but your link to the extension tubes actually brought me to my answer: they are called "reversing rings" and they are cheap (unless you want AF, which is pricey).

So, I guess the next question is: Does anybody have experience with Reversing Rings?

Oops, I was mistaken. Reversing rings are different, what I am actually looking for are called "MACRO COUPLERS."

http://www.bhphotovide​o.com …avBar&A=search&​Q=&ci=3066

Using this method really limits the DOF and the working distance to the subject also the reversed lens needs to be a fairly fast lens (f1.4) or you will get bad vignetting. The lens I use with my 300D kit lens and the G5 is a Pentax 50mm f1.4 and a homemade reversing ring (couldn't find a 58-49 ring).

Here is a good read about different methods for macro photography.

Awesome, thanks for the information. So, any thoughts on maybe keeping the 55-200 and using it with my 50mm 1.8 in a coupler situation? Or should I use my kit lens for that? Or a 75-300?

I just tried the 70-300 and the 50 f1.8 reversed (hand held together) and that is a good combination. If you already have a 75-300 I would use it, if not then try the 55-200. The kit lens with a 50 reversed doesn't give you all that much spread in magnification like the 75-300 would.