What do I mean by high magnification? That would be 1:1 or better. What 1:1 means is that the image is life-sized on the sensor itself. Which is to say that it’s like the subject lay on the sensor and was scanned. Pixel for pixel match.
Most macro lenses these days have the ability to focus really, really close and shoot at 1:1 magnification. The Sigma 105 f/2.8 is the lens I use for macro and I got it cheap on eBay … about $250. Doesn’t get much better than that. Also makes a nice portrait lens.
To increase magnification even further, you can insert a teleconverter in between the lens and the camera. This adds extra glass elements, but at 1.4x, high quality prime lenses often look just fine. But cheap lenses and zooms will have their aberrations magnified along with the subject, so think twice before using the images. Test it out for sure.
And of course you can add a nice achromatic filter (two-element corrected) to allow the whole setup to focus closer. The Canon 500D is available reasonably priced on eBay for example. Note, though, that you should typically avoid the single-element versions that cost 10 bucks, as they add blur and tons of CA to your images. Junk.
Here is the kit I mentioned on a Nikon D70s.
First, in a light box from tripod:
Now, with flash hand held":
A crop of his eyes …
So get out there and take a shot at this stuff … it’s fun …