William. Generally with the focus chart you lay it flat on a table and set the camera on your tripod, pointing it at a 45degree angle to it.
Get the camera as close as you can and focus on the centre line.
(i would focus directly on the numbers running down the side of the chart)

Fire off a few shots at different f-stops and this should tell you if its back or front focusing.

Others may have a different way of doing it, and i'm sure you will get a few ideas from those more in the know than I. Good luck with it.

Your camera could be front or back focusing. Have you tested it with a focus chart. :

Try this chart.

link

I can't see the point of it to be honest

Strange things indeed.

Did chirpy delete his post : I can no longer see it

The AF-080C is only a 49mm, a little to far to step I would suspect :

The Sigma 180 has a 72mm filter, well i'm sure mine does anyway

That looks just like my setup

amazing Whats with the GPS though :

Don't you think they lack a little contrast when using the ring flash ::

I'm a little surprised you can use it on the 180 without any vignetting, I haven't tried my AF-080C flash on my 180. Its smaller than the macro lite at 49mm, that a big stepdown :

I took some liberties with yours, just added a little contrast.

[IMG]http://i184.photobucket.com/albums/x261/ClarkyinAus/chirpysbug.jpg[/IMG]

Looks like a painting John, very nice indeed.

Throw that phone away NOW
My first thought when i read your post was to pass the phone to the person next to me saying it was for him and then running like a thief

Thanks Terry