I've just bought a Zoostorm PC for my partner and loaded it with Ubuntu (my first foray into Linux) I can't stand Microsoft and hated constantly having to fix her machine (I have a Mac)
The PC is incredible value - £99 with cash back.
and Ubuntu is flippin' awesome! so clean and easy. Absolutely no Microsoft will ever go near that machine. Office docs open perfectly in LibreOffice.
If you're not wedded to Adobe, then Gimp and a few other free apps on Ubuntu is all you'll need.
Did I say it's all free?

I've posted several iPhone shots on here over the years.
Here's one, you can tell from the blown highlights

Incidentally, here's an example of using a cheap 2x convertor versus cropping a 300*.
Mirror up, tripod, manual focus, live view x 2, no sharpening.
300 cropped to 800px


300 with 2x convertor, cropped to 800px


This image sharpens-up really nicely with 50/1/0 USM

Yes, this is not rigorous enough IMO. Sorry Mike. Far too many variables unaccounted for. All of them look soft to me. None of the lenses have been given a fair shot.
But thanks for posting them; it all adds up and they have a certain real-world use. Essentially, there's not much in it in the real world, but I'm willing to bet the 300* would be a clear winner normally, not least because it would be faster, brighter in the viewfinder and the easiest to hold.
We really need tripod, mirror up, preferably best of 3 and original images to peruse.

For printing a degree of sharpening halo is desirable.
For the web, bicubic sharpen is too unspecific; too uncontrollable.
A while back Photoshop changed its defaults to sharpen on resize; I immediately turned this off, so I can apply my own local sharpening.

Second one is a corker!
must get me an upturned bike...

Awesome guys!
Ha ha, Geourdie01 that is so ridiculous! you definitely take the lead so far even if the image was a bid lame, but it's actually pretty reasonable! bit of grit about it too, I like
GlynM, very controlled, very nice image, I like the colours and it still looks pretty new compared to my ancient example
tyronet2000 - smoooth! what was the set-up?

Nice

Ah ha, still, you 'bodged' the adapter, that's good
The IRB on the penny is slightly under 1.5 mm I think. So my image is about 3.5 x macro. So you have the advantage there by the looks of it.

It's a cheap macro rail, for stacking shots or positioning. Not very good - it moves sideways when you change direction or tighten the locking screw. So only good for course adjustments. Hence the helicoid, which gives me a further 1 inch of fine movement.