The end of the line for the DSLR?

Well no, actually I just like the header.
I must say though, that as I get older, (I'm over 21 now), my two Canon 7Ds, two zoom lenses, 2 flashguns, and assorted batteries, cards, notebooks and dog biscuits are getting heavier. Why this is, I don't know. I think they sneak off to Mac Canon's for fries when I'm not looking. I looked at them today and couldn't help thinking how they were like me, old, fat, and overcomplicated.
So, there was some disturbance in the ether when Shaun from Doverow Studios turned up with a model of a 1970s camera.......  Didn't he? "Seriously, Shaun, what's that?" Ok, it looks fantastic, but it's £1300 with the lens? Hmmmm..... expensive for a mere model, cheap for a workman's pro camera.  Is this a joke?
In the hand, it doesn't feel like a joke. It's metal, substantial and precise. It has dials and buttons everywhere, like a real camera! It has an aperture ring too!
Shaun had with him, the camera body, "standard" prime lens, a semi wide and a wide. He also had a 70-200, (roughly), zoom.  After much fussing and poking at the camera, we went out to test the new beastie against my EOS 7D and a 15-85 which have paid for themselves many times over; surely this upstart would be shamed?
Shaun and I travelled a mile or two and visited Alcester, Weethley and Kinwarton, shooting all the time and wondering how the images would compare back at base. I used the upstart camera a few times and deliberately pushed it to shoot ISO 6400, f2.8 at 1/20th, handheld in a little unlit church as I was told that noise was low, and stabilisation very good:  but was it true?
REVELATION
I have to admit this, though it pains me..... This upstart was far better than my Canon; back at base, the upstart images shone. They exhibited better noise control, better dynamics, better sharpness - better everything really. Originally, I paid about £1900 for the Canon and this one lens, and this lens is slower than Shaun's, plus, stabilisation is not as effective. Overall, the Canon is 3 times the size of the upstart and at least twice the weight for about 2/3 the performance. What’s going on?
All I can say against the upstart is this: It may not be fast enough in it's focusing for high speed sports and sudden action, (maybe some wildlife). Other than that, I'm yet to figure out what to complain about:  and I have tried! Oh, what is it? It's a Fujifilm XT1.
ADDED FOR CLARIFICATION....... I WANT ONE!!!

See some pictures from the Fujifilm XT1

DOF

So what is depth of field?
Sounds grand, doesn't it. Depth-Of Field or DOF.
Actually it's very simple in it's basic form. This is what it means:
The distance in acceptable focus, from the closest, to the farthest point.


So why does it change? Can I control it? 

OK, at a given distance and at a given aperture, DOF will (without the confusion of focal length for now), be a given value.
That is to say, that there  exist a mathematical formula for depth of field.
I'm not going to even approach it.

Whilst it is vital to understand the basic principles of DOF, it isn't necessary to delve into the science of optics and obtain a certificate!
I shall discuss DOF as though we only had one lens to hand. One lens of a fixed focal length, (known these days as a "prime" lens).
Consider the two images above. The first shows a shallow depth of field of about 9 inches.
The second shows a somewhat deeper depth of field of about 4 feet. The lens in this case, is a 60mm prime on a 1.6x APSC sensor, (Canon). The reason that the two look so different, (apart from my poor framing....Sorry), is that one is shot at an aperture of f2.8, and the other at f8. Now, f2.8 is a fairly wide aperture, that is to say, it's a fairly large hole in the lens.  F8, on the other hand, is moderately small. Which one is which?
The answer is, that the larger aperture, (in this case f2.8), produces the LEAST DOF.
As the aperture, (or hole in the lens), gets smaller, so the DOF, or area showing acceptable focus gets DEEPER.

Got to go now............. More soon.