Just nitpicking: I would say, the Leica M9 was the first full-frame mirrorless, but it didn't have an electronic viewfinder.

The M9 isn't a mirrorless, it's a range finder camera (where the view finder sees through a separate optical light path than the main lens). A mirrorless is a DSLR (i.e. what you see through the view finder is exactly what you see through the lens) where the mirrored optical light path for the viewfinder has been replaced by a digital screen, hence mirrorless. Range finder cameras have existed for many decades and have never had mirrors, so they can't be converted to mirrorless in the way that term is now used. The defining characteristic of a mirrorless camera is its digital view finder that sees through the main lens. Without that it can be a range finder camera, a point-and-shoot, hell, even a smartphone, but not a mirrorless.

Well, the word mirrorless implies for me most of all, that it doesn't have a mirror, in contrast to a (D)SLR. Of course, most of the time, mirrorless is used for cameras which have exchangeable lenses and an electronic viewfinder. That is, why I explicitly stated in my post, that while not having a mirror, the M9 didn't have an EVF.

The M(240) then added the EVF, which also precedes the A7.

All of this is a bit of trivia, as most people are not aware of the Leica M series, so I thought it would add to the discussion. The A7 certainly was the first EVF-only mirrorless 35mm camera and was sold in far higher numbers than any digital M.

>Nikon and Canon both thought mirrorless was a toy and both of them made shitty cameras that are basically point and shoot with interchangable lenses.

I hope you realize that live-view shooting was essentially turning a dslr into a mirrorless one (caveat obvious OVF/EVF differences). Canon's dual pixel AF tech is still miles ahead of Sony's PDAF when it comes to low light focusing, and video AF. Each pixel on a canon sensor can be used for AF as well as imaging. Sony uses masked pixels which limits them because they canno't mask too many pixels for fear of IQ degradation, and having fewer AF pixels limits them in low-light focusing.

>Both Nikon and Canon have realized their mistakes and recognized mirrorless is serious business and is the future. Nikon has scrapped the Nikon 1 line and started making Nikon Z, which is a super pro/prosumer oriented mirrorless lineup with a full frame sensor. Canon hasn't scrapped the old mirroless line but is pushing the RF mount lineup which is also full frame.

Or rather, like mature businesses, they realized that they could keep making money with DSLRs and slowly milk them dry and then ramp up mirrorless and make money there too.

>One thing of note is that Sony has opened up the E mount spec and allowed 3rd parties to create lenses.

That's because Sony had no expertise in making high quality professional grade lenses and teamed up with Zeiss and others to help them get up to speed initially.

Most mirrorless had poor AF, crappy menus, poor ergonomics, low battery life, limited lens lineup and very expensive lenses.

Now, this is starting to change somehow but many, me included will wait a few more years because the cost of replacing many pro grade lenses is still very high.

A7III and A9II are the first good mirrorless that are finally pro-grade.

Camera aren't terribly expensive, but if you have 8 - 10 pro grade lenses which will cost on average $2000 to replace with E mount variants that might sound expensive. Particularly if you don't produce more money by switching to mirrorless and buying those lenses.

Yes, the existing lenses out in the field certainly kept Nikon and Canon in their position. Anyone with a large amount of lenses would stronly prefer to upgrade to a compatible camera.

This is what makes their move to mirrorless so tricky. While adapters for the existing lenses exist and work, in the long term you would want to upgrade many of your lenses to their mirrorless counterpart. Especially, if most new lens designs are made for the mirrorless lines.

A7ii isn't quite pro grade but if you want to spend $1000 or so for a full frame camera Canon and Nikon don't come close.

I got sick of the kit lens so I got a cheap used 50mm which can shoot tack sharp and I just unboxed a 90mms macro from the G series and will try it out today.

Is there any way to adapt the old lenses to the new body style?

Isn't Sigma making the best lens at the moment anyway?

That’s debatable. The Art line is really good from a technical perspective, but some people feel they don’t have “soul.” I think a bigger problem is that they have no concern for weight. For instance, their 105mm 1.4 is over 3 and a half pounds, and Nikons equivalent lens is a a little over 2 pounds.

That might not seem like a big deal but it certainly is when it’s hanging off of you for a full 12 hour wedding.

That said I still have a Sigma 35mm and 20mm in my kit.

Depends on how you define "best". Sigma has improved a lot in recent years and is generally great value, but Zeiss / Leica / Schneider / etc. are arguably still superior (at much higher prices).

I would call them “good” or “competitive”. There is no such thing as a “best” lens. It’s all about what you are looking for. My “best” lens for portraits is an old manual Pentax lens which is quite flawed but the images just look great.

Ehhhhh...

IDK what they're like nowadays, but Sigma has in the past had a reputation for a larger quality variance than others.

Sigma improved a lot, apprently they developed proprietary testing equipment involving their Foveon sensors.

Old Sigma lenses were often pretty bad, but the new Sigma Art lenses are amazing!

And they moonlight as dumbbells in a gym.

To be perfectly honest, my Canon EOS M6 Mk II has impressed me greatly with its performance.

Sony has had great sensors since they debuted back in like 2006. I’m pretty sure it may even be the same mount now on their mirrorless camera.

They had great sensors from when they bought Minolta