Blackmagic Video Assist vs. Atomos Ninja Blade

I would be interested too in knowing more about this.

The BM Video Assist has LUT support since the newest firmware updat which is really good and will be very usefull with your A7r when recording slog. Mine just arrived, havent had the chance to use it a lot. But I like it. Its also very compact. In my opinion the best value monitor outthere feature vise. Also has false color which I think is essential

I currently use the a7r ii and the blackmagic 7" 4k. There are a few answers to this question. But first, you should be looking at only the BlackMagic 7' or Atomos Flame since you have a a7r ii you are getting 4k @ 4:2:2 8-bit into the unit more then the camera supports internally and "unlimited recored times" if you just want a field recored go get one for $150 on ebay/amazon. But if you want to get more out of the a7r ii, then read on. The blackmagic is great on size and the case protects the screen. I had a shogun and one little bang and I needed to replace the screen $800. Atomos make a great product and they are ahead as features. So why am I using the BlackMagic Video Assist (BMVA) size dual sd cards and dual battery. when I am shooting interview i can run for as long as I have power and ability to dump sd cards. Atomos uses hard drives and single battery that goes fast! I had to get a V-mount and run from that = larger unit, heavy batter, bigger drives SSD's and cable. Also I find the BMVA to have a bit better audio, but I am still in evaluation with it. The big question image = the same! If you asked me this a few weeks ago before the update I was about put my BMVA on ebay... but now I am keeping it and just hope blackmagic makes one update that I really miss on the atomos. 4x zoom and ability to move image around on screen. this is very helpful since the BMVA only zooms 2x and center of screen. Oh and your going to spend the same $ since the BMVA only supports very expense 64g SDXC cards... hopefully they will add a few tweaks to the firmware for larger cards.

What would yo think would be better for a C100 (original) user?

5" Video Assist owner here. If colour accuracy is important to you I would not recommend the Video Assist. The VA has a known green tint issue. Blackmagic recently released a firmware update which claimed to have improved this, but I haven't seen any major improvements in the colour accuracy of my VA. Other than that it's a pretty good monitor/recorder with some great features, but the green tint is really quite annoying.

I can't speak to the Blade specifically, but I own the BMVA (5"), and it's a great monitor and recorder for my BMCC. It is very well-built and reliable, and it definitely improves my workflow and footage. It's also nice to have a backup recording.
I have worked with other Atomos monitors, and I definitely prefer the BMVA.
It isn't without it's downsides, though. The on-screen image has a slight green colour cast (not recorded, though), which means you're not sure of the colour. It is a battery pig, too. I can easily burn through two batteries in an hour and a half, and have essentially given up on using Canon LP batteries in favor of a tap from a larger battery.
If you're going to pair it with the Sony, you should probably be looking at 7" 4K model, though. I'd also check if the model you are looking at is compatible with the a7r. As I mentioned to another poster in this thread, I have had compatibility issues with some Canon cameras.

Hello, what's about Canon 5DIII? Will it be good with either Ninja or BMVA?

Hello, what's about Canon 5DIII? Will it be good with either Ninja or BMVA?

Regards Andy