Let’s start with the why though. Essentially, third-party EVF offers you consistency across any camera no matter how good or bad the built-in EVF is. If you use a product like the Zacuto EVF, you always know exactly what you’re seeing in the EVF is consistent. You can trust that the colors are what you think they are. It’s good to know that the scopes and focus assist are accurate. Some cameras don’t allow you to install custom LUTS, which is another very handy feature that the Zacuto EVFs have.
Just about all cameras come with a built-in EVF, so why would you spend thousands of dollars on a Zacuto Gratical HD EVF?
Well, not all EVF’s are created equal. Also, not all cameras are created equal when it comes to monitoring options. Here are some examples. The resolution and quality of built-in EVFs on cameras vary hugely. You may get a camera that is amazing, but its EVF is not the best. You may then also get a camera that has an amazing EVF, but the camera may be missing features. When it comes to the EVF, here are some of the features that could be missing in-camera, but the Gratical adds: