Noam Kroll of Premiumbeat wrote an article on camera sensors and their crop factors. He admits that full frame shots undeniably look great and full frame cameras were a breakthrough in the indie filmmaking work, but there's no doubt that crop sensor cameras also have their advantages and according to Noam, crop sensor cameras offer some huge advantages over their full frame counterparts. He reports that while full frame sensors offer you an ultra shallow depth of field, smooth bokeh, and a surreal almost bigger than life feeling, it comes with many compromises - for example a full frame camera has a much larger frame size than Super 35mm film. Another disadvantage is that your lens choices on a full frame camera is more limited and such lenses are usually much more expensive.
In the case of crop sensor cameras there are also a few problems:
"The Lumix GH4 that I mentioned at the top of this post, that have a Micro Four Thirds sized sensor, which is significantly smaller than full frame and will effectively give you a 2x crop. What this means is if you put on a 50mm lens, it will look more like a 100mm lens on your MFT camera. (...) The downside to this is that it can be challenging to get some specific types of shots that are relatively easy on full frame cameras. One example is the extreme wide angle (non-fisheye) shot, which would need a very specific type of wide angle lens. Luckily there are a number of MFT lenses that fit this bill, but many of them are either slow or not particularly great quality."
But there are some other issues. Full frame cameras are way better in low light conditions, so you need to have fast primes if you want to shoot with a crop sensor camera and fast lenses are quite expensive. On the other hand you can buy an old Canon lens that offers some great specs and the choice of lenses is really wide thanks to various adapters.
So, which type of sensor should you choose?
"It all comes down to what you are going to use the camera for. There have been absolutely gorgeous images captured with cameras across the board – full frame, MFT, APS-C, you name it. So don’t worry about the image quality too much as part of your decision making process, because at the end of the day if the camera is in the right hands, the images will look good.
Instead, focus your attention on what you as a filmmaker need. If you plan on shooting a lot of run and gun material, or documentary content, I would strongly suggest thinking about the MFT format."
For more head over to the full version of the article (here).