Last fall after I first bought and worked with the Nikon D750 for a while, I put together a review of it's video features. The response to that review has been really helpful to me because I learned that a lot of viewers thought I didn't much care for the D750.
Nothing could be further from the truth and let me be 100% clear: I love my Nikon D750!
I think the confusion came as I felt I had to explain why I bought a DSLR instead of the amazingly popular Sony a7S which is also a full-frame camera but with a mirrorless design. Oh, and the a7S can record 4K via its HDMI output. Oh, and it can also record S-Log.
Why would you go for a Nikon D750 instead of a Sony a7S, particularly when they are priced within a couple of hundred dollars of one another? I could have dropped the additional money without an issue at all.
And don't misread me when I give my explanation here. I love what Sony is doing, the direction they're heading. They are leading in a direction that is amazing - large sensor cameras and small bodies that ditch the mirror design of SLRs since the focus technology is at a point where that doesn't sacrifice anything. What's not to love about that?
But that's what made everyone think that I don't like the D750. I essentially said that it is a decent full-frame DSLR for video. Just decent. Not amazing. And I still think that is fair. The bitrate of the internal codec is relatively low compared to cameras like the latest generation Sonys or Panasonics. It is 1080p. It still doesn't have focus peaking. It doesn't do waveforms or false color. The footage it produces is good 1080. It is a totally workable solution for many types of shooters. Just not as much of a commitment to video from Nikon as I would like to see and that Sony and Panasonic are putting into their cameras. As a result, shooting video with the D750 is a good experience, but not as pleasurable as with my GH4.
When I'm going to shoot video and I have a choice between my D750 and Panasonic GH4, I'll choose the GH4 90% of the time as the main camera. It is a pleasure to use when shooting video and it produces lovely 4K footage. But there are 10% of cases where I'll choose the D750. Those are usually cases where I'll be doing an interview or talking head on location. Only the D750 allows me to blur the background like full frame cameras allow. The color it produces is great. It works beautifully with my Atomos recorders, both the Ninja II and Shogun. And in fact, with the Shogun, it becomes almost pleasurable to use (because the Shogun has all those video exposure and focus tools that make things so much easier and quicker). That setup gets a little bulky and isn't for everyone but it works well for interviews for me.
Now when it comes to shooting still photos and I have a choice between the D750 and the Panasonic GH4, I choose the D750 99% of the time. It is that amazing. Dynamic range on this camera is stellar. When I'm shooting still photos for weddings or portraits, the D750 is unrivaled in its ability to pull out shadow detail. That allows me to create stunning wide dynamic range type images in post. The focus is snappy, the flash eco system that Nikon provides is still pretty good (where are the RF transmitters, Nikon? That's one thing you're missing). The lenses available, both from Nikon and others, are top notch optically.
If I could only keep one of my cameras, I think I would keep the D750. Why? Because 4K is nice but not critical for me at this point. Paired with the Atomos Shogun, I have all the exposure and focus tools I need for shooting video. The large sensor produces amazing quality footage. On the still photo side, the GH4 is not bad, but not even in the same league as the D750 which is probably the best DSLR for the price on the market right now in most ways. Low light/high ISO performance on the D750, while not quite as amazing as the a7S, strikes the perfect balance of resolution (24 megapixel) and high ISO performance. That means this is an incredibly versatile camera.
And now, of course, it is priced at about $300 less than when I bought it last fall.
If I had to make the choice again today, I'd still choose the Nikon D750.