Canon 90d or r7 for event videos in low light?

[lame153]

I'm thinking of upgrading from 80d to get that 4k and 120fps FHD for slow motion shots, but am not sure which one to get. Is one of them far better on low light settings? And how is mirrorless for capturing fast movements, is there risk for getting rolling shutter on video when panning to keep focus on subjects that are moving? Is r7 (+ adapter) worth 500€ more compared to 90d?

[deebatman316]

Do you have a budget to spend on a body or an adapter too. What lenses do you currently own this is important too. Don't overlook your lenses this has an effect on your ISO and usable aperture range. Do you own an IS (Image Stabilized) lens. The R7 has IBIS something the 90D doesn't offer. Lens IS + IBIS work in tandem on R series cameras which have IBIS.

[shadowsports]

Greetings,

If you are considering a new camera body, then mirrorless is the way to go period. (probably)

The only exception might be if you were replacing a 1D series pro body or camera with a very specific use in an existing line up.  The industry has moved on.  This doesn't mean that DSLR's aren't good, they absolutely are, but if you are going to invest in something new, it should be mirrorless. 

There is a $200 dollar difference in price 90D / R7

Canon 90D vs Canon R7 Detailed Comparison (cameradecision.com)

Side by side, the R7 smokes the 90D at every turn.  With the exception of battery life.  Mirrorless cameras use a "terminator" style EVF that uses more power than a camera with a mirror.  Early on, (R, RP) this was more of an issue.  Its not today.  You buy an extra battery or two, or use a USB-C PD and its a non issue.  I don't even notice and I have one of the most power hungry camera's that Canon makes. 

This is a perfect example where spending $200 more makes a world of difference, and financial sense.  Or for $100 more get a Canon adapter for your EF / EF-S lenses.  

**Edit - I didn't address the rolling shutter question.  This is going to depend on your use case.  The speed at which you are panning or the speed of an object that enters and travels across the frame.  In this case, I might use the mechanical shutter, keeping in mind that the R7 still outperforms the 90D here.  The degree of shift is very low, so again the R7 is superior.  Couple it with ibis, and it still comes out on top.       

[rs-eos]

I'm going to assume that what you outline in terms of requirements wouldn't all be needed at the same time.

For example, if you're not planning on doing any slow motion work in low-light situations, that will be extremely challenging.  Since by the 180º shutter rule, your shutter speed would be at 1/250 s (1/240s on a cinema camera) and you'll need a fast lens and/or really crank up the ISO.

For low-light video by itself, you'd want to at most capture 30 fps footage (slightly better when 24/25 fps) to have a slower shutter of 1/60 or 1/50 s.  The EOS R7 will probably edge out the EOS 90D in terms of having better ISO performance.  However, you should primarily use a lens with an aperture of f/2.8 or faster.    For a zoom lens, preferably one with a constant f/2.8 aperture.

Rolling shutter will be present to some degree unless you have equipment with a global shutter.  Only some of Canon's highest end cinema cameras have that, so you'll need to adjust your panning speed and/or use correction in post-processing to minimize rolling shutter.