I’ve recently updated my main camera to a Canon 5D Mk IV - mainly because of it’s better dynamic range and low light performance, although the snappier focussing and a host of other improvements were attractive too.

I decided to carry out a few tests to see if the Wifi performance was any better or worse than the 6D. The short answer is that it seems about the same. So no surprises there.

I thought it might be worth recording some results though. First of all, let me say that this was not a proper scientific test. The wifi network is supplied by a BT router downstairs, and I was connecting to an iMac in my office upstairs. There are other bits of hardware on the network, although none especially active at the time. But the signal was good. I used the EOS Utility to transfer the data.

I attached each camera in turn, selected different image qualities (file sizes), and used my phone to measure the time from pressing the shutter to when the file appeared on the computer, ready for use. As I said before, not very scientific (or even accurate) but it gives some idea of what you might get in the field.

Here are the results:

There are some interesting points to note:

There is a “start=up” time of about two and a half seconds or more (I measured 2.69) from pressing the shutter to the transfer actually starting. This is for the camera to call up the computer and the EOS Utility to respond.
After that, the transfer rate is about 0.8 Megabytes per second.
This means that the minimum rate you can get a medium or small jpg file transferred is about 5 seconds. A large 5D JPG is likely to take a bit over 7 seconds.
I did find a couple of anomalies. The 6D LF (Large Fine) transfer was faster than the Medium Fine. This, in turn, was faster than the Small image. I think this was probably because the EOS Utility was still in an active state and hadn’t gone back to sleep. Or it may have been that the computer was busy doing other things at the time. Nevertheless, it seems pretty representative of what you are likely to achieve in a real world situation.
Overall, the wifi capabilities of the 5D Mk IV are more or less the same as the 6D. It does however that the additional ability to link to an FTP server if you don’t want to use the EOS Utility.

Recommendations: No surprises here.  For event photography, most users will be using medium or small jpgs - you don’t need a 30 megapixel image to print an 8x6, or even 10x8 print. The 5D is fine for this. The camera buffers transfers, and I have found the 6D wifi connection to be fine for this use in the past. For studio work, or other situations where you need RAW files, you’re better off shooting RAW + JPG and just transferring the JPG for instant proofing work* - checking lighting and so on - then have a coffee while you transfer a batch of RAW files using a card reader.