Currently I use Canon 1D X for my wildlife photography. I take them out in all sorts of weather and they have never let me down. However the low cost airlines are getting tight on weight these days and I was thinking of swapping them both for 2 x 5D Mark IV to save weight & get a better image quality. I know that the Mark III were not great in the wet. Has anyone had any problems with the Mark IV? How do people think it would compare with the 1D X?
Neither the 1D X nor the 5D Mark IV are "weatherproof." Canon refers to both as 'weather resistant'. If you use either in the rain and water damages the camera it is not covered under warranty.
The main advantage with regard to weather resistance any of the 1-series cameras have over the other recent higher end models such as the 5D Mark IV and the 7D Mark II¹ is the integrated vertical grip. If you're going to put a battery grip on the 5D Mark IV or any other Canon body that is not a 1-series, it increases the number of possible failure points for allowing moisture to get past seals and o-rings and into the camera.
But then again, if you add a grip and a second EP-L6N to a 5D Mark IV, the combined weight at 48 ounces is only 6 ounces less than a 1D X at 54 ounces.
Roger Cicala, founder of lensrentals.com and well known blogger, says the 5D Mark IV's weather sealing "appears pretty robust." In the same blog he compares the level of weather sealing for the 5D Mark IV to the 7D Mark II.¹ He also notes that it is improved over the 5D Mark III.
Of course, Roger also says:
OK, as you all know I don’t take cameras out in the rain without plastic covers. Because we write off ‘weather resistant’ cameras for water damage every week. But I know you young people live life in the fast lane and like to take risks.
¹ When he did his first tear down of a 7D Mark II, Roger Cicala said it may be the best weather sealed camera he had ever seen. Presumably that would include the 1D X that had been out over two and a half years when the 7D Mark II was released.
I took my 5D Mark IV out in very windy and raining conditions at the beach recently. I was using a lens that had a mounting gasket seal and did not change lenses as the conditions were almost unbearable. The camera got very well saturated. This is my experience.
During shooting I had issues with the touch screen registering water on it as presses. I just switched the Lock button on (which I setup to disable the touch) and this issue was resolved. I did not have any other issues with buttons not registering or strange errors or behaviours.
When I got home I wiped the whole camera down with damp cloth and then used compressed air on all the buttons which blew a fairly reasonable amount of water out of all those crevices. I had one grain of sand wedge into the top LCD light button, but I carefully removed that with tweezers and there was no further issue.
I had some dust in the mirror box / focusing screen that was there prior but was beginning to get annoying so I blew that out, and I think that was the cause of the issue I had next - the inside of the viewfinder dioptric began to accumulate condensate. I unscrewed the four screws around the viewfinder and opened up a small gap and then with all the doors open let the camera dry in a heated room. The foggy viewfinder was not a problem in the field - it only developed when I got home.
After about half an hour the viewfinder became clear again.
As this was at the beach it was salty water. I cannot comment on any corrosion damage that might occur down the track, as that will take time to develop, so bear that in mind.
Images of the weather sealing can be found: