Here comes the mark IV !
When Mark III came in, it set up new standards of autofocusing and movie making. How much of a game changer is Mark IV ? Is it important to immediately upgrade ? Do you need the jump from 21 megapixels to 30.4? Full HD to 4K ? Better AF and ISO ? Lets compare one by one.
A 10 Megapixel leap is worth it for all those who need more detail in their photographs.along with a wider exposure latitude. An increase in the number of pixels will continue to go on. While cameras used to have just about 6 megapixels, people even used to say, "You don't need more than this !" Interestingly, its been increasing and increasing and the older images from those cameras are kind of out of focus today.
The Performance at ISO 32000 will be a good factor for low light photographers to decide, if this is an upgrade worth considering immediately. The current version is excellent at higher ISOs but the higher ISO is limited at 25600
5 + to 6 + Engine for better noise reduction may again help those shooting in low light situations. A marginally higher bust mode may not be very attractive for everyone but to some a small difference in demanding situations will certainly make a difference. Burst shooting rate is better at 7fps compared to earlier 6fps
4K video recording ! at 4096x2160 pixels at 24/25/30 frames per second rates. This alone is expected to command a lot of respect from videographers !
Adding to the video is the HDR movie mode. A lot of still photographers use the mark III's inbuilt HDR mode in certain situations. This HDR movie mode will help extend the practice to videos.
Then you have the "Dual pixel Raw format". Because of this technology the out of focus highlights can be shifted horizontally. This will also help in adjustments in reducing the ghosting effects like lens flare. All these can be achieved though canon's Digital Photo Professional (DPP)
The Mark IVs Auto Focusing is revised with 41 cross type AF points in its 61 point AF system which cover a much wider area now. For telephoto users all 61 points remain effective even at f8, which will be an additional benefit while shooting birds or wildlife. More points remain cross type, with more and more lenses.
Auto focus Detection range has been broadened to -3Ev from -2EV on Mark IV
Dual Pixel CMOS AF with Touch AF enables easy subject tracking as you shoot sports or wildlife. Mark IV supports autofocusing throughout 80% of the image area in horizontal and vertical directions, enabling AF in areas where phase-difference detection AF does not reach. FlexZone-Multi AF is equipped for the first time on a full size sensor model.
Since I generally wear, Polarized sunglasses, its will be good to have the Mark IV's LCDs better visibility outdoors with polarised sunglasses.
The screen resolution has seen a jump from 1.04 million pixels to 1,620,000 pixels here for better screen resolution. Besides being a touch screen, the tone of LCD can also be changed in 4 different ways.
For Exposure metering, The Mark IV has a 150K RGB+IR sensor , the kind that is inside 5DS, 5DSR and 7D mark II
The silence modes in the Mark IV are a good feature for those shooting street, wildlife, conferences etc. Anywhere, when you want to be more discreet.
GPS, Wi-Fi and NFC are other additional features. Depends on an individual, how much of these features will one make use of. This is particularly of use who shoot remotely through a tablet or a smartphone, wirelessly. On the wire front, faster USB 3.0 port has been introduced.
Digital lens optimiser mode is applicable on JPEG files as well besides RAW in the earlier version. This helps correct effects such as diffraction and softness due to the low-pass filter of the camera.
Anti Flicker technology of 7D mark II has been added. This helps capture shot just at the right moment under artificial light sources, so that the white balance and exposure are not influenced by flickering.
Should you switch over to Canon EOS mark IV ?
If you shoot mostly in the studio, do not need the additional megapixel and the Mark III is serving you quite well, you may not really want to rush to replace the good old mark III.
If you shoot outdoors or in areas where you can well use the additional features of this new camera, it certainly makes sense to upgrade to the new Mark IV. It will be good to upgrade to 4k videos but for multi camera setups, more such cameras would be required, and hence more investments.
If you are learning photography and planning your first camera or a first pro full sensor camera, go for this one without any second thoughts. If budget is a constrain, the earlier mark III will certainly not let you down. You may also explore EOS 6D mark II
I have always felt that the camera should be very reliable and if you are using good equipment, it lets you concentrate on lot of other things to create better photographs. If there is new technology, why not make the best use of it. Not that you will not continue making good photographs without this camera but then we all move ahead with times and make our lives easier, don't we? Will of course go for this version like all the earlier versions as soon as possible.
Technical facts sourced from Canon websites.
In nutshell- More megapixel, faster focusing, Better Low light performance, 4K videos, Faster Burst mode, Better LCD with touch screen, Better metering, Silent modes, HDR movie mode,
wireless capabilities (WiFi, NFC, GPS) to name a few