If a FF camera has crop mode ? then why have crop sensor cameras? and other questions

[KMR13]

Maybe that is a ridiculous question but I am reentering the camera market and in my research (thanks to all here who have been answering ny other questions) ... I just read that the R8 can go into crop mode and wa-la, you now have a crop sensor camera on an otherwise FF camera.... so why are there dedicated crop-sensor models?

Also... separate item:   does the R6Mii have the same battery issues as the R8.... I've been reading that the R8 battery life is lousy for video, and moderate for photography (I have no interest in video content creation).  And if the R6 is getting updated in 2025, what kind of price drop might be expected on the Mii?

[shadowsports]

Greetings ,

Crop sensor cameras have smaller sensors. They're less expensive to produce.  By forcing a  24MP camera into crop mode, your resulting images will be 9.3MP.  Why? Because the image circle projected by an RF-S lens is smaller and only projects an image circle to the center of your full frame sensor.  

A full frame lens doesn't have this limitation.  It is larger and projects an image circle greater than the size of an APS-C sensor.  So you get a field of view that's cropped by 1.6x, at the full resolution the sensor is capable of.  

The battery in the R6 Mark II is the highest capacity available for Canon's prosumer body's.  The R3 and R1 user a larger more powerful battery.  If you can swing the R6 Mark II over the R8 you won't be disappointed.  

The R6mkIII is rumored to be coming Q1 of 2025.  Will it be better than the current R6mkII. Sure.  How much better is anyone's guess.  For someone re-entering photography, the R6mkII is nothing to shake a stick at.  Christmas 🎄 is coming.  I expect the R6mkII to remain competitively priced.  

[Ron888]

Besides cost,crop sensor cameras are also smaller,lighter and have more depth of field for a given aperture.That last one may or may not be what you're wanting.

[KMR13]

Yes, I  understand that is useful for photographing people or animals esp when background is less desirable or for dramatic effect ill do some of that but most of what I plan to shoot is outdoors - at the beach (a lot) , woodsy areas , holiday family / school events l& graduations (2 to go!), my daughters swim meets(only 2 years of that left) pets, and traveling around town looking for interesting perspectives to capture. . 

[KMR13]

With budget and photography aspirations in consideration::   Is it better to go with the R10 with full frame lenses or just go right to the R8?

Recall that I am reentering the photography world as an enthusiast who intends to have a solid photography hobby, (but still has 1 kid in college an 18 mom from that step)  and trying to contain budget (camera, strong lens, memory cards, bag all will be needed with the first purchase)....