is the EF-EOS R adapter worth buying?

[zzler]

Hello, I'm and intermediate-experienced photographer and currently have a canon t2i with the EF-S 18-55mm and 55-250mm lenses. I'm looking at buying a Canon R7, which would require that I buy a EF-EOS R mount adapter to use the EF-S lenses I already have. I mostly do sport photography (and want to get into videography), so the strong autofocus and stabilization capabilities of the R7 is what is motivating me to buy the camera.

Would using the adapter and EF-S lenses have the same autofocus and stabilization ability as using an RF lens? And thus, would you recommend trying the adapter or just buying RF lenses? Thanks.

[rs-eos]

This can be a tough call.  On one hand, picking up the adapter will let you use your existing lenses.  On the other hand, you could spend the cost of the adapter towards an RF lens and over time add more RF lenses.

One thing to consider though if going to adapter route... if you forsee using your EF-S lenses for a long period of time, do consider the version of Canon's adapter with the control ring. 

[kvbarkley]

For an "intermediate-experienced photographer" with limited budget, by all means get the adapter if you plan on keeping the EF-S lenses. (i.e., not selling them to buy the R7). You can get shooting right away with a full range of focal lengths and start saving your pennies for RF glass. I also think the control ring is a good add.

[johnrmoyer]

I find that my Canon EF-S 55-250mm f/4-5.6 IS lens works better with my EOS R5 than it did with my EOS Rebel T1i, but i seldom use it because I have EF100-400mm f/4.5-5.6L IS II USM. I no longer find my EF-S 18-55mm lens useful.

I do not use the adapter with the control ring, but use the less expensive one without the control ring.

I often use EF-S18-135mm f/3.5-5.6 IS USM on my EOS R5 with an adapter because it works well for focus stacking.

I expect that the inexpensive RF-S18-45mm F4.5-6.3 IS STM would be better than the EF-S 18-55.

A photo I made with the 55-250 on my EOS R5 is at https://www.rsok.com/~jrm/2021Sep08_birds_and_cats/2021sep02_bumblebee_IMG_3837c.html

[Waddizzle]

“ Would using the adapter and EF-S lenses have the same autofocus and stabilization ability as using an RF lens? “

Negative.  If your 18-55mm and 55-250mm are kit lenses that came with the T2i, then you will not get the same performance that you would from RF lenses.

You can expect better AF performance with the older lenses because of the vastly improved AF when it comes to shooting stills.  You can expect sharper photos, but not faster focusing.  I doubt if either lens can keep up with the frame rate of the R7.  You might have a low keeper rate during bursts.

When shooting video, I would expect limited AF performance that does not take advantage of all the features available with Dual Pixel AF sensors.  For example, Movie Servo AF may not be available with the older lenses.

Check the full User Guide for the R7.  The R5 and R6 User Guides contain a section that lists the EF lenses that are fully compatible with Dual Pixel AF sensor cameras.  If the R7 User Guide does not list compatible lenses, then look inside the R5 or R6 User Guides.  I would not expect there to be any difference.