The Canon SL3 was released this year and has a couple improvements over the T7i, but it also has some setbacks.

The biggest differences that I could find are the image processor, battery life and autofocus. The SL3 has a newer DIGIC 8 image processor versus a DIGIC 7 on the T7i. The battery life on the SL3 is superior to the T7i, 1070 shots versus 600 shots (under the same conditions). There is a catch though. The T7i has 45 cross-type autofocus points, whereas the SL3 has only 9 regular autofocus points (one of which is cross-type). The SL3 does however have dual pixel autofocus, but that only works in live view.

This is going to be my first camera. I would like to be able to shoot anything from portraits to kids running around (hence my worries about the autofocus) and sports every now and then. Live view may be a great way to start photography, but I feel like I will probably only be using the viewfinder later on, rendering the dual pixel autofocus unusable.

I don't mind the slight difference in frame rate, 5 on the SL3 and 6 on the T7i. I will also primarily be doing photography, but when I shoot video it will only be in 1080p because of the crop factor and lack of dual pixel autofocus in 4K.

Two specific things I would like to know:

  • How does the autofocus on the SL3 compare to the autofocus on the T7i (for both photo, with and without live view, and video)?
  • What difference does the newer image processor make (in lowlight)?

How do these two cameras compare? Is there a difference in general image quality? Are there any other differences that I missed? Which one would be the right choice for me?

Edit: I am going to shoot in RAW.

  • \$\begingroup\$ have you searched for reviews and compares on the internet? like cameradecision.com/compare/… or apotelyt.com/compare-camera/canon-sl3-vs-canon-t7i for example. after reading reviews you can easily make your own choice and decide for the one you think is the best for you. but the body is one thing you also need some good lenses and think about them. \$\endgroup\$
    – LuZel
    Oct 16, 2019 at 10:17
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    \$\begingroup\$ Have you considered going to a camera store to try different models? Since this is your first camera, you don't have a lot of existing gear tying you to a system. How did you narrow your choice to these cameras in particular? \$\endgroup\$
    – xiota
    Oct 16, 2019 at 10:24
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    \$\begingroup\$ One difference you missed is the hotshoe. The SL3's hotshoe has had its sync contact removed, which makes 3rd-party flash gear compatibility more problematic. \$\endgroup\$
    – inkista
    Oct 16, 2019 at 22:30
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    \$\begingroup\$ Pete, just a FYI, your question is likely to be closed as a "shopping" question or as too broad (more than one question). Your question is specific enough to only be good for you for a limited amount of time. We want Q&As that are still relevant five years from now for a wider audience. This doesn't mean we don't like you or don't want you to ask questions. :) But maybe take the time to read the Tour to get a sense of how to shape your questions so they help all of us. \$\endgroup\$
    – inkista
    Oct 16, 2019 at 22:34
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2 Answers 2


To put it in general terms that will be more useful to more readers for a longer period of time:

You're trying to decide between a newer lower tier camera and an older camera from one tier higher up. Which works best for you will still be based in which features are most applicable to the types of photography for which you plan to use the camera. In terms of low light performance, the most important thing is the sensor. How the AF system works in low light will also be a consideration.

  • Both cameras appear to use the same imaging sensor. If it is not the same one, they are near identical in terms of both specs and measured performance. Draw
  • The newer camera has a newer processing chip. There are cameras more advanced than these two that use each of these same chips. It's probably pretty safe to say that neither of these two cameras are utilizing all that each respective chip offers. Since you are planning on saving raw image data, the only difference in image processing will be how the JPEG preview (what you see on the back of the camera when you review the image) will look. It shouldn't affect the raw data collected by what appears to be the same sensor in both cameras. It might affect how fast that data is processed and sent to the memory card, but those other potential differences between the two processors are already reflected in things such as frame rate, buffer depth, shutter lag, etc. Draw
  • The older camera has a far more sophisticated OVF (optical viewfinder) based AF system capable of operating in significantly lower light. 45 vs. 9 total AF points. 45 vs. 1 cross-type AF points. 27 (9 of which continue to operate as cross-type) vs. 0 AF points capable of operating with f/8 lenses or lens/TC combos. Big Advantage: Rebel T7i
  • Both cameras have Dual Pixel CMOS AF in Live View. Draw
  • The older Rebel T7i has an RGB+IR color light meter vs. the newer Rebel SL3's older technology dual layer meter. Advantage: Rebel T7i
  • The older Rebel T7i has a slightly more powerful built-in flash that can act as a "Master" flash in the Canon optical wireless flash system. The newer Rebel SL3 has a slightly weaker flash that is not "Master" capable. Slight advantage: Rebel T7i
  • The older Rebel T7i has an ISO compliant hot shoe that can manually fire any center-pin flash (that doesn't have a trigger voltage that exceeds what the T7i can handle) or flash trigger transmitter. The newer Rebel SL3 has a "borked" hot shoe with no ISO compliant center pin that makes using anything other than dedicated CAnon TTL flashes a pain, if possible at all. Advantage Rebel T7i

Personally, the borked hot shoe would be all it would take for me to forget considering the Rebel SL3 for anything. If you don't ever plan to use any external flash (in other words, if you don't plan on learning how to be a photographer instead of snapshooter) it won't make any difference.

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    \$\begingroup\$ Ugh. I'd agree with the last paragraph especially. Unless you are certain that you'll never need this for anything more then casual pics, forget the SL3. I've come across borked shoes, as well as manufacturer specific shoe designs and it's worse then useless. \$\endgroup\$
    – AutoBaker
    Oct 18, 2019 at 8:41

Either camera will do everything you want to do for many years.

And more importantly either is an excellent choice for a first camera.

The differences in image processors won’t make a difference to you, and neither will have issues with battery life because in practice, the best way to get “enough” battery life is carrying spare batterie. That way one can be charging while another is in your camera.

The important thing is getting a camera and using it.


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