Canon f/4 17-40 or Tamron f/2.8 17-50?

[WillK]

I currently have the T3i with 18-55 and 55-250 Kit lens, along with the 50mm 1.8.

I'm not sure which lens to upgrade to next. the Canon EF 17-40 f/4 L or the Tamron SP 17-50 f/2.8 XR Di II VC?I do't know whether to go with Canon's glass and sacrifice f/4 during indoor events, or go with the fast Tamron 2.8, but the glass won't be top notch? I do landscape, street, and events. I've been invited to a culture performance inside a campus theatre, so it was packed in there. Also I was front seat capturing images so sometimes I need the wide angle. I also do landscapes so I tend to use the wide a lot.

I'm interested into medical field and for HOSA competition, I'm doing medical photography, so I have to take pictures of the professionals in action. This brings up situations like hospital rooms, operating rooms, and close patient interaction. The focal length for this would be fine for either lens, but the aperture is what I'm worried about.

The features I'm focusing on: aperture, focus/sharpness, image quality

 

[greybeard]

I had the Tamron in a Nikon mount and it was noisy to focus and very soft at f/2.8. I ended up selling it and going back to my kit lens until I bought my 16-85

 

[David444]

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