llareggub wrote in post #15652940
Looking for some thoughts on an impending lens purchase...
I have narrowed down my focal length to one of the 70-200mm lenses, my budget does not extend to an IS version so at present I am looking at the following.
Canon 70-200mm f4L
Sigma 70-200mm f2.8
Tamron 70-200mm f2.8
I have pretty much decided on the Canon in my mind, I don't shoot a great deal in low light situations although am tempted by the extra stop for the rare occasions when I do.
I shoot with a 50D and Tamron 17-50mm (non VC) and Sigma 50mm macro at present, looking for thoughts on pros and cons on the Sigma and Tamron

Cheers in advance
Brian
Pictures from a non-stabilized Tamron 70-200mm f/2.8 lens.
| Byte size: ZERO | Content warning: NOT AN IMAGE |
Focal Length: 182.0mm
Aperture: f/2.8
Exposure Time: 0.0013 s (1/800)
ISO equiv: 100
Exposure Bias: +0.67 EV
Metering Mode: Matrix
Exposure: aperture priority (semi-auto)
White Balance: Auto
Flash Fired: No (enforced)
Orientation: Normal
Color Space: sRGB
| Byte size: ZERO | Content warning: NOT AN IMAGE |
Focal Length: 200.0mm
Aperture: f/2.8
Exposure Time: 0.0031 s (1/320)
ISO equiv: 1600
Exposure Bias: +0.67 EV
Metering Mode: Matrix
Exposure: shutter priority (semi-auto)
White Balance: Auto
Flash Fired: No (enforced)
Orientation: Normal
Color Space: sRGB
Pictures from a
non-stabilized Sigma 70-200mm f/2.8 lens.
| Byte size: ZERO | Content warning: NOT AN IMAGE |
Focal Length: 200.0mm
Aperture: f/2.8
Exposure Time: 0.0013 s (1/800)
ISO equiv: 2000
Exposure Bias: +0.33 EV
Metering Mode: Matrix
Exposure: shutter priority (semi-auto)
White Balance: Manual
Flash Fired: No (enforced)
Orientation: Normal
Color Space: sRGB
| Byte size: ZERO | Content warning: NOT AN IMAGE |
Focal Length: 200.0mm
Aperture: f/2.8
Exposure Time: 0.0008 s (1/1250)
ISO equiv: 100
Exposure Bias: none
Metering Mode: Matrix
Exposure: aperture priority (semi-auto)
White Balance: Auto
Flash Fired: No (enforced)
Orientation: Normal
Color Space: sRGB
These examples and observations come from having actually owned and used the Tamron and Sigma lenses. Both can create good images, but the Tamron version is saddled with slow and inconsistent autofocus response. Since my work deals with moving objects, I gave up on the Tamron lens, which is the least expensive 70-200mm f/2.8 lens sold as new on the market. The Tamron is best suited for work with subjects that are more or less stationary.