Has anyone got experience of both these lenses? Is the Tamron worth the extra money in terms of IQ and AF speed over the 55-250? I own a 60D and aleady have a tamron 17-50 VC and have been very impressed with this lens. I would like to add telephoto but in the scheme of things it will probably be my least used lens. Is the AF fast and accurate enough for a running 3 year old? Is BIF possible? I know I can get a used 55-250 for £139 which is very reasonable or I culd save for another year and get the Tamron? How does the Bokeh compare? I see from the les review the 55-250 has greater distortions. Any advice appreciated.
[quote name='vickylou' timestamp='1324027966' post='13833']
Has anyone got experience of both these lenses? Is the Tamron worth the extra money in terms of IQ and AF speed over the 55-250? I own a 60D and aleady have a tamron 17-50 VC and have been very impressed with this lens. I would like to add telephoto but in the scheme of things it will probably be my least used lens. Is the AF fast and accurate enough for a running 3 year old? Is BIF possible? I know I can get a used 55-250 for £139 which is very reasonable or I culd save for another year and get the Tamron? How does the Bokeh compare? I see from the les review the 55-250 has greater distortions. Any advice appreciated.
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No idea if the AF of each of those lenses is fast enough for fast accurate tracking of a running person. Depends on the distance from the person and used focal length too. The Tamron probably will have a bit of an edge here.
The distortion is not something to worry about, you will never notice it in your images.
BIF.... AF has to work hard when the bird is flying towards you. If it flies past, then it is more your technique and the camera's AF logic that is being tested.
The Tamron has nicer bokeh, and is optically a bit better too. the Canon is of course very affordable and less heavy/bulky.
For both there is something to say.
Is the AF fast and accurate enough for a running 3 year old? Is BIF possible?
In bright daylight with a 7D, yes. I can't speak for 60D but I think you'll be okay. Indoors, forget it.
How does the Bokeh compare?
The 55-250 has decent bokeh at 55 mm and 250 mm. Bokeh for in-between focal lengths (e.g. 135) is lousy.