Canon or Tamron?

M

MiqsPix

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173
Name
Roger
Edit My Images
No
I am considering buying either the Canon EF 28-135mm or the Tamron 28-75. I don't fully understand the Tamron in that it is f2.8 full time. I acknowledge this could be beneficial in low light but as there is no image stabilisation on this lens exposure times will be required to be fast. My question is this. If it is f2.8 full time does that mean that the focal length is permanently short so taking a shot for example of a group of people, or a landscape, the shot will have more out of focus areas than a lens that stops down? Does the camera compensate for this? I hope this doesn't sound elementary (it probably is to the informed) but I genuinely can't understand this point. :help:
 
No, having a faster aperture does not always means having a smaller DoF. You can still stop down to get larger DoF, you just have the ability to open to f/2.8 should you want to.

I'd go for the tamron. It doesn't have IS, but it is faster, so it'll be easier to get faster shutter speeds when you need them.
 
A "full time" f/2.8 doesnt mean its cant go higher, just means it can stay at f/2.8 throughout the zoom range. Most zooms shift the aperture up as they zoom out, so its not uncommon to have a 70-200mm zoom with f/4.5 at 70mm and f/5.6 at 200mm.

The tamron will stay at whatever aperture you select throughout its zoom.
 
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