Tamron 28-75 f2.8

[Colin the King]

I've just purchased this lens and decided to take some test shots to ensure the sharpness is acceptable. I've read comments that sometimes the quality control isn't quite what it should be.
I've attached 2 shots from a series I took and wonder if you reckon if the difference in sharpness is what I should expect. The f2.8 seems a tad soft to me, however I'm not sure if I'm expecting too much from a £270 lens.

The first image is f2.8 @75mm ISO 100
The second is f4 @75mm ISO 100

Thanks in advance.

[kawter2]

was it on a tripod?

what was the shutter speed?


Might want to try to have a test shot with a lot more ambient light, and post a 100% crop. It is hard to tell with these if it is camera shake, or interpolation etc..

[Colin the King]

Not on a tripod but sat on a solid table. Shots were taken using a remote control.
1st shot 1/40 second - White Balance tungsten - Sharpness +2
2nd shot 1/20 second ditto the rest.

I'll try some daylight shots (grey sky & rain !!) this weekend.

[quickben]

I have this lens, and mine is also not as sharp at 2.8 as it is at 4.0. It is, however very sharp from f4.0 onwards. I'm sure you already know this, but a lens is generally at it's sharpest one or two stops short of it's biggest aperture. So, what you have there is a perfectly servicable lens :-). I generally use F3.5 for low light and F4.5 for daylight.

You'll like this lens. For the money, I don't think you'll get a better one (optically) without a red band (L series). It produces decent bokeh, due to the 7-bladed diaphragm and the colours are good also. It's on my 10d about 75% of the time. Enjoy.

Gary.

[Colin the King]

quickben,
thanks for this, it's the answer i expected & hoped for. I'm looking forward to trying this out seriously in the near future.