Last night as I headed out for dinner I was almost blinded by the brilliance of a cloudless night and a rising full moon. Once I got back ome I had to get the camera, but which lens. My 135 f2L is my sharpest lens. It is also 5 times more expensive then either of my longer zooms, both of which retail for under $200.
Over time I learned that if I shoot my zooms at f11 and then in post resize my image to about 1/2 of it's original I can get a pretty good image. But can I do the oposite? Can I shoot a picture with my 135 prime and scale it up in Photoshop and have it looking as good as the zooms at full size?
Yes and No, actually I am leaning more heavily toward No. If you compair the enlarged moon (bottom center) to the Sigma (top right) at full size you'll see the Sigma is a little bit sharper. Yes I can sharpen the enlargement but really, I can do the same with the Sigma.
So, at the end of this little experiment I have decided to keep the Sigma in my bag. It is more of a pain, having to shoot at f11 and fast shutter speeds (faster then 1/500th). On a overcast day I generally have to shoot at ISO's upwards to 3200!
Chris