This is why I bought the 70-200 2.8 with 1.7 converter

[ceeboy14]

It's not a bad shot and was shot with a Nikon 55-300 but it clearly shows the difference between a $1600 piece of glass and a $500 piece of glass.

View attachment 32790 and this guy was darting about all over the sky. Both were shot at approximately the same distance.

 

[jaomul]

Not sure. The one on the right is brighter and all but the one on the left seems like its in different lighting, cloudy and darker so possibly a slower shutter. No doubt the newer glass is better but a proper comparison should show the best both can produce.

 

[ceeboy14]

I was only comparing sharpness at equal distances.

 

[matthewo]

it surprised me how well the 70-200 works with the tc20e iii also, I bought the teleconverter for my 300mm 2.8, but it makes the 70-200 a very compact 140-400 f5.6 lens...

 

[ceeboy14]

Other than one of the honker 600mm's I couldn't be happier...The gull was shot at the equivilent of 330mm while the Ospreys were at about 280 on the 55-300 where 300 is fuzzy. It can be argued the extra 50mm provided more sharpness but at approximately 50 feet for each, the 70-200 w/1.7 wins it hands down. I'm going to sell my 55-300 which is good to a point - a bit closer and closer to 240mm at f/8 with the subject closer than 50 feet.