Sell 70-300 IS for 70-200L f/4 non-IS?

Would this be worth it?

Depends on how much you rely on IS.

For me, IS is crucial on a telephoto lens. I shoot handheld though.

Upgrading to a non-rotating front element would be enough for me.

Yes!

*personally*, I'd save up and go for the f/4 IS, instead. I find that IS is useful in the longer lenses more often than it's not; I don't find a lot of situations where those focal lengths are in use that it's possible to keep 1/200 or better, without really running the ISO up.

Worth it. The non-IS is a very good lens. I personally don't think IS is worth the extra $600 for the f4 IS, but thats just me.

I use my 70-200mm f/4L IS 4-5x more often than I was ever able to use my non-IS version of that lens. The reason: I can hand hold this lens at 200mm down to 1/60 second with every expectation of a sharp image. I can hand hold at 1/30 second with not quite 100% expectation of sharp imagery but the keeper percentage is respectable.

I needed 1/300 second or more with the non-is lens. That is a two to three stop difference.

I know that IS doesn't stop subject's motion but, I don't always shoot subjects that are in motion!

Additionally, IS Mode 2 facilitates smooth panning shots.

The IS lens is probably 2x the price of the non-IS model. Since I can use it 4-5x more often it is cost effective for me. I carry it everywhere and use it as half of my two lens setup on a pair of 1.6x cameras. The other lens I pair with it is the 17-55mm f/2.8 IS. BTW: I don't miss the 55-70mm gap!

The IS capability is not the only difference between the IS and non-IS lenses. The IS model has better weather proofing, slightly better IQ and smother bokeh due to its rounded aperture blades.

In fact, it is my favorite portrait lens on my 7D camera!

RPCrowe wrote in post #15085360
I use my 70-200mm f/4L IS 4-5x more often than I was ever able to use my non-IS version of that lens. The reason: I can hand hold this lens at 200mm down to 1/60 second with every expectation of a sharp image. I can hand hold at 1/30 second with not quite 100% expectation of sharp imagery but the keeper percentage is respectable.

Exact same experience I had with the one I had.... now the Sigma is 100% keepers at 1/20 at 200mm. The OS works great (when it works, mine had to get replaced and is back in route to me now)

Exact same experience I had.

i wouldn't