Comments on new review of 600mm II just posted

[FastGass]

Finaly there is someone with the 800mm on this forum!

I am sort of in between Bryan and you about the 800mm being obsolete, if you use 800mm more than 1200mm than I see the advantages with the 600mm II. But in your case (and my case) I would probably choose the 800mm over all because I would use 800mm+ range more often. So the way I see it there is a place for both of these lenses but the 600mm is more versatile.

But it is sure is temting to have a 600mm f/4 and still have a very good, if not equivalent IQ in the reall world, and a still decent 1200mm. And because of that I still havent made up my mind completely on which one I would pick up once I have saved up enough money for either.

I have not shot alot with 600mm on a FF, I have shot some with film on my 600mm f/6.3 but not enough to know exactly how much I would use it, I think I would use most in setup blind situations were the extra IQ would be more prevalent than in the field were many shots will probably be above ISO 800 or have VERY slight motion blure in fast action.

But really the deal breaker for me would be AF performance with extenders. If it's like the older extenders were AF is reduced by 50% with the 1.4x and 100% with the 2x that would push me over the edge for the 800mm.

BTW, I plan to upgrade to FF when I jump on either lens. Probably the 5D III or if I have saved enough the 1D X.

Cheers,
John.

[HDNitehawk]

But really the deal breaker for me would be AF performance with extenders. If it's like the older extenders were AF is reduced by 50% with the 1.4x and 100% with the 2x that would push me over the edge for the 800mm.

Unless you have a 1 series body you will not be able to focus either of those lenses in Auto, unless you tape the sensors.

The OP mentioned he used a crop body, for a crop body I am more impressed with the 600mm with the 2x ISO charts than the 800mm with the 1.4x. The reason is that the crop body will not even be using the corners. The mid frame of the 600mm than the 800mm mid frame, and the 800mm in the center has a very slight edge. The 800mm wins in the corners, but unless you are full frame the corners do not matter. In actual use I don't think you will notice much difference between these two combinations unless you are full frame.http://www.the-digital-picture.com/R...mp=3&APIComp=1

Really I am not that impressed on any of the lengths ISO charts longer than the 500mm with the 2x, I think at 1200 and 1120 the 600mm and 800mm are loosing to much. http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=745&Camera=453&Sample=0&FLI=2&API= 0&LensComp=459&CameraComp=453&SampleComp=0&FLIComp =3&APIComp=1

Edit; One other point, I don't think the 800mm ISO is really beating the 600mm with the 1.4x;http://www.the-digital-picture.com/R...mp=1&APIComp=1