Canon RF 100-500mm f/4.5-7.1L IS USM images here.

Besides having a zoom the short and minimal Focus distance is very nice.

Thanks for the comments, Sys.

edmidlifecrisis wrote in post #19224158
Hi Ed, if you're asking me, I don't have the 800 anymore and I don't have the 1.4 RF converter. I haven't decided yet if I'm going to get one......

The one thing I liked about the 800 is the size/weight and that it points to the subject VERY easily. I had no trouble finding the subject in the lens which I can struggle with with the big white lenses. And the AF was very good.

I just wasn't happy with IQ and the high ISO needed since a lot of my photos are not in bright light. I will say, that after seeing some of the photos in this thread I am wondering if I was premature to return it!!! For travel it would be great. This 100-500 is also going to be great for travel since it's not seriously heavy or large (at least to me).

SYS wrote in post #19224179
I'll chime in....

The 800 can provide very good IQ but quite limiting when the lighting isn't good. Even in a decent lighting condition, I'm typically shooting in higher ISO than with the 100-500 with the 1.4x. For this reason as well as the lens FL, I prefer to use the 800 on my monopod or tripod in order to get away with a lower shutter speed that would in turn lower the ISO. Wish that Canon had provided the lens collar for the 800. Hopefully, a third-partier would come up with one.

The only advantage that the 800 has over the 100-500 are its light weight, the FL and the cost, while for everything else (built quality, versatility, weather sealing, IQ, etc.) the advantage goes to the 100-500.

Since for the most part, the combination of the 100-500 and the 1.4x meets my FL needs, I tend to grab the combo way more than reaching for the 800. I do intend to use the 800 more when I'm traveling to, say, the Yellowstone NP and other places more for wildlife than birding.

Thanks for the comments, guys. SYS, you say higher ISO with the 800mm. But the front elements are the same size for the two alternatives. Light gathering is equal. So you might be 1/3 stop lower ISO with the 100-500/1.4, but that is 700mm, and by the time you crop to the same view, the noise should be the same, should it not? Maybe there is more to it, and experience means more than some calculations.

I was speculating that the resolution of the 100-500/1.4 might be better than for the 800mm, even after correcting for the view, but I don't know.

I'm just beginning to get experience with the 800 and am getting mixed results so far.

Archibald wrote in post #19224202
Thanks for the comments, guys. SYS, you say higher ISO with the 800mm. But the front elements are the same size for the two alternatives. Light gathering is equal. So you might be 1/3 stop lower ISO with the 100-500/1.4, but that is 700mm, and by the time you crop to the same view, the noise should be the same, should it not? Maybe there is more to it, and experience means more than some calculations.

I was speculating that the resolution of the 100-500/1.4 might be better than for the 800mm, even after correcting for the view, but I don't know.

I'm just beginning to get experience with the 800 and am getting mixed results so far.

I don't know the adjusted value relationship between the ISO and the amount of cropping. At their respective fixed FL at far end, the 100-500/1.4x gives you f/10 while the 800's f/11, but I haven't done any calculative comparisons. Perhaps I've been shooting at higher SS with the 800 in order to get the desired outcome on par with the 100-500/1.4x. It's not that I'm not dealing with the noise issues with the 100-500/1.4x combo, just more with the 800 in my experience.

This image, for example, shot with the 800 at 1/1000sec in a good lighting condition still had the Auto ISO kicking it up to 5000. Even at 1/1000sec, only about half of the shot series of this Northern Flicker came out tack sharp given its constant pecking movement. Given the 5000 ISO, I didn't want to kick up the SS, settling for about a 50% keeper rate. Topaz did a pretty good job with the noise clean up without sacrificing much detail. This is a typical experience with the 800.

From this afternoon. Liking these images so far.

IMAGE LINK: https://flic.kr/p/2kTq​V66

one more from this afternoon, more lens testing

SYS wrote in post #19225993

Hosted photo: posted by SYS in
./showthread.php?p=192​25993&i=i106812561
forum: Lens Sample Photo Archive

Nice and sharp!

Archibald wrote in post #19226461
Nice and sharp!

Thanks, Ed ~~

heavy crop

IMAGE LINK: https://flic.kr/p/2kUp​jQY

A mosquito lunch....

SYS wrote in post #19230175

Gallery photo (hosted):
posted by SYS originally in forum: Canon Digital Cameras

Nice shot, uncluttered.

Archibald wrote in post #19230182
Nice shot, uncluttered.

Thanks, Ed ~~

Finally got to see some birds and BIF with this lens early this morning at a rookery. More to follow. So far the flight shots look good. Have a lot to sort through.
Early morning Egret

IMAGE LINK: https://flic.kr/p/2kVY​gLL