RF extender experiences with RF 100-500 1.4x vs 2.0? Locked

David M. Anglin wrote:

I have been shooting Canon gear for years including long lenses and teleconverters. I have owned the 1.4x & 2x version I, II, III. As of switching to the R5, I have decided that I do not like the IQ loss of any of the 2x extenders I have tried to date.

I shot for for 17 days in YNP/GTNP with the R5 + RF 1.4x TC + 100-500 f4.5-f7.1, every thing from birds to bears.

• The 100-500 is as good or better than the 100-400 II with only a little loss of light @400mm.
• the 100-500 is nice to carry at almost 1/2 lb lighter than the 100-400 II
• AF is fast/accurate shooting both bare and with the RF 1.4x TC.
• You can crop the R5 + 100-500 + 1.4x image to an 800mm FOV and and still have a 33mp image.
• The 100-500 + 1.4x looks is sharp and looses very little IQ if any.
• I do not plan to purchase a 2x extender, I would just rent a 600mm f4 and use a 2x extender
  • I bought / returned the RF 800 f11, liked the IQ but didn't like the bokeh and f11.
• Here is what I don't like about the 1.4x + 100-500
  • lens has to be extend to 300mm before you can add the 1.4x and will not retract below 300mm
  • Loose the use of the 100-420 range of the lens with the 1.4x TC connected
  • Inconvenient to add/remove TC when animals are rapidly changing distance and limits creative framing to include the environment.
  • Solution: If you have the 100-400 II, keep the lens and place it on your backup body for the 100-400 range shots. Treat the R5 + 1.4x + 100-500 as a dedicated 420-700 zoom.

This is exactly my experience. I would add that the RF 70-200 2.8 is also a great combo with the 100-500 + 1.4x if price is not an issue. The size, weight, IQ, and max aperture of the RF 70-200 2.8 are really nice.

Even having a single body and swapping two lenses back and forth is easier than adding and removing the TC on the 100-500. The TC also requires two caps when removed, which is a real pain compared to the single cap if swapping lenses. With a lens swap, the cap on the lens to swap gets reused on the lens removed. With the TC, the two caps have to be kept up with separately.

I haven't tried the RF 800, but bokeh from my RF 600 was not too bad provided I was shooting close to minimum focus distance and the background was sufficiently far away. My biggest objection to the f/11 lenses is the reduced AF spread, which is limited to a box in the center of the frame (although that can be worked around somewhat by shooting in crop mode, which causes the AF area to at least fill the frame top to bottom).

Just this weekend, I've been able to compare the EF 400 5.6 prime on the EOS Ra against the 100-500 at 400. Sharpness is equal if the EF prime is stopped down to f/6.3 to match the zoom. Vignetting, contrast, and color is better with the prime even wide open at f/5.6. Bokeh can be matched with the zoom if the zoom is shot at 500mm or if the closer focus of the zoom is taken advantage of.