RDM5546 wrote:
Jon555 wrote:
rrc1967 wrote:
Jon555 wrote:
quiquae wrote:
John Sheehy wrote:
quiquae wrote:
Jon555 wrote:
They will definitely AF as-is, f/11 is fine for all DPAF, but I doubt you'll be able to add the extenders, especially the 2x, and have AF work (other than with a R5 or R6 that is).
Actually, I think you're wrong about that. Canon's official product pages for the extenders are now up, and they don't say anything about the extenders not working on R or RP.
It's not about the TC itself where there may be an issue; it is about the resulting open f-number. Canon says f/22 works on the R5 and R6, meaning that AF is reasonably fast and reliable by some standard. It is possible that the same f/22 will be more difficult for the R and RP, with more hunting in low light and low contrast.
EOS R actually has exactly the same low-light focusing spec (EV -6 @ F1.2) as R5, and only half a stop behind R6 (EV -6.5), which suggests that it shouldn't lag much the newer bodies in low-aperture focusing, if at all. But we'll see.
The question is will the R and RP focus at f/22, and I've never heard anything vaguely like that mentioned (just f/11, e./g. see the quote below). The issue is the size of the aperture rather than the amount of light you are getting.
"The AF points on the EOS R are compatible with maximum aperture f/11 at all AF positions (when used with a compatible lens and extender, such as the EF100-400mm f/4.5-5.6L IS II USM lens paired with a 2x extender). This makes AF possible even when shooting at a super-telephoto 800mm, dramatically expanding shooting possibilities for wildlife photographers."
F22 probably not. however, F22 is with a tele extender. F11 probably yes.
I seem to recall F16 being a limit, but to be honest after a while at this over the past week i'm lucky to remember my birthdate.
It still counts with an extender, take a f/5.6 lens and add a 2x you get f/11 and it won't AF on a DSLR that AFs to f/8.
AFAIK all Canon live-view went to f/11 (and possible a teeny bit more, 1/3 - 1/2 stop) prior to these cameras.
I was curious about the existing performance of the EOS R I now own. The EOS 5D mk IV only would focus or even try down to an f8 lens.
The EOS 5D only works with my f4 and f2.8 zoom lenses using my EF 2X iii , EF 2X and Sigma 2X extenders. For smaller aperatures it does not even try to focus. I only recently learned that my EOS R gives new life to smaller aperatures with the 2X extended lens. They work well at f5.6 and the 2X extender, f11/12 is a useful aperture on bright days.
The 2X iii is softer than the 1.4X extenders that I use more frequently but it still is useful if it can make the shot. Sometimes cropping the 1.4X is better though.
Some forum members may gag but I stackered two 2X extenders which is not easy to do. Both the 2X II and the Sigma 2001 2C have a small front so it is possible to stack behind the Canon EF 2X iii to create 4X to try with the EOS R to see how far it goes with small aperatures. I used it with my EF 100-400mm at 400mmm f5.6. The focus is not real fast but the EOS R does focus the 1600mm f22 attrocity.
I then tried the Sigma 150-600mm using the two stacked 2X TCs at 600mm f6.3 making a 2400mmf25.2 long lens. Amazing it still tries to focus and sometimes it locks on. I shot a picture of a brightly illuminated section of a distant palm tree successful. It want not crazy sharp but not real horrible especially for such an experiment. However, darker region of tree not in sunlight did not lock on focus.
My take away from this trial is the EOS R works well at low light and is better at using my 2X TCs than my EOS 5D Mk IV. I am sure this is only nonsense to the 100 ISO or bust sunrise shooting crowd. I am hoping the EOS R5 will have lower sensor noise shooting ISOs above 1600 like 3000 or 4500 ISO and make better shooting possible with longer , lighter and cheaper lenses having smaller apertures.
Today I took more pictures using the EOS R with the Sigma 150-600 and the Canon EF 2X iii TC with the Sigma 2X 2001 TC stacked. The two TCs form a 4X TC (usually a horrible idea perhaps) and will add to the Sigma 150-600mm four f stops. When the Sigma is at 600mmf2.3 this combineation 2400mmf25.2.
Pretty dark you say? Here is an actual picture using two stacked 2X TCs. I was surprised with hour the f25.2 2400mm lens worked so well in the the bright outside afternoon daylight
Note the transformer label on this power pole about 65 yards away from the shooter
1/500th f13 ISO 2000 (2400mm equivalent f25.2)
Compare with the same lens with only a 2X TC (the Sigma 2001)
1/2000 f13 at ISO 2000 (1200mm equiv f13)
This one is at 300mm with the Sigma 155-600 and a the Sigma 2x 2001 TC
1/500th f10 ISO 2000 (600mm equivalent FL f10)
