08-14-2022 04:09 PM - edited 07-08-2024 02:15 PM
I had been observing a lot of chatter about the performance of 3rd party lenses with the new RF mount. In particular the comments that the very popular Sigma 150-600c has focusing issues on the RF mount. Sigma went to the effort of publishing a video to the effect that their lenses do work perfectly, demonstrating with the FF R6 bodies:
How to use Sigma lenses seamlessly on Canon RF via the EF-EOS R adaptor (youtube.com)
However, as it turned out it seems to be an issue specific to the R7, which has an APS-C body and crammed 32MP into that smaller sensor and that has implications in many areas, given the sensor is used for focusing. After much back and forth, photographer Duade Paton get a letter from Canon Japan that admitted there is issue was with the R7's focusing system, combined with higher shutter speed. You can see that video:
CANON RESPOND, THEIR ADMISSION SURPRISED ME! (youtube.com) (see section on Canon's response)
So, I decided to take my FF R5 (45MP FF) combination to a gannet colony close to where I live. Without doubt, the lens, used with the Canon basic EF-RF adapter, was not quite as fast as the native RF 100-500L lens, which is an amazing optic and has dual Nano-USM motors. However. it performed very acceptably - according to my statistics I got about 73% with a lock on the Sigma, and 84% lock with the RF 100-500 lens - the keeper rates are as much a function of the speed of these birds rocketing along and photographer error, so it was pretty good at getting the shots.
So, here are a few of images of my experience.
The bottom line is that the lens is capable of generating acceptable results for those who have this lens and are not updating to the RF native tele lenses yet.
08-15-2022 10:26 AM
Interesting question and reply. I have a T7 and the Sigma 150-600 lens. Nice photos, BTW.
08-16-2022 09:23 AM
Question: How do you insert the camera settings at the bottom of the photo? Thanks.
08-20-2022 07:44 PM
I think I answered this question in another post of yours. Anyway...
When you have selected an image to upload, and it appears in the upload dialogue box, directly beneath the image will be a space to type a caption. That is where you put the information to which you refer.
I hope that helps! 🙂
08-21-2022 03:29 PM
Nice photos and I admire your skill
08-21-2022 03:39 PM
Thanks John for you kind words. I am really appreciative of the performance of the gear in helping me get those shots. Gannets move at a tremendous speed and change direction very quickly, so the ability to use the animal eye tracking with the super wide range of this lens is a real boon.
The 150-600 is no slouch either, but much lighter and much cheaper. There are a lot of them appearing on the web for sale as people move to the RF 100-500 - which is a brilliant lens, but it is very expensive and does not have the range at the long end of the Sigmas.
08-22-2022 09:42 AM
A lesson one might take from your post is that the EOS R5 makes whatever lens one already owns look better and it is likely not necessary to buy a new lens. I admire your work.
I use "EF100-400mm f/4.5-5.6L IS II USM +1.4x III" and also the 2x III for a long focal length with the EOS R5. So far, the only non-Canon lens that I use with the EOS R5 is an adapted 45 year old Minolta 50mm from a film camera. I do not have any RF lenses. I also often photograph birds, so I am impressed by your photos. The EF100-400mm f/4.5-5.6L IS II USM also is good for closeups as well as distant subjects. I often use EF-S lenses as well. I use Canon DPP digital lens optimizer for the Canon lenses and for the Minolta lens I export a 16 bit TIFF from DPP on my iMac and use the GMIC plugin in gimp on my Linux machine for Richardson/Lucy deconvolution to remove small aperture diffraction blur.
08-22-2022 03:24 PM
Thank you John!
I too have the EF 100-400 MkII, and the 1.4 and 2.0x MkIII extenders, although I have not tried those last two units with the R5, I must admit. I had success with the 100-400+1.4x on my DSLRs, but found that the 2.0x degraded the image quality significantly. I see that a bit in the image of your eagle, where your shutter speed is very high and at that distance focus should not be an issue, but the image is soft - something I put down to the 2.0 extender. I love your photo of the Black-eye Susan plants in full bloom!
I often used the 100-400+1.4x combination on my 7DII and that gave the extra boost in FoV that I was seeking - the 2.0x extender has worked OK with my 70-200 lenses, but then I have that range covered by the 100-400, so there is no need. The EF 100-400 is an awesome lens and I put it under some serious testing with the rather unforgiving EOS 5 DsR, which at 52MP and no AA filter, shows any flaw in the lens or technique. In some ways the R5 is a bit like that too - it is so precise that it will show the least flaw, but that is rather compensated for by the IBIS and eye tracking, which are amazing.
08-22-2022 04:58 PM - edited 08-22-2022 04:59 PM
Thanks. Your skill is greater than mine.
I was swinging the camera about wildly trying to track the eagle. If I had stopped down to F/13 there would have been less blur after correction for diffraction. Also, even over that short distance changes in air density caused distortion. Sometimes the 2x works and sometimes it doesn't. Here is one under less challenging conditions where it worked. Hand held, but from an automobile window to avoid scaring the bird. The water has the famous Oklahoma red dirt in it. Image is reduced to 50% to make it small enough to upload. Second is 100% crop and not reduced.
08-22-2022 05:23 PM
This shot is a lot cleaner, and given the optical limits of the system and the downsizing, it's great. I am just not a great fan of the 2x with the longer FL. Furthermore the extenders render very different results on different bodies, I have found. Canon published a long list of camera/lens combos that worked or did not work with the extenders.
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