topic Re: canon rf 100-500mm f/4.5-7.1l is usm lens, please explain, setting focal distance range in EF & RF Lenses

canon rf 100-500mm f/4.5-7.1l is usm lens, please explain, setting focal distance range

ahardy — Fri, 13 Oct 2023 02:00:12 GMT

I have they canon rf 100-500mm f/4.5-7.1l is usm lens. Can someone explain the "settng focal distance range".

I am photographing wildlife ie moose, bears, wild horses. I am having trouble with clarity of the animal at a distance. I read the manual and I'm still not sure if I should use "full" or "3 meters to infinity". I had it on the latter, and feel like thats not working. I have been on a good tripod, and hand holding with shutter speed up to 1200. Appreciate any advice. Alicen

Re: canon rf 100-500mm f/4.5-7.1l is usm lens, please explain, setting focal distance range

Anonymous — Fri, 13 Oct 2023 02:09:35 GMT

If your subject is further than 3 meters away, setting the lens on 3 meters to infinity will help the lens focus more quickly. If closer than 3 meters, then set it to full so the lens can focus closer than 3 meters. If set it to full and you shoot a subject farther away, it may take a little longer to obtain focus, but should work. Full gives you the full range of focus for the lens, without concern on your subject distance.

The focus limit switch just limits the range of focus distance to enable quicker focusing.

Re: canon rf 100-500mm f/4.5-7.1l is usm lens, please explain, setting focal distance range

rs-eos — Fri, 13 Oct 2023 02:08:53 GMT

If what you're photographing will always be 3 m (approx 10 ft) away, then set the lens to "3m to infinity". By restricting the range, that will help achieve focus more quickly.

You'd set it to the full range if you'd end up taking photos where subjects could be at varying distances, to include down to about 1 m (3 ft) which is the minimum focusing distance.

Can you further explain what is not working? Do you have example images you have taken? Can you estimate how far away your subjects were?

Re: canon rf 100-500mm f/4.5-7.1l is usm lens, please explain, setting focal distance range

ColinBROWN — Fri, 13 Oct 2023 04:28:41 GMT

I just say stay more than 3 metres away from the bear for safety reasons, when it comes to the EVF focal distance scale. I am not expert on wildlife photography, but I just have an inkling that my advice makes sense.

Re: canon rf 100-500mm f/4.5-7.1l is usm lens, please explain, setting focal distance range

ahardy — Fri, 13 Oct 2023 17:17:07 GMT

yeah, I live in Wyoming. Pretty bear aware. My question is: at a distance of ie 100-200 yards and the lens at 500mm is it better for a sharpest photo to use 3 meter to infinity or use the "full" setting that also has a focal distance to 500mm? thanks 🙂

Re: canon rf 100-500mm f/4.5-7.1l is usm lens, please explain, setting focal distance range

ahardy — Fri, 13 Oct 2023 17:21:57 GMT

I live in Wyoming. Pretty bear aware. My question is: at a distance of ie 100-200 yards and the lens at 500mm, is it better for a sharpest photo to use "3 meter to infinity" or use the "full" setting that also has a focal distance to 500mm? My foreground and background are pretty sharp, but the bear or other large animals are soft. I think it is the law of physics (too far away) but wondering which setting to use on the focus limiter. thanks!

Re: canon rf 100-500mm f/4.5-7.1l is usm lens, please explain, setting focal distance range

ahardy — Fri, 13 Oct 2023 17:24:00 GMT

ok thanks! better explanation than the manual.

Re: canon rf 100-500mm f/4.5-7.1l is usm lens, please explain, setting focal distance range

ahardy — Fri, 13 Oct 2023 17:28:49 GMT

thanks again, never shooting less then 3 meters with this lens. So sounds like 3meter to infinity will focus faster! I live in Wyoming. Pretty bear aware. Mostly at 100-200 yards and the lens at 500mm My foreground and background are pretty sharp, but the bear or other large animals are soft. I think it is the law of physics (too far away). ALICEN

Re: canon rf 100-500mm f/4.5-7.1l is usm lens, please explain, setting focal distance range

shadowsports — Sat, 14 Oct 2023 00:51:44 GMT

Hi ahardy,

RS-EOS & 5DIV (Ricky and Bob are both so wonderful!) 😎

The RF 100-500 has a MFD (minimum focus distance) of 2.95 ft (a little under 3ft) at 100mm. This means it cannot focus on a subject closer than that. Lens|-----3ft----|subject . The MFD increases as you increase FL (focal length).

If the subject is at or beyond this distance, no problem. If the subject is closer than 3ft, the subject will be blurry (not in focus)

Focal distance range

Full (Basically) 3ft to Infinity. This tells the lens it will be looking for subjects between 3ft and infinity.

3 meters to Infinity (Basically) 9ft to Infinity. This setting does two things. It tells the lens it will be ignoring subjects between 3-9ft. It also changes the logic the lens uses to acquire focus on subjects at greater distances. The MFD still varies based on the set focal length, but the lens doesn't do the full focus "pull" from blurry to sharp when it being told to lock its focus on a distance subject.

As the guys pointed out above, the lens is able to acquire focus faster (more quickly) if it knows it should not be looking for subjects closer than 9ft. Remembering that the lens cannot focus on a subject closer than its MFD of approx 3ft. at the minimum FL.

"Its not "better" per se to use 3m to infinity on distance subjects, this setting just allows the lens to focus more quickly. The same focus will be achieved, it might just take a micro second longer if full is used. The latter is a focus acquisition (speed) performance improvement, not an image sharpness improvement.

The performance enhancement is different based on the focal length you have set. Try setting your AF to a single focus point. Use the focus limiter switch to improve focus speed on subjects at greater distances.

Go ahead and experiment. I think after a few shots you'll see what we mean.

Re: canon rf 100-500mm f/4.5-7.1l is usm lens, please explain, setting focal distance range

rs-eos — Fri, 13 Oct 2023 19:52:15 GMT

Thanks, Rick! Yep, agreed that the range will not have any impact on sharpness or other quality aspects in the photos. It's just there to improve speed of acquiring focus (effectively a hint for the lens).

Re: canon rf 100-500mm f/4.5-7.1l is usm lens, please explain, setting focal distance range

wq9nsc — Fri, 13 Oct 2023 22:19:10 GMT

The focus limiter won't have any effect upon sharpness once the lens is in focus, ONLY on how quickly it may achieve focus. For wildlife situations like you describe, setting it to limit to 3 meters and beyond will provide faster focus acquisition under SOME conditions but image quality will be the same regardless of the limit switch setting.

150-200 yards is a long distance for a 500mm lens. At 600 feet, the field of view is going to be around 28 by 42 feet so even a grizzly is going to occupy only a small part of the sensor.

If lighting conditions permit, try stepping the lens one stop down from fully wide open and it might marginally help with image quality but if lighting isn't excellent then the increase in ISO would more than offset any gain in IQ.

What is the ISO for your captures? As sensor amplifier gain is increased at higher ISO, so is noise and some softening will occur as part of noise reduction. This becomes much more problematic when heavy cropping is needed due to focal length and distance issues. This is a case where you want to use the slowest shutter speed possible that avoids blur in order for the ISO to be as low as possible for a standard exposure.

Rodger

Re: canon rf 100-500mm f/4.5-7.1l is usm lens, please explain, setting focal distance range

kvbarkley — Sat, 14 Oct 2023 02:34:44 GMT

Two points:

Are you hand held?

If one of the allowed focus points has an object closer than the subject - like a branch in front of your wildlife, the camera will focus on that. DPP will tell you what the camera is focused on. I also suggest keeping the focus points in the center.

Re: canon rf 100-500mm f/4.5-7.1l is usm lens, please explain, setting focal distance range

ahardy — Sat, 14 Oct 2023 04:11:24 GMT

thanks, after reading everyones comments, I understand it much better! you all are great!

Re: canon rf 100-500mm f/4.5-7.1l is usm lens, please explain, setting focal distance range

ahardy — Sat, 14 Oct 2023 04:13:17 GMT

thanks again, you all are great. I have a much better understanding. Most my shooting is distant, so will keep on 3 to infinity, but remember to flip it if something is closer (not bears, lol).

Re: canon rf 100-500mm f/4.5-7.1l is usm lens, please explain, setting focal distance range

ahardy — Mon, 16 Oct 2023 20:19:57 GMT

yup, Usually use spot focusing, appreciate the reply.

Re: canon rf 100-500mm f/4.5-7.1l is usm lens, please explain, setting focal distance range

ahardy — Mon, 16 Oct 2023 20:26:48 GMT

If I'm hand holding my shutter speed is 500-1000, which sometime I need to to get around trees or I can't get out of the car. Your reply makes great sense to use my tripod (it's manfrotto 055) if possible to lower the shutter speed. Thanks for the reply!

Re: canon rf 100-500mm f/4.5-7.1l is usm lens, please explain, setting focal distance range

ahardy — Mon, 16 Oct 2023 20:27:38 GMT

Also, I realize the distance shot are difficult, just trying to improve them as much as I can.

Re: canon rf 100-500mm f/4.5-7.1l is usm lens, please explain, setting focal distance range

ahardy — Mon, 16 Oct 2023 20:30:12 GMT

thanks, I learned from your comment that 3 to infinity maybe helpful to avoid a tree branch. Hasn't really been a problem yet, but will keep that in mind.

Re: canon rf 100-500mm f/4.5-7.1l is usm lens, please explain, setting focal distance range

kvbarkley — Mon, 16 Oct 2023 21:23:23 GMT

As you can see, I learned the hard way: