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Canon EF and RF Lenses – All Autofocus Motors

exclusivearchitecture.com

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Re: Canon EF and RF Lenses – All Autofocus Motors

#91

Post by dylan604 »

genewitch wrote: post #62
dylan604 wrote: post #40

Earlier quoted context omitted.

Yeah, online rental places have pretty much made the locals fade away. The one in my local area requires a "deposit" worth the full sales price which makes it out of the reach of anyone but those well off. We used to joke about the B&H rental by taking full advantage of the 30-day return policy. Even Amazon's return policy qualifies now. You just need to the up front funds available and hope that wear&tear is not not…

Hard for local shops to keep up with fraud? You don't say.

I like how the messenger is getting shot. It's as if my reporting of what actually happens is being interpreted as that's what I do. Just because I know of how the system gets played does not make me a player.

Re: Canon EF and RF Lenses – All Autofocus Motors

#92

Post by shagie »

LgWoodenBadger wrote: post #90
shagie wrote: post #32

Earlier quoted context omitted.

The traditional Nikon mount has a small screw that is turned. The camera autofocus speed is limited by the amount of torque that can be applied to the screw - which can make focusing some of the heavier lenses slower. https://www.discoverdigitalphotography.com/2012/lens-mounts-... The "AF-D" lenses have contacts back to the camera body that communicate distance information (that is in turn used by the camera body to…

Nikon his shifted almost exclusively to their Z mount lenses. And some of these have in-lens and/or on-camera VR.

The SLR lenses are still in wide production. https://www.nikonusa.com/c/lenses/dslr-lenses/overview

The Z lenses are for the mirrorless bodies and only work on the mirrorless bodies. https://www.nikonusa.com/c/lenses/mirrorless-lenses/overview

As long as SLR bodies are produced, Nikon will continue to make SLR lenses (and probably for a while afterwards)

https://en.wikipedia.org/wiki/Nikon_D6 was released in 2020.

Re: Canon EF and RF Lenses – All Autofocus Motors

#93

Post by roblh »

divan wrote: post #86
Sharlin wrote: post #59

Earlier quoted context omitted.

Nowadays they use pre-trained pattern recognition AI models, yes, which has become much more impressive (and CPU-intensive) with mirrorless cameras where the entire resolution of the main image sensor is available for analyzing the scene. Some higher-end traditional DSLRs have a "high"-resolution (around 0.1 MPix or so) metering sensor that is used to assist the AF system (eg. what Canon calls iSA and iTR [1]). Tradi…

Sony A9 III even has a configuration setting of whether it should focus on the left or right eye of the person :) It also can remember faces and prioritize them if there other faces. Let's say someone shoots their kid on the football field and wants only them to be in focus.

The left eye/right eye option has been around even on lower end cameras for the better part of a decade, which is kinda wild. My fuji from 2017 has that, and Fuji are specifically known for having worse autofocus performance than Canon or Sony or Nikon. Nikon and Sony specifically seem to be top of the pile right now.

The Z8 has a whole separate processor dedicated to autofocus and the viewfinder which, in practice, means it can shoot 20 FPS full quality 45 megapixel RAW files with continuous 120fps autofocus without blacking out the viewfinder for each shot, which is absolutely insane.

Re: Canon EF and RF Lenses – All Autofocus Motors

#94

Post by genewitch »

dylan604 wrote: post #91
genewitch wrote: post #62

Earlier quoted context omitted.

Hard for local shops to keep up with fraud? You don't say.

I like how the messenger is getting shot. It's as if my reporting of what actually happens is being interpreted as that's what I do. Just because I know of how the system gets played does not make me a player.

I get upset when people defraud my neighbors and friends in my community. that's what a local shop is. Just today i went to my local pharmacy to look for l-theanine based on some commentary on HN yesterday. I could have gone on amazon, or to walmart, or to CVS. People interfering with that business aren't cool, regardless of the motivation.

let me put it this way - i never even thought of using amazon as a rental service. even though amazon loves me, and i could get away with it, my brain doesn't spend time thinking about unethical things to do.

read this as: "Someone should have gotten upset before the deposit went up from jerks either breaking or stealing the rental equipment" - as my sibling says, this is why we can't have nice things.

Re: Canon EF and RF Lenses – All Autofocus Motors

#95

Post by dingaling »

I used to have to manually focus to take photos of my dog. The apparent noise from the early Ring USM AF in the 85mm/1.8 lens drove him mad and he would run out of the room.

We did initially wonder if it was some psychological effect of pointing a camera at him, but one night I hid behind a curtain and used the AF motor and he still shot out of the room.

Subsequent USM AF motors were silent to him and he was then content to have his photo taken.

Re: Canon EF and RF Lenses – All Autofocus Motors

#96

Post by ExAr »

ashishuthama wrote: post #89

@ExAr - A treasure trove of information, thanks for putting in the effort! Do you blog about how you go about creating these graphics? For example, this view finder image: https://exclusivearchitecture.com/images/technical-articles/... looks very impressive! How do you simulate the rays+eye?

Thanks for your feedback. Until now I have never blogged about the creation of these illustrations, but it's a nice idea, there is tons of "behind-the-scenes" material. With regards to the viewfinder image, the actual path of light was drawn with the help of a Japanese optical engineer who was able to provide professional raytracing simulations.

Re: Canon EF and RF Lenses – All Autofocus Motors

#97

Post by ExAr »

fooker wrote: post #66

Great write up, thanks. I have a question I’m hoping you can answer. I have an EF 400mm f2.8 (2nd gen) lens. This thing focuses significantly faster with my old 7Dmk2 than my very new R6Mk2. With all other lenses it’s the opposite. Why does this happen? I have been told that this might be due to the old 7D and 1D bodies sending more power to the AF motors, but haven’t seen this corroborated anywhere.

Hi fooker, thanks for your feedback.

I haven't heard of this issue before, but a quick research showed me that other people have (similar) AF problems with longer lenses on an R6 II. See here https://community.usa.canon.com/t5/EOS-DSLR-Mirrorless-Camer...

Sorry for not providing an explanation, perhaps I can find some time to look deeper into this - but I can't promise.

Re: Canon EF and RF Lenses – All Autofocus Motors

#98

Post by ExAr »

nayuki wrote: post #72

Amazing website. If I didn't know better, I thought this content came from Canon itself. A couple of comments from me: > The following comparison chart shows all of the autofocus drive types that have ever been used in Canon's EF, EF-S, RF, and RF-S lenses. They missed mentioning EF-M, Canon's foray into mirrorless interchangeable-lens cameras. > Although the ultrasonic noise cannot be perceived by the human ear, it…

Thanks nayuki for the detailed comment and positive feedback.

Thanks for pointing out the missing EF-M, I am going to add that during the next polishing round. With regards to USM noise, the ultrasonic whine can be picked up by very good ears. I think the Nano USM is excited in the range of 60+ kHz, so at least that type of USM motor is absolutely inaudible.

Syntax-wise with F2.8, you got me. I know it's not 100% correct, but it was a deliberate choice that I made. Historically, there is either 1:2.8 or f/2.8 which will always be correct representments of the aperture (exit pupil) diameter. However, pursuing a cleaner look, I avoided the division or slash characters because the relation between the focal length and the f-number is known by every photographer. This is why Canon has also made the transition to the syntax "F2.8" in all their RF and RF-S-lenses - at least their product names and labels printed on the lens barrels. (The same is true with the focal length where Canon doesn't print "mm" on the barrel - to achieve a cleaner less mathematical look). So I believe what I did here was just go with the trend :-)

Re: Canon EF and RF Lenses – All Autofocus Motors

#99

Post by ExAr »

bitdivision wrote: post #61
notimetorelax wrote: post #52

Am I spoiled by expecting these images to be dynamic? I remember some wonderful posts with graphs you could interact with.

You're probably thinking of https://ciechanow.ski/mechanical-watch/ I can't imagine how long this post took to make, let alone trying to do animations.

What an absolute masterpiece this website is! Thanks for sharing.
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