61–70 of 147 posts
Am I spoiled by expecting these images to be dynamic? I remember some wonderful posts with graphs you could interact with.
I can't imagine how long this post took to make, let alone trying to do animations.
Earlier quoted context omitted.
Most shops that offered still photo rentals in my city have gone out of business, and it's a major city. I used to be able to count on renting a big telephoto that I didn't need to own, for a few hundred per weekend, but these days I'd have to take a long drive to get to the one remaining shop.
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…
Earlier quoted context omitted.
Most shops that offered still photo rentals in my city have gone out of business, and it's a major city. I used to be able to count on renting a big telephoto that I didn't need to own, for a few hundred per weekend, but these days I'd have to take a long drive to get to the one remaining shop.
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…
I have been aggravated by (and bellyaching about) the ridiculous lack of a way to control the focusing motors in these lenses directly when shooting video, using a follow-focus wheel.
Video shooters are still strapping janky gear-tooth strips onto these lenses, and then bolting bulky mechanical follow-focus mechanisms on the OUTSIDE of lenses that have focusing motors already built in.
I can only imagine that manufacturers refuse to make direct control available in order to protect their "cinema" lens lines, where a manual normal lens sells for thousands of dollars. And yet they sell some falsely-named "hybrid" lenses that are supposedly somehow better for video... despite lacking even geared focusing rings that are compatible with follow-focus units... let alone a control port that could be used for a focusing wheel to use the autofocus motors.
I looked at the Canon camera-control SDK, and sure enough... focus control is omitted from their entire line, except for two PTZ cameras that aren't suitable for cine use.
Such a cool website. In case anyone else was looking for it, this article from the same author covers the more algorithm-y question of how a camera body decides to actually use these motors when you press the "focus" button: https://exclusivearchitecture.com/03-technical-articles-DSLR... I can't find any articles on how a camera body decides what is and isn't a desired subject. I'm guessing there's some amount of mac…
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…
[1] https://cam.start.canon/en/C017/manual/html/UG-04_AF-Drive_0... [2] https://cam.start.canon/en/C017/manual/html/UG-04_AF-Drive_0... [3] https://cam.start.canon/en/C017/manual/html/UG-04_AF-Drive_0...
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.
This is why camera calibration can be tricky, and you often don't want to touch the cameras after you've done a calibration pass.
Such a cool website. In case anyone else was looking for it, this article from the same author covers the more algorithm-y question of how a camera body decides to actually use these motors when you press the "focus" button: https://exclusivearchitecture.com/03-technical-articles-DSLR... I can't find any articles on how a camera body decides what is and isn't a desired subject. I'm guessing there's some amount of mac…
I have no idea how this worked, but would have loved to see the photos they used for “training” this system 25 years ago.
Earlier quoted context omitted.
As a Canon owner, Nikon has a much longer back compatibility range. Having autofocus motors and IS in body rather than in lens seems to be a part of their trick.
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…
Contax had an AF solution (Contax AX) that actually moved the entire film plane to focus. I suppose that the same thing could be done in other axises, but I also suppose that there is a reason that only one manufacturer tried it.
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…
With mirrorless cameras the focus switched from specialized sensors to on-CMOS contiuous exposure sensors, so movement is easy to detect. At this point the cameras have specialized AI hardware to run the models, and they also accept user input (on R5 MkII you can register up to ten people to prioritize focus on[1]). The focusing options are now very complex[2][3], and combined with lots of customization options on th…
The AF settings, except those related to face/object recognition, haven't actually changed that much since the 7D Mk II days. The preset system is more general now and allows you to store and recall all AF settings rather than just the three tracking-related variables. The high-end DSLRs used to have six cases for different types of sports that you could modify but not rename.