The TPS62140's 30ns propagation delay is not enough to blow a fuse. The first rule of fuses (which many modern engineers do not understand!), is that fuses are not there to save your parts, and they simply will not do that. Fuses exist to prevent fires.
Even a fast fuse is very, very slow compared to semiconductors. I've seen transistors blow up to "protect" fuses. They're for stopping fires and preventing the slaughtering of batteries, nothing more, nothing less.
For those who haven't followed the camera world for a while, at this point a lens for a mirrorless camera will have a USB-C port to receive firmware updates.
Tamron lenses for instance will allow a wired control or a wireless dongle to communicate with an app/computer and change the lens behavior, switch what the physical buttons and rings do. Potentially you can manage stepping through settings for stop motion like effects, time lapses or stacking.
We're far from the days a lens was just metal and glass※. There are obvious downsides, but in practice it's actually a huge stepup IMHO. Every photographer is different and does different things, being able to fully adjust your gear is a godsend, especially as we need speed and reactivity.
※ there are still plenty, and plenty more will be designed and produced anew, but I don't think it's the major trend.
This is only true for photography.
For some reason, cinema lenses are still - for the most part - purely mechanical. For film and TV, most camera operators still focus manually - often via gears attached externally to the lens.
Coming from modern photography, manual focusing is inconvenient and difficult to learn. But there's something very old-school cool about cine lenses. They feel great.
I think in cine it’s a lot more important to have smooth focus and to be able to control the focus speed, hence the MF lenses
I also think cine lenses have the budget to continue making high quality mechanical interfaces. Consumer lenses must have AF and so are incentivized to reuse that functionality if it would reduce the BoM.
Hm, I'm not sure about that. I suspect autofocus motors are much more expensive to manufacture than mechanical lens throws. They're almost certainly more expensive to design. I don't know about other manufacturers, but recent sony lenses contain 4 autofocus motors, and they can snap autofocus in tens-to-hundreds of milliseconds depending on the distance. Where do they even put those motors in the lens housing?
Its probably a scale thing. Photography lenses make up for the design, engineering and manufacturing costs with scale. Everyone who takes photos needs lenses. But far fewer films are made, and cine lenses are often rented. So they really can't be manufacturing that many units in total. I suspect they often don't manufacture in high enough volume to make back the engineering costs of fitting complex microcontrollers and motors into the lens housing. And if the production can afford to hire a focus puller anyway, autofocus just isn't that valuable.
A large focus throw and more importantly, focus consistency, is paramount for cinema lenses. When you rack focus, the lens needs to show the same field of view every time, no questions asked. The early red pro cinema lenses had a design flaw where the focus rings would come loose over time and ruin shots. Someone clearly forgot the threadlocker.
Autofocus is very nice for photos, especially when it works.
Autofocus in moving pictures isn't so great. It might be nice when you're not filming, but while filming, a focus change should really be intentional; auto focus isn't that. Might depend on what you're filming though.
> a focus change should really be intentional; auto focus isn't that. Might depend on what you're filming though.
As a solo operator, autofocus is great. Maybe the right metric is the number of crew per camera. 2-3 crew per camera? Manual focus is fine. 2-3 cameras per crew member, like solo filming a podcast or a theatre show? I'd choose autofocus every time.
Indeed! I've had the privilege and honor of collimating a Cooke s4i. It's a thing of beauty, joy forever.
> For those who haven't followed the camera world for a while, at this point a lens for a mirrorless camera will have a USB-C port to receive firmware updates.
Iam not sure if this is a general truth. I recently bought a canon rf 24-70 f/2.8 which is pretty SOTA and it does not have an USBC port.
Third party lenses that cannot be updated by the camera body will include a USB port.
Why would this be a good idea to break away from the norm of what has been done before? The mechanism of updating the lens through the camera exists. Why reinvent the wheel? It only increases the BOM for the lens to include the USB and the electronics involved.
Because third party lenses cannot leverage the camera body to update.
Sigma has a dock that allows updates to their lenses in this fashion however.
First party lenses will be handled by either camera firmware or by the camera - for your lens (I'm in the Canon RF system heavily) you can do the "download to SD from canon.com" and the firmware update on the camera will recognize it as a lens firmware, not a camera firmware. And sometimes camera firmware will also bundle lens firmwares that get updated when you attach the lens (usually these are reserved for issues that have a potential to damage the lens or camera - like excessive hunting wearing the motor, etc., not 'nice refinements').
Yep. Sony lenses are the same. You can update the firmware on a sony lens by attaching it to a sony camera.
> at this point a lens for a mirrorless camera will have a USB-C port
Ideally, camera bodies should support firmware updates via the body in a non-discriminatory way, but until then I wish manufacturers support firmware updates via USB-C.
Looking at you Samyang Lens Station. I think users have been sufficiently upset, and they're adding USB-C to newer lenses.
> For those who haven't followed the camera world for a while, at this point a lens for a mirrorless camera will have a USB-C port to receive firmware updates.
Besides the slightly interesting stuff Tamron is doing, why on earth would I want firmware updates for a lens? Also, this seems like it would be much more readily accomplished by the camera itself… if you’re doing weird stop motion racking and whatnot, why would you rely on the camera and lens being separate? Seems like kind of a pain to me.
The lens is communicating with the camera body, and you might want to adjust for newer bodies supporting more things for instance.
I'm not aware of what exactly is changing, but I've already seen it happen with newer Sony bodies getting released, and an update going to Viltrox lenses to fully support thems.
On the camera and lens being separate...in an ideal world you could ask the camera to do absolutely everything. In practice that's a tough order for a single company.
The bright side is also that you can use a mildly older body while benefiting from a very flexible lens, or have different profiles for different lenses and not have the body care about which lens needs what.
I can't imagine Nikon be bothered to properly operate a software ecosystem TBH.
Because to control the autofocus motor and other features it makes sense to have a microcontroller in the lens. If you have a microcontroller in the lens you have software in the lens and if you have software in the lens you're going to need to update it.
You could argue that the camera should do firmware updates but the manufacturers for (semi) open mounts like the ones Tamron is making lenses for don't want to have to design a protocol to do updates for third party lenses through the body when the lens manufacturer can just slap a USB port on the lens and call it a day.
The port is also useful for customizing the lens functions. For third party lenses the camera can't be expected to manage those functions.
There have been plenty of motorized lenses in the past that relied on the micro-contoller inside the camera body for control. What does having the controller live on the lens permit that the pattern we've used for years doesn't afford?
> If you have a microcontroller in the lens you have software in the lens and if you have software in the lens you're going to need to update it.
No, no you shouldn’t. There’s no reason why a microcontroller should ever need its firmware updated. The only reason why you would need to update the firmware is to add features, which I guess is mildly interesting for the tamron, but like I said… you could handle all extra fancy focusing things in the camera body itself. Just give me a dumb lens that does exactly what the body tells it to do.
Lenses are only tested on bodies which are available at the time of manufacture. They might focus hunt on newer bodies, because of tweaks to AF algorithms (for example, the speed at which instructions are transmitted). Sometimes in ways that can potentially cause damage long term.
> why on earth would I want firmware updates for a lens?
One reason is to update the lens to work with new camera or new camera firmware.
> Besides the slightly interesting stuff Tamron is doing, why on earth would I want firmware updates for a lens?
Improved algorithms for focus hunting, diminishing chromatic aberration (most of it is in the glass but some positioning can tweak it).
I get it, there's not a lot that will happen there, but some of that stuff will be useful on an investment that can easily be several thousand (I don't get into the wildlife telephotos, but two of my lenses were $3,300 or so - RF 85/1.2 and RF 28-70/2).
Placing disassembled screws on double sided tape is such a great idea, I am going to try that next time I disassemble my electronics (as opposed dropping everything in a container and spend time finding the original size screws during reassembly).
There’s a very useful putty for watchmakers called Rodico, it can serve this purpose well and can also be stuck to a screwdriver to hold onto the screw while placing it, instead of relying on magnetism (no good in watchmaking to magnetize your screws, I figure cameras are similar, you can increase resistance to movement if magnetism pulls things together…)
I’ve also seen a clever technique of drawing a diagram of whatever you’re working on on cardboard, and stabbing the screw into the cardboard to keep track of where everything lives
Thanks for the input about Rodico! It sounds pretty useful. I've used mounting putty / blue-tack when assembling PCBs, but not much more than that. I've seen the card board trick used many times to ease in painting engine valve cover bolts.
It also has an interesting capability to absorb smudges and oils, I use it to clean watch dials, just dragging the putty over the surface.
I don't use anything sticky, but if it's my first time opening basically anything, one side of my working space becomes a map of the screws.
Roughly in the layout of the way they came out. Top to bottom, in layers, as it comes apart.
A habit from working on laptops in a warranty center. I might have to try some tape.
Thanks! After many lens teardowns with screws of varying lengths and magnetism, tape is truly king!
The author says PH screwdrivers may be used on JIS screws, but in my experience they strip every single time.
This is incredible work, though.
JIS screwdrivers are 100% necessary. It may seem PH fit at first, but it's _a tiny bit off_ enough to cause damage. The point of JIS is shorter and squared.
Thanks for the kind words! The ifixit screwdrivers I linked are JIS compatible.
The PH-0 and smaller screwdrivers from Good suppliers like iFixit or Wera are actually JIS because there's no downside.
But if you happen upon a real PH-0 it will destroy the JIS screws.
One of the better teardowns I've seen in some time.
Thanks for the kind words!
This is the kind of thing I'd love to see robots take over. Companies don't want to service these things much; the labor is too costly. They could just distribute the repair manuals and we could get robots to do it.
If companies could just distribute the repair manuals I'd be happy as a clam :D I'm all for automated repair!