ajdelange

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Zoom in. Way in, on the word refraction.
OK. But you know you can look up these words yourself.

Refraction definition, the change of direction of a ray of light, sound, heat, or the like, in passing obliquely from one medium into another in which its wave velocity is different.

You will find the curve matches the curve of the lens.
As there is no curve I don't know what curve you mean. Are you saying that the rays in and behind a lens are chords of a curve? And that this curve follows the curvature of the lens? Let's say I use flint glass with n=2 to make a dual convex spherical thin lens with front surface having radius 5 cm and rear surface having radius 7.5 cm. An object infinitely far in front of this lens would image on a focal place 3 cm behind the lens and an object right in front of the front focal point would image infinitely far behind it. Could you please sketch these curves? I'd like to understand where you get some of these ideas.

Your drawing uses geometry?
Well I suppose any time one draws anything on a piece of paper he uses geometry but you said something about using a surgically precise tool and making hamburger. Is this in reference to my shaky hand? It would seem to imply that there is some flaw in the drawing. You seemed to think at one point that it was that the ray to the drivers eye was missing. I added that and it made no difference whatsoever in the conclusions which one should draw from the drawing. Can you point out what the error(s) are? And better yet, correct them?




The sign is for when they are backing up. Frequently accompanied by a beep beep beep sound.
That's the great thing about the internet. You learn something every day. That's something else I didn't know. Now in my defense my misconception is a fairly common one. Just look up "if you can't see my mirrors" on the web. One article points out that one does not see these signs as often as he used to as drivers are now using cameras to see behind their trailers.



You are still mistakenly believing that the side mirrors are for capturing the rear of the vehicle. They are for capturing the lane next to the vehicle, for the length of the vehicle. Look at the orientation of a mirror on a big rig sometime. Notice its larger on the vertical than the horizontal. If seeing around to the back was important don't you think it would be different?
No. If it were for looking primarily to the side it would be wider. The vertical extent is there because things of interest in the vertical direction subtend a larger angle than things in the horizontal.


That blind spot is in reference to reverse.
Again something I didn't know! And that other Tesla drivers don't know either. Most of us, erroneously evidently, think that the issue is with sufficient assurance from the sensors, that it is safe to pull out to pass and that when the autopilot decides to pull out to pass that it does not do so unless an overtaking vehicle is safely far behind and closing at a safe rate.
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Dids

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OK. But you know you can look up these words yourself.

Refraction definition, the change of direction of a ray of light, sound, heat, or the like, in passing obliquely from one medium into another in which its wave velocity is different.

As there is no curve I don't know what curve you mean. Are you saying that the rays in and behind a lens are chords of a curve? And that this curve follows the curvature of the lens? Let's say I use flint glass with n=2 to make a dual convex spherical thin lens with front surface having radius 5 cm and rear surface having radius 7.5 cm. An object infinitely far in front of this lens would image on a focal place 3 cm behind the lens and an object right in front of the front focal point would image infinitely far behind it. Could you please sketch these curves? I'd like to understand where you get some of these ideas.

Well I suppose any time one draws anything on a piece of paper he uses geometry but you said something about using a surgically precise tool and making hamburger. Is this in reference to my shaky hand? It would seem to imply that there is some flaw in the drawing. You seemed to think at one point that it was that the ray to the drivers eye was missing. I added that and it made no difference whatsoever in the conclusions which one should draw from the drawing. Can you point out what the error(s) are? And better yet, correct them?




That's the great thing about the internet. You learn something every day. That's something else I didn't know. Now in my defense my misconception is a fairly common one. Just look up "if you can't see my mirrors" on the web. One article points out that one does not see these signs as often as he used to as drivers are now using cameras to see behind their trailers.



No. If it were for looking primarily to the side it would be wider. The vertical extent is there because things of interest in the vertical direction subtend a larger angle than things in the horizontal.


Again something I didn't know! And that other Tesla drivers don't know either. Most of us, erroneously evidently, think that the issue is with sufficient assurance from the sensors, that it is safe to pull out to pass and that when the autopilot decides to pull out to pass that it does not do so unless an overtaking vehicle is safely far behind and closing at a safe rate.
No I am not talking about the definition of refraction but the actual thing that happens to the wave when it contacts a curved medium change. That should have been obvious from the "curve matches the curve of the lens". I can see that you think a curved lens is a sharp oblique change like what happens on a flat lens like a prism but it isn't. Look it's a double rainbow!
 

ajdelange

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I can see that you think a curved lens is a sharp oblique change like what happens on a flat lens like a prism but it isn't.
No, I don't think "a curved lens is a sharp oblique change like what happens...." I think a lens is a geometric object with curved surface(s) that separate isotropic media in which the velocities of light are different. I think that when light strikes the surface at an oblique angle to the normal to the surface any which penetrates the new medium will propagate in a direction closer to the extended surface normal than that of the incident ray if n2 > n1 in accordance with Snells Law. I think Snells law applies for any surface - curved or flat - down to the point where the radius of curvature approaches the wavelength of light and I think that because all of optics depends on it and years of optics engineering have shown it to be true.

Untitled 2a.jpeg


Now we are clearly in an infinite loop here. You come up with some bizarre physics and I explain why you are wrong and you respond with something even more bizarre and I explain that's wrong - do while (TRUE). I really don't even know what you are saying with a sentence like " I can see that you think a curved lens is a sharp oblique change like what happens on a flat lens like a prism but it isn't." So I can't really determine whether I should be correcting your English or physics misconceptions. In any case we, unlike the refracted rays, are not converging so I'm withdrawing from the dialog much to the relief, I expect, of the other participants in this thread if any remain.
 
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drcarric2650

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Perhaps those that want mirrors can have them, and those that don't won't. Those that pull a trailer that like mirrors can have their wide mirrors, and those that like camera's can add a wireless camera to the trailer. I think the cameras would be more useful, and less expensive.
 

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I think that is a good solution. I like the 'idea' of cameras though I have a lifetime of using mirrors and wonder how quickly I can adapt to a new sideview location. In many cases I think that the side view with cameras would be functionally superior.
 

ajdelange

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The big advantage with mirrors is that P and T are instinctive and fast. The disadvantages are that they stick out and get knocked off by trees, garage structures etc and, of course, there is no Z. The big advantages of cameras are that they can be PTZ and that they can be put anywhere to which you can run a cable or from which you can receive a radio signal. A CT with like the one at the reveal (i.e. with cameras well forward and a backup camera) coupled to a trailer with cameras located on it at the same locations would indeed make it possible to have an "invisible" trailer. Note that the Valeo system is blind along the length of the trailer and in the lanes adjacent to it if the trailer is wider than the tow vehicle because it only, AFAIK, has the one camera at the back of the trailer.

Also note that the rear view camera in the current Teslas is not PTZ i.e. it is fixed. I don't know about the side cameras in the demo CTs. I would want them to be P&T at least and preferrably PTZ so that I could adjust them to let me view the part of the road behind I want to. This, of course, makes them appreciably more expensive than fixed wide angle. I'd like the rear view camera in the current cars to be zoomable too and reversible so I could easily read a license plate on a following vehicle, for example.
 

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I feel that if you have a 17" on the dash in front of you, which has the rear view in the center, and the side views on both sides, then I believe that we will, in a subconscious level aware of what is around us. I think the side mirrors are only instinctive, because they have already been there.
 

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Shoot... people already drive around without using there side mirrors or signals. Heck why doesn't Tesla just stream the camera views to peoples smart phones, then maybe they will see whats going on.
 

ajdelange

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I feel that if you have a 17" on the dash in front of you, which has the rear view in the center, and the side views on both sides, then I believe that we will, in a subconscious level aware of what is around us.
I don't want to give up main display real estate for mirror views. The main display is for maps, energy displays, Tesla Winds, music etc.
 

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I feel that if you have a 17" on the dash in front of you, which has the rear view in the center, and the side views on both sides, then I believe that we will, in a subconscious level aware of what is around us. I think the side mirrors are only instinctive, because they have already been there.
I feel that if you have a 17" on the dash in front of you, which has the rear view in the center, and the side views on both sides, then I believe that we will, in a subconscious level aware of what is around us. I think the side mirrors are only instinctive, because they have already been there.
The rear view camera has it's own monitor. In the videos of the interior of the CT they showed a rectangular monitor mounted where a mirror would normally be.
 

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I don't want to give up main display real estate for mirror views. The main display is for maps, energy displays, Tesla Winds, music etc.
Right. Remember that side mirror display needs to be always on. It only makes sense for these displays to be on the a-pillars.
 

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Tesla has always had the backup camera view available on demand on the visualization display. With the CT that view will be in the rear view display. So you are saying that you don’t want to give up any of the rest of the display for side views. I get that. A while back someone posted a link to a study performed by the highway safety institute (I think) that showed camera monitors in the location you mentioned. I am not sure how long it would take to get used to them but I think it is possible.
 
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While I do wonder about this, do rearview mirrors stay clean in the same circumstances?

I expect cameras should work about the same as mirrors in adverse conditions, so it is a wash.
Your expectation would be wrong. My model 3 ( which I mostly love) does not have a single camera that doesn’t REGULARLY disable due to snow and slush, turning off autopilot functionality and many other safety functions that rely on them. The side mirrors I can always see from . The front fender cameras get blocked the most, drivers side worst of all, pillar cameras reliably fog up internally at between +3 and -3 Celsius (around freezing point), which I’m told Tesla is aware of and working on a solution. The centre windshield cameras at least have heat melting ice and snow and wipers to keep wiped. Rear plate camera get snow covered by slipstream deposit, blocked pretty quick if there’s any loose snow on the road. All that to say snow and cameras have to be figured out in the real world. This truck is meant for all countries, not just southern states. I have thought about this and if Elon is checking these sites out, what about, since we have air compressor on board, the ability to shoot a high pressure jet of air at the camera to give it a quick clean. Think the headlight washer jets like Jags and beemers, but more integrated. I’d love to see the cameras work, but am very concerned as the fender location will definitely be a winter issue and I’d like to keep all functionality Tesla puts in my vehicle as much as possible.
 

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