So Cal Sam

Just curious, have you spoken to the new owner of your beautiful SL600 since you sold it to him? Thanks, by the way, for still hanging around the board - your comments and opinions keep it very lively!

LovinMercedes

Thanks so much for your nice comment. I have always enjoyed everyone here so it is nice to still participate when I can.

I did have the chance to speak once to the person that I sold my car to.

He was a very happy camper and loved the car. I have no reason not to believe that he is still very happy.

I am glad he is enjoying the car. She was a beauty.

pimpitcharlie

hey lovin, did you ever get your wife the M3? And did you ever get the Aston yet? What are you driving now if you already sold the SL600 and celica??

LovinMercedes

Actually didn't sell the Celica. My 16 year old has it. Got her license several weeks ago.

The wifey is driving the M3. Got that about a week ago. Will post pictures.

The Aston Martin starts production on July 19th and should be completed by August 30th. I have arranged for the car to be flown in by air as opposed to shipping by sea so I should have the car by the end of the first week in September. Saves about 30 days.

I am driving the Navigator and boy is it getting old.

LovinMercedes

Here is the wifey's new M3

StephenK

Nice car, the one thing I really don't like with the BMW's is the red display on the instruments clusters.

LovinMercedes

I know what you mean. This one is kinda orange. Seems like it has been this way for too many years. They do need to update that.

MerzadY_BoY

Wow, your a great husband

She gots the Bee and you got the old POS! haha

I got a 325Ci- pretty good for my age and all

Reno

The orange-red lighting is a technical issue and not anything to do with fads. That colour has been scientifically proven to be the colour that allows our eyes to focus the fastest and with the highest accuity on details. It is the same colour used in the CIC of our warships where the crew often have to enter and exit between pitch black, bright sun and the low lighting of the CIC. (CIC = Combat Information Center).

In a performance vehicle BMW is less likely to change that item although with SMG rather than a 6-speed manual you are far less likely to have critical need to check the gauges. However, red light is also the light used when critical work has to be done in the dark otherwise you have to readjust momentarily when you take you eyes away from the lit-up areas and try to make out details in the dark. So there is also a safety element.

BTW, the worst colour for visual accuity is blue - light blue being probably even worse. So the colour used in the SL is actually the worst. Green is probably the most soothing but is not as accurately focused as orange-red and our eyes do not recover as fast when we turn to look into the dark.

LovinMercedes

Incredibly interesting and informative. Now I have to brag about the lighting in our new M3.

Thank you!

CASL55

Reno, there is much in your post that is accurate, and some that isn't. I'll try to clear some things up here. For those interested in further reading on the subject, I recommend R.W.G. Hunt's book: Measuring Color, 3rd edition. The rod and cone sensitivity diagram is on page 21.

Let's separate the acuity and night-adaptation issues, taking night adaptation first. Night vision relies on the rod cells in the eyes, which are sensitive to dim light. The peak sensitivity of the rods occurs at about 510 nanometers, and they have little sensitivity to light with wavelengths above 625 nm. So instrument lighting at wavelengths above 625 nm won't fatigue the rods, and they’ll be ready if they are required for picking things out of blackness. The sensitivity of the rho cones (the ones sensitive to the longest-wavelength light, and sometimes called the red cones) drops off to nearly nothing by 700 nm, so the right wavelength for light that’s visible but that doesn’t screw up night-adaptation is greater than 625 nm, and less than 700 nm. This is fairly red light like that used in the older BMWs, not the red-orange used in the newer ones.

Now let’s deal with visual acuity. The rho cones peak at about 590 nm, and the gamma (loosely, green) cones peak at 550nm. There are twice as many gamma cones as rho cones, so the frequency for maximum visual acuity at a constant low light level is about 565 nm. This is green light with a tinge of yellow. You are right that blue light and the beta (loosely, blue) cones are the worst for visual acuity; that’s because there are 40 gamma cones and 20 rho cones for every beta cone. The rods don’t help at all with visual acuity, since there are essentially no rods in the foveola, or area of sharpest vision (which is why visual acuity at night is bad).

Now, let’s consider whether being able to see instruments without damaging your night vision is relevant to driving a car. It is most definitely relevant to operating an astronomical telescope or sailing a ship. However, in a car, at night we turn on our headlights, which are most definitely not red. The light bouncing back from our headlights is sufficient to destroy our night vision, even if the instrument panel is turned all the way down.

I consider the red illumination of a BMW instrument panel to be simply a pleasant reminder of the company’s aeronautical heritage. like the blue and white emblem that looks kind of like a propeller.

Jim

tandan

WOW!!!

Reno

Sorry, I wasn't attempting to get into a lesson in biology. I was merely quoting from personal experience though I am still not sure which part of my earlier message you considered as inaccurate. BTW, here's a URL to the same information on the rods and cones - easier to obtain than a book:

http://hyperphysics.phy-astr.gsu.edu...n/rodcone.html

I think here's where you may be inadvertently skewing the data to make a point that newer BMWs have console lighting that is more orange than before and hence less desirable. I'll show you why your point isn't necessarily true. BTW, I am not a fan of the new BMWs so I am not trying to plug their cars. But I do feel their choice of console lighting is excellent.

OK, first, the sources I have located indicate "red" cones' sensitivity peak at 558 to 570 nm (not 590nm). In any case light appears yellow at this range, not red. In addition, orange color wavelength is actually between 600 and 630 nm. If you check the sensitivity of the red cones to this range you'll see it's between 65 and 90%. But if you prefer red, at 630 to 770 nm, then the red cones' sensitivity almost zero (0) to about 65%. I think 90% looks a lot better than close to zero (0).

http://hyperphysics.phy-astr.gsu.edu...colcon.html#c1

So making the console more orange than red actually increases acuity. This is a good idea. Red cones have a range of sensitivity, if you just use red light then the red cones will be working at the far (lower) limits of their sensitivity.

Next, if you look at the "scotopic" (daylight) sensitivity of the rods at 600 to 630 nm (orange) you will find it is between 5 % and zero(0)%. Compare that to green light (500nm) at 100%.

http://www.brad.ac.uk/acad/lifesci/o...ctralSens.html

I don't think there are any problems using orange for the console. It just doesn't look like the redder colors we used in the past. BTW, the CIC colors are more orange-red than red.


Here's where you are partially wrong. I didn't say blue cones are worst for acuity - I said BLUE LIGHT is worst for acuity. Here's why I made the distinction, I didn't want to go into a physics and optics discussion earlier on:

While there are very few blue cones, the resulting sensitivity to blue light is apparently the same as for the red and green cones. Here's a quote "... There are fewer blue cones, but the blue sensitivity is comparable to the others, so there must be some boosting mechanism. In the final visual perception, the three types seem to be comparable, but the detailed process of achieving this is not known. ". You can find additional information here:

http://hyperphysics.phy-astr.gsu.edu...dcone.html#c3b

If you read this carefully, it will also tell you 2 other bad things about blue light's effects on the eyes. 1) the blue cones are outside the fovea which mean you can't focus properly on them and 2) more importantly, the refractive index of blue light is significantly different from red and green. So objects with a significant amount of blue will appear blurry even though you have focused accurately on other objects that are at the same distance. Said in another way, if you look at a flat colored label with blue, green and red letters on a white background, the blue letters will look blurred or give you a bit of a headache as you try to focus and refocus on them.

BTW, this is also one of the reasons why you used a UV filter when you took color photos as a kid. Blue and purple light are not properly focused in daylight. It's called chromatic aberration and big names in photography (like Nikon, Leica, Rodenstock, Carl Zeiss, ..etc.) have special lenses and coatings that reduce this problem.

Jim, I think you may be a bit cavalier with this comment. Many people do long distance driving at night at very high speeds. My German brother-in-law goes at full speed on non-restricted stretches in Germany at night. That means 240+ kph. I've sat next to him a few times (with white knuckles). Autobahns tend to stretch into the distance before your eyes (one reason why you can drive so fast) and you may not see anything but our instruments and the road for many miles. The headlights take care of objects within their scope but our night vision is used for everything else. Why would you want to handicap your night (and peripheral) vision and just depend on your headlights?

If we were to follow your line of reasoning then a white panel with black lettering would work better than a BMW console (yes, it's been tried). I don't think we want to look at a white instrument panel, do we?

That's nostalgic indeed and you're right, a spinning propeller is why the BMW emblem looks the way it does. Now, quickly, why did BMW pick blue and white?

pimpitcharlie

Lovin, can u put up nicer pics to the M3 like you had of your SL600, i know you have them

LovinMercedes

Wifey is doing the pictures for her car not me. I did my SL600 but here is the link to what she did.

http://community.webshots.com/slides...y=KEJoCo&pos=0

Stay tuned in September for my 2006 Vanquish S pictures. Aston Martin is redoing the interior console for 2006 and it is going to be unbelievably gorgeous.

tiggerfink

How is the road noise with a soft top? I am still debating to get the coupe or the convertible in the 645ci. That M3 is awesome. My wife likes it.

RadSteve

Jim, thank your for taking the time to expain. I knew bits of this, but certainly not this detail. I'll think of you when I drive at night. But here's a fact, the blue and white BMW emblem is simply a roundel version of the blue and white pattern on the Bavarian flag! And while it does have a certain resemblance to a propeller, the flag is the driving feature behind the design.

Steve

LovinMercedes

Actually, the road noise is not bad at all for a soft top convertible.

Notice, we also have a hard top when the winter comes around and that works great. Fits perfectly and I think looks good as well.

Reno

Actually, you are both correct about the BMW roundel. It is both a rendition of a spinning propellor and the flag colors of Bayern. BMW was originally founded as BFW in 1916. BMW even had posters made showing the blue and white propellor design spinning on the nose of a German biplane.

I realize this is primarily a social venue for SL afficionados and that is your privilege. However, when a discussion ventures into a different or general area then certainly anyone else can add some enlightenment. It only helps you to be better informed.

CASL55

I agree with your original point that dim red light does not disturb night vision. I disagree that red-orange light is the “colour has been scientifically proven to be the colour that allows our eyes to focus the fastest and with the highest accuity on details.” I stated that that color (pardon my American spelling–you’d like Hunt’s books: he spells it your way) is green with a tinge of yellow in my answer to your original post. However, the green color interferes with night adaptation of the rods.

You are right that you get greater visual acuity with orange than with red light. You also compromise night adaptation, particularly since most light sources aren’t spectral, but emit light at a range of wavelengths, some narrow (some LEDs), some wide (incandescents, filtered or not), some peaked (fluorescents, fluorescent-backlit LCDs). So as you move the center of the wavelength distribution to shorter wavelengths to excite the gamma comes (the excitation of the gamma cones is what makes the light appear orange), you also start to excite the rods. That’s why astronomers, who want the best night adaptation and are willing to sacrifice night adaptation, use red lights, and people who set up the CICs use red/orange lights.

The proper tradeoff also depends on the age of the observer. When Tom Whitney’s team at hp Labs was inventing the model 35 calculator, they chose red LEDs for the display. These emitters, built by hp Associates, were nearly spectral in their radiation characteristics. The team was composed mainly of twenty- and thirty-something engineers. They thought the display looked great. When they showed it to Bill Hewlett, in his 60s at the time, he said (as reported to me by Tom, since I wasn’t there for the demo), “Why is this darn thing so blurry?”

I’m not saying that the orange lighting is less desirable, just that it interferes more with night adaptation. In fact, I think it’s more desirable, since it provides better acuity and I don’t think night adaptation is important in instrument panel color choices.

You are entirely correct on this point. I was leaving out the inability of the lens in the eye to simultaneously focus green and blue light, trying to keep things simple.

This stems from an error on the website that you referenced. If there were no blue cones in the fovea, you wouldn’t have color vision in the most central visual field. The fovea comprises the central one and a half degrees of the visual field. Try this experiment: find something blue that’s about a foot across. Place it a hundred feet away. It still looks blue.

Also, if there were no beta cones in the fovea, the CIE 2 degree observer and the CIE 10 degree observer would be wildly different. Admittedly, the 2 degree observer is mildly blue-deficient compared to the 10-degree observer, but most color scientists attribute that abnormality to the selection of the subjects for the experiments.

This is entirely a side issue (or maybe even a quibble). It should not obscure your entirely correct point that blue light is not good for uses requiring high visual acuity. (Hey, are the engineers that picked the colors for the 2005 Sirius COMAND screen listening? Day mode is light blue on white, and night mode is medium blue on black.)

My point is that just the reflection of your headlights back from the road is sufficient to negate night adaptation. The new xenon headlights, being brighter, do that even more. As one of the web references that you posted points out, once your night vision is lost, it can take half an hour to restore it.

No, we don’t, but the reasons are unrelated to night-adaptation of the rods. The cones adapt, too, and the iris opens more in dim light. We want the instrument panel illumination to be lower than the level of illumination provided by photons from the headlights bouncing off the roadway and back through the windshield, so that the cones adapt and the iris opens as far as possible consistent with the scene illumination. So the issue of white-on-black versus black-on-white devolves to which choice provides the greatest contrast for the least illumination. Since the letters and gauges occupy less area than the background, it makes sense to make them white (or bright, if you’re using some other color), and make the background dark.

I had no idea, and now, thanks to you and RadSteve, I do. Aren’t these boards wonderful?

Jim

Reno

OK, that's a fair complaint. My original statement was with regard to our discussion of displaying information where night vision needed to be preserved. I should have taken care not to give a mistaken impression that orange-red light performs best under all conditions.

I have already pointed that out. I said the cones are significantly more sensitive to orange-red light vs. red light for a small penalty of 5 to 0% sensitivity of the rods to orange-red light. IMO this penalty justifies orange-red as being a better compromise than red for console displays.

My understanding is that combined signals from a collection of receptors actually create what our brains perceive as a particular color or hue... and due to the "messiness" of Mother Nature, actual numbers and distribution of cones in our eyes differ from person to person so in effect, we all have different brain perceptions of what spectral light "looks like". I think what can be gleaned from the HP experience you mention is speculative in the absence of sufficient scientific data. Age "should" matter but then so "should" other factors.

Well, we at least agree the choice of orange-red is a good one. I'm surprised you don't think preserving night vision is important in instrument panel color choices.

On this point I want to qualify your sentence to avoid confusion. Chromatic aberration is a physical phenomenon independent of how our eyes work. "Blue" light simply refracts at a significantly different angle than "red" and "green" lights so unless special materials are used in the lens and coating, a distinct blur will be seen in the image or resulting photograph.

IMO, it is not a minor point at all. It is the most important point when avoiding blue light for illuminating anything you have to read. It will give you a headache and eye strain (fatigue) because your brain will repeatedly fail to focus a clear image. Fatigue is a serious safety hazard on long trips at night.

Both the website and I were sloppy with this point. Apparently, blue cones are absent at the center of the fovea (Central Island, 0.17 to 0.24 degrees). So blue details are not as refined as red or green ones.

Well, I tried to infer the colour used for gauges in the SL (and other Mercedes models) is more of a fad. I am disappointed with it but I've managed to tolerate it (yes, it tires me out). I think MB simply wanted something that didn't say BMW or Japanese or North American.

On this point I do not agree. You only get blinded if the objects lit by your headlights are very close (light intensity diminishes with the square of the distance). If the object is that close to your car you don't want to waste time looking at your dashboard gauges. Being blinded by bright light at night is disturbing and you don't want to be constantly blinded to the dim surrounding space becaue people and other objects in your periphery matter a lot. The rods give us peripheral vision.

You would seem to agree night vision is a good thing.

There is another apparent inconsistency in how you stated this point. If you devalue night vision and value bright spectral imaging by the headlights then you should prefer a bright spectral console because it will cause your pupils to constrict - constricted pupils would increase your depth of field so the scene illuminated by the headlights would in theory be better resolved (if it is as bright as you claim it to be).

I think one should value night vision for night driving and just use headlights to follow the road; using a minimum amount of light to light up other objects. Brightly-lit objects mean you are too close to be safe. Finally, consider the main reason why old people can't drive at night is because their night vision is impaired - they usually can still drive in the day. So, it would seem they disagree with you. Sorry, I couldn't help that one.

This logic is flawless and I agree. However, the reason why I mentioned such gauge colour design schemes is that black on white or silver background has been and are being offered. The Nissan Maxima had such gauges I recall and there are aftermarket gimmicks for people who want to make their cars look different (at the cost of their eyesight and driving safety).

I think you know quite a lot about these topics but just like me, you probably don't specialize in these fields. You're probably curious about such matters and compile information like I do. That's one of the reasons I read messages in newsgroups like this one. Sometimes you have to ask questions and debate issues but the effort is educational in the end. I appreciate your input and your pointing out mistakes.

LovinMercedes

Man, I thought I was smart...?

CASL55

Actually, I do claim some expertise in this field. While I was trained as an electrical engineer, I spent 6 years in the 90s as an IBM Fellow working as a color scientist at the Almaden Research Center (I did do a little work on RAID, and if you Google me, that’s most of the engineering work you’ll see, but I spent 98% of my time on color). I worked on color gamut mapping, color data representation, photographic algorithms, and other color management issues. This work requires an understanding of the biology and psychology of human vision, and I worked with psychologists. To give you an idea of exactly what I did, you could look up some of the following papers and patents:

Kasson, J.M., Nin, S.I., Plouffe, W.E., and Hafner, J.L., “Performing Color Space Conversions with Three-Dimensional Linear Interpolation, Journal of Electronic Imaging, vol. 4, July 1995, pp. 226-249.
Kasson, J.M., and Plouffe, W.E., “An Analysis of Selected Computer Interchange Color Spaces”, ACM Transactions on Graphics, vol. 11, no. 4, October, 1992, pp. 373-405.
Kasson, J.M., “Efficient, Chromaticity-Preserving Sharpening for RGB Images,” Device-Independent Color Imaging, Walowit, E., Editor, SPIE vol. 2414, pp. 134-145 (1995).
Kasson, J.M., “Efficient, Chromaticity-Preserving Midtone Correction for RGB Images,” Second Color Imaging Conference, Scottsdale, AZ, November 15-18, 1994.
Kasson, J. M., “Tetrahedral Interpolation Algorithm Accuracy,” Device-Independent Color Imaging, Walowit, E., Editor, SPIE vol. 2170 (1994).
Kasson, J. M., Plouffe, W.E., and Nin, S. I., “A tetrahedral interpolation technique for color space conversion,” Device-Independent Color Imaging and Imaging Systems Integration, Motta, R. J., and Berberian, H. A., Editors, SPIE vol. 1909, pp 127-138 (1993).
Nin, S. I., Kasson, J. M., and Plouffe, W., “Printing CIELAB images on a CMYK printer using trilinear interpolation,” Color Hard Copy and Graphic Arts, Bares, J., Editor, SPIE vol. 1670 (1992).
Plouffe, W. Kasson, J.M., Easy-to-Compute Non-Linearities for Efficient Encoding of Color, Society for Information Display International Symposium, Digest of Technical Papers, Volume XXII, May 1991, pp 814-816.
Kasson, J.M. and Plouffe, W., “Subsampled Device-Independent Interchange Color Spaces,” Image Handling and Reproduction Systems Integration, SPIE vol 1460, pp 11-19, 1991.
Kasson, J.M., Color Science for Device-Independent Color Reproduction, Society for Information Display Conference, Las Vegas, NV, May 1990.
Kasson, J.M. and Plouffe, W., Requirements for Computer Interchange Color Spaces, SPSE/SPIE Electronic Imaging Conference, Santa Clara, CA, February 1990.
Kasson, J.M., “Method and Apparatus for Tone Correction of a Digital Color Image with Preservation of the Chromaticity of the Image,” USA. 5,774,412, issued June 30, 1998.
Kasson, J.M., and Plouffe, W.E., Pryor, D., Nin, S.I., “Function Approximation Using a Centered Cubic Packing with Tetragonal Disphenoid Extraction,” UCA 5,751,926, issued May 12, 1998.
Edgar, A., and Kasson, J.M., “Automatic Cross Color Elimination,” USA. No. 5,509,086, issued Apr 16, 1996.
Kasson, J.M., “Method and Apparatus for Interactively Indicating Image Boundaries in Digital Image Cropping,” USA. 5,473,740, issued December 5, 1995.
Kasson, J.M., “Color Image Gamut-Mapping System with Chroma Enhancement at Human-Insensitive Spatial Frequencies,” USA. 5,450,216, issued September 12, 1995.
Kasson, J.M., and Plouffe, W.E., “Tetrahedron/Octahedron Packing and Tetrahedron Extraction for Function Approximation,” USA. 5,390,035, issued February 14, 1995.
Edgar, A., and Kasson, J.M., “Display Calibration,” USA. No. 5,298,993, issued Mar 29, 1994.

We are in violent agreement on this point.

With apologies to Bill Clinton, it depends on what you mean by “looks like.” I can’t know what sensations occur in your brain when you see a particular Pantone chip, but, unless you are one of the 8 to 12% of the male population, or one-half of one percent of the female population that suffers from color blindness (or color vision deficiency, as it is called by the politically correct), but, within narrow tolerances, I can tell you the (chemically-controlled) spectral response of each of the three types of cones in your eye, of the rods in your eye, and (and this is the amazing part), the algorithm by which the three cone responses are combined to form a color impression. I know this because people who aren’t color blind, in controlled experiments performed over many years, match colors formed from different spectra (called metamers) in the same way. This surprising result is the basis for the CIE 1931 standard observer that I mentioned in a previous post.

While driving at night, you use the cones as well as the rods (if you can see colors, your cones are working). The rods sensitivity exceeds that of the cones at all wavelengths shorter than 670nm, which is well into the red. So, if you can see any color besides a dim red, your rods are being excited, and you won’t be able to see dim objects (say, objects that are illuminated only by starlight.) I don’t agree that only objects that are very close to the vehicle are bright enough to affect your dark adaptation. I think that just the lights reflected from the empty road is enough to diminish your ability to see dim objects.

I see we have a disagreement on the philosophy of night illumination for driving. Here I claim no particular expertise, but I do have lay opinions. You aren’t English, are you? I say that because many English seem to agree with you. I spent a lot of time in England in the 70s, and I never could get used to the idea of driving with “dipped headlamps.” I think the new xenon headlights are a great thing. You must think they’re a step backwards. While I disagree with your way of looking at things, I can’t say your approach is wrong.

With respect to old folks and night vision, both their rods and cones are affected.

And I yours.

Jim

den500sl

...where we had a lenghty discourse on the merits of paper vs. plastic shopping bags!

97 SL500 sprt pkg1 tri blk 27k miles

matsna

Have you ever considered flying to the UK to take a look at your car being built? Aston Martin allow you to do this to the best of my knowledge. Bit like collecting your car with Mercedes in Germany except you'll see your car!