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| Am colour blind, need help identifying bands |
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| SiliconWizard:
Brown and dark red are either very close or for some brown shades, the same thing. So distinguishing the two is often pretty hard and not just for color blind people. Especially true on photos for which we don't have the full lighting context. Some of you may remember people going nuts on social networks about the color of a dress: https://www.cnet.com/tech/services-and-software/why-the-dress-lives-on-infamy-one-year-later-black-blue-white-gold/ |
| 25 CPS:
I'm colourblind and remember one of my professors way back when saying, "I think the bands on resistors are scientifically designed to make you go blind," when we were discussing it once. Several things I've found handy are being able to change lighting between incandescent and LED even if it's shining a handheld LED flashlight can help different coloured bands stand out. Also having some plausible candidate values in mind based on the circuit the parts are in can help rule out some colour possibilities that just don't make sense given the context. Most of all, a DMM and LCR meter are the best thing to have. This way you get an actual value, rather than a stated value, plus it avoids another pitfall with colour codes that can affect everyone regardless of vision: Age and/or heat related deterioration of the colour coded bands can make them incredibly difficult or impossible to read. Once that happens, a measured or schematic/parts list value is what you're going to have to go with. |
| Bicurico:
--- Quote from: JohanH on August 25, 2022, 06:16:52 am ---I've been curious about those "color blind" correction glasses that are touted online, but I haven't bothered when they are all made with tinted lenses (and I would like to use them inside). They supposedly improve color contrast and I'm sure that in theory that could work, unless you have a total lack of color perception. With good lighting I anyway see the difference, so for me they wouldn't be a big benefit anyway. --- End quote --- These glasses are amazing. While I don't need them, I have recommended them to students of mine. They work by filtering frequencies. Colour blind people have receptors that have overlapping response to green/red. The glasses simply work as a filter eliminating a frequency range in-between red and green or blue, whatever. It does work, but color resolution is reduced. |
| 25 CPS:
--- Quote from: Bicurico on August 25, 2022, 10:17:58 pm --- --- Quote from: JohanH on August 25, 2022, 06:16:52 am ---I've been curious about those "color blind" correction glasses that are touted online, but I haven't bothered when they are all made with tinted lenses (and I would like to use them inside). They supposedly improve color contrast and I'm sure that in theory that could work, unless you have a total lack of color perception. With good lighting I anyway see the difference, so for me they wouldn't be a big benefit anyway. --- End quote --- These glasses are amazing. While I don't need them, I have recommended them to students of mine. They work by filtering frequencies. Colour blind people have receptors that have overlapping response to green/red. The glasses simply work as a filter eliminating a frequency range in-between red and green or blue, whatever. It does work, but color resolution is reduced. --- End quote --- This is a bit of a tough one since colourblindness takes so many forms. The overlap issue that the glasses can help out with by notching out the areas of visible spectrum that are doubled up isn't present in any of the -opia types of colourblindness where the sensitivity is severely attenuated or missing entirely. For example, the glasses won't help much for someone with protanopia since red isn't partially overlapped with something else that can be separated out by notching out the overlap, the red's completely gone. |
| Warpspeed:
Is that grey, or is it white ? Is that yellow, or orange, or maybe its brown ? Red, or perhaps brown.... who knows ???? Nothing wrong with your eyesight, but the terrible quality paint, or whatever it is they use. Time does not help, and if the thing has ever been hot, all bets are off. Often its not obvious which end to start reading from. Best solution is a way to test parts, a multimeter at least. But you can buy low cost component testing devices that are especially useful to identify the basic type of semiconductor devices, as well as the value of most resistors, capacitors and inductors. Not hugely expensive but extremely useful. I bought an earlier version of this a long time ago: https://www.ebay.com.au/itm/265208502923?hash=item3dbfa89a8b:g:vH0AAOSwNJRgEc~z&amdata=enc%3AAQAHAAAA4IluZckAF%2BuVgDj4CtuhyeHbrOwfxqW3bfuCtZGsYy4AoXppTjJaF2UK6NVRMkBelPnVfqKaxMfqllJmxlmB3at6TKNt%2B5x%2B0atNHRmb2KdAHZSMtA2hvsXohebskOzSFmzgif0FYmxFKk6aNHB4fYFxWnqz%2FKgd61KySqS7OXvmDN52BtAh5F6QYp5Z6KsEIStB6nj2L%2BgnmqgwKM%2FhfUX7%2BELy5wZOGLK5I9IgS%2BkdJy5%2BAwnbAFxIRbItSphErXTRW7Qbs1JLLawv%2FMlMVgeBj474RmcNPjlxGfBrbt17%7Ctkp%3ABk9SR5i4wIDbYA |
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