Reading API Master Test Kit colors

[isaly]

I'm near sighted with an astigmatism but my color vision is pretty good. I studied art in college.

From my beginning in fish keeping last year, I noticed that the colors in the little tubes could be difficult to read. I've developed a way that enables me to, I think, get the most accurate reading possible for me. I understand that color perception is variable among us — that we all see color differently to a degree, which was always my complaint about the swatches to compare, their being process colors, to the color in the tube which I'll call real color.

I use two LED desk lamps. I aim one at the side wall, which is white. The other I aim at the top of my desk. This gives me a balance of direct and reflected light. I place a sheet of white paper on the desk and put the booklet, swatch page up, on the paper.

The lenses in my glasses aren't tinted.

When the test is ready to compare I hold the tube above the paper and pick up the book, being careful to cast no shadows that land under the tube. I want to see the white background, shadow free, through the tube, for what I deem to be the purest, most distortion free color possible for comparison.

Comparing to the swatches, I switch between blurring my vision a bit and focusing, trying to decide which is the closest swatch for a given test in both chroma (color) and value (light to dark).

I know I've seen this issue discussed before, but I thought to post it for anyone who either hasn't seen it or is still having trouble.

Edited April 29, 2022 by isaly

[Jenja]

Definitely a good tip. Never considered using dual light sources.

If only API would create a gadget that could read the colour without any guesswork - they'd make a mint.

[isaly]

On 4/29/2022 at 8:13 AM, Jenja said:

Never considered using dual light sources.

Just make sure your reflective surfaces are white. Color will reflect and confuse your perception.

[modified lung]

Good idea with the reflected light. A good alternative to blurring your vision is setting your camera phone on manual mode and locking the lense out of focus.

[xXInkedPhoenixX]

Some apps can also read the colors- I've never used it so I cannot speak to accuracy but Aquarium Note has this feature. 

Edited April 29, 2022 by xXInkedPhoenixX
to clarify

[Anjum]

Timely post, as I just got all my test kits & was running through them last night. There were a few where I really wasn't sure if I'm reading the colors accurately, but I'm going to try all the suggestions listed. I did notice that some of the color charts have a barely perceptible difference between one step & the next, but hopefully over time my eye will become trained to the subtle differences.

[Torrey]

On 4/29/2022 at 2:51 AM, isaly said:

I'm near sighted with an astigmatism but my color vision is pretty good. I studied art in college.

From my beginning in fish keeping last year, I noticed that the colors in the little tubes could be difficult to read. I've developed a way that enables me to, I think, get the most accurate reading possible for me. I understand that color perception is variable among us — that we all see color differently to a degree, which was always my complaint about the swatches to compare, their being process colors, to the color in the tube which I'll call real color.

I use two LED desk lamps. I aim one at the side wall, which is white. The other I aim at the top of my desk. This gives me a balance of direct and reflected light. I place a sheet of white paper on the desk and put the booklet, swatch page up, on the paper.

The lenses in my glasses aren't tinted.

When the test is ready to compare I hold the tube above the paper and pick up the book, being careful to cast no shadows that land under the tube. I want to see the white background, shadow free, through the tube, for what I deem to be the purest, most distortion free color possible for comparison.

Comparing to the swatches, I switch between blurring my vision a bit and focusing, trying to decide which is the closest swatch for a given test in both chroma (color) and value (light to dark).

I know I've seen this issue discussed before, but I thought to post it for anyone who either hasn't seen it or is still having trouble.

For the test tubes, I found using my cell phone flashlight feature (exact same size as the test tube) from *below* and good lighting plus an 8x10 white piece of paper behind the API card, gives the best readings. For colorblind individuals, take a picture with another phone and use the grayscale trick illustrated in the accessibility post.

White background, sadly I can't find my photograph from last year when I used the cell phone flashlight under the test tube to illustrate from the bottom up....

Just like with test strips, you can take a picture of the test tube against the white background with the API color card beside the test tube.

Use the editing software to move the photograph into grayscale

Compare the grayscale image for an accurate reading.

 

 

 

 

 

[Torrey]

Quit looking, and finally found the picture😏 ... by accident.

You can see how the light from underneath the test tube makes it easier to see the "real color". IRL it works much better, and I don't have to use the grayscale method... my friend who is monochromatic colorblind does.

 

[dasaltemelosguy]

@Torrey I like to use the grayscale too. And your light from below is a really unique idea! In the film and darkroom days of photography, greyscale cards were a staple for anyone with a color enlarger. 

This may or not be of much value as I'm uncertain if this feature is always present on most photo or imaging apps, but many have a simple "invert colors" setting where you literally just reverse the original colors.

Of course, virtually all photo apps have color saturation to exaggerate the test colors and the chart and often makes it easier to distinguish subtle differences a little easier as well.

But inverting colors I find often shows it more clearly. I hope you don't mind my using your shots to demonstrate this, but I find a simple invert color' swap can often make a vague color test more apparent as here it seems to indicate it's 0.25 more distinctly in the inverted color shot:

 

[ReeseADHD]

On 4/29/2022 at 3:51 AM, isaly said:

I'm near sighted with an astigmatism but my color vision is pretty good.

I'm in the exact same boat. I was actually considering getting my vision tested to see if I had some sort of color blindness because of how hard it is for me to tell the difference between the colors. I'm relieved to see that I'm not alone in my struggle. There were many great tips in this thread that I'll be applying in my testing routine.

[Jawjagrrl]

On 4/29/2022 at 7:43 PM, dasaltemelosguy said:

@Torrey I like to use the grayscale too. And your light from below is a really unique idea! In the film and darkroom days of photography, greyscale cards were a staple for anyone with a color enlarger. 

This may or not be of much value as I'm uncertain if this feature is always present on most photo or imaging apps, but many have a simple "invert colors" setting where you literally just reverse the original colors.

Of course, virtually all photo apps have color saturation to exaggerate the test colors and the chart and often makes it easier to distinguish subtle differences a little easier as well.

But inverting colors I find often shows it more clearly. I hope you don't mind my using your shots to demonstrate this, but I find a simple invert color' swap can often make a vague color test more apparent as here it seems to indicate it's 0.25 more distinctly in the inverted color shot:

 

Speaking as someone that was doing design when actual real prepress was involved... I am embarrassed that I never considered this! Much more definitive in your example.

[nabokovfan87]

On 4/29/2022 at 1:51 AM, isaly said:

I know I've seen this issue discussed before, but I thought to post it for anyone who either hasn't seen it or is still having trouble.

As someone who spent many hours staring at pantone samples.... I definitely appreciate taking that mindset into these charts. They are absolutely tough to read sometimes.

 

[corydorablecaliaquariums]

Thanks for this post. Makes me feel less blind. I literally CANNOT tell the difference on my API master test kit between 40ppm Nitrate and 80ppm Nitrate. Does anyone have a digital test for this? Hanna instruments is for marine only:( Trying to keep my nitrate at like 20-50 but, cannot tell if it went OVER into the dangerous range after feeding tons of brine shrimp (oops, didn't know they were a fish laxative)!!

[modified lung]

On 5/6/2022 at 1:50 PM, corydorablecaliaquariums said:

Thanks for this post. Makes me feel less blind. I literally CANNOT tell the difference on my API master test kit between 40ppm Nitrate and 80ppm Nitrate. Does anyone have a digital test for this? Hanna instruments is for marine only:( Trying to keep my nitrate at like 20-50 but, cannot tell if it went OVER into the dangerous range after feeding tons of brine shrimp (oops, didn't know they were a fish laxative)!!

Don't feel blind. Every test has a range where the colors are virtually indistinguishable without a spectrometer. For nitrate that's usually above 30 or 40. For total ammonia it's usually anything below 0.25.

Edited May 7, 2022 by modified lung