Datacolor Spyder3 PrintSR

[Graham Ferguson]

Hi all
I have a Datacolor Spyder3 PrintSR and I am trying to learn how to drive it in respect of taking readings off my prints to determine colour accuracy, which I understand it is capable of doing.
The "Measure" function under "Tools" is greyed out so I am wanting to know, in step by step terms, how to activate this option, and from there on, how do I actually measure the different colours on my prints?
Also if I get that far down the track and can accomplish a reading, how would the reading relate to the colour values I see when I place the cursor over a colour in an image in Photoshop Elements?
Any help would be appreciated but please keep it simple!
Thanks
Graham

[Colin Southern]

Hi all
I have a Datacolor Spyder3 PrintSR and I am trying to learn how to drive it in respect of taking readings off my prints to determine colour accuracy, which I understand it is capable of doing.
The "Measure" function under "Tools" is greyed out so I am wanting to know, in step by step terms, how to activate this option, and from there on, how do I actually measure the different colours on my prints?
Also if I get that far down the track and can accomplish a reading, how would the reading relate to the colour values I see when I place the cursor over a colour in an image in Photoshop Elements?
Any help would be appreciated but please keep it simple!
Thanks
Graham

Hi Graham,

The measure function is greyed out because the white point on the spectrophotocolorimeter isn't calibrated. Just take the option to calibrate it on the menu below the measure option - pop it on the cradle - and hit the button.

Once you've done that you'll be able to get into the measure function, where it's simply a case of sampling a colour and having the result expressed in terms of a LAB number.

With LAB numbers - basically - the L (luminance) channel is a scale from 0 to 100; 0 being black and 100 being maximum reflectivity, and the AB are colour opponent channels which describe the colour (as opposed to the brightness of the colour); A is a positive or negative position on a magenta / green scale, and B is a positive or negative position on a blue / yellow scale. It sounds complicated, but ... well actually, there is no "but" - it IS complicated, but it's close to how the human brain processes the RGB information fed to it by the eyes, and it's also device independent (unlike CMYK or RGB where the "shades" of cyan, magenta, yellow, red, green, blue etc aren't defined). All you need to know at this stage though is that if the A and B numbers are both zero then the sample is spectrally neutral (ie "gray").

In terms of comparing it to screen samples in Photohop - in an ideal world (assuming the sample is displayed in LAB notation) then the numbers SHOULD be identical (assuming a perfect print), but in practice one NEVER gets a perfect print. In practice, black ink always reflects some light (typically as low as about 4 for paper and 17 to 25 for canvas with photo black ink) (lower for matt black ink), but whites can bet close to 100. In terms of the AB channels, you need to compare the numbers eg if you had 50,0,0 on screen (a perfect medium gray) and measured 45,6,-11 on the paper then you'd have something that was slightly darker and with a shift towards magenta (6) and a slightly bigger shift towards blue (-11).

In reality though the printer driver will adjust the tonal range to fit (so if the black point is 10 and the white point is 90 then it'll fit requests for values of between 0 and 100 into this 10 to 90 range) (which can be a help or a hinderance). It'll also adjust colours so that the the printer prints the colour requested by the "image" (or as close as it can to it). It's all very much a compromise though.

Not sure if you have this already or not, but Real World Colour Management 2nd edition by Fraser, Murphy, and Bunting is the industry standard reference text for learning all this stuff.

Hope this helps!

[Graham Ferguson]

Hi Colin
Thanks for that ( I think! ) Thats a whole lot to think about. I have managed to get to the "reading a colour value" stage but the next step looks like a long one indeed.
I might just have to get "the book".
Thanks
Graham

[Graham Ferguson]

Hi Colin
Since I only have Elements 8 I cant sample the image in Lab.
Seems I have 4 options:
Grayscale
RGB Colour
Web Colour
HSB Colour. Hue Satuaration and Brightness.
Can I do anything with these values using the Spyder Print?
Thanks
Graham

[Colin Southern]

Hi Colin
Since I only have Elements 8 I cant sample the image in Lab.
Seems I have 4 options:
Grayscale
RGB Colour
Web Colour
HSB Colour. Hue Satuaration and Brightness.
Can I do anything with these values using the Spyder Print?
Thanks
Graham

Hi Graham,

Not sure to be honest -- I only use Photoshop. Perhaps there is a web-based calculator somewhere that could approximate some conversions?