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Author Topic: Comparing spectros  (Read 5657 times)

Ethan Hansen

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Re: Comparing spectros
« Reply #60 on: June 23, 2017, 12:53:51 PM »

Jeff - Patch size matters when you use the i1 in normal scanning mode. As Graeme mentioned earlier in this thread, the signal-to-noise level in the i1Pro appears to be lower than in other instruments. Modern cell phone cameras have pixel resolution comparable to a mid-range DSLR. Which one are you going to use for your next job? Throw in the need to determine which measurements only contain colors from a single patch and problems can arise.

If you use the i1p2 in spot patch mode, you should not need to worry about patch size. As long as the layout detection is accurate, you essentially turn the i1iO into a Spectroscan. Move, stop, measure, repeat. Your main worry is heat. An improved dark current sensor makes the i1p2 less sensitive to thermal variations than the original i1Pro. Nevertheless, it still exists. Our only use for the i1p2 is measuring spot colors or ambient light in remote locations. A more regular user can offer better advice than I. A simple minded test would be to measure a page of a single color. Compare readings and see if there is variation for patches read immediately before and after visits to the white calibration tile.

Jeff-Grant

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Re: Comparing spectros
« Reply #61 on: June 23, 2017, 10:58:33 PM »

Thanks Ethan. I just tried a repeatability test on the i1p2 on io2. I printed a 140x210mm page with half at RGB 15,15,15 and the other half at 245,245,245. Using the measure chart in i1p to give me 600 7mm patches. Choosing dark and light seemed to be a good test as the i1p seems less comfortable at the ends of the spectrum. I scanned in spot with two reads per patch. The max de of 0.61 works for me. I can live with that.
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