Lightabsorption

It can be useful to think about the primary colours of light when working out which colour of light will be transmitted by a filter. Remember that white light is made up of red, green and blue light.

Absorbance AU

Although that i had my measurement set to 1cm and 2 decimals, that was not fine tuned enough so i switched to 10mm with 2 decimals, which gave a better resolution for the data.

I see that you have a length measurement. I think the simplest solution would be to rescale the measured length based on the ratio of old to new pixel size.

If the saved tiff contains the lines as selection it should be possible to add them to the ROI Manager, split the selection and do a multi-measure (all in the menu of ROI Manager) after setting the new scaling.

I have multiple of these saved images with lines on them, i would like to select all of them and remeasure them with a new scale is that possible or do i have to re-draw all of them? Would be glad if there is a simple trick i’m missing else, i have to re-draw 15k lines

Red, green and blue filters each transmit a single primary colour. Any other colours present in the light are absorbed.

Just like filters, it can be useful to think about the primary colours of light when working out which colour of light will be reflected by a surface.

This effect can be demonstrated using red/green 3-D glasses or coloured cellophane – like the type used to wrap some sweets.

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That’s why i would need to remeasure it with the new scale, since the value in excel is saved as the rounded value to the 1cm scale

Visiblelightwavelength

Image

Notes for reflection oflight

Viewing coloured objects, or images through different coloured pieces of cellophane can cause objects to appear a different colour. They may even seem to disappear.

When looking at a coloured surface, the colours which are reflected enter the eye, which determines the colour the surface appears.

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This is because the cellophane acts as a filter, partially or completely absorbing some colours of light, while other colours are transmitted.

now, i can click on each line seperatly and remeasure it but just clicking M but how could i reselect all lines in one and measure with M? CTRL A or any selection does not work, except clicking on each individually

Okay, so all numbers in the excel file are rounded and can’t be used. But you have saved the image with all annotated lines? Did you save the ROIs from the ROI manager under “More”?