How to compare two camera quotes when the resolutions differ
When two camera quotes differ in resolution, convert both to pixel size at the same web width, then compare the price. 4000 pixels on 300 mm is not 4000 pixels on 800 mm.
When two quotes give different resolutions, turn them into pixel size at the same web width before you compare the price. 4000 pixels across 300 mm and 4000 pixels across 800 mm are not the same capability. Pixel size is about the web width divided by the pixel count.
Why it is judged this way
When a supplier writes “4K camera,” ask how many pixels across and how wide the coverage is. Work out a few tenths of a millimetre per pixel, then multiply by 3. That is roughly the defect you can see steadily. After both suppliers have done this division, the quotes can be ranked.
What to compare
| What you see | What to call it | What not to do |
|---|---|---|
| At the same web width the pixel size is smaller | Better capability for a fine defect | Look only at whether the camera model is newer |
| The pixel count is the same but the web is wider | Worse capability | Treat them as the same |
| The calculation does not reach your defect | This set is not enough | Buy it and plan to upgrade later |
At job change or when a roll is opened
- Ask both suppliers for the across-web pixel count and the coverage width.
- Calculate millimetres per pixel.
- Divide your smallest defect by that number and see whether you have about 3 pixels.
