Help with wide angle lens with out of focus photos
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04-09-11, 02:45 PM
Join Date: Feb 2011
Originally Posted by
I think that jetkit may mean calibration.
No, don't think so.
Collimation is the process of aligning the elements of a complex lens to ensure proper focus at the focal plane. It's not the sort of thing you do in your shed, but lens manufacturers/repairers will have the gear to do it.
What you need is to draw some fine lines on a piece of card about 1mm apart over a distance of about 150mm (Yup, that's a lot of them). Make the centre line thicker than the rest and that's your point of focus. Set the card up at 45 degrees (so the bottom of the card is closest to you and the top furthest away) and focus on the centre line as close-up as the lens will allow at max aperture. Load the image onto your computer and look at it @ 100%. If the lens is correctly collimated the centre line will be sharp and this sharpness will tail off in front and behind that spot. If it's out, the point of maximum sharpness will be elsewhere and you can use that image to show the shop.
The day you think you've found perfection is the day you stop looking, then someone else will find it and move in front of you.
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