# Required Distance to Backlight @ 100mm f/8

**URL:** <https://forums.negativelabpro.com/t/required-distance-to-backlight-100mm-f-8/9293>\
**Category:** Guides and How-Tos\
**Created:** [May 4, 2025, 4:17pm UTC](https://forums.negativelabpro.com/t/required-distance-to-backlight-100mm-f-8/9293 "2025-05-04T16:17:14Z")\
**Posts on this page:** 1\
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**Author:** ![Digitizer](https://avatars.discourse-cdn.com/v4/letter/d/57b2e6/32.png) [@Digitizer](https://forums.negativelabpro.com/u/Digitizer)\
**Post date:** [May 6, 2025, 8:52am UTC](https://forums.negativelabpro.com/t/required-distance-to-backlight-100mm-f-8/9293/8 "2025-05-06T08:52:54Z")

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> [@Harry](#):
>
> it would be easy to use the CS-Lite and just move it away in stages

That should work. You should see differences quite early, and as long as the light is in view of your capture, lighting should bee even, but dropping with every step you move the light away.

Find a few images in here: [Collimating light for more sharpness - #15 by Digitizer](https://forums.negativelabpro.com/t/collimating-light-for-more-sharpness/3901/15)

Pragmatically, if a light source is at least 10 x FL away, it can be considered collimated

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