Free NPF Calculator! View Larger Image During my astrophotography workshops, I get asked many times about the proper exposure time. How to find the “perfect” exposure for the lens used, to capture pin point stars, without trailing. So I decided to make a very simple excel file in order to help you find the proper exposure based on your camera and your lens. It’s absolutely free to download it. Feel free to contact me in case you have any questions about it! Stay Safe! #KeepLookingUp Download Here!Share This Story, Choose Your Platform! christophe2021-04-15T07:35:48+03:00April 13th, 2021| Like This Post? Share It With Others! FacebookTwitterRedditLinkedInPinterestEmail Related Posts Why Less is Actually More (in Photography) From a Thought, to a Photograph What Type of Photographer are you? A New Series of Blog Posts is Coming Soon! 2 Comments Matt Begg 12/01/2022 at 20:21 - Reply Nice spreadsheet but does not account for Canon APS-C sensor which 22.3mm as opposed to the 24mm you have in the dropdown and with the spreadsheet locked I cannot change it. Looks like I will quickly write my own christophe 13/01/2022 at 08:44 - Reply Hey Matt, thanks for your comment. Although the difference is very small, I will update the table. Thanks again! Leave A Comment Cancel replyComment Save my name, email, and website in this browser for the next time I comment.