That 30 second exposure rule I always used might be wrong

I was reading through this old astronomy forum from 2008 and found a post breaking down the 500 rule for star photos. Turns out that rule gives you streaks way before they're actually visible on most modern cameras. I tried it myself last weekend with my Nikon D5600 and a 24mm lens, did a 20 second shot next to a 10 second one and zoomed in. The 20 second one had obvious trailing I never noticed before because I only ever looked at the full frame. Anyone else go back and recheck their old settings after learning this?

2 comments

2 Comments

karenlane1mo ago

I used that old 500 rule for years with my Canon T3i and a 50mm lens, never had a problem. You're looking at pixel peeping on a 24 megapixel sensor which is way more demanding than what most forums were talking about back in 2008. Those guys were probably shooting on 6 or 10 megapixel bodies where trailing was a lot harder to see. Plus half the people obsessing over perfect round stars are just making 1920x1080 slideshows for YouTube anyway. I'll take a 20 second shot with some trailing over a 10 second one that's dark and noisy any night of the week.

averym821mo ago

Haven't you ever blown up a print and seen how bad that trailing actually looks though?