Beehive Cluster (M44) comparing 1.3 and 1.6 second exposures

After realizing I accidentally photographed the Beehive Cluster earlier this winter, I tried for an honest attempt on February 12, 2013. I tried two different exposure durations to see if I could tell the difference between 1.3 seconds and 1.6 seconds in terms of the length of star trails.

24 subs, f/5.6, 300mm, 1.3 sec each stacked in DSS

According to the 500 rule, I shouldn't be able to see noticeable trails at 500 ÷ 1.6 (Canon image sensor crop factor) ÷ 300 (for 300mm focal length) = 1.042 seconds

According to the 600 rule, this time would be 1.25 seconds

There's a lot more to it than that (and much better resources than mine) to help you figure it out. I'm also limited by a smaller f/5.6 compared to other f/2.8 lenses, so I went with 1.6 vs. 1.3 sec to see if I could even tell the difference.

Turns out you can definitely tell a difference, and looking back I probably should have been around 1 sec rather than 1.3 or 1.6 sec.

I'm glad I at least got to experiment with this photo because for some reason my light .CR2 files wouldn't load into DSS, so I was stuck with my JPG's and couldn't even use my dark or bias frames even though they would load fine. I think it's because I was messing with them in Photoshop before stacking them, and that might have done something to the files - not really sure. I just know that next time it'll be straight from the camera to DSS and no mucking around!

Found an accidental Beehive Cluster (M44) photo

I was looking through my old Geminid meteor shower posts and saw a fuzzy blob in the sky. I looked it up, and turns out it's a Messier object (M44) known as the Beehive Cluster. Who knew! Aside from the ones I've already photographed, I'm still unfamiliar with the location of Messier objects in the sky. Since I don't have a scope, I only have access to the brightest deep sky objects.

The Beehive Cluster is down and to the left of Gemini, which makes it fairly easy to find (that is, if you know to look for it in the first place). This makes a total of five Messier objects that I've photographed so far. I suppose I should start a checklist!

I'm making a note to revisit M44 on the next clear night. Last night I spent some time on the open cluster in Canis Major (M41) that I'm still processing. That will take my new total up to six!