Transit of Mercury, anyone?

BackdoorArts

Senior Member
When astronomical or atmospheric events occur around here it's a better than even money bet that my corner of NJ will be clouded over. Somehow yesterday it was not, so I found myself climbing down and back up the flight of steps from my home office to the front yard every 10 minutes. These old knees are aching, but I managed to get it.

Mercury-Transit-2019-11-11-copy-2.jpg



Shot with a D500 with 300mm f4 pf + 1.4TCii plus ND400 & ND8 filters. I tried stacking an additional ND4 & ND2 but any additional filters caused reflectivity between them and blurred the image. Exposure varied as the sun rose but ultimately I was at 1/5000 & f/16.

I should note that astrophotography is not my thing, so while I could reason out the explanation from my 5 semesters of college physics I should inform you that the path of Mercury you see here is not what I saw straight out of camera. What I got there was more of an arc from the lower left (about 7 o'clock) to the right edge (about 2:30 on the dial). I suspect with the earth's rotation in order to produce a straight line the camera should have been rotated over time instead of remaining level to the ground. I based the line on the median points in the arch and rotated images around the center to line up since it's what I've seen in all other transit composites.
 
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BackdoorArts

Senior Member
Fantastic! I wish I had the equipment to spot that myself, but it's great seeing your capture. Great job!


Thanks. Would have loved to try it with the 500mm but I have 77mm filters and nothing to step down from 95mm. Since I'm shooting on DX I may have been able to use the step down without ghosting on the edges but I don't know. May need to invest in the ring to find out.
 

nickt

Senior Member
Great work Jake! Of course it was cloudy up here in NY. I got 3 shots through thinner cloud moments. Not even worth putting them together. Without a good series, they could pass for sensor dust. I don't have the right filter. I used an n400, set focus for infinity, 1/8000, f32 and quickly pointed the camera at the warm spot without putting my eye to the viewfinder. I'll risk a melted shutter or sensor, but not my eyes. Here's my best of 3, lol. 12:55pm. Its that little spec to the right around the 2 o'clock position. Probably even without clouds, f32 would have prevented a clear dot.


D72_7220.jpg
 

hark

Administrator
Staff member
Super Mod
Contributor
Amazing, Jake! I didn't even try but wouldn't have even thought of creating a composite. I wondered why you didn't use the 500mm PF. Now I understand! Those 95mm size filters must be rather pricey.
 

BackdoorArts

Senior Member
Amazing, Jake! I didn't even try but wouldn't have even thought of creating a composite. I wondered why you didn't use the 500mm PF. Now I understand! Those 95mm size filters must be rather pricey.


Had I known about it ahead of time I would have at least purchased the step down ($25 from B&H), plus I originally thought it was Sunday and I was away. Got lucky.
@nickt yeah that's my usual experience. There were strong clouds and branches across the sun in the first couple (nowhere else to go) but thankfully not where Mercury was. 12 stops is the minimum I'd use for the sun again, but I'd love to be able to do 15. I use dark sunglasses as well when I'm lining it up along with a "curtain" (think old view cameras) so I don't need to look towards the sun when reviewing. Lens gets covered with a ball cap until I'm ready to shoot. With the mirror plus the ND's I figure it's my eyes more than anything risking damage. Wouldn't do it with a mirrorless.
 

hark

Administrator
Staff member
Super Mod
Contributor
Had I known about it ahead of time I would have at least purchased the step down ($25 from B&H), plus I originally thought it was Sunday and I was away. Got lucky.
@nickt yeah that's my usual experience. There were strong clouds and branches across the sun in the first couple (nowhere else to go) but thankfully not where Mercury was. 12 stops is the minimum I'd use for the sun again, but I'd love to be able to do 15. I use dark sunglasses as well when I'm lining it up along with a "curtain" (think old view cameras) so I don't need to look towards the sun when reviewing. Lens gets covered with a ball cap until I'm ready to shoot. With the mirror plus the ND's I figure it's my eyes more than anything risking damage. Wouldn't do it with a mirrorless.

I hear you! I like the Sensei brand of rings via Adorama, but unfortunately there only seems to be one manufacturer that makes a 95-77mm step down ring. There's also the option of getting a 95mm solar filter although I'm not sure how good this one is. No reviews on it yet. Marumi is a brand of solar filters that gets decent ratings, but it doesn't appear they even offer any in 95mm.

https://www.bhphotovideo.com/c/product/1423197-REG/ice_ice_100k_95_95mm_nd100000_filter.html

You still did an amazing job with what you had to work with! I'm not sure how you could have improved on this image even if you had access to step down rings or a filter to fit your 500mm. This is just stunning, Jake. :)
 
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