The "apoc-eclipse"

[Kevin D'Haeze]

Ok, just to be clear. If I set my camera up with a wide shot that includes the sun... my sensor will get fried during the eclipse, and I need a filter?

 

[D. O'Bryan]

Yes. Have heard various warnings about using a wider lens, as it focuses the energy into a denser spot on the sensor. On the flip side of that argument, how many times have we all shot into the sun while focusing on a more earthly subject? I'm on the fence with the thinking that it'll actually cook the sensor...

For shooting straight into the sun I've been told that two polas in a rotating MB stage will make a very powerful vari-ND which pairs with stopping ht lens down really far should make shooting the eclipse practical. Big disclaimer: these are all things I'VE HEARD. Cannot confirm they actually are true and ymmv.



Our rig for monday is a 1250mm ƒ13.5 optical tube from a maksutov-cassegrain telescope with a T-adaptor to EF mount. Swing away matte box (to quickly reconfigure for totality) with an eclipse mirror filter and ND 2.1. Sun fills the frame and sunspots and other details are visible.

 

[Kevin D'Haeze]

Wow, nice setup! Your point cuts to what was going through my head. How many times have I included the sun as part of the shot? Lots. With no issues. So what is it about the eclipse that poses greater threat? I have seen several time lapse DSLR videos of prior eclipses. Doesn't seem like they used anything special for their wide shots. But... don't want to risk my sensor if I am wrong. Just trying to understand the physics here.

 

[Mark Phelan]

Yes. Have heard various warnings about using a wider lens, as it focuses the energy into a denser spot on the sensor. On the flip side of that argument, how many times have we all shot into the sun while focusing on a more earthly subject? I'm on the fence with the thinking that it'll actually cook the sensor...

For shooting straight into the sun I've been told that two polas in a rotating MB stage will make a very powerful vari-ND which pairs with stopping ht lens down really far should make shooting the eclipse practical. Big disclaimer: these are all things I'VE HEARD. Cannot confirm they actually are true and ymmv.



Our rig for monday is a 1250mm ƒ13.5 optical tube from a maksutov-cassegrain telescope with a T-adaptor to EF mount. Swing away matte box (to quickly reconfigure for totality) with an eclipse mirror filter and ND 2.1. Sun fills the frame and sunspots and other details are visible.

Your setup reminded me of another option if needed. Since you are using cinefoil on the front of your matte box, you can also use the cinefoil as an iris to reduce the aperture. If necessary, you can cut a small circle, (offset from the center mirror) to stop down the lens.

 

[Brandon Kelly]

I have done wide angle time lapses with my red camera many times with the sun in the frame for 30-60 minutes etc. The eclipse is no different then the regular sun. Granted I would usually be doing more sunrise or sunset, but still I'm having issues seeing how this is any different.

 

[D. O'Bryan]

Aaaannnnndd then I wake up to find this article on the homepage of The Verge:

https://www.theverge.com/2017/8/19/16173784/total-solar-eclipse-photography-no-filter-dslr-camera-zoom-lens

:scared:


Mark, great idea using it as an iris!

 

[Owen Rennie]

I've shot time lapses of the sun setting with my Red Dragon and Canon 800mm a few times with no filter.. solid 10 minutes aimed at it with no dramas, however after watching that video above I will never try that again haha

 

[Kevin D'Haeze]

@ D. O'Bryan,

Ouch... I could see how a mega tele lens might really concentrate those rays onto the sensor and fry it. But I'm wondering if it's apples to apples if you're just shooting a wide landscape shot. Finding a wide shot of an eclipse is easy on YouTube, a la this:
https://www.youtube.com/watch?v=ZAxl0S7za8I

And the BTS of that video... not seeing any obvious filters:
https://www.youtube.com/watch?v=2qXDrxdd_Bw

 

[D. O'Bryan]

I'm thinking the wide angle argument has got it backwards. Tele's are focusing mush more energy onto the sensor than a wide, which is only shining light onto a small spot...?

In other news, trying to wrap my mind around the best settings for catching totality.

http://xjubier.free.fr/en/site_pages/SolarEclipseExposure.html

This calculator is helping. Thinking about running 6k (it's going to be SO zoomed in!) HDRx with a 3 stop spread. Or see if I can run a lower FR and get the full 8k HDRx.

I entered ISO 640, ƒ20 (ƒ13 telescope + ND 1.2) with the diamond rings as my "ideal exposure" baseline, and according to that calculator it looks like theres a +7 stop difference between the chromosphere and diamond rings, and a -5 stop difference to the outer corona. Honesty, that sounds like it's inside Helium's useable DR without using any HDRx. Am I missing something?

Only going to have a few precious minutes to get it right, so these settings need to be dialed beforehand!