Filming a total solar eclipse

[Ranb]

I'll be going to Salem Oregon in August 2017 (from the Seattle area) to watch and photograph the eclipse.  This will be the first time I plan to have a camera and camcorder to record such an event.  I was able to observe partial eclipses over the years, but never had a camera with me. 

I have a Nikon D50 with a 300mm zoom lens and a doubler as well as a basic camcorder; both will be tripod mounted.  I also have a remote for the D50.  I plan buying or making solar filters for the cameras and practicing this summer.  I want to showing the eclipse moving across the stationary camcorder's field of view from start to finish while taking photos with the D50 every five minutes or so with the sun in the center of the frame.  I'll take the solar filter off of the D50 during the nearly 2 minutes of totality.  I'll need to find a way to increase the recording time on the camcorder as the eclipse will last 2-3 hours from beginning to end as far as I know.

Any suggestions?  Thanks.

Ranb

[Zakalwe]

Whatever you do, do not attempt to use anything but the correct solar filters. I have seen all sorts of BS YouTube videos suggesting that you used CDRoms, Mylar, welding glasses- even 8.5" floppy discs!.

DIY materials can pass dangerous amount of IR and UV energy. IR can burn the retina. UV can cloud the lens. Some damage happens straightaway, whereas some can develop over a number of hours after exposure.
Welding glass will block the visible, IR and UV. however, welding glass is made from ordinary float glass and is not optically flat. The uneveness of the glass will result in blurry images.
The recommend material to make a solar filter is Baader Solar film:
http://astrosolar.com/en/

There are dedicated glass solar filters available, from the likes of Thousand Oaks, but in my experience they are inferior to the Baader film. Again, these are made of ordinary float glass and introduce optical effects.

There are 2 versions- ND5 and ND3.8 The ND5 is the one that is suitable if you are going to look through the viewfinder. ND 3.8 is for imaging purposes only and will pass potentially dangerous amounts of energy through.

I would not recommend taking the filter off during totality as the Bailey's Beads will still pass dangerous amount of UV and IR. If you have your eye on the viewfinder, then you can permanently damage your eyesight. If you are using a remote screen to view then you should be safe...the worst that could happen is a knackered camera.
http://www.camerarepair.org/2012/05/solar-eclipse-burned-camera/

I do a lot of solar imaging and I pay a very healthy respect to the damage that solar imaging can do. It's just about the only form of astronomy that is inherently dangerous.

[smartcooky]

Zakalwe

What is wrong with a proper mylar solar filter?

I used one of these on my Celestron 8" Schmidt Cass for many years with no problems or eye-damage



http://sctscopes.net/SCT_Tips/Nice_to_Have/Solar_Observing/solar_observing.html

The only thing I will say is yo make absolutely sure that the filter is attached securely... you don't want being knocked or blown off by accident.

All the newer ones actually lock-in to the front end of the telescope.

[Zakalwe]

Zakalwe

What is wrong with a proper mylar solar filter?

Mylar is a lot more delicate and the coatings can become damaged fairly easily, leading to pinpricks or general erosion of the reflective surface.
My natural paranoia makes me very suspicious when doing any form of solar work though. I'd personally be very cautious of sticking my eye to a telescope unless i was 100% sure that the filtering took care of the visible, UV and IR.

The Baader stuff is so cheap it's not worth (IMHO) using anything else to be honest.  An A4 sheet costs £20, so (again, IMHO) I can't justify using anything else.

[Zakalwe]

The only thing I will say is yo make absolutely sure that the filter is attached securely... you don't want being knocked or blown off by accident.

All the newer ones actually lock-in to the front end of the telescope.

A very good point. Ive heard of filters getting blown off the front of scopes.

[Sus_pilot]

Back when there was a partial eclipse of the Sun in the Chicago area (spring 1970, IIRC), I shot monochrome of the event using an SLR and a 50mm lens, with red and green filters stacked, looking through the viewfinder.  Interestingly, although there is no known history of color-blindness on either side of my family, I can't pass the Ishahara dot test to save my life.  I do see colors and I carry a night-flying waiver from the FAA because I was able to demonstrate that I could see colors (it would be embarrassing to land on the taxiway [blue lights] instead of the runway [white/amber]). 

I've often wondered if I damaged my retinas slightly that day.

[onebigmonkey]

Whilst no expert I also wonder about the wisdom of removing a filter midway through, mainly from a continuity perspective. If you need to you can always increase the film brightness post-filming and introduce it gradually. It's a lot easier to recover from slightly under-exposed than it is from over-exposed!

Good luck - I'm very envious!

[Ranb]

Thanks for the tips.

I've been reading up on various techniques for filming/photographing eclipses.  One said that a total eclipse being safe to took at with the naked eye, using a solar filter would block too much light.  With nearly two minutes of totality, I can take photos with the filter off and on.

I'll not bring using the viewfinder on my D50 at all, just the digital display on the back.  I'll also be equipped with an arc welding mask and some solar sunglasses.

I'll be using the large/fine format on the camera to maximize resolution.  I have several SD cards to hold lots of photos.  What do you guys think of raw vs jpeg formats for solar photographs?

Ranb

[ka9q]

I have a Canon 40D. With cards so large, I now shoot RAW for everything unless my shooting rate is so high that it temporarily fills the buffer in the camera and slows shooting while it gets flushed to the card. Then I'll use JPEG. That's pretty rare; the last time I remember it being necessary was capturing the liftoff of a high power amateur rocket at 6 fps, being unsure of when the engine would actually ignite.

[Zakalwe]

I have a Canon 40D. With cards so large, I now shoot RAW for everything unless my shooting rate is so high that it temporarily fills the buffer in the camera and slows shooting while it gets flushed to the card. Then I'll use JPEG. That's pretty rare; the last time I remember it being necessary was capturing the liftoff of a high power amateur rocket at 6 fps, being unsure of when the engine would actually ignite.

Memory density is increasing all the time...its cray that you can now get 1/2 terabyte on a micro-SD card. 

For anything astro-related, always shoot in RAW mode. JPEG compression algorithms destroy the data that is lurking in the dark stuff, which is the very stuff that we are trying to capture.

[ka9q]

For anything astro-related, always shoot in RAW mode. JPEG compression algorithms destroy the data that is lurking in the dark stuff, which is the very stuff that we are trying to capture.

Absolutely.

[molesworth]

Just to add my two pence/cents : definitely get some Baader film for filters, definitely shoot raw, and definitely be careful observing the sun with any kind of instruments.

And... there's an interesting project which this particular eclipse is almost custom made for - The Eclipse Megamovie! http://www.eclipse2017.org/2017/photo/mega_movie.htm. (There's more detailed technical info around the web as well.)

I'm planning to get across to somewhere on the eclipse path, and hopefully can get some decent images to contribute to the movie :-)