Sun Filter Test Run

[crimbfighter]

My Thousand Oaks Optical solar filter finally arrived a few days ago for my Nikon 200-500. Today was the first sunny day I could try it out. There wasn't anything special about the sun today, but it was nice to see how it performed. Quite well as it turned out!

D800, 200-500 f/5.6 @ f/6.3, 500mm, 1/320sec, ISO100

 

[birdbonkers84]

That looks ace!

 

[smoke665]

Pretty awesome. I wonder if this will let you capture solar flares?

 

[petrochemist118 143]

Good result but a shame there were no sun spots (we're currently around a solar minimum so sun spots are less common at the moment).

Pretty awesome. I wonder if this will let you capture solar flares?

IIRC solar flares are considerably darker than the main solar disk, and can only be captured if something blocks out the main disk of the sun. The Eclipse back in august would have been ideal. NASA have a set-up with an artificial disk blocking the main disc but for us mortals alignment of that sort of thing is not practical

With a bit of research you should be able to take shots of the space station crossing in front of the sun but each time it only takes a few seconds & you need to be in just the right spot...

 

[TCampbell]

To see prominences, filaments, coronal mass ejections (flares), etc. (all features that require viewing the "chromosphere" instead of the "photoshere") you would want to use a Hydrogen alpha solar telescope. These completely block out all the wavelengths except the Hydrogen alpha wavelength (656nm which shows up to us as a fire-engine red color).

I have an Ha solar telescope, but usually before I set it up, I take a peek at the National Solar Observatory website to see if the sun is showing off anything interesting at the time. You can see that here: https://gong2.nso.edu/products/tableView/table.php?configFile=configs/hAlpha.cfg

Today's sun is showing lots of prominences.

You would also see prominences during a total eclipse (but it has to be a total eclipse... not partial and not an annular eclipse.)

A "white light" solar filter (such as the one Tanner used to capture the image above) let's all wavelengths pass... but only a tiny fraction of the total light. Basically it's like a really strong pair of sunglasses (usually it's ND 5.0 and blocks 16.7 stops of light ... or about 1 photon out of every 100,000 passes through and the rest are blocked (and still the sun looks this bright)).

The Thousand Oaks filter blocks slightly stronger toward the "blue" (short wavelength) end of the spectrum and less on the "red" (long wavelength) end. This creates the orange color cast. If a filter is precisely even with how much it blocks of all wavelengths (perfectly neutral) then you end up with a "white" sun and that's why they call them "white light" solar filters (even the ones that give a bit of a color cast are still called "white light" filters.)

 

[crimbfighter]

That looks ace!

Thanks!

Pretty awesome. I wonder if this will let you capture solar flares?

The filter may allow it, but I don't know that I would have the resolution to capture a solar flare. They are quite small compared to the total circumference. On the full res image, zoomed in, you can see variations in the outline, but I imaging that was probably caused by atmospheric variations as opposed to actual topographical features.

Good result but a shame there were no sun spots (we're currently around a solar minimum so sun spots are less common at the moment).

Pretty awesome. I wonder if this will let you capture solar flares?

IIRC solar flares are considerably darker than the main solar disk, and can only be captured if something blocks out the main disk of the sun. The Eclipse back in august would have been ideal. NASA have a set-up with an artificial disk blocking the main disc but for us mortals alignment of that sort of thing is not practical

With a bit of research you should be able to take shots of the space station crossing in front of the sun but each time it only takes a few seconds & you need to be in just the right spot...

I so wish there was something on the surface to capture, but of course this was only the first test run, so I anticipate playing with it more. I actually thought about working out the size disk needed and making a contraption that suspended a disk on the lens to see what happens. It'll probably fail miserably, but worth a shot! I was actually already planning to find out when the ISS will transits the sun from my area as that would be awesome! That and the next planetary transits that I could see.

To see prominences, filaments, coronal mass ejections (flares), etc. (all features that require viewing the "chromosphere" instead of the "photoshere") you would want to use a Hydrogen alpha solar telescope. These completely block out all the wavelengths except the Hydrogen alpha wavelength (656nm which shows up to us as a fire-engine red color).

I have an Ha solar telescope, but usually before I set it up, I take a peek at the National Solar Observatory website to see if the sun is showing off anything interesting at the time. You can see that here: Solar data view select

Today's sun is showing lots of prominences.

You would also see prominences during a total eclipse (but it has to be a total eclipse... not partial and not an annular eclipse.)

A "white light" solar filter (such as the one Tanner used to capture the image above) let's all wavelengths pass... but only a tiny fraction of the total light. Basically it's like a really strong pair of sunglasses (usually it's ND 5.0 and blocks 16.7 stops of light ... or about 1 photon out of every 100,000 passes through and the rest are blocked (and still the sun looks this bright)).

The Thousand Oaks filter blocks slightly stronger toward the "blue" (short wavelength) end of the spectrum and less on the "red" (long wavelength) end. This creates the orange color cast. If a filter is precisely even with how much it blocks of all wavelengths (perfectly neutral) then you end up with a "white" sun and that's why they call them "white light" solar filters (even the ones that give a bit of a color cast are still called "white light" filters.)

A lot of good info, thanks for posting!