Solar Filter and Framing Test

[Mike Lewis]

So just a quick image of the Sun, a single snap to show the framing in the RF100-500 at 500mm on the R5, and to check out my camera-safe AND eye-safe 77mm screw in solar film filter from Thousand Oaks Optical. Not as many sunspots on the old girl today as I expected, but a couple showing up. 2 versions posted - the 1st showing the framing size of the Sun in a full frame sensor at 500mm, and the 2nd heavily dropped to show a little of the sparse but visible sunspot detail.

These filters do not look like the most robust things ever but with some careful handling should get the job done, and I do like the naturally orange rendition they produce (no color adjustments were made to these, just some exposure tweaks and minor sharpening).

A quick final note alluded to above. All solar filters are not created equal. Many will attenuate the Sun enough to protect your sensor but are NOT certified as eye-safe. The actual ISO requirement for eye protection is specified here http://eclipse.aas.org/eye-safety/iso12312-2 While that standard does not actually apply to solar filters used for lenses, when manufacturers use material that complies with ISO12312-2 in their lens filters it means they are eye safe and camera safe at the same time. So to be conservative look for mention of ISO12312-2 compliance or be very careful when using a non-compliant filter...

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Zoomed In View

ML

 

[JimFox]

That looks good Mike! That should for sure work for you.

Thanks for the information on Solar filters, that will be helpful.

For my regular cameras I have gotten the ND style glass screw in filter. I already have 4 different filter sizes of them to cover every need I might have. but I will look at what you linked, maybe I will get one of those too and test it out compared to my ND style.

 

[Jameel Hyder]

With mirrorless cameras as long as it is sensor safe it should be fine as one isn’t directly to my looking at the sun.

are the sun filters different than regular 20 stop filters?

 

[JimFox]

With mirrorless cameras as long as it is sensor safe it should be fine as one isn’t directly to my looking at the sun.

are the sun filters different than regular 20 stop filters?

Solar ND filters are 16 stop I believe.

There are 2 main types of solar (sun) filters. Glass and film. What Mike got is a film one. Think of like Mylar film, it's kind of similar. The interesting thing to me is if I stretched a film over a filter holder, I would stretch it tight and taunt. By typically these filters have some wrinkles or bends in them. But that's how they are supposed to be. No idea why..

Anyway with the film I think there are 2 types of film, one gives the image an orange cast, the other a white cast.

Mike can hopefully clarify that more.

 

[JimFox]

Oh, and as far as I know, one type isn't really better then the other, it just depends on the look you want.

 

[Mike Lewis]

• So yes, I have seen white light and orange light versions; as Jim says, one is not better than the other, more of an aesthetic preference.
• I also don't know why these film filters are typically not taut stretched? Maybe they are more robust if they get poked if they are not stretched taut? Doesn't seem to affect the image in any way.
• The solar filter I used here is specified to block 1/1000th of 1% of the light. Someone can do the math to see what that comes out to in ND specifications...
• It is possible that sensor safe is OK for mirrorless as Jameel says, but I would prefer to be conservative at this point. And if you use this kind of a filter then no issues on a DSLR either.

ML

 

[BlackRockArt]

So just a quick image of the Sun, a single snap to show the framing in the RF100-500 at 500mm on the R5, and to check out my camera-safe AND eye-safe 77mm screw in solar film filter from Thousand Oaks Optical. Not as many sunspots on the old girl today as I expected, but a couple showing up. 2 versions posted - the 1st showing the framing size of the Sun in a full frame sensor at 500mm, and the 2nd heavily dropped to show a little of the sparse but visible sunspot detail.

These filters do not look like the most robust things ever but with some careful handling should get the job done, and I do like the naturally orange rendition they produce (no color adjustments were made to these, just some exposure tweaks and minor sharpening).

A quick final note alluded to above. All solar filters are not created equal. Many will attenuate the Sun enough to protect your sensor but are NOT certified as eye-safe. The actual ISO requirement for eye protection is specified here http://eclipse.aas.org/eye-safety/iso12312-2 While that standard does not actually apply to solar filters used for lenses, when manufacturers use material that complies with ISO12312-2 in their lens filters it means they are eye safe and camera safe at the same time. So to be conservative look for mention of ISO12312-2 compliance or be very careful when using a non-compliant filter...

Full Frame

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Zoomed In View

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ML

Mike, this looks great.

I gotta practice more.

Oliver

 

[Bill Richards]

If you are planning to use a filter to photograph the eclipse, I suggest you NOT use a screw-on lens filter. I bought an expensive one for my 600mm lens and after practicing the removal/re-attachment process several times, it quickly became apparent that precious time was being lost fiddling with it. And during one practice run, I dropped the filter and it hit a sharp metal corner on one of my equipment rails, putting a tiny nick in the filter glass. After that, I decided to build my own filter using Baader film (which yields the "white" colored sun) that I can quickly slide on and off my lens. This was constructed using a 4" PVC coupling and two pieces of 1/8" foam core board that sandwich the film, and some very thin felt strips on the inside of the tube to make the fit nice and snug. It slides off and on my lens quickly and easily in less than 1 second. There are numerous YouTube videos showing how to do this.

The color difference is simply due to the passband curves of the filter material. The "white" filters passes red, green, and blue light in roughly equal amounts, while the "orange" filters pass a lot more red than blue. The other consideration is, as Jim pointed out, not all filter material has the same number of stops, and more stops is not necessarily better for eclipse photography. When the eclipse reaches peak totality, you will probably want to be taking long exposures to capture stars and Earthshine, or the longest limbs of the corona. A 16-stop filter will require twice the exposure time than a 15-stop filter, cutting the number of images you could potentially get in half and leading to more motion blur due to sun/moon progression, wind, ground vibrations, etc.

 

[Bill Richards]

Further details... Here are two images of the sun along with the RGB histograms, one taken with a Thousand Oaks SolarLite filter and one taken with the Baader film. There's a hugh difference. And although the Baader film has a slight blue tint to it, that is easily removed in post to yield a balanced, white image (which is more natural, albeit maybe not as pleasing to the eye).

 

[Kyle Jones]

I used a magnetic mount for my solar filter during the last total eclipse. I'm sure it was more expensive but worked like a charm.

 

[JimFox]

Further details... Here are two images of the sun along with the RGB histograms, one taken with a Thousand Oaks SolarLite filter and one taken with the Baader film. There's a hugh difference. And although the Baader film has a slight blue tint to it, that is easily removed in post to yield a balanced, white image (which is more natural, albeit maybe not as pleasing to the eye).

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Great idea Bill! I like your creativity.

My solar filter for the Askar Fra500 just slips onto the lens hood. But my other filters for my regular lenses and cameras are all screw in. You have me wondering if I should go your route for my regular cameras.

 

[JimFox]

I used a magnetic mount for my solar filter during the last total eclipse. I'm sure it was more expensive but worked like a charm.

Magnetic is a good way to go. I haven't done that as they are a bit expensive, but it's definitely a good way to go.

 

[BlackRockArt]

Magnetic is a good way to go. I haven't done that as they are a bit expensive, but it's definitely a good way to go.

Jim, after getting lost in the desert badland a few times, I am little wary of placing magets near my phones. Yes, magnetic filters are very handy in any other scenes.

Oliver

 

[JimFox]

Jim, after getting lost in the desert badland a few times, I am little wary of placing magets near my phones. Yes, magnetic filters are very handy in any other scenes.

Oliver

Oliver that's a concern for sure. I have found the compasses in our cameras to be very finicky and unreliable. It's why I have a regular old fashioned compass in my Astro tool box. Because not just a magnet, but any metal can throw off the compass in a phone.

In this case though, I am not sure that should be the case as the magnet would be sitting on the end of a (probably mostly) metal lens. If you have the phone right next to the lens even without the magnet it could through the compass of the phone off.

Getting lost in the desert is never any fun, especially if you are with a horse with no name.