Solar Photography, including Eclipse Photography and Safety

[atigun]

...I have an Orion filter cell made using Baader film & a full spectrum Olympus E-M5. ...the image from the full spectrum camera was about 2 EV brighter than the unconverted camera image.

In other words, no problem.

That pretty much confirms what I reported above for an IR converted D40x - the red channel is 2 stops above a non converted body, so yes, no problem.

I have on multiple occasions used the Baader film on my 300mm f/4 with my Nikon 1 AW1, which has an electronic shutter only that could be sensitive to excessive exposure over time - no ill effects seen so far, even on a tracker. Best to stay away from the 3.8 OD film though, which is not considered safe for viewing anyway and harder to purchase in small sheets.

Partial solar eclipse in Fairbanks, Alaska at sunset on March 8, 2016, NIKON 1 AW1, with 300mm f/4 E PF + TC-14E, 420 mm @ f/8, 1/50 sec., ISO 160, Baader AstroSolar film 5 O.D. , daylight white balance (natural sunset color).

Mercury transit from Fairbanks Alaska 2016, NIKON 1 AW1, with 300mm f/4 E PF + TC-14E 420 mm @ f/8, 1/500 sec., ISO 160, Baader AstroSolar film 5 O.D. on Skytracker, warming of colors added in post processing.

--
Atigun valley, a place north in Alaska

 

[rnclark]

One way we can overcome the reflex reaction - but definitely should not - is to stare at the sun through a tiny pinhole, as I did when viewing a partial eclipse when I was about 8 years old. DON'T!! That morning in the schoolyard, I felt no pain whatsoever, nor any other symptom of the harm I was doing. My injury was the photo-chemical type, not a thermal burn. But it was ultimately life-altering, when it showed up a decade later during an academy entrance physical, and put an early end to my dream of becoming a naval aviator and astronaut.

Hello Lyle,

So sorry to hear this. Would you mind giving a little more detail on the injury?

Assuming your pinhole was about a mm in diameter, the aperture area would have been about 0.008 square cm. With the sun high in the sky, at sea level with solar energy about 0.07 to 0.08 watts/sq. cm, that would mean about 0.008 * 0.08 ~ 0.6 milliwatt into your eye for a full solar disk, less for partial phases, showing not much energy is required for damage.

How was the damage diagnosed as due to the eclipse? This should help as a warning for others.

Roger

I'm an optometrist with interests in both astronomy and photography.

It is possible to quickly glance at the sun when it is just above horizon because under those conditions, the atmosphere is so thick. However, it should be said that we mustn't tempt fate. Simply put, looking with the naked eye at the sun when just above the horizon can be safely done if only for a second. One should not look at the sun overhead using the naked eye and one should not look at the sun through telescope nor binoculars.

I did find one paper suggesting that a duration of staring at the sun for 90 seconds and longer correlates with increasing damage.

http://www.djo.org.in/articles/23/4/acute-solar-retinopathy.html

90 seconds seems like a long time to me, i would never use my own eyes in that manner. Long story short, do not take chances with your sight. Any amount of looking at the sun long enough to allow dangerous levels of UV energy to the retina can result in a burn of the macula. A burned macula cannot heal. Such damage results in a scotoma (blind spot) that is most likely in the center of the sea of vision.

Thank you very much for the reference. That paper leads to many more that can be searched for. The paper cites a 22 degree C rise in temperature with a 7 mm pupil and 90 second exposure, unaided eye. But with, say a 6-inch telescope, about 520 times more light, that 90 seconds becomes 90/520 ~ 0.17 second. If the filter passed infrared (half the solar light) but not visible, that raises it to only 1/3 second while the image appears reasonable brightness. So you cook your eye without knowing.

If the IR blockage is 1%, then in 30 seconds the temperature would rise to the 22 C--still not good.

I have made extensive changes to the article:

How to Photograph the Sun, Clarkvision.com

including new figure 15a, 15b which provides a better estimate of brightness away from the sun at mid eclipse (I had an error in my original equation--constants in the original equation used the European method of using commas for decimal points--that is now corrected in the equations I used). I also added more transmission data on Orion solar filter but still do not have IR data.

Roger

 

[ThrillaMozilla]

Thank you very much for the reference. That paper leads to many more that can be searched for. The paper cites a 22 degree C rise in temperature with a 7 mm pupil and 90 second exposure, unaided eye.

There has to be something wrong with all those explanations. Do you know anyone who always keeps the sun out of the field of vision? I don't. And if you look away at a 45 degree angle, does that mean there's only a 16 degree rise? I doubt it.

 

[rnclark]

Thank you very much for the reference. That paper leads to many more that can be searched for. The paper cites a 22 degree C rise in temperature with a 7 mm pupil and 90 second exposure, unaided eye.

There has to be something wrong with all those explanations. Do you know anyone who always keeps the sun out of the field of vision? I don't. And if you look away at a 45 degree angle, does that mean there's only a 16 degree rise? I doubt it.

The 7 mm pupil giving a 22 degree rise is a derived number if the full energy of the Sun were to be incident on a 7 mm pupil. If you read the paper referenced, you would see that a 3 mm pupil results in a 4-degree rise. But in bright sunlight, the general minimum pupil diameter is about 2 mm, so less than 1/2 that energy. The Sun off at a high angle reduces it even further, e.g. another factor of 2 or so, so the temperature rise is on the order of a degree or less.

The problem with eclipses is people do stare at the sun, and often with optical instruments, which means more energy entering the eye. My point was that if you use the wrong filter that blocks visible, but transmits infrared, it could be very very dangerous and you would not know it.

The eclipse in August will be very widely observed in the northern hemisphere. Please do your best to educate people to the dangers and use proper filters. I started writing my article after I became aware of photographers recommending standard neutral density filters for the eclipse that were very inadequate.

If you see a web site recommending filters that are not safe for solar viewing, please let me know.

Roger

 

[Glack]

I finished my article on solar photography enough to release it. See:

http://www.clarkvision.com/articles/photograph-the-sun/

Comments welcome. I still have work to do, but need to complete some other things first.

Roger

Roger, thanks for very useful information.

In your exposure sequences for solar eclipse, the smallest exposure is

ISO100 f/16 1/8000 s

However, 1/8000 s seems to be too long for the Baily’s beads (as the intensity of the solar limb is a million times higher than that of the corona).

On the internet, you can find a lot of good images of solar corona, chromosphere and prominences but there's no or very few good images of Baily’s beads. When using ND 4-5 solar filters, the beads look underexposed, but without any filters they look overexposed.

What if to use neutral-density filters with optical density of ND=1-2? Yes, it will cut off the corona, but for the Baily’s beads, chromosphere and prominences such a filter might be suitable.

Any thoughts?

 

[tradesmith45]

I have made extensive changes to the article:

http://www.clarkvision.com/articles/photograph-the-sun/

including new figure 15a, 15b which provides a better estimate of brightness away from the sun at mid eclipse (I had an error in my original equation--constants in the original equation used the European method of using commas for decimal points--that is now corrected in the equations I used). I also added more transmission data on Orion solar filter but still do not have IR data.

Roger

This is wonderful work Roger. The new figures are (pardon me) illuminating - really. I'm wanting to refine my understanding of your exposure recommendations to account of highly variable field conditions. And I'm hoping this info will warn others about the variability of recommendations they will find out there.

I've looked through several eclipse exposure tables on the internet. Boy are they varied even from NASA. The following is recommended exposures for prominence (picked that so there's no confusion about different parts of the corona but the brightness of all these features can vary some).

Espernak circa 1996 ISO100, F8, 1/250 OR 1/125

Espernak 2008 ISO100, f8, 1/1000

Astro Adventures ISO100 f8, 1/125 (from early Espernak?)

Jerry Lodriguss ISO100, f8, 1/1000 (table), 1/500 (1991 film image w/ color detail)

Xavier Jubier ISO100, f8, 1/1600

NASA ISO100, f8, 1/1000 (Espernak?)

R Clark ISO100, f8, 1/5000 DN=128

Several thoughts about why these are so different (5 1/3 EV). These people (at least most of them) aren't dummies. Possible explanations are differences in final image brightness, atmospheric transparency & brightness of prominences. Thankfully you have been explicit about final image brightness! No one else has. But might it also be the case that variations in prom brightness and atmospheric transparency are really significant? I'm thinking mid-August Oregon air will certainly have photochemical haze when we have a million visitors driving all over for the eclipse.

All of this lead me to another considerations - not just the range of exposures but spacing. Your table includes 2 EV steps in several places. Doesn't that presume atmospheric transparency and solar feature brightness will be as predicted? And if they are not will the 2 EV gaps cause blending problems in post? As I've said in a couple other threads, I sure wish I had experience blending 15-16 exposures of an eclipse so I had more confidence about getting the best captures. I'm wondering if 0.7 EV exposure spacing would be helpful. My last eclipse was 1979 and a single exposure on Kodachrome- My current camera will do 7 capture brackets w/ 0.7 EV steps & Eshutter to 1/16000. But sadly no scripting software is available for it.

What do you think about these sources of differences & steps in exposure sequences that should be used? Haven't read all of November, L. J. & Koutchmy, S. so the answer to the brightness/transparency questions may be in there. Has the brightness profile been adjusted for being on Mauna Kea?

 

[rnclark]

I have made extensive changes to the article:

http://www.clarkvision.com/articles/photograph-the-sun/

including new figure 15a, 15b which provides a better estimate of brightness away from the sun at mid eclipse (I had an error in my original equation--constants in the original equation used the European method of using commas for decimal points--that is now corrected in the equations I used). I also added more transmission data on Orion solar filter but still do not have IR data.

Roger

This is wonderful work Roger. The new figures are (pardon me) illuminating - really. I'm wanting to refine my understanding of your exposure recommendations to account of highly variable field conditions. And I'm hoping this info will warn others about the variability of recommendations they will find out there.

I've looked through several eclipse exposure tables on the internet. Boy are they varied even from NASA. The following is recommended exposures for prominence (picked that so there's no confusion about different parts of the corona but the brightness of all these features can vary some).

Espernak circa 1996 ISO100, F8, 1/250 OR 1/125

Espernak 2008 ISO100, f8, 1/1000

Astro Adventures ISO100 f8, 1/125 (from early Espernak?)

Jerry Lodriguss ISO100, f8, 1/1000 (table), 1/500 (1991 film image w/ color detail)

Xavier Jubier ISO100, f8, 1/1600

NASA ISO100, f8, 1/1000 (Espernak?)

R Clark ISO100, f8, 1/5000 DN=128

Several thoughts about why these are so different (5 1/3 EV). These people (at least most of them) aren't dummies. Possible explanations are differences in final image brightness, atmospheric transparency & brightness of prominences. Thankfully you have been explicit about final image brightness! No one else has. But might it also be the case that variations in prom brightness and atmospheric transparency are really significant? I'm thinking mid-August Oregon air will certainly have photochemical haze when we have a million visitors driving all over for the eclipse.

It is more likely that the solar corona and the prominences vary a lot. So we do not know the exact brightness to expect, thus must bracket.

All of this lead me to another considerations - not just the range of exposures but spacing. Your table includes 2 EV steps in several places. Doesn't that presume atmospheric transparency and solar feature brightness will be as predicted? And if they are not will the 2 EV gaps cause blending problems in post? As I've said in a couple other threads, I sure wish I had experience blending 15-16 exposures of an eclipse so I had more confidence about getting the best captures. I'm wondering if 0.7 EV exposure spacing would be helpful. My last eclipse was 1979 and a single exposure on Kodachrome- My current camera will do 7 capture brackets w/ 0.7 EV steps & Eshutter to 1/16000. But sadly no scripting software is available for it.

The problem that I see with eclipse photos is many have overexposed prominances, e.g. pink edges with saturated white cores. I have also seen the experts question why the prominences are pink (think red hydrogen alpha). But like emission nebulae, there is also H-beta and H-gamma, which combine to produce pink/magenta in RGB color. E.g.

Loading…

en.wikipedia.org

So I set some very high exposures so as not to saturate any bright prominences.

The 1EV gaps where derived with film which has lower dynamic range than modern digital cameras, and lower signal-to-noise ratio. Two EV gaps should be plenty and this eclipse is very short, thus a compromise. I have combined much greater gaps in general and HDR software handles it pretty well these days.

What do you think about these sources of differences & steps in exposure sequences that should be used? Haven't read all of November, L. J. & Koutchmy, S. so the answer to the brightness/transparency questions may be in there. Has the brightness profile been adjusted for being on Mauna Kea?

The brightness profile has been corrected for atmospheric extinction. But extinction is not that much, typically 0.15 magnitude in V per airmass. The larger problem is scattering from aerosols in the lower atmosphere. The scattered light will reduce contrast making it harder to extract the signal. This is what light pollution does in night sky imaging: it is scattered light off of aerosols adding signal. So the challenge for eclipse viewers is finding low aerosol sites. And if on dirt roads, how many cars will be driving to the last minute stirring up a huge dust storm? On the East coast, humidity will be a problem.

Roger

 

[tradesmith45]

It is more likely that the solar corona and the prominences vary a lot. So we do not know the exact brightness to expect, thus must bracket.

All of this lead me to another considerations - not just the range of exposures but spacing. Your table includes 2 EV steps in several places. Doesn't that presume atmospheric transparency and solar feature brightness will be as predicted? And if they are not will the 2 EV gaps cause blending problems in post? As I've said in a couple other threads, I sure wish I had experience blending 15-16 exposures of an eclipse so I had more confidence about getting the best captures. I'm wondering if 0.7 EV exposure spacing would be helpful. My last eclipse was 1979 and a single exposure on Kodachrome- My current camera will do 7 capture brackets w/ 0.7 EV steps & Eshutter to 1/16000. But sadly no scripting software is available for it.

The problem that I see with eclipse photos is many have overexposed prominances, e.g. pink edges with saturated white cores. I have also seen the experts question why the prominences are pink (think red hydrogen alpha). But like emission nebulae, there is also H-beta and H-gamma, which combine to produce pink/magenta in RGB color. E.g.

https://en.wikipedia.org/wiki/File:Hydrogen_discharge_tube.jpg

So I set some very high exposures so as not to saturate any bright prominences.

The 1EV gaps where derived with film which has lower dynamic range than modern digital cameras, and lower signal-to-noise ratio. Two EV gaps should be plenty and this eclipse is very short, thus a compromise. I have combined much greater gaps in general and HDR software handles it pretty well these days.

What do you think about these sources of differences & steps in exposure sequences that should be used? Haven't read all of November, L. J. & Koutchmy, S. so the answer to the brightness/transparency questions may be in there. Has the brightness profile been adjusted for being on Mauna Kea?

The brightness profile has been corrected for atmospheric extinction. But extinction is not that much, typically 0.15 magnitude in V per airmass. The larger problem is scattering from aerosols in the lower atmosphere. The scattered light will reduce contrast making it harder to extract the signal. This is what light pollution does in night sky imaging: it is scattered light off of aerosols adding signal. So the challenge for eclipse viewers is finding low aerosol sites. And if on dirt roads, how many cars will be driving to the last minute stirring up a huge dust storm? On the East coast, humidity will be a problem.

Roger

Helpful & reassuring, thanks. Yes, this is an event where it would be hard to bracket too widely. Thanks for deriving exposure ranges based on best available data. There certainly are plenty of eclipse images w/ blown-out highlights. The popular Diamond Ring images essentially require overexposure.

While I picked on prominence exposures, Bailey's is reportedly brighter so brief exposures will be needed for that as well. Perhaps, the over exposed captures of these that are very common are more a product of the slower shutter speeds and diffraction free apertuers available on older cameras than of an analysis of solar brightness.

Sorry I merged the weak effect of atmospheric extinction and scattering in my thinking. Though we all obsess about cloud cover, clear skies leading up to the eclipse will yield more smog. A hot mid-August will certainly produce conditions ripe for haze production in much of the U.S. even without fire smoke. I'm thinking we need to plan for haze. I'm considering a moderately strong UV filter (yes I know they don't do much but there must be something that does?). Will try to test that w/ daytime lunar photography.

The current Climate Prediction Center 3-month outlook centered on August (3.5mn) is showing high probability of much warmer than average temps for the whole U.S. http://www.cpc.ncep.noaa.gov/products/predictions/long_range/seasonal.php?lead=4 Note too the small region of elevated probability for precipitation (e.g. clouds) centered over WY and covering the N. Rockies. I recall you are planning for a WY location. May want to have an alternative location. These long lead outlooks will get updated but I have found them reasonably good at describing seasonal patterns that actually occur.

 

[JustEd]

Back in the day, when i used to regularly post white light solar images to the alt.binaries.pictures.astro newsgroup I started using the Baader solar filter material, and found it to be the best and safest objective filter around, as did most of my contemporaries.

You can get it inexpensively in reasonably-sized sheets here: http://agenaastro.com/solar-astrono...ar-film-sheets/shopby/baader_planetarium.html . Of course you have to roll your own. I don't know anything about this store, but I ordered one this afternoon and they've already shipped it.

Agena is one of the best places to get astro gear. I've been ordering from them for years. If you have any questions, the owner is more than happy to answer them quickly. Maneesh(sp?) is very well known for his customer assistence.

 

[rnclark]

I finished my article on solar photography enough to release it. See:

http://www.clarkvision.com/articles/photograph-the-sun/

Comments welcome. I still have work to do, but need to complete some other things first.

Roger

Roger, thanks for very useful information.

In your exposure sequences for solar eclipse, the smallest exposure is

ISO100 f/16 1/8000 s

However, 1/8000 s seems to be too long for the Baily’s beads (as the intensity of the solar limb is a million times higher than that of the corona).

On the internet, you can find a lot of good images of solar corona, chromosphere and prominences but there's no or very few good images of Baily’s beads. When using ND 4-5 solar filters, the beads look underexposed, but without any filters they look overexposed.

What if to use neutral-density filters with optical density of ND=1-2? Yes, it will cut off the corona, but for the Baily’s beads, chromosphere and prominences such a filter might be suitable.

Any thoughts?

Bailey's beads are tiny portions of the solar limb shining between lunar mountains and through valleys on the lunar limb. But if you want the classical view, it is best to overexpose the beads to make them appear brighter. There really is no time to switch filters, image them, and then remove filters for totality. Maybe if you have solar filters on a turret they could be switched quickly, but do you really want to be futzing with filters during the eclipse? So my strategy is to include some really fast exposure times and have only one filter change (filter off for totality) and back on at the end of totality.

 

[tradesmith45]

Just in case you don't know it, fhis is a very brief feature of the eclipse. At my location in Oregon, this site predicts Bailey's will last only 3 sec. Not much time. http://www.eclipse2017.org/xavier_redirect.htm

You can check for your location there.

 

[atigun]

I made a comparison with and without my home brewed Baader AstroSolar film based filter, after carefully blocking out any new pinholes that had appeared (likely on only one side of the film). Here are the results:

NIKON D7100, f/4 @ 300 mm, 8s, ISO 1600, Baader AstroSolar film 5 O.D. based filter, viewfinder covered, tripod.

NIKON D7100, f/4 @ 300 mm, 1/800, ISO 200, no filter, viewfinder covered, tripod.

(The difference in exposure corresponds to to about 15.5 EV values if my reckoning is right.) Even with no detectable pinholes the Baader AstroSolar film gives quite low contrast. (I found similar results with a wide lens). Perhaps not surprising considering the highly reflective inner surface. However this makes me curious if this is typical for the Baader Astrosolar film (flare is usually said to be indicative of pinholes) or if something else is going on. I have seen no problems with quality in practical solar captures with this filter (see below).

Would someone with a Baader AstroSolar film 5 O.D. based filter please repeat this test and post the results here?

It is useful to have a good baseline for how an intact film behaves when doing preliminary non-solar testing. (It could also be interesting to compare to a different solar filter).

Here is a capture with this filter, the large sunspot 3 days ago:

Crop from NIKON D7100, f/7.1 @ 420 mm, 1/320, ISO 100, Baader AstroSolar film 5 O.D. based filter, contrast enhanced to compensate for haze/light clouds in the sky.

--
Atigun valley, a place north in Alaska

 

[KeithL55]

Thanks for that link - very useful.

 

[tradesmith45]

I made a comparison with and without my home brewed Baader AstroSolar film based filter, after carefully blocking out any new pinholes that had appeared (likely on only one side of the film). Here are the results:

NIKON D7100, f/4 @ 300 mm, 8s, ISO 1600, Baader AstroSolar film 5 O.D. based filter, viewfinder covered, tripod.

NIKON D7100, f/4 @ 300 mm, 1/800, ISO 200, no filter, viewfinder covered, tripod.

(The difference in exposure corresponds to to about 15.5 EV values if my reckoning is right.) Even with no detectable pinholes the Baader AstroSolar film gives quite low contrast. (I found similar results with a wide lens). Perhaps not surprising considering the highly reflective inner surface. However this makes me curious if this is typical for the Baader Astrosolar film (flare is usually said to be indicative of pinholes) or if something else is going on. I have seen no problems with quality in practical solar captures with this filter (see below).

Would someone with a Baader AstroSolar film 5 O.D. based filter please repeat this test and post the results here?

It is useful to have a good baseline for how an intact film behaves when doing preliminary non-solar testing. (It could also be interesting to compare to a different solar filter).

Here is a capture with this filter, the large sunspot 3 days ago:

Crop from NIKON D7100, f/7.1 @ 420 mm, 1/320, ISO 100, Baader AstroSolar film 5 O.D. based filter, contrast enhanced to compensate for haze/light clouds in the sky.

--
Atigun valley, a place north in Alaska

Pretty sure the contrast loss is being caused by small light leaks that are reflecting off the Baader film & contribute significant light during the very long exposures for photo 1. The leaks are to small to mater when your aimed at the sun.

 

[ThrillaMozilla]

That's pretty terrible. Because it's nearly 100% reflective, I think you're getting about 10 or 12 times the flare that you would get from an uncoated glass filter.

Back to the drawing board. One thing you could try is to air-space it. Locate it as far in front of the lens as you can. I was thinking about mounting it on the front of a lens hood, but I won't be able to try it any time soon.

 

[tradesmith45]

That's pretty terrible. Because it's nearly 100% reflective, I think you're getting about 10 or 12 times the flare that you would get from an uncoated glass filter.

Back to the drawing board. One thing you could try is to air-space it. Locate it as far in front of the lens as you can. I was thinking about mounting it on the front of a lens hood, but I won't be able to try it any time soon.

Actually, I can duplicate this problem when using a flat DIY foam board frame to hold Thousand Oak filter film. And TO film its not reflective or subject to pin holes. The light is leaking in between the the two pieces of foam board used for the filter holder. Pretty sure this is not flare from pinholes in the film. The poster about this said he couldn't see any pinholes in the Baader film.

 

[atigun]

A filter holder was not used. Rather the film has been glued to a filter/stepdown ring, and after the epoxy had completely set, another step-Up ring was glued to it. I also described the procedure here: http://nikongear.net/revival/index.php/topic,3435.msg50041.html#msg50041

Epoxy is allowed to completely set before next step to avoid tension in the film. (The male threads had been removed from the filter ring to provide a wider bonding surface.

Epoxy has set, film has been trimmed, and ready to be glued onto the 77-82mm stepup ring.

The finished filter fits in a slightly modified Nikon fIlter case.

The filter rings are glued tightly together so I doubt that is the problem, however I might have a try to add some black paint onto the epoxy/film at the edge between the two rings.

It still would be interesting to see if anyone are able to get a clear non-solar image without flare though the Baader Astrosolar film etc. .

--
Atigun valley, a place north in Alaska

 

[tradesmith45]

The filter rings are glued tightly together so I doubt that is the problem, however I might have a try to add some black paint onto the epoxy/film at the edge between the two rings.

It still would be interesting to see if anyone are able to get a clear non-solar image without flare though the Baader Astrosolar film etc. .

--
Atigun valley, a place north in Alaska

I did do tests but using foam board holders w/ lots of light leaks using both Baader & Thousand Oaks films. Both filters showed loss of contrast from light leaks. It was easy to greatly reduce but not completely eliminate the light leaks on my holders by simply taping them together. FWIW, at the time, couldn't see any pin holes in my Baader film filters. Probably have some now that need black paint.

With the very generous exposures needed to get an image in full sun light w/ these filters, even tiny light leaks could cause what we are seeing. They could be occurring anywhere including at the lens mount. I think this is a known problem for eclipse chasers.

I'm working on other problems (wind) & will be out doing more testing. I'll try try to redo the Baader contrast loss test in such a way that light leaks are not a problem & report back here.

 

[tradesmith45]

I finished my article on solar photography enough to release it. See:

http://www.clarkvision.com/articles/photograph-the-sun/

Comments welcome. I still have work to do, but need to complete some other things first.

Roger

Here's a bit of info to add to Roger's great work. I have been uncomfortable with the frugalness of Baader film. An Orion cell using Baader film had arrived new w/ numerous pinholes. I'd bought Seymour back polymer film but that batch (they have new material now) turned out to be close to OD 6 & too dark. So I wanted to test Solarite. Short answer, it works fine & is less susceptible to damage but is about 2 EV darker (measured in the green channel) than Baader. Like others have reported for black polymer, the orange cast of Solarite seems to do a bit better job revealing the granulations on the sun's surface.

An important caveat, these 2 images were obviously made on different days & (over) processed differently - one is a 7x0.3EV HDR & the other stacked 5 images w/ manual alignment. So a direct comparison is problematic. I'm showing them just to demonstrate how both these work - just fine IMHO. The Solarite image had no color adjustments. The Baader was adjusted to be bit warmer.


Solarite


Baader Solar Safety Film

 

[tradesmith45]

It still would be interesting to see if anyone are able to get a clear non-solar image without flare though the Baader Astrosolar film etc. .