Film Solar Filters... Never Again!

I made two solar filters relatively recently.  One was made a little over a year ago (pictured at right) and the other was made a little over two years ago (next picture, below).  I was happy with these two filters but rarely used them because I have far better types of solar filters to use.  I think my primary reason for this exercise in making these filters was simply for the experience more than any other reason although there were a couple of other reasons (which I'll address below).  But let me start this blog entry by saying that I will never again use one of these piece-of-garbage, flimsy, and consequently, dangerous Baader film solar filters!

I haven't used either filter more than three or four times each in this two year period and they have been handled exceptionally carefully (never touching the filter material) and stored in protective zip-lock bags and these bags placed inside protective boxes for storage until the next use.  Even though these two filters were handled and stored exceptionally carefully, in recent days, I have found that the film material used (Baader solar safety film) has developed a series of tiny pinholes rendering these solar filters useless.  It is also worth noting that I am the only one to have used these two filters so I know they were not mishandled.

Honestly, I was never really fully comfortable with the idea of using this solar film to make solar filters so losing these two filters is not a heartbreakingly huge loss.  I was never all that comfortable using film filters because they are, by far, the most fragile of all solar filters.  Cost-wise, they are the least expensive option so the loss is very minimal.  

I am, however, definitely frustrated and aggravated due to the time and effort I put into making these filters now being time lost as well as losing the time and effort in carefully handling and storing these film filters.  I'm left wondering why I bothered to be so careful with them if they are so ridiculously fragile that even delicate and careful handling and protective storage seems to make no difference in longevity.

People who know me know that I am a perfectionist bordering on exhibiting OCD tendencies so you can believe me when I say that I cared for these two film solar filters exceptionally carefully.  I admit that I may appear to be a bit OCD but people with exceptionally high standards are often accused of being OCD.  I am actually quite proud of my high standards.  

Truth be told, I've always hated whenever some ignoramus gleefully and ignorantly states "Well, it's good enough for government work".  In my opinion, nothing is ever "good enough" unless it is done right and this was especially true in my government career.  And, of course, after a career in government work and more jobs in the private civilian world than I care to remember or discuss (because they will never compare to high standards of my government career), I find it completely idiotic and ignorant to think that 'government work' is in any way sub-par to any other work.  My experiences have shown quite the opposite.  My many years of experience in this career has refined my attention to detail as well as refined my ability to attain higher standards.  These high standards have carried over into everything in my life.

When I say that I never touched this fragile filter film in these filters with my fingers, I mean that I never touched the film in these filters with my fingers.  When I built these two filters, I actually wore tight-fitting stretchy latex gloves and only very carefully touched the edges of the film material with gloved fingers.  I never touched the part of the film material that would be the actual filter.  These outside edges that were lightly handled with gloved fingers while assembling these homemade filters were cut off after sealing the filter film to the filter frames.  

Additionally, and definitely worth mentioning is that I am the only person to have handled these filters.  I only took these filters out of their safe storage on three or four occasions each and I can tell you with absolute certainty that I never touched the film material because my bit of OCD tendencies intentionally avoided touching this fragile film nor does it take a genius to be well aware of the catastrophic consequences of touching the film.  So it is worth noting that any degradation or defects were not due to mishandling nor carelessness on my part.

A couple of days ago, I noticed that the smaller of the two filters had developed about a dozen or more pinholes all within the area perhaps the size of a dime.  Even a single pinhole is bad news and must be blocked because it will cause permanent damage to your eyes if the filter is used in this condition.  A single pinhole, here or there, could be repaired with a dab of nail polish but a series of about a dozen pinholes over any larger area means the filter is irreparable.  The extremely dangerous sunlight shines through the pinhole(s) and then is magnified by the telescope and then enters your eye.  This magnified sunlight that bypasses the solar filter will blind you so I have always been exceptionally careful in handling and storing these two solar film filters.  (Think Mr Monk and how he would handle these filters...  that is me.)

The moment I noticed the deteriorated and degraded filter material in the first filter, I angrily ripped out the film filter material from this homemade filter.  I quickly found a better use for that homemade smaller filter frame.  I'll write more about that project sometime in the future after more testing and use.

So, this morning, I pulled out the larger homemade film solar filter to inspect it hoping the filter material held up better than the film filter material in the smaller homemade filter.  I removed the filter in its sealed zip-lock bag from its box...  then carefully removed the filter from the zip-lock bag...  held it up to a bright light...  "Uggg..."  the same exact thing happened to this filter!  Needless to say, a few choice words crept from my mouth.  As you can clearly see in the photo below, there is a series of about a dozen pinholes in a small area the approximate size of a quarter (this time I shot a few photos of the damage!).  This filter, like the first smaller filter, also had never been touched and had always been handled exceptionally carefully the three or four times I used it.  Yet somehow, this filter has degraded and is also useless now. 

Also worth mentioning is that neither of these homemade filters showed this damage whenever I inspected them before each use the three or four times I used each of them.  This damage only became visible in the period between their last use this past autumn and this past week.  

This larger homemade filter frame required a bit more time and effort to build than the smaller filter which is a bit disheartening since I now feel as though I wasted a bunch of time and effort in making this nice filter frame.  I made this one out of layers of wood.  It is a really nice filter frame now sporting really crappy film filter material that is useless today.  Maybe, or hopefully, I will find a new purpose for this homemade wood filter frame in the future.  I know it won't be used for holding solar film though!  

What is really frustrating is that I never really wanted to use this film filter material because I knew it was rather fragile.  The fragility of this film filter material made me nervous when used for viewing our dangerous sun through a telescope.  If too much sunlight gets through even a single pinhole and then is magnified by the telescope, it will cause permanent vision damage to anyone looking through it.  This is the reason for close inspection before every single use as well as the reason for such careful handling and storing.  People choose to use this filter material because it is cheap not because it is robust, resilient or safe.  They compromise safety for the sake of saving a few dollars.  

Aside from the aforementioned primary reason of "the experience in building my own solar filters", I really only made these film filters for two additional reasons.  First, the cost would be far lower than purchasing a manufactured filter (hence the "cheap" description in the previous paragraph although "cheap" also infers lesser quality which is certainly the case here).  The other reason for making my own filter(s) using this Baader film solar filter material is because so many other astronomers seem to absolutely love this filter material for making solar filters so I figured it might be a good idea.  Basically, I wanted to see what all the fuss was about and whether it would live up to the hyper-hype.  

I suspect that, in hindsight, maybe we simply don't hear from those with an opinion similar to mine for fear of being castigated by the solar astronomy crowd for our contrary opinion.  I was still a bit skeptical of this hype but accepted the opinions I had heard, however, I accepted these opinions with cautious optimism because I was already well aware of this film's fragility.  I knew that at the very least, the filters would be exceptionally low cost and these filters would allow me to directly compare them to other (better) solar filter types.

After I built these Baader solar film filters, I did indeed compare them to my other solar filters.  

First I compared them to my Spectrum glass solar filters.  Many astronomers badmouth all glass white light solar filters but I found that the glass solar filters made by Spectrum were clearly better than the Baader solar film filters.  I should point out that I have no idea how the other brands of glass solar filters fare by comparison but I know the Spectrum glass solar filters are very good.  

When compared to my homemade Baader solar film filters, the Spectrum glass filters were crisper, sharper, showing more detail and in a more pleasing color (orange).  Although these glass solar filters are a bit more expensive than Baader solar filim, they are significantly more durable.  

Compared to my Spectrum glass solar filters, I found that my homemade solar film filters made with Baader solar film were sort of hazy, lower contrast yet overly bright, and had a horrendous bothersome pale blue tint to the view.  I found the views through both of my Baader solar film filters were rather cold (in color) and a bit hazy.  After these comparisons, I cannot understand why people swear that solar filters made with this Baader solar film are so great.  I found them to be lackluster and the color balance to be bothersome.  

To make matters worse for the film solar filters, I now find that even after exceptionally careful handling and storing, both of my film filters are useless in a relatively very short period of time due to some sort of material degradation.  So, not only are the views provided by this film filter material inferior but their durability is poor.  

Even worse yet for the Baader solar safety film filters was the fact that these filters actually pale in comparison to my Herschel solar wedge filters!  As far as viewing clarity, safety, durability, and ease of use, my current opinion based on my own direct comparisons and my own experiences is that the Baader solar safety film filters are near the bottom of the barrel in quality.  The only possible filter material that I have used that might be worse is polymer solar film material...  hmmm...  even that is debatable, in my opinion...  a comparison between those two may be a draw for various reasons I won't get into here because it is unrelated to this blog entry.  

My obvious conclusion after seeing two filters degrade for no apparent reason after only a year or two is that Baader solar safety film is dangerous.  Even putting aside its dangers, I find the material as a solar filter to be lacking and, to be honest, quite disappointing.  I suppose it has its place in astronomy though.  It can be used as a cheap, inexpensive way to make a one-time use solar filter when in a pinch for a one-time event if you were unable to purchase a real solar filter.  Make it, use it, then toss it in the trash with only a minimal cost while providing a safer view than without the filter.  

Also worth noting is that what I experienced is not a one-off isolated problem which is why I'm carefully writing about it here.  If it were just a one-off isolated problem and if I had some good experiences to write about this filter material, I probably would not have felt the urgent need to write this blog entry.  Unfortunately, it is not a one-off isolated problem.  I made each of these two filters a year apart using Baader solar film purchased separately also a year apart yet both filters developed the same dangerous problems.  These were two separate occasions...  two separate filters... two separate purchases of the solar film at different times...  using two different filter frames...  and separated in time by a year...  yet the result was exactly the same.  I ended up with degraded film filters with a series of pinholes in each filter and that is extremely dangerous especially since we have no idea why these filters degraded so quickly even while being handled and stored as carefully as possible.

This left me wondering why this happened.  

Could these two packages have been damaged during rough handling at the retail store where I purchased it at two different times?  Perhaps.  

Could these two packages have been damaged in the manufacturing facility?  Perhaps, but less likely.  

Could these two packages of Baader solar safety film have been damaged by rough handling in shipping at two different times a year apart?  Perhaps, and more likely.  

Damage during shipping (rough handling or heavier packages being placed on top of my package, etc) is the most likely place where all controls of safe handling went out the window.  I have no more control over shipping than I do the weather.  What I do remember is that this Baader solar safety film was shipped in a flat cardboard envelope shipping container...  although it had warnings of "fragile" and maybe even "do not bend", it clearly had been through rough handling (both packages).  Even if this thin package was held tightly with a thumb applying pressure to a slightly kinked bend in the cardboard envelope, the Baader solar safety film would indeed be damaged.  This is the most likely cause of damage.  

I vividly remember wondering about this potential problem when the package(s) arrived in my mailbox but I reassured myself that many people purchase this solar film and have it "safely" delivered to their homes so I should not worry about this.  I was absolutely wrong but, as I said, I have no more control over handling during shipping than I do the weather. 

What I do have control over is I can choose whatever solar filter material I feel will protect my eyes while providing high quality views and years of safe service.  And, that will NOT be any type of film filter!

Understanding the above mentioned possibilities for potential damage does not help guarantee that future purchases of solar film will provide safe solar film.  Understanding and acknowledging these possibilities also does not change the fact that I experienced catastrophic and dangerous failures of this solar film within two years, after only three or four uses each, even though I handled these filters exceptionally carefully and stored them with double protection.  I provided controls that should have kept this Baader solar safety film safe for many years yet I experienced catastrophic failure of the product, twice, and within only a year (one filter) or two (the other filter).  I provided as many safety controls as possible but what I can't control is how this product is handled before it gets into my hands and that is a very big problem, a very dangerous and risky problem, which renders Baader solar safety film dangerous and absolutely useless, in my opinion.  

Never again will I use or recommend this Baader solar safety film...  without a doubt, never again!  

On the other hand, I've never experienced a single issue with my Herschel solar wedge filters and my Spectrum glass solar filters through exponentially far more uses.  These are the only quality white light solar filter products I will use and, just as importantly, will recommend.