Thousand Oaks Optical SolarLite Solar Filter Film (ND 5) - 3" (76mm) Square Piece

works

Easy to work with

Works perfectly.

It's the real deal, made in the USA. This stuff was more valuable than gold in the days before the GAE and everybody wanted it.I tested it against various high-brightness sources such as high intensity 5W LED flashlights, and a 100mW 395nm UV laser. You could see the LED die structure in great detail with the minimal amount of light that would pass. This filter material would be perfect for inspecting LED die structures or as a means of taking low intensity measurements for quality control. The UV laser would not pass through the filter at near 100%. Only the occasional photon or two would pass when moving the laser at different angles, due to what I think is scattering. I tested some of the recalled solar viewing glasses from China and found that there was varying degrees of UV light passage in about 30% of my sample. Please, folks, don't do this kind of testing with your eyes and instead use a camera as a sensor.I made various camera filters out of the filter film by carefully tracing the glass element of a disassembled UV filter and then reassembling the filter with the film behind the glass. Even my besting cutting skills weren't enough to prevent imperfection around the edges, and that is why I put it on the backside. The compression of the glass ensured the filter film was against the back inside edge of the black anodized aluminum UV filter assembly and prevented any light bleed. Ideally, laser cutting these would be better.For personal viewing with my 20-100 x 70mm monster binoculars, I crafted two identical cardboard tube rings around the outside edge of the objective lenses with a few wraps of coiled 2" wide card stock cut from cereal boxes and then a few wraps of tape to hold them together. I then put strong double-sided tape around the outside of the tube rings. The filter film was cut into 3/4" oversized circles using appropriately sized round plastic food containers as a template. I then set the binoculars upright with these card stock ring sleeves and centered them over the pre-cut circular filter films. With everything aligned and pressed against the filter film and a cutting surface, I cut outward radial slits into the film "over-sized area" around the peripheral of the card stock rings at 1/2" intervals. This allows one to fold these "flaps" of film onto the sides of the tubes and double sided tape, to tape everything together. A few more layers of silvered Mylar tape were wrapped around these flaps to seal everything up.Complete totality was observed from Franklin, MO, which is on the center line of totality for the GAE and provided us 2m 39s of viewing. The local weather conditions were slightly hazy, and so we were able to make out detail on the surface of the moon due to the slight dimming of the Corona. It was the most amazing astronomical convergence I've ever seen. If you missed it, you really missed it.

I got the material to cover a variety of lens objectives I use for solar observation and photography. The material works great and ends up being significantly cheaper that if I'd bought commercial versions. Measure it carefully and you can get a lot of coverage for multiple lenses. I cut the sheet into circles and mounted them on clear filters that screw onto the threaded ends of my telescopes, binoculars and camera lenses.

Half the cost of a factory solar filter.Easy to assemble.

The second time I used this - there was a hole melted in the film - I have a 10" dob. I do a Cheshire and laser culmination before every session. I aim the telescope simply by looking at the shadow cast on the ground, then peer through a 40mm from a distance of 2-3 ft. If all safe then I will (with caution) proceed with my viewing session. In this case I kept seeing a glint of sunlight while doing the final aiming (again not looking through eyepiece directly) it's then I noticed a 2mm hole towards the edge - the film appears to be heat stressed in 3 areas - it mounts only one way on the scope - I live in S.Florida - but that shouldn't make any difference. Any ideas from the community what's going on here. I don't have much faith in this solar filter now. I'm not faulting the film - it works great. A hole appearing during a viewing session would be disastrous. I believe it's something on my end causing this.The sweet spot is not dead center in the primary mirror - can this be the cause? Any idea folks?

I ordered one size too small, but I can work around it. Otherwise I am quite pleased with this product. I have tested the film and it does filter the sun properly so that viewing the sun can be done safely. About the only thing that can be seen through this filter is the sun itself, and you can see the sunspots, eclipses, etc. This solar optical filter arrived in good condition and on time.My advice is if you order this film you will need to make a mount for it to attach it to your telescope. Many people apparently tape it to the telescope, but I plan to make a mounting with screws to hold it on, and with Plexiglas lenses to protect the film from damage. By making a more permanent mounting my plan is to be able to use the solar optical filter over and over again whenever I need it. The design I've come up with has the film sandwiched between the two plate discs of the Plexiglas, which will be attached to the mounting by screws through the Plexiglas into the mounting. The mounting itself will slip over the outside of the telescope and will be secured with set screws. I'm a woodworker and my neighbor is a machinist, so I'm debating on whether I will make the mounting using wood or have my neighbor mill an aluminum one.Important notes:1. This solar optical filter film is intended to be used over the aperture (largest opening) on the telescope. Do not use it to make an eyepiece or in the eyepiece part of the telescope.2. It is best to order a size larger than the aperture of your telescope. The film is square, not round. My telescope aperture is 6" and the film I ordered was 6" by 6". I should have ordered the 8" by 8" or even the 10" by 10". The 6x6 leaves small gaps where it doesn't cover the opening. To solve this problem the mounting I'm making will have some material sitting inside the aperture.

It is much darker and shows less clear details than the Baader Astrosolar film. In general, I would say outright avoid it for apertures under 4". For larger telescopes if you don't try to zoom on details (e.g. viewing the full disk), it will look crisp and some people actually like the orange color of the sun (because we commonly associate the sun with the color of the sunset) - when, in fact, the sun is white (the Baader filter is accurate in that respect). However, high power views even in large telescopes won't show the same detail as the similarly priced Baader Astrosolar film and photography in particular suffers considerably. Sunspots are much less well defined, you can't really see granulation etc. Also you can't use some interesting blue/green filters (like the Continuum) that can better show some features, as the Thousand Oaks filter blocks most of the blue/green light. I did see some improvement in photography when using a CLS filter with it, so do try that if you have one.I am attaching one image to show the comparison of color & brightness (note ISO and exposure) between this filter and the Baader film. I am attaching an additional one through a 2x barlow and a CLS filter that is a stack of a few hundred frames of a Canon 550D video crop mode movie to show the difference in detail of the Thousand Oaks and the Baader after full processing and sharpening (and both color adjusted to a pleasant yellow). All images were taken with a Skywatcher Evostar 80ED Pro.PS. You might notice that one side is more shiny. Most people have that side facing the sun to reflect more heat, but there are no actual instructions about it from the manufacturer so don't worry if you installed it the other way, it seems to function the same both ways.

Had a 6 inch telescope to cover up for solar work. Cut a quarter out and mounted in a cardboard frame to fit the end of the Newtonian. Works great.

Ne trouvant pas de filtre solaire adapté à mon télescope de 150 ou beaucoup trop cher, j'en ai fabriqué un avec une cornière de 25 mm en aluminium que j'ai cintré par allongement et une couronne en plexiglas adaptée au ø extérieur de la cornière, puis collé le papier filtre solaire, intercalé par une couronne en tissu velours, sur la cornière et fixé par rivets extensibles la couronne en plexiglas après peinture.J'ai fait de même pour le chercheur mais à partir d'un bouchon pour tuyau PVC ø 35 mm.Cout de l'opération 30 € papier filtre inclus.

La filtration est excellente et reproduit le soleil dans sa couleur (jaune) J'ai bricolé un filtre et la feuille filtrante est emprisonnée entre deux minces feuilles de plexiglass ce qui la met à l'abri d'un éventuel choc, (bien qu'elle semble résistante) Donc ravi de cet achat !