Celestron – EclipSmart Safe Solar Eclipse Telescope and Camera Filter – Meets ISO 12312-2:2015(E) Standards – Works with Your Telescope, Spotting Scope, or DSLR Camera – Observe + Photograph Eclipses

I tested this filter out against a lot of other ones and while this one wasn't the best, it did have the virtue of being the most versatile. The ability to collapse or expand the opening to fit a lot of different telescope and camera lens sizes is very handy! And it has excellent design and construction for what is basically a paper-craft project with a bit of solar filter film super-glued to a bit of cardboard. The directions are a bit hard to follow because of the uneven drawing skills of whomever did the art, but once you have the idea, it's fairly easy to construct and get it into the proper configuration. The solar filter is obviously not H-alpha quality, so you won't see solar prominences, but I was able to make out sunspots without too much difficulty. The color balance of the filter is also fine, tinting the sun to the orange-red side of the spectrum, which reduces eye fatigue when keeping the sun under longer observation. This will work fine for the coming eclipse or for any other solar observation use!

Works great!

I had to use my lens shade for this to fit on my Nikon D3400. Needs to be adjusted each time you zoom in and out since the rubber bands that hold it go around your camera lens. Once you get things set, though, it stays on well and keeps you lens protected. It came with three rubber bands, I only needed two for my camera. The box feels more like it’s lined in plastic and keeps a sturdy structure around your camera.

Does what it's supposed to do. My images come out clean though this filter.

The description of the size is inaccurate and deceptive. It says will fit a 75 to 100 mm lens; that number describes the EXTERIOR diameter of the lens barrel over which the cardboard housing will fit. The actual solar filter is ONLY 60 mm diameter! I did not find this number in the item description. I tried the filter on a 70 - 300mm zoom DSLR lens. This lens has a glass aperture of 65mm and uses a 67mm filter. The filter worked just fine with this lens for solar photography. At 300mm, the image of the sun is only about 5mm on the sensor. I did not notice any vignetting. My primary lens for solar photography is a 1000mm, f/13 mirror reflector lens. I got some great images in 2017 of the eclipse, but had to be VERY careful as I had not properly prepared for solar filtering. I tried the Celestron EclipseSmart filter and actually got an image. However, it was obvious the filter blocked a significant area of the lens aperture; this darkened the image on an already slow lens by an unacceptable amount. A reflector lens has a large, flat glass in the front; in the center of the front is the secondary mirror that directs the light into the camera. On my lens, the front glass has an outer diameter of 85mm; the central, secondary mirror is 35mm. Normally, this leaves a ring opening of 25mm radius to admit light. (85/2 - 35/2 = 25mm). Using the 60mm Celestron filter leaves a ring aperture of only 12.5mm radius! (60/2 - 35/2 = 12.2mm). That is a reduction of 60.4% in aperture area (about one whole stop.) The filer comes packed flat and will be easy to take along, especially for the April 2024 eclipse. It has easy to use velcro to strap on the front of the lens barrel. I will keep this filter and use on my 300mm zoom. If you have a refractor telescope with a front glass up to about 65mm, this Celestron EclipseSmart filter should work fine. If have a large aperture reflector or Cassegrain telescope, I think you will be disappointed. I gave this only 3 stars not because of any fault of the design but because the description is incomplete and deceptive.

I have an inexpensive (affordable, but not 'cheap') backpack telescope. I wanted something for it for sunspot gazing and this seems like a good option. Coming from Celestron, I'm confident in its design over unknown alternates. It comes in a flat pack, but is really easy to fold into shape and using the included straps to attach it to my scope. In use, it does block out a large amount of sunlight to make the sunspots viewable (I didn't have a camera attachment when I tried it, so I can't show it). Construction is basically heavier cardboard and coated paper filter and plastic velcro. Glass filters are more than 10x as expensive, so this option is good choice for me. NOTE: the instructions state this and I'll repeat it here: remove the spotting scope before pointing at the sun to avoid damaging it or anything behind it.

This filter worked great for photographing the Ring of Fore eclipse in October! It was a tad big for my lens, but nothing some tape couldn't fix!

This Solar Filter ISO 12312-2:2015(E) does not work at all. Zero sunlight makes it through....in fact ZERO light makes it through...no idea if I have a bad one or if too many filters were placed in it during manufacturing. I'm returning back to the ISO 12312-2 filters as they work without problems. Something is not Right with this one. Update: I decided to cut open the filter and found 3 filters inside it....I removed the excess 2 and the filter works now just as my other Solar filters. Not sure why so many were inside this one. Looks like a quality control issue. 1 filter works perfectly....no need for 3....absolutely zero% light makes it through with 3 of them. Looks like 5% of purchasers have also had this issue of too many filters being inserted during manufacturing. Again it's a quality control issue. Be cautious buying this product... POOR QUALITY CONTROL