Also, Will the upcoming MAVEN Ultra Dark NDS be available for the upcoming Eclipses?
(TL/DR- We have some 15 Stop & 20 Stop beta units available as of today, but if you want them for the upcoming eclipse, you will need to act fast. Contact Adam to get on the Beta Testers program if you are not already, and he can ship them to you immediately: email@example.com)
WARNING: Solar Photography is dangerous and if precautions are not taken, you WILL damage your eyes & your camera gear. Please read this article and the warnings below carefully).
We have many new ND filters coming in Wave 2. Keeping in line with our tradition of ultra-thin, light-weight, color-neutral magnetic ND filters, many are wondering:
1. Can these heavy density NDs also be safely used for Solar or Eclipse Photography, in addition to simply non-solar related long-exposures?
2. Many of you have also asked about the availability of these filters for use of the upcoming eclipses on October 14th 2023 (partial), as well as April 8th 2024 (Total)?
The first is a complex question. Whenever we make a filter, there are gives and takes.
We have achieved Tier 1 Neutrality for the upcoming 15, 18, 20 Stop filters, which is what our non-solar shooting customers want.
Many dedicated Solar filters are not designed for general photography use, and therefore we do not classify these MAVEN NDs as “solar” filters. They are ultra dark NDs.
Let’s bullet point the important safety items and then get into the details:
1. Never look through an ND filter at the Sun. Ever. No Matter its rating. Even if it is for only a few seconds.Especially through lenses or optical viewfinders which essentially act as magnifiers of the sun’s harmful rays. Always look at the back monitor only. If you do this without protection, assume you will badly damage your eyes at some point. We cannot feel IR light burning our retinas until after the fact. There are very specific glasses & filters made for solar viewing & others for telescopes, MAVEN ND filters are not those.
2. Avoid aiming a naked (non-filtered) Zoom lens at the sun. Its like combining a few hundred lasers together. Even just few seconds can be enough to melt your aperture blades, if you have a telephoto zoom with a wide aperture. Always have your filter on first. Do a quick safety heat test (described below) with any new filter before actually shooting. This test can save your camera!
3. Never Use ND filters for zoomed in Solar Photography (anything over 24mm) unless the manufacturer has published the spectrometry performance charts from visible at least through 1500nm and if possible higher. There are greater risks the more you zoom in or the wider the aperture lens.
Different manufacturers use different types of dyes when creating their NDs, and some types of organic dyes will allow more Infrared Light to pass through. I have no idea what other manufacturers are using, but I know it is safe to say there are a number of suspect ND filters out there.
For the sake of this discussion, The 3 main spectral wavelength ranges we are concerned with:
UV Light – 120-400nm
Visible Light – 400-750
Near Infrared – 750 – 2500nm
Along with Infrared Light is also a lot of heat. If a manufacturer posts a spectrometry chart up to 700nm, it doesn’t tell us anything about what is happening in the near IR range (750-2500), and you might be literally cooking your camera as you shoot without knowing it, even with a filter they claim should be ok. If there are no spectrometry charts for that filter into at least the 1500 range, do not use it.
This is why we see blanket statements that say “do not use ND filters for Solar Photography” because for the most part,NDs Infrared Performance are unknowns without spectrometry data and you should not rely on an unknown filter when shooting the sun.
MAVEN filters uses Titanium, a metal, as our darkening agent in its magnetic filters and we spend a lot of time trying to get these ND filters to be color neutral. Regardless, it became necessary to answer the question of their performance in the near IR range and that chart is published below (with some explanations as to how these data were obtained).
4. Typically 16.6 Stops is widely considered the minimal filtration needed for solar photography. The sun is VERY bright, and yes, while you could lower your ISO, use a smaller aperture with a faster shutter speed to get to that ideal 16.6 Stops, but there are still limits in regards to light entering the lens as you are previewing it. I have done solar tests with our MAVEN 15 stop at 600mm on an APSC camera (or 900mm Equiv), and it works fine, just be aware – Your camera might get warm, and it could get warm faster or slower depending on a number of other variables. If you are only shooting for 20-30 minutes, you should be ok with a 15 stop. If you are going to be shooting for hours, you will want to be in that 16.6-17 Stop Range.
5. Can I stack multiple NDs to achieve the recommended 16.6-17 Stop Range? We believe this will be mostly ok. Again, it will also depend on the focal length of your lens and its aperture. We use very high-quality, high-definition optical glass, which means even 2-3 layers won’t see much sharpness distortion, however fewer filters are better. Adding a 2-3 Stop ND to a 15 Stop would get you into the 17-18 Stop range.
6. Will any of the new filters be ready and shipping before mid-October? Not for Kickstarter Wave 2 Backers or normal customers. However, and this is important: we do have a beta-testers program available today. If you are not already signed up for it, contact Adam at firstname.lastname@example.org – Sign the NDA, and not only can we make the new 2, 4, 15, & 20 Stop NDs available to you, but some of the other new products as well and your feedback can help answer many of the in field testing questions we have.
Doing beta tests helps us get more data about the filters, with what lenses, and how to improve them before mass production. We should be able to get the new filters to Beta testers in the USA before October 14th 2023.
7. Will you make a dedicated Solar Filter that isn’t defined as an ND? We are looking at all options in the near future, we wanted to have ultra-dark NDs for the sake of long exposures, but the truth is, dedicated solar filters are designed to eliminate ALL IR and protect vision, typically looking through a telescope for example. This is beyond the scope of what we are trying to do right now.
8. Will MAVEN have 16.6 or 18 Stop Filters in the Near Future? The 18 stop is not yet available, but it will be part of Wave 2 Kickstarter.
General Heat Build Up – Regardless of which lens, focal length or filter you use, shooting into direct sunlight, even leaving the camera on with a lens cap, will warm your camera up. This is simply because the camera body is also absorbing heat. More so in warm places.
For this reason, I strongly recommend making a shade shield for the rest of your camera. In the tests that I did, one of the test cameras, a Canon R8 began to overheat after about 40 minutes of being directly in the sun. I didnt see this on the Fuji XH2s.
The heat shield / shade break I made from an empty Dr Pepper case, did the trick to keep temperatures stable:
Testing 15 & 20 Stop ND filters was not as straightforward as we wanted. Because they are so dark, the spectrometry machines do not have enough power to measure them as a single filter. So we had to create single sided filters during the same process of making a double sided ND filter. Suffice it to say, we broke it up into 2 halves instead of one filter. For the 15 Stop filter, we really tested one side at 7.5 stops, and for the 20 Stop, we tested one side at 10 Stops.
Let’s take a look at the Spectrometry charts:
UV Light – 120-400nm
Visible Light – 400-750
Near Infrared – 750 – 2500nm
We get good filtration of 350-400 UV, and you will notice a flatness of visible light from 400-700 (This flatness in the visible range is a strong indicator of color neutrality) followed by an increasing ramp from 750nm – 2400nm.
For the 20 Stop Filter (Orange), we can see that at about 2400nm, we get about 1.8% coming through. Or .018. But remember, this is only one side, so .018 x .018 = .000324, or .0324% at 2400nm. For the 15 Stop ND we get .035 x .035 = .1225% at 2400nm
Suffice it to say, there is a very small amount of Near IR coming through the filter itself on a spectrometry machine, for both of these filters, but as we zoom in more and more, we are essentially using a bigger light catching bucket, which is also increasing the total amount of IR entering the lens.
A few Important Caveats:
A. Nearly all modern photographic cameras today have IR filters on the sensors (unless they have been modified). So with the transmission data in mind, and including the IR filter we know is on modern sensors, its safe to say that virtually no IR will be captured by the sensor. There is still the heat to be considered at the filter of the sensor, however.
B. The more you zoom in, the more it magnifies the light, including the near IR. So even if you have .0324% of light coming in with a 20-Stop, if you put a 2000mm lens on it, the actual total volume of IR light coming in increases. For this reason, we are saying if precautions are taken (you are careful & don’t look at the sun through them) the dark NDs should be fine for photography purposes up to 800mm on FF and 600mm on APSC (900mm Equivalent). This is what I have tested personally without issues.
If you are going with a modified telescope in use with photography, we recommend getting a telescopic filter specifically designed for the purpose of solar viewing or shooting.
C. Roger Clark, (a world expert on light emitted from celestial bodies) has a good, easy test to help you know if your filter is bad for the lens you are using (Very deep article but highly recommended), it amounts to putting your hand at the focal plane on a lens focused on the sun. If you can feel heat, it’s a bad filter. This won’t tell you how good the filter is, but it might save you from burning your camera with a bad quality filter.
D. Even after all this theoretical testing, consulting, and testing on our own, ultimately we need skilled photographers to do more field tests. I have personally used both the 15 & 20 Stop MAVENs on a Fuji 150-600mm zoomed in to 600mm. I did have my camera heat up on one of the tests, but it was 87 Degrees out, and it was more related to the camera body getting hot, not so much the filters.
I would still like to get more data before saying everything is fine and dandy for any photographic lens, (More tests between 600- 800mm FF). I am just trying to do my due diligence to make sure our customers can maximize the use of their ND filters safely.
I hope this answers at least some of the questions you have about using the new 15, 18 & 20 Stop ND filter for Solar photography. We will get more data and continue to update you as we learn.
Thank you again for your continued support!