Tag Archives: Sun

Catching the Moon Simplified

Freedom Gazes at the Moon [5_055475-7deB]

Freedom – the statue at the summit of the Nation’s Capitol – Gazes at the rising Moon

One of our popular webinars is Night Photography 111: “Catching the Moon (and the sun)”. The next webinar is April 2, 2014, by the way. Long before the many tools that now exist to help solve for moon+landmark alignments I began working on a tool I call the MoonChase Tool. As snazzy tools came into being like Stephen Trainor’s Photographer’s Ephemeris, SunMoonCalc, MoonSeeker, and many more, I neglected the MoonChase Tool and focused more attention on the Advanced Stacker PLUS. In fact, after Google discontinued the V2 map interface upon which MoonChase was built the tool languished for about a year and a half. I also stopped teaching how to use it in the NP111 Webinars. But, I kept finding that all existing tools just didn’t do what I needed, so I resurrected the MoonChase tool. I ported it to the newest Google Maps API (V3), and I then added some of the features I had on my wish list.  I’m really proud of what the tool can do now. And I have some fiendishly clever plans for the future of the tool, time permitting, of course. Operationally the MoonChase Tool is simple. The hardest part is coming up with the location where you want to stand and the landmark you want to face. If you know that there is a sightline to a landmark in the distance you can fire up MoonChaseTool and in 3 steps know when to go to get the moon or sun behind your landmark!  That’s right. You paste, paste, click and click. Or drag, drag and click. We cover how to cook up good locations in the Webinar. How do you get your hands on this tool? We’ll tell you! If you’ve attended a NP111 webinar with us, or purchased the video and notes you already HAVE access through the “private page” (you did save the password, right?).  You’ll find the link to the MoonChase Tool on the private page.  Or sign up for our webinar which includes the notes and video AND access to the MoonChase Tool – and you don’t have to wait for the webinar, we send you all the links when you sign up (see below). The tool isn’t especially pretty, we admit that.  But it is pretty EASY to use and it works even from your iPad or tablet as long as you have internet access.

3 Steps to Moon (or sun) catching

3 Steps to Moon (or sun) catching. And there is more: you can check the view with Google Street View, and even check the weather with the weather button.

After clicking “Moon” you get the report thanks to Jeff Conrad’s SunMoonCalc tool. Be careful to be sure it selects the time correctly. Below it’s off by an hour due to Daylight savings time.

LickFromSJC

Moonrise over Lick Observatory from near SJC Airport… all opportunities from this location for the next 4 years!

 

What Problems Does the MoonChase Tool Solve?

The tool was designed to do the trigonometry for you. Did you know there is trigonometry involved?  Don’t worry, you don’t have to know trigonometry or math.  Nor do you have to know about spherical coordinates, azimuths, altitudes or the three different kinds of twilight.  All you have to know is where you want to stand, and what you want to be in your picture. Drag the markers around on the map and click one of the Solve buttons. OR use the tool in concert with The Photographer’s Ephemeris.

What Do I Need to Know to Do?

It’s very helpful to be able to do the following things: grab GPS coordinates from Google Maps and/or Photographers Ephemeris.  We teach how to grab GPS coordinates in the course. You’ll also want to know how to find heights of your favorite landmarks. Google comes in really handy for finding heights of buildings!  One more thing you’ll want to verify is whether you can See the landmark from the place you want to stand. Again, we describe 4 different ways you can do that in the webinar. The rest is dragging and clicking!

How Long Will it Take?

If you already have the coordinates, it will take perhaps thirty seconds – or not even that long.

I WANT THAT! How Do I Get It?

Easy: Sign up for the webinar and you’ll get immediate access to the private page plus the videos and notes. If you’ve already taken the webinar, go to the private page and you’ll find the link in the Resources section.  Or as a prior purchaser, just sit tight as we’ll be sending the new materials out to all prior purchasers over the next 3 weeks.

Webinar: NP111 Catching the Moon and the Sun
Not Scheduled but usually 7:00 PM PDT (7 MDT / 8 CDT / 9 EDT) for 2 hours
Captured [C_044450-2tc] In this 110 minute Webinar, you will be introduced to several free (and almost free) tools that you can use to plan a moon (or sun) shot - including a tool written by Steven and made available only to attendees. Have you wanted to capture the moon "right where you want it" but weren't sure how? If you know you could resort to photo editing and fake it but you'd rather get the real deal then this class is for you. Steven will demonstrate how to determine when and where to go to capture an image like the Moon over Lick Observatory or the moon at the Transamerica Building or the sun shining through a portal in the Pacific Ocean (below). This is a Webinar so you can conveniently attend from your computer at work or home anywhere in the world. This course includes notes, access to a private page with details - including landmark events Steven has already solved for you, an online viewable recorded webinar with unlimited online viewing that you can watch NOW before the webinar is held. One indispensable tool covered in detail is the Photographer's Ephemeris by Stephen Trainor.

What You'll Learn

Steven will show
  1. How to Plan a moon or solar "contact" shot.
  2. How smartphone based tools may help - or sabotage - your attempts to get an alignment
  3. How to use the moon to illuminate your foreground,
  4. How the presence of the moon affects photos of the night sky,
  5. How to find information about interesting celestial events,
  6. How to find compelling locations for "alignment" images, and
  7. What camera settings you need to get it all exposed just right.
Photon Worshippers **Winner Astronomy Photographer of the Year, 2010 - People and Space **
Remember that this event INCLUDEs online videos, notes, and access to a special tool that Steven uses to solve lunar and solar contact shots.
New Dome [5_009671]

The moon rises behind Lick Observatory on Mount Hamilton, San Jose, California

Photo Pills Ultimate App for Photography

Originally Published Nov 29, 2013
Last Updated April 18, 2016

For me this app is why I have a smartphone.  It has a lot of features, which makes it one of the most inclusive apps out there for photography.  Even just one of their modules would make up the entire functionality of others apps.  You are essentially buying many apps in one since is has a plethora of functions and shortcuts. It is going to take a long time to master so do yourself a favor:  sit down with it for a while read up and explore.   First go to the section on learning and learn! Tapping and swiping allows you to switch dates, times, modes, and more. Getting the feel of the app without trying some critical calculation will put you in a better frame of mind.

Accuracy

Steven likes to point out that the app is only as good as the hardware it is built on, and I can attest to this. Steven’s iPhone 4 compass and accelerometer must be off – the sun and moon locations are wrong by up to 10 degrees (more than 16 moon diameters).  Inaccuracy seems to also be a problem with the 4s and the 5s there have been many complaints. The iPhone 5 seems to have better sensors.  See the Macworld article: Six Phones Can’t Agree on Magnetic North

While the Macworld article is the result of poorly conducted calibration, the important takeaway is that the app can only be as accurate as the environment you run it in and the hardware you run it on. It can’t be said enough: trust but verify. Then recalibrate and try again.  Bring your own GPS and compass to verify the accuracy. We are not suggesting to use the iPhone as a navigation device just an aid. Apple maps didn’t work out so well remember! We are suggesting that this can be a useful device for the visualization of photos or getting an idea of your compositions and bringing your most accurate tools to bear. If you’re fanatical about accuracy, like Steven you can also bring your compass, maps, GPS, planisphere (ref 123,) and sextant.  Ok, the sextant was a joke but I wouldn’t be surprised if he has one. Steven is crazy about accuracy in predictions.

Navigation Basics

Navigating the app is easy to get started. Start swiping and you will be unlocking all sorts of functionality.  At first you will be surprised by all of the hidden things you are doing.  For me the first time I opened it up I was like, Wow, what was that? What did I just do?  Once you begin to get a little more advanced you will start to realize you may not be remember the proper, tap, drop, swipe, handshake combination to get where you want to go.  Generally it will take some practice but let me give you some tips out to help.

More content dots – The dots in the image below are a symbol that shows there is more content on this topic available just swipe in the correct place to the left or right.

More Content Dots

The next page dots are sneaky because they blend into the background.  However, they can be found in the same general location so just look to see if they are there.

Transition between right and left pages by swiping seeing the more content dots.

Transition between right and left pages by swiping by paying attention to the more content dots.

Previous page button – Found in the upper left.  This button brings you back to the prior menu, usually. It can be helpful for getting around the app so don’t forget about it. Even when it says something strange, it usually is a “back” button – except when it is not there and is instead a “Done” button on the upper right.  There are also important buttons that appear in the upper right so when you are finished look up there for some important info.  Like what you ask? The save button often appears here – or at the upper right.

Photo Pills back button on upper left.

 

 

Changing your location or a value generally requires just a tap however in some cases it requires a tap and hold or double tap.  My solution try them all.  In the planner, the map will find have some icons you can tap (sometimes by accident).  Or save yourself a bit of hunting by finding the Learn page and reviewing the options described there.

The Photo Pills Menu in all of its glory

Photo Pills

The three main menus of Photo Pills.

 

What does every module Do?

Here is a short summary:

My Stuff

Plans – Where your Plans are saved.

Points of Interest – Local points of interest. Over 10,500 all over the world! Also has a search functionality.

Settings – Calculations are based in the units of measure you select, on the Camera body you select.   I would suggest starting here. Imperial and Metric are the options.

Pills

Planner – The Photographer’s Ephemeris (TPE)-like functionality. Is used for Sun and Moon alignment planning similar to what we cover in our Catching the Moon Webinar.  Mostly used for planning, as well as scouting, but has some nice sharing functionality which will help in the organization of scouted locations on the fly.

Planner looks a lot like another program I know

Sun – Detailed information about Sun rise, set,  Time to set Azimuth Elevation, Distance, Shadow Ratio, start of different twilights (Civil Nautical Astronomical), Magic Hours (Blue, Golden), Calendar, Augmented Reality, Seasons, and Sharing (Facebook, Twitter,  email, or save as an image).

Moon – Detailed information about Sun rise, set, Time to set Azimuth Elevation, Distance, Shadow Ratio, start of different twilights (Civil Nautical Astronomical), Magic Hours (Blue, Golden), Calendar (Phases each day), Augmented Reality, Distance (Perigees and Apogees), and Sharing (Facebook, Twitter,  email, or save as an image).

Exposure – Allows you to determine equivalent exposures, that is equivalent brightness using different settings. Determine equivalent exposures by changing shutter speed, aperture, ISO. Will also help you understand how a ND (Neutral Density) filter will affect the exposure.  This also calculates the change in EV value.

DoF – Is a DoF (Depth of Field) calculator using your current exposure settings, (Camera, lens, aperture, distance to subject, lens set up teleconverter status), a DoF table, augmented Reality, and Sharing (Facebook, Twitter,  email, or save as an image).

Hyperfocal – A table which shows at a given focal length (14mm) and a given aperture value (F/1.4) what distance everything is going to appear in focus (15 ft 4in) to infinity.  We talk about it a lot now you have no excuse for looking it up.

FoV – Is a Field of View calculator using your current camera, lens, and distance to subject, Camera orientation (landscape or portrait) to give field of view information.  You can also inverse this so you know where to stand or use Augmented Reality to see it in the phones camera.  Oh and you guessed it; share (Facebook, Twitter, email, or save as an image).  Also allows you to find equivalent FoV settings between cropped sensor cameras.  One application Steven recently used was to determine what focal length to use to fill his field of view with Mercury, Saturn, Comet ISON and Comet Encke (136mm).

Night – Includes 3 main features Night AR, Star Trails, and Spot stars. Night AR allows you to see the location of the Milky Way, the rise of the moon, and the direction stars will rotate. Aids you in the pre-visualization of how long your star trails would be. Inversely, it allows you to calculate how long it would take for the stars to form a specified arc in the sky.  Finally, under Night is Spot stars which calculates the shutter speed necessary to make stars appear as spots without the aid of an equatorial mount.  For an in depth article on this subject, see here.

Time Lapse – Allows you to calculate data about your timelapse before you art.  Information such as Event duration in real time and as a final product, FPS, total number of photos and the file storage necessary to capture the sequence on your memory card.

Learn

Help – In depth help on the app, tips on the menus and how to navigate, what buttons do what.  There is a lot.  After a quick stop at the settings then go over here. Check it out.

About– Learn about the developers, Contact the support staff, rate the app, applaude the team.

The Awesome Parts

The app is just so big that I am not going to be able to cover all of it in detail.  There are a lot of parts of the app I want to touch on.

The data –  The data on every tab is amazing and detailed.  You want the data on what phase the moon is in, data on when the phases are that month.  The data just does not stop, it is not just the Sun or moon tab it is on FOV or DoF tabs.  For a guy who does a lot of panos all of the hyper-focal, FoV info is impressive.  I LOVE ALL of this data presented in a logical, clear and concise way.  But, wait we want more data.

Augmented reality – This is one of the most useful parts of the app.  For my money this was the best tool to teach and help students visualize where the North Star is and where the Moon and Milky Way is going to rise.  The overlay on the scene is the magic that allows students see where the Milky Way will be because it is super-imposed on the live picture.  There is AR for everything Night, Sun, Moon, Depth Of Field… Yes, even DoF – not a preview, but an on screen indication about the range of the DoF setting.   In my experience the AR has been accurate and responsive however this has not been everyone’s experience depending on your phone hardware.  I am told the inaccuracy issues are due to the hardware not the software, but that is not going to stop the complaining.  Can you use if for any scouting?  Well that is highly debatable (Steven and I have had heated discussions about this).  We would love to have more data on the photogenic parts of the Milky Way (i.e. Sagittarius, is much more deep and milky than Cassiopeia but the current depiction is rough).  Location of Stars to aid in the orientation.  I personally don’t care about the size of the moon.  Steven would like to see the size be more realistic – it’s currently shown about 8 times its actual size. I can foresee problems with people with bad vision or people not patient enough to search for the moon (I know a lot of those, bad vision not the part about being patient). The on screen display (AR) also doesn’t show the GPS, exact angle of elevation, or exact compass direction – the data is drawn in grids that are increments of 10 degrees vertically and 12.5 degrees horizontally.

But I digress, the great part about AR is that it can help you see what might be possible, when might the moon be near that object.  You may still have to do the work over again because we have seen the predictions be as far off as 10 degrees if you rely on the phone hardware for compass direction.   

The moon is 0.5 degrees if you are running photo pills with a bad compass (bad hardware or just a bad calibration) The moon could be 20 moon diameters away in this photo (10 degrees / 0.5 degrees = 20 moon diameters). The moon would be out of this frame in that case.

The moon is 0.5 degrees if you are running photo pills with a bad compass (bad hardware or just a bad calibration) The moon could be 20 moon diameters away in this photo (10 degrees / 0.5 degrees = 20 moon diameters). The moon would be out of this frame.

 

Planner – It is not as good as I would have liked.  My main gripe was the small screen is difficult to navigate and to pinpoint the exact point where the alignment is going to be.  One thing is that there is elevation profiler which will allow you to determine what the height of the object is on the horizon.  Useful yes but useless if there is a huge building in the way.  It also currently doesn’t have ready access to a Topo Map so determining where there might be a hill in the way is not simple – unless, of course you are on site..  I like the share options, in the Points of interest tab you can export all of your points to a KMZ file you can open in a map editor (like Google Earth).   The win for me was the portability, I always have my phone so I can just scout whenever I see something interesting so I can come back later.

I can plan a shot where ever I am, unless I need the map and am not able to get a data connection, that is.  If I see something interesting, I can check for an alignment right on the spot.  I can figure out if it is possible then bring out the big guns for double checking.  I think this is one of the biggest advantages.

One thing that tripped us up… there are two AR modes in the Planner. The outer one – which is for “getting an idea” and the inner one that appears after you start a Find operation. The AR choice after selecting Find allows you to use AR to set the location of your desired target. Point the display and tap it to place the moon or sun where you want to capture it. Remember, though, that the moon or sun will be shown about 12 times larger than actual size.

To close this app is the most comprehensive and inclusive of features, some planned usability enhancements will definitely kick it up a notch.

Enhancements We’d Like to See

What we would like to see alignment prediction tool additions.  Photo Pills has so much. Now that we have seen what it is capable of we want more.  Serious, understatement there because, honestly we what a whole LOT more, and that’s not to say we hate the app – not at all. It still packs more punch than everything else we’ve looked at.  However, as noted, we would like to see more data in the AR and in the planner.  We would like to be able to take a photo of the scene and have the all relevant data overlaid on the same photo.  Further, we would like to have access to the meta-data burned into the photo.  When we share a plan, it doesn’t seem to include the elevation (altitude), azimuth (compass direction) and tolerance information. We are geeks we want to write scripts to sort and map that data, and track our exploits much like Spyglass.

There are a couple of little niggles in the interface that are annoying. Lines that don’t get drawn on the planner map, accidentally resetting the observer location by dragging our finger over the “set location here” icon while scrolling the map, and others.

If possible, we’d like to see an “enhanced accuracy mode” so that you can be 90% confident that the AR alignment that you are shown will indeed be within 0.5 degrees.

Even though of how we’d like to improve the visual interface… but hey, that doesn’t mean it doesn’t work well as is.

How Accurate Is The Application? Participate and Find Out!

We want to collect data from testing in many environments on many devices, not just from our own half dozen devices.  Please do the following.

  1. Play with PhotoPills a bit to be sure you understand it.  Go to the help menus and learn about the AR and other functions.
  2. Kill your compass app and Photo Pills (all apps preferably). This is to insure that you have a chance to calibrate.
  3. Start PhotoPills. Go to “Moon” make sure that “Info” has the current time (double tap the center of the Moon).
  4. Click on AR.
  5. Verify that the current date and time are correct in the upper left. If not, go back to Info and double tap the Moon or go into settings.
  6. If/when the phone asks, perform a calibration on IOS 7.0 and later you “roll a ball around”. Older IOS versions may ask you to wave the phone in a figure 8. Hold your phone normally (Portrait mode)
  7. Point the camera at the Moon. Obviously the moon must already be up in the sky for this test. You CAN try this using the sun instead, but that wouldn’t be good for your eyes or the phone unless the sun is just rising or just about to set.
    Once your target is in view select the “Action” button (lower right).

    • If you have a Twitter account choose “Twitter” and send your photo to @starcircleacade be sure to include #photopillstest and your iPhone version e.g. #iphone4 or #iphone5s and your ios version e.g. #ios703.
    • If you don’t have Twitter, please use email and send your photo to results@StarCircleAcademy.com
    • If you don’t have email available, you can save the image or post it to Facebook – just be sure to share it with us!
  8. Next turn your device 90 degrees to Landscape mode, spin yourself around a full 360 degrees (trying not to get dizzy), point the phone back at the target and repeat step 7.
  9. Super Extra Credit would be to take a photo of multiple iphones on a table all set to compass mode.

Please only send two photos one in portrait, one in landscape mode per each device you have Photo Pills on.   Thank you for your help! Also, please note that large metal objects (your car for example), computers, electronics and what-have-you will affect the accuracy of the compass. If you can move away from such things to do your calibration and take measurements that will help.

We will publish an update to this material once we get enough data to make some calculations.

Fakery Exposed….

In my last article, I discussed Bending Reality and where my personal ethical limits are in relation to photo manipulation. There has been some insightful commentary from very thoughtful people.

In this article I reveal all the ways in which my “Solar Corona, Keck & Subaru” photo (below) can be discounted as a fake.

Solar Corona + Keck & Subaru

Let’s start with the easy things.

  1. The EXIF date taken can be seen on Flickr as July 31, 2011. So there is an immediate red flag! Had I left the exposure information intact, there would have been more clues, but I wanted to hide the “iPhone” data!
  2. The implication that this was taken in 1991 fails the following tests:
    1. There were extremely few generally available digital cameras in 1991. Most were less than 1 Mega-pixel. A Hassleblad digital back or a professional TV broadcast camera were among the few that were larger than 1.6 Mpix – the size of the original photo on Flickr.
    2. The Subaru Telescope construction didn’t begin until 1992 and the enclosure wasn’t completed until 1994.
    3. The Keck Telescopes similarly didn’t exist in 1991. The first dome became operational in 1993, and the second in 1996.
  3. The 1991 Total Solar Eclipse was visible in Hawaii near sunrise but this view is facing Northwest as can be determined from Google maps.Now on to the less obvious things:
  4. There is a very suspicious small “orange ring” around the perimeter of the sun. Suspicious because it indicates an annular eclipse, not a total one.
  5. The relative sizes of the sun and foreground are way out of proportion. The eclipsed portion of the sun in this image appears to be slightly larger than the base of the Subaru telescope enclosure. That base is 40 meters wide (131 feet) and 43 meters tall.  For the base of the Subaru to be same angular size as the moon/sun, the photograph would have to be taken 114.6 x 40 meters away. That works out to 2.8 miles to the South East. But…
    1. The view is clearly taken from above since the horizon is visible about 1/2 a degree above the telescopes. The summit is less than 2,000 feet away after that it’s all down hill!
    2. The only way to move far enough away and still look down would be to do so from the air.
  6. The central (dark part) of the eclipse is alarmingly dark relative to the rest of the image. It’s darker, even, than the foreground which lies in shadow. At minimum this would indicate a composite or photo manipulation.
  7. The center is slightly off axis from the diffraction spikes above and below the sun.
  8. There are visible bright reflections off of the Keck domes – more characteristic of an un-eclipsed sun.
  9. If that is REALLY the solar corona it is much more extensive than very sophisticated instruments have observed – even more impressive than NASA photos.

So there you go. Got anything else to add? Please let me know.

PS Is THIS a photo of the Annular Solar Eclipse?

Solar Filters

Publish Date: April 9, 2012
Last updated May 29, 2017.

If you’re just now trying to get a solar filter for the upcoming total solar eclipse, hurry! Try a telescope store if there is one near you.  Trust me, most of them are sold out. PLEASE DO NOT attempt to photograph or observe the sun if you are not properly prepared. PERMANENT BLINDNESS or DAMAGE TO EQUIPMENT may result.

I  have been asked a lot about solar filters and why I was strongly encouraging people to get them. First let me explain how you might use them, then I’ll talk about the different kinds of solar filters and their costs.

Here are several shots of the sun rising behind Lick Observatory on Mount Hamilton, San Jose, CA. All shots are without any filter.

It Happened One Morning

The upper exposures are pretty conventional.  The exposures at the bottom, however, are clearly MUCH shorter and exhibit excessive flaring mostly due to IR light.  Indeed, here are the settings from upper left to lower right:

  • ISO 200, f/11, 1/80
  • ISO 200, f/11, 1/640
  • ISO 200, f/11, 1/8000
  • ISO 100, f/36, 1/2000

What is probably immediately obvious is the glare / flare and color fringing.  Compare the above shots to this one:

Rise and Shine [C_037951+77]

This is NOT a single shot, it’s a blend of two shots.  The thing to notice is how much better tamed the violently bright sun is. Another important consideration is that a solar filter provides a boatload of protection to both the eyes and the camera equipment more on that in a moment.  The bottom line is that the flare is well controlled and the sun exposure is sufficient that if there were a large sunspot on it, you’d be able to see it.

What Can I Do With A Solar Filter?

So glad you asked.  Consider these:

  1. Safely capture a Solar Eclipse prior totality.
    Why: Because it’s cool and solar eclipses visible from any given area are relatively rare.
  2. Safely capture the Transit of Venus on Tuesday, June 5, 2012.
    Why: Because this event won’t repeat for another 105 years! It’s rarer than Halley’s comet and it’s visible from everywhere in the continental United States. [Sorry your missed it!]
  3. Capture sunspot activity.
    Why: We are approaching the solar maximum where sunspots and coronal mass ejections are at their most active.
  4. Composite a nicely formed sun into your shots.  You can use my “Easy HDR” method described in a prior column.
  5. Seek solar alignments where the sun forms the back light to silhouette a foreground object.
  6. Catch the International Space Station (or other spacecraft) as it hurtles across the face of the sun.
  7. Use the solar filter as an “ultra stopper” to make extremely long daytime exposures of e.g. waterfalls or surf.

For some good background on how to observe an eclipse, see here.

Do I Need Protection?

For your eyes, absolutely. For your camera, HIGHLY recommended.  People often go “over the top” in their worry that a big lens will burn an instant hole in the sensor or camera body should they aim it at the sun. The image projected is onto a broad area at least as big as your sensor.  In a short period of time i.e. a 1/4,000 of a second exposure nothing horrible is likely to happen to the sensor at least. The combination of a mirror and shutter in a DSLR provides SOME protection to your camera and sensor from “certain doom” however if you were to ask my advice, I’d say DON’T use your camera to photograph the sun unless you have a SOLAR FILTER.  Most especially do not use live view (or a point and shoot camera) pointed at the sun. That tactic is very likely to damage your camera.

When I zoom in on the sun, isn’t that concentrating the light even more?

Well actually, just the opposite.  Instead of focusing all the energy on one spot, you’re spreading it over the sensor surface. So in fact, the sunlight is more concentrated when you don’t use a telephoto lens.

DO NOT look through the viewfinder to compose your shot unless you have a proper solar filter!  Permanent eye damage may result. Even then be careful.  And we just figured out that it’s not a good idea to use Live View to compose a shot.

What Kinds of Filters Are There? What Do They Cost?

Protection For Your Eyes

There are filters that you can wear or hold over your eyes. I highly recommend you get a pair. These are rated “ND 5”** and allow only 1/100,000 of the energy to pass through – they are effectively 16.6 f-stops of light reduction. Alternatively you can use a welders mask (though I bet not many of you have one!) #13 or greater.  Cost of wearable / simple filters ranges from $1 or so to $20 and more depending on the type.  Wearable filters are usually made of black polymer which blocks all wavelengths of light (important to prevent eye damage from non-visible light) and renders the sun a yellow-orange color.  Most locations only sell the personal filters in bulk (10 or 25 are the usual minimums).  I purchased a stock of 60, for example and have sold them all.

**IMPORTANT NOTE: There are at least FIVE different standards for measuring the transmissiveness of filters: “Neutral Density: ND, Optical Density – also often called OD, Shade Number – for welders glass, transmissiveness, and stops).  For a photographer who is familiar with the ND scale used to rate Neutral Density filters this is NOT the same scale as the “Optical Density” scale used to rate solar filters!  An ND3.8 (photo solar filter) in the optical density scale is equivalent to the ND8192 neutral density filter!  An ND8 filter for your camera is 3-stops of light. For safe visual viewing you need about 14 stops! So an ND8 is  woefully short of light snuffing capabilities. Moreover neutral density filters used with cameras may or may not extinguish harmful Infra-red and Ultraviolet radiation.  

  • What about using an 8-stop Vari-ND (ND2-400 Filter)?

At the maximum 8-stop setting (ND400) the filter is passing 0.4% of the sun’s energy.  That’s more than 40 times the recommended energy for PHOTOGRAPHIC use. A photo filter should transmit less than 0.01% (1/10,000). Even a 12-stop reduction in light (ND4096, Optical Density 3.6) may pass too much energy for safe and effective photographic use. 13-stops which is the same as Density 3.8 or ND8192 is preferable.

  • What about the “Big Stopper” by Lee or Hitech?

10-stops sounds like an impressive reduction in light but the resin filter (Hitech) passes quite a lot of IR and UV light. And 10-stops still really isn’t enough.  I haven’t see the response curve for the Big Stopper. It would be UNWISE to assume the Big Stopper or any filter is safe if it isn’t solar specific – especially if you plan to try to take more than a few shots. These filters certainly aren’t visually safe.

In addition to not reducing the light to safe levels, having an insufficient energy reduction means that you’ll have problems with flare / glare.

Photographic and Visual Filters

There are several varieties of solar filters that can be used for photography.

  • Black polymer screw-in solar filters – pre-made you order them to screw in on the end of your lens(es). There would be little point in getting such a filter for any lens that is less than about 200 mm effective focal length.  It might be worth making your own from an existing UV filter.
  • Black polymer “covers” or black polymer solar sheets from which you can make filters.
  • Silver solar mylar sheets (make your own) which render the sun a more natural white to a blueish cast. Mylar is less durable than polymer.
  • Glass solar Filters in a housing to fit over a lens hood or dew shield (ND 5.0)
  • ND 3.8 (Photographic) solar filters which are NOT suitable for visual observing.  This type generally only comes in sheet form and you must make your own filter. Not suitable for visual use because it allows too much of the suns energy to pass through to your eyes.
  • Tuned solar filters (also called Hydrogen Alpha) – like those found in the Coronado solar telescope. I don’t have a background in these, but normally you will need a set of filters and they are primarily designed for use with telescopes. The cost is upward of $600.

Normally when you buy a solar filter, you select a size that will cover your lens hood (or for a telescope the “dew shield”).  Fit on filters should be snug so that they cannot come off if bumped or buffeted by wind. You really do NOT want your eyesight destroyed by a gust of wind!  The filter should also seal out light leaks since most solar filters are reflective.

Filter Costs

Since the upcoming event(s) all require solar filters, they are in short supply. It may take literally MONTHS to get a filter from some suppliers.

Costs depend on the size and quality of the filter. For the average telephoto lens expect to pay from $60 to $100 for the glass type filters.  For very large lenses or for telescopes that cost could reach up to $200 and more.

Black polymer or silver mylar sheets will run you about $35 not including shipping.  The ND 3.8 Baader photo filter is about $90 for a 19 x 39″ sheet.  I also ordered a “natural color” Mylar polymer sheet (12″ x 12″) for about $30 from RainbowSymphony. RainbowSymphony also has the solar glasses at minimums of 25 pieces. Finding things on the RainbowSymphony site is a bit tedious. (NOTE These prices were as of May, 2012)

There are many references on the web for building your own solar filter if you choose not to buy a glass filter.

As with all things, quality varies quite a bit. I do not have the resources to exhaustively test all filters, but so far my best photographic results have come using the Baader Astrosolar Film (PHOTO) and hand made filters.  This filter passes enough light to keep the exposures fast at low ISOs and is optically superior to any other mylar or polymer material I’ve tried.  The glass (visually safe) filter I have darkens the image to make it visually safe and renders the sun an orange color (which it isn’t by the way).  Somewhat longer exposures are needed for this.

 

Resources

I’ve placed these in order according to my experience surfing and buying from the company.

Recommendations

If your goal is photos, get a Baader Astrosolar filter. It is not eye safe, but it does allow higher shutter speeds and versatility. Practically this means you’ll have to make your own filter from sheets as there are few resources with pre-made photo transmissiveness filters. Making your own filter is not that hard.

Second choice based on quality is a glass filter that seals well over your lens hood (you do have one, right?). The “outside diameter” of your lens hood must be about the same as or slightly smaller than the inside diameter of the glass filter you’ll put over it.  Since most glass filters are designed for visual use, you’re shutter speeds will be a bit slower but good quality glass will keep your photo sharp.

Get a pair of solar glasses for your eyes regardless of what else you do.