Solar filter for DSLR?

[Shooting_Star]

Hi all,

Does anyone know about solar filters for DSLRs? I came across this blog post about taking photos of the sun directly and I find the concept intriguing: How To Take Photos of the Sun with your DSLR (http://www.photographyblogger.net/how-to-take-photos-of-the-sun-with-your-dslr/)

I've searched on some telescope company websites and the searches mainly come up with solar filters for scopes. A camera shop advised a neutral density filter is okay for short exposures but to look for a proper solar filter from a telescope company for longer exposure.

I'm wondering if a neutral density filter is enough to take shots like the ones featured in the blog post, or whether I'd need a solar filter. I'm guessing the latter, but not sure where to find one!

I've got a Canon EOS 1100D and am just exploring the possibilities of the camera before venturing into buying a telescope ...

Any advice is appreciated :thanx:

[BlackWidow]

I think the article you have posted about has the answer you are looking for. You need to purchase a small amount of solar film.. Baader solar film.. You will find it at you Astro shop or online at sites like E- bay. You can fit it to the end of your lense and you good to go. You could use a spray can lid or a cardboard tube the fits over your lense. The cut the end off and tape or glue the solar film to the end.. You have now made yourself a solar filter for only a few dollars.

Will work really well and you will get images like the ones in the article you posted.


Hope this helps
Mardy

[JB80]

I used a pringles container. If you remove the inside of the lid so your left with just the outer ring you clip the lid ring back to the container with the film in between and then all you need is a bit of take or two to stop the filter from falling off.

Definitely film is your best option.
A ND filter does often get touted about as useable but remember you can't look through your viewfinder as it will still fry your eyes.

[Forgey]

I cut up a pair of solar Eclipse glasses and taped it to my lens hood.

[Shooting_Star]

Thanks for the ideas, everyone!

I was a bit wary of making one myself, but now it seems simple enough. I might give it a try :)

Have any of you posted up any solar images on the forum? :question:

[sil]

The Baader film comes in two types, one for visual observing (eg making your own glasses) and one for photography (eg tape over the front of your lens).

Even with the film you are taking very short exposures (I can easily shoot hand held with 1,500mm focal lengths), a neutral density filter will still let through some of the harmful (non-visual) portions of the light spectrum which can damage your camera sensor if you get your exposure times wrong. So the Baader film is the right tool for the job, not an ND filter. You can add a ND or polarising filter as well if you want to shoot longer exposure times, but you don't gain anything in the image worth bothering to do that.

The images in that article have probably been processed and colourised too. With the Baader film you get a "white light" (black and white basically) image. It may be tinted blue/violet or something depending on your camera and white balance settings and may not be quite as sharp and clear as those images. You can align, stack and use wavelets though to combine multiple shots and bring out sharper detail of sunspots.

Also the Baader filter restricts the light coming through and the sun's surface will appear featureless except for the sunspots. The edge of the disc will also be smooth and featureless: no dramatic flares. The sun has a lot of spectacular features but they require special scopes filtered to reveal just those feature types. As far as I'm aware there is no other type of filter you can stick on the front of a camera lens to allow you to see strong granularity or flares etc as the light energy coming through for those can damage camera and/or lens.

A white light filter though is great. It's affordable and easy to get into solar astronomy, without long cold late nights :)

Hope this link works, its a shot I took during the transit of venus: http://ocau.com/pix/4jzfm
Taken with a 500mm lens with a 2.0x teleconverter on a Nikon DLSR through a Baader white light filter. Only cropped and resized from the JPG (I processed my shots using RAWs, this was a quick one just to post an example). Camera was using auto white balance so this is how it handled for the JPG. Exposure time 1/800s @ ISO100 f/16, I had it resting on a monopod but easily hand held settings. After stacking I was able to bring out more detail on the surface than this single shot, but it gives you an idea of what you can get with your existing camera and spending a couple of bucks on Baader film.

[Shooting_Star]

Thanks for the detailed explanation, sil. That's exactly it, trying to get the most out of my camera without spending a tonne of money!

I like your example image, it still does look nice with just a white light filter. And I guess you can always have some fun and colourise the image, like you mentioned. Of course, it is tempting to want to take photos of the flares and whatnot!

I think I'll definitely look into the Baader film and try it out some time soon! :thanx:

[naskies]

Yep, and I've noticed many photographers are tempted to look through the view finder when they have plain ND filters on the camera. Very bad for the eyes if the ND filters allow UV light to pass through (as many do) - it's like looking at a partial solar eclipse without protection.

[sil]

Ah yes, speaking of eclipses, I was able to get nice clear shots (with sunspots showing) of a partial eclipse THROUGH horizon to horizon cloud cover with the baader filter in place. It's an astonishing amount of energy that gets through cleanly when even when you only have a vague idea of where the sun is behind the clouds. We are so naturally attuned to experiencing the world through our sight we often have the attitude that if we can't see it, it can't hurt us.

So be careful. When shooting solar use the right tools and also don't be put off by the clouds, it doesn't entirely spoil things :)

I'd be interested to know if Coronado/Lunt solar scopes also cut through the clouds or if their restricted wavelengths are blocked by cloud cover.
I ended up with bunch of smaller offcuts of the film after making my filters so I used one on a cheap spare monocular I had gathering dust. Now I can quickly pop outside with that to take a peek at the sun and if I can see sunspots I'll go grab the camera :)

[Shooting_Star]

Haha the monocular sounds like a fun little tool!

Would like to see your sunspot pics, if you've processed them!

It does seem quite dangerous, this solar photography business, if you're not careful. I accidentally looked directly into the sun with the naked eye the other day and it hurt! So I can imagine the damage if you looked through a lens :(

For the moment, I think I'll keep at trying to get some nice star fields. I got a 50mm lens recently which is apparently a good starter (not forking out $600 for experimenting with wide field shots!). So hopefully that will provide some entertainment for a while, before launching into learning about solar photography too!

[Garbz]

I've used the Baader film with my telescope and on my DSLR lenses. Just a tip when you finish making your filter hold it up to the sun and do a very detailed inspection. The film is fragile and easy to do slight tears or pinpricks. If you find any pinholes just dot over them with dark black nailpolish.