Photographing Solar Eclipse

Just beware of damaging your eyesight....

The one I have which is designed for solar and is equivalent to 16.5 stops. Thats more than a Lee big stopper and a little stopper combined. You will lose too much IQ if you just stack loads of x2 and x4 filters.

Plus read up about the fact that a 10 stop filter is 'different' to a x2 (which in reality is a 0.3 stop) filter although notation varies between manufacturers.

http://en.wikipedia.org/wiki/Neutral_density_filter

Unfortunately getting it correct and saving your eyesight ain't cheap.

Try the www.widescreen-centre.co.uk in London for anything solar eclipse related.
 
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I've just ordered some Baader film from Amazon to make a filter to slip over my lens hood , This is always assuming we shall actually be able to see the sun, knowing the British weather !!!
 
:plusone: for "proper" solar film. While a load of ND filters may be enough to cut it for your camera, your eyes are irreplaceable and are sensitive to other wavelengths that aren't filtered out by NDs or welding glass.
 
Use Live View for composition and focusing instead of looking through the view finder...
 
:plus1: for "proper" solar film. While a load of ND filters may be enough to cut it for your camera, your eyes are irreplaceable and are sensitive to other wavelengths that aren't filtered out by NDs or welding glass.

Welding glass DOES filter out ALL eye damaging wavelengths! That's the whole purpiuse of welding glass!
 
http://sunearthday.nasa.gov/2012/transit/viewing.php Suggests that it does as long as it's #14 or stronger and that many welders use weaker glass (presumably so they can see what they're doing before they strike the arc.) I stand corrected.

I believe a lot of welders use active masks these days, ie the window blacks out when they strike the arc. But yes seeing through the window before striking the arc was in my long distant past experience, nigh on impossible.
 
Yeah just ordered some Baader film, thanks artyman!

I've recently done the same. At the risk of a slight thread hijack, what's the best way people have found of attaching it to a lens? I tried the way they describe on the back of the pack (basically sandwich the film between two rings of card and stick this to a tube of cardboard which has been put around the telescope/lens). However this way seems to leak quite a bit of light.
 
I've recently done the same. At the risk of a slight thread hijack, what's the best way people have found of attaching it to a lens? I tried the way they describe on the back of the pack (basically sandwich the film between two rings of card and stick this to a tube of cardboard which has been put around the telescope/lens). However this way seems to leak quite a bit of light.

Nah its all good I will need to know this as well, I was thinking of the same, but was also thinking just elastic band around the lens hood and once that in place duck tape to hold it tight, just creasing then becomes an issue, will need the ring cards solve that
 
I haven't made my filter yet but am thinking of a sandwich between card to keep it flat and a square tube that will slide over the lens hood with perhaps a circular baffle at the back of the tube to remove most of the extraneous light.

And make sure it gets taped on so you don't get any sudden blast of pure sunlight
 
For those of use that haven't prepared is liveview coupled with either one or two 10 stop filters going to work?

Thanks

Ivan
 
For those of use that haven't prepared is liveview coupled with either one or two 10 stop filters going to work?

Thanks

Ivan

No, absolutely not - your a few thousand stops short and will likely damage the camera sensor.

I guess we should get the mods to put out a warning or something when someone loads the forums that trying this with anything other than the proper stuff (as iv found out now from researching) will likely result in people going blind or cameras melting.
 
You will need something like -
Baader AstroSolar Safety Film ND 5.0

Unfortunately, firstlightoptics.com, are sold out and won't have any new stock until after the eclipse.
 
No, absolutely not - your a few thousand stops short and will likely damage the camera sensor.

I guess we should get the mods to put out a warning or something when someone loads the forums that trying this with anything other than the proper stuff (as iv found out now from researching) will likely result in people going blind or cameras melting.

Are you sure about being a few thousand stops short?

Can you post some of the links you used as I have found conflicting information and agree that we dont want people burning sensors or even worse fleshy bits

The filters I would be using are

ND3.0 (1000x), 10 stops, 0.1% light transmission, also when stacking filters do you end up with 10+10=20 or 10x10=100?

Thanks

Ivan
 
No, absolutely not - your a few thousand stops short and will likely damage the camera sensor.

I guess we should get the mods to put out a warning or something when someone loads the forums that trying this with anything other than the proper stuff (as iv found out now from researching) will likely result in people going blind or cameras melting.

Being an ignorant fool I tried photographing sunspots with both one and two of the oddly cheap but even more oddly pretty good XCSource 10 stop filters over my 500mm lens. I found that a single 10 stop wasn't quite enough, the sun was a bit overexposed at max shutter speed. Two was fine. I spent a lot of time checking focus etc. with liveview, and the camera was on a tripod, so conditions were optimum for melting my camera, burning a hole in the sensor, etc.. Luckily whatever damage (if any) was caused is quite undetectable.

Now that I'm better educated, in the sense of having seen all the dire warnings about damaging my camera, I'm going to see if I can devise some tests to discover whether there is a factual basis to these warnings in the case of my particular 10 stop filters. I do have some astrosolar film, but as other have noted, it's a bit tricky making a lens cap type of filter from it. So before I do that I'm going to check out the infrared blocking capabilities of my XCSource filters. I shall see how much I can warm them up with radiant heat compared to a heavily smoked piece of similar glass. I shall also compare their heat blocking ability to the astrosolar film.

If anyone has any good suggestions for how to conduct such tests I'll be glad of the advice.
 
Being an ignorant fool I tried photographing sunspots with both one and two of the oddly cheap but even more oddly pretty good XCSource 10 stop filters over my 500mm lens. I found that a single 10 stop wasn't quite enough, the sun was a bit overexposed at max shutter speed. Two was fine. I spent a lot of time checking focus etc. with liveview, and the camera was on a tripod, so conditions were optimum for melting my camera, burning a hole in the sensor, etc.. Luckily whatever damage (if any) was caused is quite undetectable.

Now that I'm better educated, in the sense of having seen all the dire warnings about damaging my camera, I'm going to see if I can devise some tests to discover whether there is a factual basis to these warnings in the case of my particular 10 stop filters. I do have some astrosolar film, but as other have noted, it's a bit tricky making a lens cap type of filter from it. So before I do that I'm going to check out the infrared blocking capabilities of my XCSource filters. I shall see how much I can warm them up with radiant heat compared to a heavily smoked piece of similar glass. I shall also compare their heat blocking ability to the astrosolar film.

If anyone has any good suggestions for how to conduct such tests I'll be glad of the advice.

I know baadar film is approx a 100,000x light reduction - so 2x 10 stops would seem to fall a lot short of this.
 
Telescope House still have the Baader film in stock. I bought mine last week - order to my letter box in 2 days. I made one filter with a circular aperture in a square card 'sandwich', made a tube then cut slits part way down, splayed them out and stuck them to the 'filter'. I made another with a square aperture in a square card which fits into a Hitech filter holder. I haven't tried either yet as the clouds have descended on Somerset............
 
This post over at OCUK is brilliant and says what you need to do - my mind was blown that people were still thinking of using ND filters -_- does anyone else get frustrated at people that dont listen? lol, fine if you don't know, but once you have been told or found out, why keep asking,lol

http://forums.overclockers.co.uk/showpost.php?p=27697229&postcount=2
 
I know baadar film is approx a 100,000x light reduction - so 2x 10 stops would seem to fall a lot short of this.

100,000x is about 16.5 stops, LESS than the 20 stops of 2 x 10 stops filters. Remember that a stop is a factor of 2x, and 2^10 = 1023 ~= 10^3.
 
Telescope House still have the Baader film in stock. I bought mine last week - order to my letter box in 2 days. I made one filter with a circular aperture in a square card 'sandwich', made a tube then cut slits part way down, splayed them out and stuck them to the 'filter'. I made another with a square aperture in a square card which fits into a Hitech filter holder. I haven't tried either yet as the clouds have descended on Somerset............
Any chance of a quick picture?
 
I took this yesterday with my Celestron Telescope - call it a practice run for next Friday. I used a Kendrick Solar filter from Grovers of Kent, not the cheapest solution but entirely feasible (the price at this link is typical only - there are cheaper/smaller ones).

Tring Astronomy had some Baader Solar Film in stock earlier in the week

Sunspots by Barry Cant, on Flickr
 
For those of use that haven't prepared is liveview coupled with either one or two 10 stop filters going to work?
No, absolutely not - your a few thousand stops short and will likely damage the camera sensor.
Let's clear this up.

The recommended solar filters are about 16.5 stops. Two 10 stop filters gives you 10+10 = 20 stops. So as far as visual light is concerned two 10 stop filters is more than enough.

Or to look at it another way: solar filters have an effect of 100,000x - in other words, they let through only 1 part in 100,000 of the light, and they make your exposure 100,000 times longer. A 10 stop filter is 1,000x, and two 10 stop filters is 1,000 x 1,000 = 1,000,000x. Again, if you're only concerned about visual light, two 10 stop filters is more than enough.

Anybody not understand why I added in the first example and multiplied in the second? It's because stops are a logarithmic measure. When you multiply numbers together, you add their logarithms. If you never really understood logarithms at school, don't worry about it. I did maths at university and I know this stuff. Trust me.

BUT - I was very careful back there to say, so long as you're only concerned about visual light. If you don't know for certain that your filter blocks infrared and ultraviolet, the only sensible course of action is to assume that it doesn't. I'm finding it hard to get quantifiable data on what effect IR and UV can have only your camera or eyeball, but even if my camera were disposable I wouldn't want to risk my eyesight. Safety first.
 
There is a similar thread in talk equipment, I'll paste in what Isaid there after calling specialists- hope it helps

I'm not an expert on photographing the Sun (despite my avatar) but I am interested in the eclipse, so I phoned a few specialist shops. I was advised that an ND or a combination of NDs is not the way to go as they dont stop IR radiation, the consequence of this is the camera overheating due to the lens acting like a magnifying glass held to the Sun. Its one thing to expose the sensor briefly and another to leave the camera aimed at the sun while composing a shot.
Also, you should be using live view and NOT the viewfinder.
That was the advice given to me.
 
There is a similar thread in talk equipment, I'll paste in what Isaid there after calling specialists- hope it helps

I'm not an expert on photographing the Sun (despite my avatar) but I am interested in the eclipse, so I phoned a few specialist shops. I was advised that an ND or a combination of NDs is not the way to go as they dont stop IR radiation, the consequence of this is the camera overheating due to the lens acting like a magnifying glass held to the Sun. Its one thing to expose the sensor briefly and another to leave the camera aimed at the sun while composing a shot.
Also, you should be using live view and NOT the viewfinder.
That was the advice given to me.

No, no, no ! If you use Live View then the camera lifts up the mirror, stoping light getting into the pentaprism and view finder. It also hits the sensor directly and can cause damage. Check your camera manuals !!
 
These are the filters I made from a cereal packet and double sided tape. There's a thicker piece of card forming the 'front' of each just to make them a bit more durable. With hindsight I'd make the flat one a bit longer to make it easier to pull back out of the filter holder. They look very wrinkled but it's just the way the flash is reflecting. Indoor photography is not my thing, as you can tell!


SF1
by Jannyfox on Talk Photography


SF2
by Jannyfox on Talk Photography


SF3
by Jannyfox on Talk Photography
 
No, no, no ! If you use Live View then the camera lifts up the mirror, stoping light getting into the pentaprism and view finder. It also hits the sensor directly and can cause damage. Check your camera manuals !!

I think they were assuming you would be using the correct solar filter, then you use live view in case the filter fell off or leaked etc. Rather the sensor than your eyes
 
How I made my solar filter - LINK

One problem with many of the home-made solutions is that there's nothing to prevent the film getting damaged. And you don't need a very big hole to let in a harmful amount of light. That's why I made mine sandwiched between to UV filters - the glass protects the film.
 
Realise I've left this waaaay too late but, if anyone has any spare Baader film left over they want to sell to me then inbox me :)

Hey, it's worth a shot :)
 
How I made my solar filter - LINK

One problem with many of the home-made solutions is that there's nothing to prevent the film getting damaged. And you don't need a very big hole to let in a harmful amount of light. That's why I made mine sandwiched between to UV filters - the glass protects the film.

That's a concern for any film type solar filter including eclipse viewers, especially if you have the latter left over from 1999. All my kit is carefully protected and packed in a handy sized cardboard box. Even so I shall be testing it before I use it and if I'm in the slightest doubt I won't. One reason why I have 2 eclipse viewers, 2 filters. But they can all last for years if looked after.
 
Just a point about filters dropping or getting blown off.

Place three strips of tape at equidistant intervals around the lens barrel and attach to the cardboard for 'top hat' designs.

The good camera/telescope filters have velcro straps performing such a function.
 
So having gone about making or buying a solar filter using proper materials - how do you go about assessing exposure times for photographing the eclipse
Depends what you want to catch. If you want to catch what might be interesting clouds around the eclipse, some interesting bit of skyline, etc., you'll want to overexpose the sun as much as possible without blowing the definition of the crescent shape. Whereas if you want detail on the sun's surface like sunspots, plus best detail on the craggy edge of the moon obscuring it, you'll want to avoid blowing out the sun, probably pull it back a bit from maximum but not overblown exposure.

It's easy to find out how to expose for both of those choices by taking photographs of the plain sun today, or tomorrow before the eclipse. Your autoexposure will likely get it wrong, overexposing too much, because this is too unlike an ordinary photograph. So use the histogram and take experimental photographs. Slight mist or minor cloud through which you can see the sun perfectly well will make a big difference.

If your camera offers live view with WYSIWYG on the current exposure settings, plus an optional histogram in the display, this is easy to do on the run in seconds :).

Another possibility to consider is doing some rapid exposure bracketing for HDR or blending across the huge dynamic range between sun's disc/crescent, clouds, and local skyline, etc..
 
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