Use of ND filters to take lightning in daylight

[timarmes]

Hi all,

 

I have a friend who's passionate about taking lightning pictures.

His wife has asked me if there is any equipment available that'll

allow him to take photos of daylight lightning.

 

My immediate thoughts were to buy him a Cokin P filter system holder

and adapters, and then get a very dark ND filter that would allow

long exposures even in daylight.

 

Looking on the Cokin site, I see that they now offer two new ND

filters: the P155 ("ND100") and P156 ("NDX"). The actual stop values

of these filters aren't mentioned on the site - does anyone have any

further information? I'm assuming that the ND100 is a 10 stop

filter, although their 8 stop filter is called ND8, not ND80. I

can't imagine that the ND100 is really a 100 stop filter, so the

change of naming convention is a bit confusing.

 

These two filters are both hard to get hold of and very expensive.

What would be the potential advantage of using a single very dark

filter over two or more lower value ND filters?

 

Finally, has anybody here tried to take lightning in daylight? What

level of filtering would you suggest? I was thinking of getting him

2 ND8 filters - is this enough/too much?

 

Regards,

 

Tim

[alan_olander1664878205]

I can't tell you what the ND100 is as far as stops, but the ND8 is only a 3 stop filter. Cokin has a weird numbering system; the ND2 is one stop, ND4 two stops, ND8 three stops because they reduce the light by 1/2, 1/4, and 1/8. (I'm assuming that's how they came up with the numbers.) There's an article in the latest "Photo Techniques" magazine about lightning photography. The author doesn't use any filters for daylight lightning just good timing and lots of film! ;)

[frank uhlig]

How about suggesting a pinhole camera. f/185 or so will give long exposure times and might just be able to catch a lightning bolt.

[mark_chappell]

ND filters (and low ISO and a small aperture) may help, but not much. Lightning strikes

usually occur every few seconds at best, so to catch one, or several, you would need a

multi-second exposure. That's difficult to achieve during daylight. <P>

 

An alternative (for cameras that can use one) is a device called a 'lightning trigger'. These

(there are at least two brands, I believe) sense the initial phase of the bolt and open the

shutter in a few milliseconds (plus whatever shutter delay the camera has). Since the total

duration of a bolt is tens of milliseconds, the final stages (the very bright bolt we see) get

captured. It' happens much too fast for our reflexes, but not for electonics.<P>

 

I have successfully captured a bolt during an intense storm that had frequent multiple

bolts. I fired the shutter (exposure was about 1/20 sec if I recall) as soon as I saw the first

bolt, and once (out of about 20 attempts) I got the <A HREF="http://biology.ucr.edu/

personal/MACphotos/easternSierra/thunderstorms.html">second bolt.</A>

[Michael R Freeman]

<i>"I can't tell you what the ND100 is as far as stops, but the ND8 is only a 3 stop filter. Cokin has a weird numbering system; the ND2 is one stop, ND4 two stops, ND8 three stops ..." --- Alan Olander </i><P>

 

Actually, not so wierd, as Nikon uses the same system. Divide your normal exposure shutter speed by the ND number to arrive at the exposure with the filter in place.<P>

 

If your normal exposure is 1/1000 @ f8, then a ND2 gives 1/500 @ f/8 (1 stop), ND4 gives 1/250 @ f/8 (2 stops) and ND8 gives 1/125 @ f/8 (3 stops).<P>

 

One would assume ND100 follows the same convention, so the exposure with filter would be 1000/100 or 1/10 sec @ f/8 or approximately 6-1/2 stops.<P>

 

Haven't the foggiest idea what NDX would mean.

[alan_olander1664878205]

Ahhh, that makes sense!!

[grahams]

Photographing lightning in daylight is no different to photographing lightning at night. If you want to capture the entire scene including the lightning, use normal exposure values minus one EV. If your shutter speed is too slow to accomodate the smallest f-stop of the lens, then consider ND filters, not otherwise.

[timarmes]

Hi Graham,

 

My intention of using ND filters isn't to reduce the effect of the lightning on the exposure, it's to allow very long exposures that correctly expose the background whilst increasing the chances of capturing a strike.

 

I've since read the the ND filter will probably result in very weak streaks of lightning, so these aren't the solution after all.

 

The only solution is the lightning trigger, which is too expensive.

 

Tim

[timarmes]

For those who are interested, I've spoken to the Cokin UK importers, and they've given me the following information:

 

"The ND100 (P155) is just over 6 stops and the NDX (P156) is 12 stops."

 

Useful for eclipses I imagine.

 

Tim

[tony_riddle]

<p>Hi,<br /><br />i have been looking for a lightning trigger for quite some time. The followings seem the optimal ones in terms of cost and quality.<br /><br />The expensive one which seems more professional:<br />http://www.lightning-trigger.com <br /><br />The cheaper one which has lots of positive feedbacks on ebay:<br />http://www.pmgadgets.com<br /><br />Any feedback will be really appreciated from those who have experience with them.<br /><br />Tony<br /><br /></p>

[ronald_j._stein]

<p>I have a lightning trigger and you can have it!! I have gone back to long exposures esp at night- I do much much better!! I have the iPhone app for lightning and it works better than the lightning trigger. The trigger seems to miss a "LOT"!! I have not tried a ND filter but was told by a friend that the strikes are very dim using the filter during the daylight hours. Just keep shooting!!!</p>

 

[glen_h]

<p>At least from the usual distance, I don't think lightning is bright enough with a high ND filter.</p>

<p>At least not with as much ND as I think you mean.</p>