Camera settings for Leonids

[Taff]

Hi With the Leonids shower which are the best settings on the camera to catch them thanks.Mark

[callump]

Well no-one else has chipped in, so I would suggest:

Digital SLR on fixed tripod with remote shutter release.

Moderate to high ISO - 400 to 1600

Wide angle lens - closed one stop

30 second exposures - possibly longer if your camera will do it.

I usually use large or medium jpeg, rather than raw, so I can get more images on the card - but if your card can take it, then raw would be best.

/callump

[jgs001]

Mark, Just to add... if you're card is big enough, shoot RAW + Large JPG. Set the camera to continuous shooting and lock your remote shutter release. Just let it hammer away and capture a large number of frames. Then you can also combine all the jpg's and make a star trails out of the jpg's without having to process all the RAW's to do it.

[themos]

Don't forget to set the Clouds: OFF menu option

[Merlin66]

Assume you're exposing ( without an LPR filter) to get best sky backgound image you can; this will depend on sky glow and light polution.

The meteor trail only lasts a fraction of a second so basically it gives its own exposure.

[brianb]

ALWAYS shoot RAW .... you can dig down into the low significance bits to extract surprisingly faint details.

Here's a meteor (not a Leonid - possibly a Taurid) which I accidentally captured recently.

2009 Nov 11, 0512 UT. Crop from RAW frame, green layer only, Canon 40D, 50mm, 6 sec @ f/2, no filter. The ISO was actually set at 400 but the way I work it actually makes no difference....

The field is in Gemini's "feet", the prominent star cluster is M35. The frame was exposed as part of a set to measure the brightness of some of the bright variables in this area.

If I was shooting for meteors I'd have the lens pretty well wide open, use a antipollution filter (CLS or B+W 491 "Redhancer") and expose for as long as the sky fog remains at a reasonable level - probably 1 min @ f/2.8 for me.

[johnb]

Im planning 30 sec exposures as ISO 800 and RAW format, and will set it to take 999 of them, basically it will stop when my memory card is full, its a 4Gig Card and each pic is about 18Mb so by my calculations thats about 220 Pics and just under 2 hours. I must catch a couple i hope ?

John B

[Merlin66]

Brian,

I've got to disagree with the use of CLS or red filters etc.

The light emission from a meteor is due to the ionisation of the air and the components of the meteor.

http://members.shaw.ca/epmajden/index.htm

Ed Majden has been imaging them for over 30 years.

Typical emmision lines are:

H and K lines of CaII (3934Ǻ, 3969Ǻ)

Calcium (4227Ǻ, 6162Ǻ)

Iron (4046Ǻ-4144Ǻ, 4268Ǻ-4427Ǻ, 4886Ǻ-4988Ǻ, 5371Ǻ-5456Ǻ)

Magnesium (3855Ǻ)

MgI (5167Ǻ, 5173Ǻ, 5184Ǻ)

Oxygen (5577Ǻ, 6157Ǻ)

Sodium (5890Ǻ, 5896Ǻ)

SiII (6347Ǻ, 6371Ǻ)

[brianb]

I've got to disagree with the use of CLS or red filters etc.

To squash the sodium glow. The B+W 491 "Redhancer" is didymium glass which cuts sodium glow by at least 90% whilst transmitting most of the visible spectrum.

I would not recommend using a colour filter for meteors. If you have a dark sky then by all means shoot without a filter, but that's very, very few of those of use who live in the UK.

The image I've posted above is green layer only simply because that's the way I get magnitude estimates with spectral response close to the standard V band photometric filter.

[Merlin66]

I understand, but the sodium is a possible strong emission line for the meteors.