Discussion in 'Nature' started by sarahdu4, Apr 21, 2009.
Any suggestions on shooting the meteor shower tomorrow night in the Los Angeles area?
1) Get up in the mountains away from the light.
2) Point the camera a bit away from the point of origin. The streaks are longer
3) Use film. (No Sensor Heat Issues.)
4) The Lyrids are frustrating. Few per hour requires long exposures if using film.
5) If you use digital take a series of 5 to 10 minute exposures to reduce heat issues and then layer together.
And if you heed #3, then use an old-fashioned all-mechanical camera (if you have one) so you don't drain the battery with one or two long bulb exposures.
When I shoot star trails I set the camera to a shutter speed of 30 seconds then use a remote release to lock the shutter button. The camera takes a series of 30s exposures, one right after the other, that I can stack later using 3rd party software. This solves both the heat/noise issue and lets me control light pollution.
I have caught meteor streaks on some exposures, but they tend to be faint. I'm not sure if that's a function of aperture and ISO (I'm usually at f/4 or f/5.6, ISO 200-400) or lack of luck.
If I were specifically going out to capture meteors (can't tonight) I would head for the local deserts or mountains, father away from light pollution than normal, and shoot at a wider aperture and higher ISO than normal to try and get more brilliant streaks.
The odds of you even seeing a Lyrid is fairly low but you can listen to them with an AM radio on a very quiet band or, if you have an internet connection in the field, you can listen to them here:
A couple of nights ago I was walking my dog. It is very dark here in Central Oregon. Behind me were two huge flashes, like lightening that was close by, but no thunder. Then I saw several major streams of material fall out of the sky, all the way across the horizon in front of me. It was very spectacular, so maybe we'll get lucky.
You need to find the strewn field and garner a little extra coin. Recoveries from seen falls are almost priceless.
JD, I know. I didn't see the one behind me, and the one in front of me was very far in the distance. Too hard to tell how far though.
1) What kind of equipment are you using?
2) How far out of the city are you willing to go?
it depends on he equipment and on the character you'll want for the final images. I suppose you do not have a mounting that rotates the camera against the earth, so that the stars would be spread out to streaks on a more that 15 to 30 second exposure, depending on focal length. So, here's some advice:
Lens : Use a short focal length, to maximize field of view. However, also use largest real aperture you can. Stars (and meteors, for that) are point sources, and as such the real aperture, in mm, is more important than focal ratio, this dimensionless 1/something parameter. I would go for a 50mm, used at 1/1.4 or less (meaning 36mm or more real aperture), which gives a good trade-off between field size and aperture IMHO.
Camera settings : If digital (I just suppose), get a huge memory card and take exposures of a few to a few ten seconds at most, until the card is full, basically. The exact time depends on the brightness of the sky at your location and the sensor noise and dark-current behavior. The average fall time is a fraction of a second, so you are not going to lose anything from the meteor, but depending on your location you minimize background stray light and smearing of stars into streaks (unless you want that, of course, but this makes it harder since it is another type of optimal settin). Use at high ISO, even if the shutter is open for seconds the exposure time for a meteor will more likely be of the order of 1/100s per pixel, then it has moved to the next pixel. Higher ISO beats reduction of background, rather reduce exposure time if background is an issue.
Postprocessing : Identify the frames with meteors on. Since you most likely have not tracked the stars (see the mounting thing above), you'll have to shift/rotate/etc those frames to be able to stack them (btw, at least crudely follow the field with your camera by tracking manually every 15 minutes or so). Same procedure as for combining hand-held panorama sots, just on a single field. Then combine them, no idea what the algorithm would be called in your software, but in principle it would be something like "only superimpose brighter pixels". If you feel you have too much noise, too few stars, chose some of the frames with no meteors, construct a nice background image for the field, and then superimpose only the meteors/bright stars from the shooting star combined image.
Good luck then, and although Lyrinds are not spectacular, it is oing to be a good training run for the Perseid and Leonid showers lather in the year.
Thanks everyone, y'all have been duper helpful! Mr. Axel your story is amazing! I read your story with my mouth hanging open, my co-workers are now looking at me funny. I hope we get lucky too!
Here is all the equipment I have: Nikon D300, Nikon D40, 18-55mm lens, 55-200mm lens, SB-800 flash and tripod. Old school equipment: Nikon N65 with kit lens and all manual Olympus OM 10. I wanna say a 50mm lens and 200mm lens for the Olympus, can't remember.
I will not be able to get very far out of town unfortunatly. I just wanted to see what I could get playing aroung tonight. When the Perseid and Leonid showers come, I will make a trip out of it to get some amazing pictures, hopefully.
So last night was a bust. It was way too cloudy and overcast, we didnt get to see anything. But thanks for all the suggestions. I'll save this post and use it for next time. Thanks again!
Meteor showers always seem to be the best time for the clouds to move in! It's clear here this weekend, there might be some leftovers.
thoughts-if you wish to take a meteor shower with your dslr then should also consider the power requirements of the dark frame image. this image will take place immediately after the 8 hr shot. so the full exposure will be 16hrs long. no dslr being built can take a 16hr exposre. this why many above has talked about stacking a bunch of shorter exposures. for any long exposure heat builds up in the sensor and electronics. this heat shows up in the form of noise in the images. you should check you owner's manual to see at what exposure length is the limit for a nondarkframe exposure. then use a series of images shorter than that length. the simple way to do this is with a interevalometer which can be set to shoot a shot every so many seconds of a certain length. both canon and nikon make them for their dslrs.
the other problem is supplying the power to the dslr for a very long exposure. and note that you have to double the exposure when you consider the dark frame shot time too. one possibility is to use a 12volt deep cycle car/marine.recreational battery. then use a 12v ro 110v cxonverter with alligator clips to supply 110v power to the dslr. you use the 110v power source puck for supplying the power. the 12v battery could be used for days to supply the power to your dslr and any accessories. just put the 12v on a board or something to keep it from direct ground contact.
personally, if i was to take a meteor shower or startrail image i would use a film slr. i have 3 in the basement. this means no stacking of images, no heat buildup problems and no power requirements/problems. all the digital difficulties are gone with film. many yrs ago i took 4 and 6 hr startrail images without any problems. now all that is needed is to scan the image to the pc. i have a nikon coolscan v to do the scanning with. i fully realize that after buying that expensive digital dslr it tempting to use it to take all shots. but this could be the time to shoot the image with a film slr. also consider that a 1hr startrail is going to appear on your image a 1/24 of a cxircle curve. that is not that long. the 4 and 6 hr starttrails that is shot with film wrew 1/6 and 1/4 of a circle respecxtively. that is much better to look at and has more color too.
if you insist on shooting with digital then the following 2 free programs are available-startrails.exe and registax. try google. also available are the following- astrostack(not free) and deepsky stacker(free). also try goggle.
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