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DPChallenge Forums >> Photography Discussion >> Planets Align for the Perseid Meteor Shower - NASA
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08/11/2010 03:02:14 PM · #1

On Thursday, August 12th, an alignment of planets in the sunset sky will kick off the finest meteor shower of 2010, the Perseids.

//science.nasa.gov/science-news/science-at-nasa/2010/05aug_perseids/

08/11/2010 04:07:14 PM · #2
How would be the best way to photograph this event? I'm fairly new to all of this especially using a dslr. Long exposures? I know a great place in the country with no lights around, and there's a good sized hill for Oklahoma to park on so I'm excited. Anybody's help would be so appreciated.
08/11/2010 04:15:01 PM · #3
Originally posted by monster-zero:

How would be the best way to photograph this event? I'm fairly new to all of this especially using a dslr. Long exposures? I know a great place in the country with no lights around, and there's a good sized hill for Oklahoma to park on so I'm excited. Anybody's help would be so appreciated.


The best advice I have is not to bother and just to enjoy it. At best your meteors will look like short streaks across the image (identical to an airplane, BTW) and you will be very disappointed. I can tell you this from personal experience.
08/11/2010 04:17:03 PM · #4
Sounds good to me. I have enough pictures of airplanes flying by leaving streaks during thunderstorms. Our airport is directly south of our house. I'll just kick back and watch.
08/11/2010 04:34:04 PM · #5
I probably won't see this, but if I lived in the country I'd make an effort. Meteors are already visible, but the peak comes later. The article said the best time is probably the darkest hour before sunrise, but to see the planets one has to look after sunset.
08/11/2010 04:59:46 PM · #6
Originally posted by monster-zero:

How would be the best way to photograph this event? I'm fairly new to all of this especially using a dslr. Long exposures? I know a great place in the country with no lights around, and there's a good sized hill for Oklahoma to park on so I'm excited. Anybody's help would be so appreciated.

i've Photographed them before with my film camera (Canon AE-1) but didn't have a chance to try since i purchased my DSLR.
the best way is to set the shutter speed to slowest appropriate (which is 1000/F if equator is also included) set your camera on continues mode & lock the shutter. then lie down and enjoy watching the meteor shower.
when you download your images to your computer, you have 3 exciting things to do:
1. review your images and look for a beautiful meteor or FIREBALL shot.
2. stack your images together to form a Start Trails Picture.
3. turn your photos into a great time-lapse video.
number 2 & 3 could be done using this freeware: StarTrails ("startrails.de/index.html")
be careful to download the en version. the original in another language i don't remember.
(someone make that link useful, please.)

Message edited by author 2010-08-11 17:06:43.
08/11/2010 05:02:21 PM · #7
(i accidentally posted the same thing two times, sorry)

Message edited by author 2010-08-11 17:06:56.
08/11/2010 05:13:08 PM · #8
Ok I'm pretty slow with all of this. What do you mean "set the shutter speed to slowest appropriate (which is 1000/F if equator is also included)"? Sorry for my ignorance.
08/11/2010 06:08:12 PM · #9
Originally posted by monster-zero:

Ok I'm pretty slow with all of this. What do you mean "set the shutter speed to slowest appropriate (which is 1000/F if equator is also included)"? Sorry for my ignorance.

you have to take the longest possible exposure to capture more stars. if you set your shutter speed to -say- 50s, stars start to move and wouldn't look pinpoint.
ok, what's the longest exposure time we can have without stars start moving? here's how you can calculate it: 1000/f.cos[delta]
[delta] is actually the declination (=the angle that a celestial body forms with celestial equator) of the part of sky you're shooting.
if you can't find celestial equator or guess the angle or just hate astronomy... just forget about them and let's make it more simple: the worst thing to happen is for cos[delta] being 1, then we'll have 1000/f (f: focal length).
just insert the focal length and set the shutter speed.
for instance, if you're shooting with your 18-200 lens set at 20, then set the shutter speed at 1000/20=50s. of course don't forget to take the crop factor into account, if your camera is 1.6x crop then it'd be 625/f

08/11/2010 06:09:13 PM · #10
1000/F = 1000 divided by focal length? So at 24mm, 40 sec? Possibly, so as to not include any star motion. The more zoomed in you are, the more motion will be recorded by your camera because of the earth's rotation. So at 50mm, the stars may "move" across the sky visibly in more than 20 sec, so you set it to 20.

PS: I think these are 35mm-equivalent focal lengths. So on a 1.5x-crop sensor, 60 sec @ 12mm, 40 sec @ 16mm, 30 sec @ 18mm, 25 sec @ 24mm. I think these are still a bit too high. I'd say divide them by two, and use a wider aperture.

Use something like DIYPhotobits.com Camera Control - freeware tethered shooting "app" for Windows. Set the time-lapse to S+1, where S is your shutter speed (for 30 sec shutter, set time-lapse to 31 sec). Don't use autofocus, it won't find anything; autofocus first on something bright and distant, and then switch to manual focus. If you're shooting wide enough (28mm or less for full-frame, 18mm or less for crop sensor) and you focus on something far enough (20 ft or more), you'll get the stars in focus even at f/2.8 according to this calculator. Again, underestimate the DoF and focus on something really far (say, 100 ft?) just in case your focus ring moves or something. Oh, speaking of focus rings moving... make sure you know how well the focus ring stays put. Mine will stay put for, like, 20 shots max when pointed that high up... so I have to refocus every once in a while.

Message edited by author 2010-08-11 18:27:12.
08/11/2010 06:23:57 PM · #11
Originally posted by AmirTaheri:

Originally posted by monster-zero:

Ok I'm pretty slow with all of this. What do you mean "set the shutter speed to slowest appropriate (which is 1000/F if equator is also included)"? Sorry for my ignorance.

you have to take the longest possible exposure to capture more stars. if you set your shutter speed to -say- 50s, stars start to move and wouldn't look pinpoint.
ok, what's the longest exposure time we can have without stars start moving? here's how you can calculate it: 1000/f.cos[delta]
[delta] is actually the declination (=the angle that a celestial body forms with celestial equator) of the part of sky you're shooting.
if you can't find celestial equator or guess the angle or just hate astronomy... just forget about them and let's make it more simple: the worst thing to happen is for cos[delta] being 1, then we'll have 1000/f (f: focal length).
just insert the focal length and set the shutter speed.
for instance, if you're shooting with your 18-200 lens set at 20, then set the shutter speed at 1000/20=50s. of course don't forget to take the crop factor into account, if your camera is 1.6x crop then it'd be 625/f


From personal experience you will already get star trails at 20mm at 30sec. I have done a fair amount of night photography with both 16mm and 24mm and I notice blurring at 30second but less so at 15-20 seconds.

Here is a formula that will tell you how many pixels the star will move given various factors.

Message edited by author 2010-08-11 18:25:58.
08/11/2010 06:53:17 PM · #12
Originally posted by George:

Don't use autofocus, it won't find anything

yeah, focusing in astrophotography is really tricky, even setting the ring on infinity wouldn't work most of the times.

Originally posted by DrAchoo:

From personal experience you will already get star trails at 20mm at 30sec. I have done a fair amount of night photography with both 16mm and 24mm and I notice blurring at 30second but less so at 15-20 seconds.

Here is a formula that will tell you how many pixels the star will move given various factors.

i had fine photos with my film camera at 50mm at 20s shooting equator, maybe it's because of the wide lens or even the camera being digital, huh? i'm gonna try it tomorrow night anyway.
thanks for the page, though. pretty Useful Formulas i needed.

Message edited by author 2010-08-11 18:54:57.
08/11/2010 07:12:16 PM · #13
I`ve tried this before and like Jason said - it was very disappointing - however since I will be driving out somewhere superdark tomorrow night to view them, I will probably stick the 5D on a wide angle point it up and run some long bulb exposures.
08/11/2010 09:15:52 PM · #14
Originally posted by AmirTaheri:

Originally posted by George:

Don't use autofocus, it won't find anything

yeah, focusing in astrophotography is really tricky, even setting the ring on infinity wouldn't work most of the times.

Well, if you have an infinity mark, it shouldn't be that far off (meaning as long as you're above f/1.4, infinity should be infinity). However, turning it all the way without actually having an infinity mark is usually focusing beyond infinity with 99% of new lenses, which is not "setting the ring on infinity."

Originally posted by AmirTaheri:

Originally posted by DrAchoo:

Something about personal experience and calculators.

Something about personal experience, and thanks for the calculator.

I just went out tonight, and got trails at 18mm/20sec, and no trails at 18mm/15sec. This is 24mm equivalent (crop sensor), 6 MP.
ETA: My sensor area is about 42.5% that of a full-frame sensor, if you want to do more calculations. That's from official specs.

Message edited by author 2010-08-11 21:19:01.
08/11/2010 09:28:06 PM · #15
Originally posted by DrAchoo:

Originally posted by monster-zero:

How would be the best way to photograph this event? I'm fairly new to all of this especially using a dslr. Long exposures? I know a great place in the country with no lights around, and there's a good sized hill for Oklahoma to park on so I'm excited. Anybody's help would be so appreciated.


The best advice I have is not to bother and just to enjoy it. At best your meteors will look like short streaks across the image (identical to an airplane, BTW) and you will be very disappointed. I can tell you this from personal experience.


Man, from DrAchoo to DrBuzzkill in 1 paragraph flat! ;)
08/11/2010 10:25:35 PM · #16
I have found that it works pretty well to find a tower or some light that is at least a mile or two away, focus on that, then don't move that focus. Another option is to focus on the brightest star that you can find, shoot one shot, and look at it in the LCD zoomed in to see if it's in focus.
This is 75 sec @ 15mm ' . substr('//images.dpchallenge.com/images_portfolio/65000-69999/69008/120/Copyrighted_Image_Reuse_Prohibited_739960.jpg', strrpos('//images.dpchallenge.com/images_portfolio/65000-69999/69008/120/Copyrighted_Image_Reuse_Prohibited_739960.jpg', '/') + 1) . '
If you are lucky enough to get clear skies, and are in the right place on the planet, you might also get to see the space station fly over. There is a link with the photo to NASA's shuttle sighting calculator.
08/11/2010 10:39:29 PM · #17
Hmmm. This is alternately awesome and annoying. I was intending to go up into the middle of nowhere backpacking Friday, and was thinking "hey, I'll get some sweet star trail photos." Now they'll be peppered with meteors. But it should be a great show to watch @ 11,500 feet :)
08/11/2010 10:45:42 PM · #18
Originally posted by spiritualspatula:

Hmmm. This is alternately awesome and annoying. I was intending to go up into the middle of nowhere backpacking Friday, and was thinking "hey, I'll get some sweet star trail photos." Now they'll be peppered with meteors. But it should be a great show to watch @ 11,500 feet :)


Shoot star trails anyway. The meteor trails will be at angles to the star trails so it will be evident which trails are meteors. You may even catch a huge fireball which would make a very nice image against star trails.
08/11/2010 10:48:21 PM · #19
We'll see. Just checked the updated forecast, which is now calling for partly cloudy. Clouds in the area I'll be move hyper fast due to the weather patterns, so single clouds can botch whole scenes. Regardless, it should be pretty awesome to watch.
08/12/2010 04:11:02 PM · #20
Well, we decided to pack the family up tonight and head out to the dark skies (Bortle Scale 3-4) about 25 minutes away and watch from 12-1. I don't think I'll take pics, but I may bring the camera to try some 5D2 video and see how that works. They are "predicting" (how, I don't know) about 75 meteors/hour. I'll report back tomorrow! :)
08/12/2010 04:36:12 PM · #21
Originally posted by DrAchoo:

Well, we decided to pack the family up tonight and head out to the dark skies (Bortle Scale 3-4) about 25 minutes away and watch from 12-1. I don't think I'll take pics, but I may bring the camera to try some 5D2 video and see how that works. They are "predicting" (how, I don't know) about 75 meteors/hour. I'll report back tomorrow! :)

Have fun! It could be the prediction is just based on past years' experience.
08/12/2010 05:27:12 PM · #22
Originally posted by DrAchoo:

They are "predicting" (how, I don't know) about 75 meteors/hour.

It's the day of the peak (traveling through the most dense part), with no moon. On average, you expect about 100 per hour with these conditions. East coast, subtract a good amount unless you're REALLY out in the hicks, in which case you still subtract a bit.
08/12/2010 08:09:38 PM · #23
' . substr('//www.newsvine.com/_vine/images/users/600/boyle/4871372.jpg', strrpos('//www.newsvine.com/_vine/images/users/600/boyle/4871372.jpg', '/') + 1) . '

How do you do a shot like this? It's not fair!!!
08/12/2010 08:46:07 PM · #24
FWIW Looks like bulb setting (30 seconds +) was used, along with a dark location and a tripod, possibly mirror lockup too, and a remote shutter release. You trip the shutter to open it, then wander out a little later and stop it. Ideally, eh wala. Hope this helps, and good luck!
08/12/2010 08:55:27 PM · #25
Hopefully the clouds will not obscure the view....looking forward to just watching the show but may whip out the camera to take a shot or two...
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