iPhone Astrophotography: My First Attempts
This evening I decided to try some iPhone astrophotography. This blog post will let you see how I got on, and give you the info you need to get started yourself.
While the iPhone 4 camera is far from ideal for astrophotography (the sensor is small compared with a DSLR; in fact it’s not even as good as most point and shoot cameras) it does have one distinct advantage – it’s usually very much to hand, just in my pocket in fact.
There are two kinds of astrophotography you can do with an iPhone: with and without a telescope. The former is called afocal astrophotography, but it is the latter that I tried out tonight: just using the iPhone camera, some extra hardware, a 59p app, and a clear sky.
Afocal Astrophotography. Simply hold the camera to the eyepiece of a telescope (or binoculars) and snap a picture of whatever is in the field of view. For this you can just use the standard camera app on the phone to snap a picture, and it’ll use software to ensure that the image is exposed correctly (although this might not always work). I’ve tried this once before, using the Moon as my target, with decent enough results:
You can also buy several apps that claim to allow you to take longer exposures, even letting you use a bulb setting (this isn’t actually possible with the iPhone shutter hardware – each of these apps is actually using a clever software work around, but you’re not getting a true 60 second exposure when you set your “shutter speed’ for 60 seconds).
The apps that I use are:
Slow Shutter Cam: has shutter speeds of 0.5, 1, 2, 4, 8, 15′ and a B (bulb) setting, plus a crucial self timer delay to prevent wobble when pushing the “button” to take the shot (£0.59 on iTunes App Store)
Magic Shutter: has shutter speeds of 1, 2, 4, 8, 15, 30 and 60′ and a B (bulb) setting, but no self timer (£1.79 on iTunes App Store)
Both of these apps have a variety of software setting to allow you to get the best picture; tonight I used Magic Shutter with a 60s shutter speed.
(These apps might allow you to take better images while the camera is mounted to a telescope, but I haven’t tried this yet. Watch this space for test of this later in the year.)
Afocal Astrophotography Hardware
The main obstacle to taking long exposure shots with the iPhone (apart from the fact that the hardware won’t actually let you!) is that you need to make sure that the iPhone doesn’t move at all during the duration of the exposure, so holding it in place with your hand isn’t an option. Luckily there’s a great gadget available from a company call Magnilux. The device is called the Magnilux MX-1 Telescope Adaptor, which allows you to attach your iPhone to any telescope eyepiece. It also doubles as a tripod adaptor.
Astrophotography Without a Telescope
Tonight I didn’t connect my iPhone to my telescope since my target, the International Space Station (ISS), moves so quickly and travels across such a large part of the sky that you need as wide a field as possible to catch it.
To capture the ISS you need a long exposure (use Magic Shutter app – see above). The pass tonight lasted 4’19”, and traveled 90° through the sky (from 254° WSW to 164° SSE). The iPhone 4 camera field of view is only 60.8° so I couldn’t capture the whole pass. Instead I decided to try to capture a 60s exposure as the ISS rose to its highest and brightest, at 206° (SSW).
With a 60″ exposure, of course, I had to have my iPhone mounted to a tripod. I could have used the Magnilux MX-1 Adaptor set up for tripod mode (see above) but instead I opted to use my new Kungl iPhone case with built in tripod thread, which I attached directly to my tripod.
This held the iPhone still, and using the Magic Shutter app set to 60″ exposure I managed to get this image:
Far from ideal, but not bad given (a) it was my first attempt, (b) I had one chance to take the image before the ISS faded from view, (c) the sky was very bright (this was taken at 2344 on 23 June 2011, just after midsummer, with the sky just out of civil twilight), (d) cars kept driving past (note the light art in the foreground!).
Once the sky darkens again later in the year I hope to test this set up under a truly dark sky to see whether it can pick up sharp star images. I suspect that might be tricky!
If anyone else has tried iPhone Astrophotography please let me know in the comments.
UPDATE: See my latest attempts at iPhone astrophotography here.
Nice pics!
Another fun experiment with your tripod attachment could be time lapse video. iTimeLapse works really well and allows you to shoot full HD time lapse video on a 3GS. A sequence from sunset to sunrise (presumably with the iPhone plugged into the mains) would be pretty cool I reckon.
Steve,
Now that’s impressive. I can see a whole new category opening up in our annual Astrophotography competitions!
Can’t wait to see the results later this year.
Colin
Hi Colin,
I think there’s a real limitation with the iPhone camera though, in that it only mimics long exposures. Last night’s images were taken in “automatic” mode where the software deliberately kept the images at the correct “exposure”, regardless of what i set the “shutter speed” to. Once the nights get darker I can try out the “manual” mode which claims to collect and use every photon hitting the sensor, and so should be more like a DSLR image. You never know, if it stacks a bunch of short exposures it might look ok…
Fascinating. I’m grabbing Slow Shutter Cam today. The self-timer delay is a great feature lacking in the other apps I’ve used. I’ve neglected my telescope for far too long and this should be fun. Thanks for the tips.
Nice article, thanks for sharing. I’ve been trying to do some afocal stuff with my iPhone 4S, with some great pics of the moon, but my favourite so far is a pic of the Orion Nebula. So pleased I got anything at all with my iPhone. You can see it at http://troyski.org.uk/home/?p=2853
wow great work and also patience.