Thursday, January 31, 2013

Dying to use my Glif tripod mount for iPhone

It's rare that I buy a new accessory for a camera, but the Glif tripod adapter for iPhone is simply awesome, and technically it's a phone accessory. No more bent binder clip, welcome to the big leagues of mounting phones to tripods!

glif for iphone 5
A nice rubberized plastic feel, grips the phone well, with the security of metal 1/4" threads

There are a bunch of knock offs for like $4 online. I read some reviews saying they don't fit right but who knows. $20 feels worth it after using a binder clip for 9 months, I've had more than one project ruined by the mount shaking so at this point I feel liked I "earned" the piece of mind that comes with the higher price. 

glif for iphone 5
Glif for iPhone 5 - neat packaging from Studio Neat

My recommendation: Get the Glif if you have already tried something else and gotten frustrated, but I wouldn't go from zero to $20 right off the bat. After messing with other solutions for a while, the $20 will feel like a lot less. The security of doing it right and not having to worry about it anymore is surely included with the purchase!

The same company sells an attachment called the Serif that holds the phone more securely for extreme situations. So far (although I haven't even used it outside yet) I've found that the phone is snug enough. So I guess you could say my Glif is sans serif (har har har). 

Now if only the skies would cooperate, I could get on with my iPhoneography! The weather has been zany in Ohio - going from 57°F down to 25° overnight, and with plenty of snow flurries and hideous flat gray skies.

Monday, January 28, 2013

Nikon D5100 window shopping torture

I've been spending a lot of time on Snapsort.com comparing and evaluating different cameras. Even though I'm a long way off from being able to afford an upgrade, I like to have a goal to shoot for - at least something specific to fantasize about.

Nikon D5100 at Best Buy
So close but so far, the camera I want mocks me at work... #want


I forget where I first read about the Nikon D5100, but I remember it was close to the top of a list for low noise at high ISO for the price. That stuck in the back of my mind, and the next day at work (I work evenings and weekends at Best Buy for some extra money), I crossed paths with the D5100 in person. Not fair! I swear it must have been following me just to taunt me.

After comparing the D5100 to other cameras on Snapsort, it looks like a pretty amazing buy! It would definitely be an upgrade from an 8MP camera, and has much higher ISO and a flip out screen (so I wouldn't have to squat next to my tripod to aim the camera).

The major drawback, from what I can tell, is the lack of an autofocus motor, which means that every lens I buy would have to have a motor in it. Looking around LensHero.com a bit, it looks like the lenses with motors increase the price by over $100 easily. So every lens I get would be more expensive - and surely there are less options when you require a built in motor.

Comparing the camera I'm currently using to the D5100, it's crazy to see the differences in features. There isn't even a thumbnail image of the Rebel XT (circa 2005). For some reason the oldie is a lot more expensive - probably because it's becoming harder to find. I dunno who's out there buying an 8MP DSLR for almost $700 when you get an 8MP camera on your phone these days!

My one-year anniversary of deliberate stargazing!

A year ago, January 28, 2012 was the day I learned that my point and shoot camera has a long exposure mode (15 sec). From then on, I've been spending "way too much time" (as my partner sees it) photographing the night sky. Although I did photograph comet Hale-Bopp back in 1997, today marks the 1-year anniversary of me taking a modern interest in the night sky, and photographing it with any real seriousness and patience.

To celebrate this skywatching milestone, I'm posting my personal favorite / best shots of year one:









The details of each shot are, unfortunately, scattered throughout my blog. I didn't want to link to each one because I want the link to show the larger image. Here is a brief description with links to the original posts:

Left to right, Top down:
  1. Tripod Orion stack in DSS, 168 subs, 1.6s, ISO 1600 ea
  2. Tripod Pleiades stack in DSS, 205 subs, 1.3s, ISO 1600 ea
  3. Orion, Jupiter, Pleiades, 25s, ISO 800
  4. Sorta pretty light pollution
  5. November conjunction Moon/Jupiter
  6. January conjunction Moon/Jupiter
  7. Lightning with iPhone 4 Slow Shutter Cam app
  8. Venus transit with iPhone 4 held up to 8" scope
  9. ISS with Dragon C2+
  10. My first point-and-shoot star trails
  11. Won a trip to tour Johnson Space Center with Olympic gymnast Jonathan Horton
  12. Local observatory viewing party for Venus transit
  13. Color adjusted urban night sky
  14. My first Andromeda stack in DSS, 318 subs, 1.6s, ISO 1600 ea

Saturday, January 26, 2013

Red ring around the Wolf Moon

This red and blue ring around the full "Wolf Moon" tonight is a corona, not a halo. "Coronae differ from haloes in that the latter are formed by refraction (rather than diffraction) from comparatively large rather than small ice crystals. Reddish colors always occupy the outer part of a corona's ring" (source).

red ring around moon is a corona
ISO 800, 1/10 sec, 80 mm, handheld
The lunar corona is formed the same way a rainbow is formed in daylight (diffraction), but that doesn't make it a moonbow.

A closer look at two kinds of light pollution in my apartment courtyard

I dream of the days when I will have a dark backyard, possibly surrounded by trees to block the light from neighbors. This view from my typical skywatching location leaves something to be desired, and the lights from the parking lot interfere with my view of the night sky in more than one way.

light pollution
View from my apartment doorstep, taken with iPhone 5 standard camera mode
After noticing a persistent orange glow in a number of my photos, I thought that I might be burning out the image sensor on my slightly older Canon 350D. Then it dawned on me that the glow was probably coming from a combination of parking lot lights and overall skyglow in the area.

When I first saw this I thought my camera was broken. Combination of skyglow and glare.

According to Wikipedia, light pollution comes in a number of forms:
  • Light trespass (light spilling into a neighbor's yard or through a window)
  • Over-illumination (excessive use of light)
  • Glare (reduced contrast due to scattered light)
  • Light clutter (excessive grouping of lights)
  • Skyglow (glow over populated areas caused by light escaping and reflecting upward)

The two forms of light pollution that most affect my night photography are glare and skyglow.

light pollution
Example of Skyglow

light pollution
Example of Glare

light pollution
My apartment complex uses two kinds of lights at night (see difference between blue/white and yellow/amber lights above). The most annoying are horizontally oriented lights that bathe the parking lot in a soft orange glow. From what I can find online, these lights appear to be sodium lights (based on the yellow/amber color). Because "white or blue-rich light contributes significantly more to sky-glow than an equal amount of yellow light," these yellow lights should be less of a contributing factor, if it weren't for their orientation (source).

These yellow lights are oriented at 90° above the nadir (e.g. they're oriented horizontally). The best lights to reduce light pollution are oriented at the nadir (or straight down) and shielded from the sides to keep light aiming straight down.

So while these lights WOULD contribute less to skyglow (if they were properly oriented and shielded) they also interfere in another way, by adding glare.

Because of glare, I'm unable to shoot anything near the horizon. Even when the light itself isn't in my field of view, I still have to contend with glare and its resulting reduction in contrast.

light pollution
Glare
light pollution
Skyglow/Glare

I think the strong rusty red color is more due to glare than skyglow. Skyglow in my area normally shows up as a white/yellow haze up to 40° above the horizon. However, if my lens is directed anywhere toward these horizontal lights, my image quickly floods with an orange glow. It's poison!

Check out this example of light trespass and over (necessary) illumination, the parking lot light is shining right into this poor sap's bedroom window and lighting the side of the building for no reason. That's definitely two in one!

Light Trespass and Over-Illumination
Example of Light Trespass and Over-Illumination

Wednesday, January 23, 2013

iPhone Star Trails using NightCap App with Infinite Interval Photos

NightCap for iOS is the best app for capturing images of the night sky, and its "endless photos" burst mode lets you shoot a well controlled batch at intervals up to 60 seconds for stacking on computer software later.

Instead of standing around using the headphones as a remote shutter release, NightCap () lets me take endless (until the battery freezes) photos at timed intervals. I made the image below from 22 photos at 30 second intervals, each 1 sec shutter at ISO 3200. Light pollution is from downtown Bowling Green and the bright moon.

I'm so close! If only it were a bit warmer out, I'd have the first (to my knowledge) impressive star trail photo on iPhone. It can be done!

star trails using night cap app for iphone
It was so cold, my iPhone only managed 22 photos in 10 min before the battery was drained
I imagine this app coming in pretty handy in warmer months when my camera lasts more than a measly 10 minutes and the sky isn't a total wash from the moonlight. Still, with a bit of color correction, this isn't a bad image - remember it's photographed on an iPhone!

star trails using night cap app for iphone
Same image with slight color adjustments in Photoshop to remove noise pollution

The app also lets you choose between JPEG, HQ JPEG and TIFF outputs, however the TIFF isn't available for burst mode. Manual exposure lets you select from 1/20 to 1/1 sec, or just do what I did and lock the exposure when you find the right combination of shutter and ISO.

night cap app screen shot settings

Tuesday, January 22, 2013

Space.com gave me the title "Skywatcher," that's pretty boss!

Ok, so anyone can submit a photo to Space.com for consideration for a story - especially around an event like a conjunction. Out of all the photos that were submitted, however, mine was 1 of 3 chosen for an accompanying write-up of the event, titled "Close Encounter of Jupiter and Moon Wows Stargazers."

space.com screenshot
My image on Space.com, 15 seconds of fame!

It's always fun to see my name in print, especially when I'm introduced as Skywatcher Eric Teske. I guess Skywatcher is the first level in the imaginary merit badge system I'm picturing in my head. The ranks would be something like this:

Skywatcher > Amateur Astrophotographer > Astrophographer > Astronomer

For some reason, Skywatcher reminds me of World of Warcraft. It has a mystical sound to it, like a lvl 50 Night Elf priest. (LFG need Tank).

What fun! I'm definitely going to submit more photos in the future (hopefully ones with round stars).

Conjunction of the Moon and Jupiter, January 21, 2013

These photos were taken around 7:30pm when the Moon was still approaching Jupiter - so they weren't exactly at their closest point, but the weather was already turning sour so I had to go early. Snow flurries were rushing in from the NW, and I had to wait to get shots between the clouds. We're currently under a wind advisory (20 mph with gusts up to 35 mph), so the 10°F temperature feels like -8°F.

The first image shows the moon and Jupiter over-exposed through thin clouds, taken at 300mm, ISO 200, 1 sec, f/5.6. It was quite an eerie sight!

jupiter moon conjunction single exposure


When the clouds parted, I was able to grab two photos for a clean composite image. The moon was shot at 300mm, ISO 1600, 1/4000 sec, f/5.6; and Jupiter was shot in the same position at 1/200 sec.

jupiter moon composite photo


I also got a wide angle shot at 18mm, ISO 400, 25 sec, f/4.5 which includes a radiant lens flare from the bright moonlight.

wide angle jupiter moon conjunctioniphone weather screenshot


I was out for about 20 minutes total and couldn't feel my fingers as I was packing up my gear and rushing back into my apartment. Less than ideal conditions, but at least I got a couple cool shots. I couldn't let this event pass me by - I knew I'd be jealous of everyone's pics on Instagram!

Monday, January 21, 2013

How to Photograph the Moon on an iPhone using Exposure Lock

The best way to photograph the moon using an iPhone is to lock the exposure on something bright before going outside. Since posting "How to photograph the moon on an iPhone: One possible solution" I've come across a more straightforward technique described below.

Update: For more advanced iPhone photographers, check out "Most Detailed iPhone Photo of the Moon Possible"

The moon is a very bright object, which is why it normally looks like a washed-out white dot using an iPhone camera. Even using a DSLR, the only way to get detail on the face of the moon is to treat it like the bright object that it is by using a low ISO and fast shutter speed.

Because the iPhone camera doesn't include settings to manually adjust ISO and shutter speed, you have to trick the camera into the right settings on something other than the moon.

Update: New apps in the upgraded version of iOS now allow you to adjust the ISO manually! Finally! 


The app Manual - custom exposure camera is a good example of one of these apps.


moon photo with iphone
Difference between iPhone camera auto exposure on the moon, and locked exposure

1. Locking the Exposure

iphone camera focus and exposure lockBefore going outside to take a photo of the moon, hold your iPhone up to something bright. I used the light in my kitchen. Holding it directly up to the light will let you lock the exposure for anything bright (probably better for full moon), or holding it slightly further away or at an angle will let you lock the exposure for a dimmer moon (such as crescent or clouded moon).

Basically, you're using a bright light as a stand in for the moon so that you can adjust the camera settings. The moon is just too small in the sky for the camera to adjust the exposure appropriately - I think the iPhone uses more of the field of view to determine when to adjust the settings, and the moon is a very small area in the field. I've even tried locking the focus and exposure on the moon outside, but it just doesn't trip the settings like a light that fills up more of the viewfinder.

Tap and hold the screen area to lock the focus and exposure (AE/AF Lock).

Note: AE/AF Lock comes with the iPhone 4S and 5, and I believe was added to the iPhone 4 after the iOS 5 update - but I don't have every version of the iPhone to test this so I'm going on what I've read.


2. Use an App that Shows ISO and Shutter Speed

The default iPhone camera has the ability to lock auto focus and exposure, but we want to lock the exposure without locking the focus. A number of camera apps will let you do this, my favorite so far is 645 Pro (). This app lets you lock exposure and focus independently, and shows the ISO and shutter speed values on the screen.

iphone camera exposure lock
Exposure lock (AE-L) on kitchen light at ISO 50, shutter speed 1/742 seconds
Apps that tell you the ISO and shutter speed will let you practice with different values to get a better moon photo. With the default camera, you'll be left guessing exactly what settings you're using.


3. Focus on the Moon

With the exposure locked using the kitchen light as an under-study, we're ready for the star of the show to make her appearance. Go outside and focus on the moon. I used a DIY $1 tripod to try to hold the phone still, but at shutter speeds faster than 1/500 second you might get by with just a steady hand. Thar she blows! The moon is in my crosshairs.

Thar she blows! The moon is in my sights

4. Lower Your Expectations

Even with an appropriately-exposed photo and the super nice iPhone 5 camera, the moon will only appear about 50 pixels across in your final shot. I know, it stinks, but it's better than a big bright ball of nothing. You can actually see some of the details on the face of the moon, and you did it on your PHONE! That's pretty cool!

Looks like a kidney bean!

Here's another I took using the app Night Cap (), allowing for a slightly longer shutter (1/257 sec) also at ISO 50. I also used a tripod on this one, which helps squeeze any last details out of the tiny moon.

Crop at 100%, photo from iPhone with Night Cap app, ISO 50, 1/257 sec
Progressive zoom/crop of full moon 1-26-2013 using Night Cap app

Goodbye orange glow! Is this cheating?

The more I learn about astrophotography, the more I realize that really amazing images are very rarely published straight out of a camera. Finding out the Orion Nebula looks like a gray green blob even through a high power telescope is sorta like finding out there is no Tooth Fairy (spoiler alert?).

But, where the magic fades, my appreciation for the work increases. Brilliant photos take time and skill, and I guess I'm becoming more comfortable with manipulating images to represent reality using some "little white lie" Photoshopping.

Now that the curtain has been pulled back, it seems less dishonest to kill the orange glow of the rural suburbs to more closely represent the sky how I perceive it in person. See below:

night sky over bowling green ohio
25 sec at ISO 800 shows lots of orange glow straight from the camera

photoshop color adjust night sky
Same image adjusted in Photoshop to match what I saw in person - is this cheating?

Which of these is more authentic? The one that I didn't touch (but the light pollution junked up), or the one that looks more like what I really saw (but didn't have the ability to capture).

Friday, January 18, 2013

My first Andromeda in spite of the waxing gibbous

Although the nearly-half moon was in the same general vicinity as the Andromeda Galaxy, I couldn't pass up the first clear night in a week. I wanted to test my deep sky stacking abilities with a new target (I get the feeling my Orion Nebula posts are getting a bit tired).

I want to try re-stacking my batch with some different parameters, and I'll eventually re-shoot Andromeda without the Moon glaring at me.

I created this image with 318 subs, 30 darks, and 30 bias frames in Deep Sky Stacker (DSS). Total exposure time 7 min 45 sec.

andromeda galaxy 300mm lens
318 light frames, ISO 1600, 300mm, 1.6 sec each, stacked in DSS, adjusted in Photoshop
andromeda
Labeled version of the same picture above
stellarium view of andromeda to the west
Planning my shot earlier last night, view generated in Stellarium

The hardest part was FINDING the faint gray blur in the sky in the first place! I turned my shutter speed down to 8 seconds to try to find a smear in the general area where I thought it would be. Nothing. Next I tried going from landmark to landmark - leapfrogging from the Moon to surrounding stars to the general area where I thought it should be.

300mm, 8 sec at ISO 1600 used to locate Andromeda for the first time

I saw a rusty orange smear on the 8 sec exposure. Having never seen Andromeda "in person" before, I had to assume that this was the real thing. 300+ exposures later, manually tracking using the visible stars as a reference, I stacked my batch and came out with something pretty cool (for a newbie). Next time finding it should be a breeze. It's fun knowing that I know where to look, or that I could show off by pointing it out to someone :)

I get a little blown away thinking about the light coming from ANOTHER GALAXY and landing in the back of my camera in the courtyard of my apartment complex - and the light that must surely be landing on me as well. It's kinda spiritual in an atheist way.

Update 1-21-2013: I did another pass at stacking in DSS and used Median Kappa Sigma (whatever that is!). I wanted to see if there was any more data hiding in there, so I really blasted it out with levels and contrast. I think dust trails are slightly more visible. I think this set is about maxed out, I need to try again from a darker sky and shoot for 400 subs.

andromeda
Re-stacked same image set, blasted out the levels and contrast in Photoshop

Take Star Photos and Make Star Trails Using iPhone 5

Finally, a way to take star photos and make cool star trail images using your iPhone. This will take true iPhone astronomy and astrophotography to the next level! I learned about a new app called "Night Modes" from Steve Owens' Dark Sky Diary blog. The app takes advantage of the iPhone 5's improvements in low-light, and includes up to 1 second true exposure time (not just simulated exposures). The app promises "15 times more light gathering capability compared to the Camera app!" Night Modes ().

Update: Take even longer iPhone star trails using Night Cap with infinite interval photos

star trails on iphone
Proof of concept: 29 stacked images, each at 1 sec, ISO 3200, only using iPhone for photos, stacked photos using StarStaX software
stars and jupiter photo on iphone
Single exposure with iPhone 5 using Night Modes app

You have to keep the camera very still while using the app, because the autofocus is delayed by the long shutter. I recommend using a tripod and the headphone volume shutter button, but you can also set the phone on the ground and walk away because the app includes a timer up to 10 seconds.

iphone star circles
66 stacked images over a 20 minute period using unmodified iPhone as the camera

I'm not usually the type to make excuses, but the severe wind advisory could be a reason why my star trail lines aren't smooth.

starstax screenshot
Screen shot of the images loaded into free StarStaX software

Here is a look at my set up:

iphone tripod
Using the headphone shutter (+) volume remote, I manually took 29 shots

iphone shutter release
iPhone headphone (+) volume button works as a shutter release

tripod mount for iphone
Simple binder clip holds the iPhone in position

tripod mount for iphone
Bent binder clip with a little athletic tape to prevent scratches

Related Posts Plugin for WordPress, Blogger...