Sunday, January 31, 2016

Quick Winter Sky iPhone Photo

The iPhone can indeed do wide field night sky photos, like this one of the popular stretch of sky from Sirius to the Pleiades. The stars are slightly out of focus, which actually makes them look larger and easier to see - so it's not a bad effect. This photo was taken with NightCap Pro using long exposure mode. Doing a 1/2 second exposure helps reduce the background noise because I believe NightCap is averaging the pixels to clean it up a bit.

iphone 6 star photos

iphone 6 star photos
iPhone photo f/2.2, 1/2 sec, ISO 4000, 4mm

Thursday, January 28, 2016

Winter Hexagon Star Color Comparison

The Winter Hexagon or Winter Circle is an asterism (not an official constellation) that takes up a huge portion of the southern sky in winter with some of the brightest stars (including the brightest Sirius). You really can't miss it! As the hexagon moves across the sky through the season, it becomes the Spring Arch setting in the west at dusk.

Did you know the human eye can detect the temperature of stars? Amazing! We know that cool stars radiate and emit energy in the red and infrared regions of the electromagnetic spectrum and so they appear red or orange. Likewise, hot stars appear white or blue because they radiate their energy in the blue and ultra-violet wavelengths.

Using the same technique from a previous color comparison, I wanated to look at the entire Winter Hexagon. I also used the same exposure settings to keep everything constant, so the difference in brightness is also relative to the star's perceived brightness to us (Sirius is clearly the brightest). This makes it a little harder to determine color, because some of the stars are dimmer, but it's clear at least that there is a variety of color out there in this popular region of the sky.

I arranged them in this composite photo to show their position in the hexagon. It looks like a jewel box of beautiful colored orbs or marbles. This was fun and easy to put together. I feel like trying it again with different exposures to hold the brightness constant and then trying to organize them from coolest to hottest. Do you think you could? Which one looks the most blue?

winter hexagon star colors
Composite out of focus stars from the Winter Hexagon in their relative positions, all taken at 300mm, f/5.6, 1 sec, ISO 200
winter circle star colors
Winter Circle star colors with labels

It looks like last time I used ISO 800 and 1.3 sec exposures, which would have blown out Sirius for comparison but made Rigel brighter blue so it's easier to see. I bet if I looked at the histogram instead and just focused on getting that centered for each star I could get a good color comparison while holding brightness constant (or at least not washing anything out to pure white).

Sunday, January 24, 2016

How to Bulk Delete iPhone Photos: Hundreds or All Photos at Once

There is a new and better way to delete all the photos from your iPhone at once, or just choose hundreds or thousands at once without wiping them all out. You can do it all from within the iPhone, you no longer have to download a special app or hook it up to a computer. I was amazing it was so simple, I wanted to delete over 4000 photos at once without erasing my settings. I couldn't believe it was so easy to quickly do a bulk photo delete like this. Hopefully this simple tutorial walk through graphic shows you how to do it super quick:

  1. Open your Photos and click 'Select' in the top right.
  2. Rather than tapping each photo one at a time, slide right to select an entire row. This already saves a lot of time but we can do better...
  3. Slide right and then down at a right angle to select an array or rectangle of photos, you are drawing with your finger the rectangle you want to select. 
  4. Ok not bad but we can do better. Slide right and then down off the bottom of the screen, you can actually scroll to the bottom and select hundreds of photos at once to delete.

how to delete all iphone photos or lots at the same time
Simple steps to delete all or hundreds of iPhone photos at the same time without additional apps or hooking the phone up to a computer. Give it a try and comment below!

What do you think? Was this a simple way to delete lots of iPhone photos at the same time? Comment below if you like this tip!

Tagging Planets with Theodolite iPhone App

There's been a post going around Facebook about this amazing event: 5 planets visible in the same sky. It's pretty rare, but I think the pop social media crowd might be over estimating the excitement a little. Yes, all 5 naked-eye planets in our solar system are visible at the same time: Mercury, Venus, Mars, Saturn, and Jupiter.

They present themselves in a nice arc across the sky, but they're not all in the same field of view - at least not with my lenses. It's fun to imagine looking at the solar system side-on and all these planets in their respective orbits all on approximately the same side of the sun. But let's not get crazy.

Anyway, I couldn't get a photo of them all at once. So my group of 4 is still my best planet family photo. But I did use the app Theodolite to help me spot Mercury. I wasn't sure if it was over the roofline yet so I looked up it's current position on StarWalk and then used Theodolite to see if that would be over the roof. I confirmed with binoculars.



Theodolite and StarWalk are both on my top 13 astronomy and astrophotography app recommendations, so check them out!

theodolite screen shot mercury
Screen shot of Theodolite identifying approximate position of Mercury

venus with theodolite
Venus: Theodolite lets you export photos and it puts detailed information on the screen, this is a great way to tag and document the exact position of bright objects - still need to test it at night

jupiter with theodolite
Jupiter: Theodolite detailed position capture

Monday, January 18, 2016

Best of Year 4: My Highlights from 2015

I can't believe another year has passed! I'm usually someone who gets tired of hobbies after 6 months and moves on, but it seems the challenge of astrophotography combines all my interests into something with real staying power. I've made incremental steps this year, witnessed some amazing nighttime displays, and continued to practice.

It's been 4 years since I started playing around with night sky photos. I've turned each year into a gallery with my best, favorite, or most memorable photos [Year 1, Year 2, Year 3]. I think I'm reaching the upper limit of what I can do with my current gear. I think the next step is going to be some new glass or a reflecting telescope to gather more light. I'll give that a shot on the motor driven mount and see how frustrated I get before upgrading to a computerized mount. All in due time!

But for now, here are my accomplishments from the past 12 months:


4 planets in one shot
I caught a traffic jam of planets in the morning before work. It was the most planets I caught in the same photo at once. Always nice to see Mercury peaking up over the horizon. Although the conjunction wasn't exceptionally close, it was cool to ponder the shape of the solar system from this scene. 

I called this photo 'celestial chimney sweeps' it was a fun twist on an otherwise ordinary conjunction between the moon and Venus. There's something about having foreground objects that make me love photos so much more. That's something I keep telling myself I'll work on, finding better composition. 

comet lovejoy
Comet Lovejoy from last year, only the 3rd comet I've photographed with a visible tail. I'm not sure why this same deep sky treatment didn't work on other comets, but either way I'm glad I got both color and a tail from a stacked image.

last boots on the moon
The last boots to leave footprints on the moon. I love this photo and this artifact that marks an end to human activity on the moon. It's so sad and cool at the same time. I'm glad I got to spend some time at the museums in Washington DC while I was in town for a conference. It was lonely walking around by myself, but I got to take my time and read almost everything. 

april 2015 lunar eclipse
The April 2015 lunar eclipse was only partially visible from Indiana. I guess I shouldn't complain, I had clear enough skies to see two lunar eclipses in the same year. This was a fun morning because I chased the moon down the street to watch it after it went behind the houses in my backyard.

perseid meteor 2015
A really nice Perseid meteor and plenty of star trails. This was one of the first night sky events I caught after my mother in law let me borrow her lenses again. I caught a total of 8 meteors that night. 

super blood moon
The September 2015 "super blood moon" a total lunar eclipse and supermoon at the same time. I was lucky to catch it between patches of haze. I didn't get the total sequence, but I was able to at least see it before the clouds rolled in. Lucky break on this one, but not the best atmospheric conditions for clean photos.

purple red sunset
An epic sunset, nothing too technical about it, just a nice combination of colors and a highlight of Indiana's gorgeous sky

dslr andromeda
My personal best Andromeda and one of my only thorough-treatment deep sky photos of the year. I find that the more I know, and the more steps I add to my process, the less I go out. I guess that's just how it goes. Nevertheless, this is an example of what my DSLR gear is capable of with my best effort.

crescent moon over roof
This shot of the crescent moon setting over my neighbor's roof with earthshine. I actually made a video sequence out of back to back shots to show the moon setting behind the roofline.

comet catalina dslr gif
This GIF showing the movement and color of Comet Catalina. This was a fun night and I dabbled with a variety of media for this session. I did a timelapse of me setting up my gear, I did this GIF along with single frame photos, and I tried to do a thorough deep sky treatment but couldn't get much more than a fuzzy blob in the end.

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