Category Archives: Intervalometer

Exploring Night Photography: Lesson 3 – Gear

Two weeks ago in class we covered basics (what is a photograph, using manual settings) Last week we learned a bit about noise, and its primary causes – temperature being the principle problem. And we explored different creative directions under the umbrella of night photography. We also got outside under a half-full moon (first quarter) and shot on campus. And learned a little about the night sky.

This view is southwest. From left to right are Canis Major, Orion and Taurus. The moon is off the top edge.

This view is southwest. From left to right are Canis Major, Orion and Taurus. The moon is off the top edge. The glow in the lower right corner is the glow bracelet on one of the student’s tripods. The sky remains blue due to the moonlight. Settings for this shot are ISO 800, f/2.8, 10 seconds, 20 mm on Canon 5D II.

Now it is time to talk about gear. Fortunately we already wrote a nicely detailed article about gear. Take a look here. We even updated it recently.

Too busy to read the details? That’s a shame, but here is the super quick summary in order of importance:

  1. GOOD tripod.
  2. Night photography friendly lens (wide angle recommended)
  3. Decent camera body with an optical viewfinder. Full frame preferred, but not necessary.
  4. Layered clothing and good shoes, including lightweight gloves (G) – and heavy gloves in cold season.
  5. Sturdy camera bag
  6. Extra batteries and memory cards
  7. An intervalometer (1), and extra batteries (2)
  8. Headlamp (B) and flashlight assortment (C, 3, 6)
  9. Other needful things: clear shower cap (A), lens cloth, hand cloth.

What About Other “Gear”?

MiscGear
Here is what is usually in our bag besides the camera gear.

  • (H) Glow bracelet/stick to mark the camera location (we have just started experimenting with other methods, too, like the LED band (4).
  • Hand warmers (F and 5) and rubber bands (G) for dealing with dew formation
  • Creative lights – bulbs, keychain lights,  and cord (3, 4, 6, 7, 8, 9)  Item 7 is a green laser pointer.
  • Insect Repellant  (E)
  • Gaffers Tape – flat black duct tape (L). We don’t take a whole roll though!
  • A smart app that shows the positions of the stars, planets, and bright satellites. Also helps if it shows meteor showers.
  • A smart app that shows the location(s) of sunrise, sunset, moonrise and moonset.
  • A game or two on the smart phone to pass time.
  • An external battery to keep our smart phone juiced (5) and the appropriate matching cord.

Before We Leave We Also Use the Following

  • A star map (planisphere). On our desktop, we favor Stellarium, but it is a little geeky to use well. On iOS we like Sky Safari, Star Map.
  • Weather prognostication tool
  • Sunrise/set Moonrise/set predictions.

 

Last Week’s Homework

We asked you to pick a creative direction. Here are some shots our students took including “semi transparent” you, moving lights.

XNP_Alex_assignmentsTop: f/4 1/30, 500 ISO, 20mm; Lower photo: f/4,  1/4, 1600 ISO,  20mm. Bottom was from moving the camera body

 

XNP_Tracie_Assignment

XNP_Troy_assignment

 

This Week’s Homework

  1. Use the light you were given in class to write a message or draw an image in light.
  2. The moon is full, if you didn’t work out settings for capturing the moon. Now is another chance. If you did work out the settings, compare them to your last shot when the moon was half-full. Notice anything?
  3. Find a way to make a strong white flashlight a different color. Use the colored light to illuminate your foreground. Your light may have to be really bright to compete with moonlight.
  4. If you are using a “white” LED flashlight, you’ll notice it is significantly cold (blue). Can you think of a way to make it a warmer color?
  5. Is there any “Other Gear” listed above that intrigues you? E.g. what can you use Gaffers Tape for?

Next… Lesson 4.

Intervalometer Tricks

Red Rockin' Spiffed Up

Scratching your head and wondering what an Intervalometer is?  We’ve covered that in this article, and talked about some super fancy Intervalometers in this article.

Before we launch into the tricks, let’s first get some terminology straight.

  • Long Exposure – in my vernacular this is an exposure over 30 seconds – the limit of most DSLR cameras.
  • TimeLapse – a series of photos taken over time that compresses (or expands) the actual time when made into a movie. Usually all the exposures use the same settings.  An event that takes 3 hours can be distilled into a 30 second video.  An event that takes fractional seconds – like a balloon popping – can be shot at high speed and expanded into a movie that lasts much longer.  Usually expanding the time is called “Slow Motion”.
  • StarTrail – like its timelapse brethren, implies a series of shots taken over time and combined into one exposure to show the star motion OR a StarTrail can be created from a SINGLE very Long Exposure.
  • Bramping (aka Bulb Ramping) – a timelapse techinque in which the length of the exposure is changed over time to accommodate the setting sun, rising moon – anything that involves a gradual change in the ambient light.

How is a Timelapse different from a Star Trail?

The two are not different, except that by intention a Star Trail created from multiple exposures requires a minimal interval between one shot and the next or gaps result. For a timelapse – which can be taken at night or day – the key is having a regular interval between each shot.  Changing the interval between shots has the effect of warping time.

Ok, Got it. Tell Us About the Tricks

Sub-Second Intervals

Why would you want sub-second intervals?  For one, to catch as many meteors as possible. The second or so that the camera spends with it’s shutter closed is a second you might miss that brilliant fireball. Another reason to keep the interval REALLY short is to reduce or eliminate gaps in star trails.  But sub second intervals are the hardest trick of all.  There are almost no intervalometers that allow setting an interval shorter than one second, and even if it’s possible many cameras can not handle sub-second intervals. However, there are a few devices that can do sub-second intervals: Trigger Trap for one.  The best way to find the shortest possible interval is to set up the camera and try! Set the interval to say 700 ms and see if your camera can run off a sequence of 15 to twenty 30-second shots without missing a beat. If that works, set the interval to say 500ms.  Note that the minimum interval will depend on the camera, as well as the size of the image, and speed of the memory card. Once you find the minimum, leave a little extra time and use that. My Canon 5D Mk II was happy with 450 ms intervals between shots. That’s HALF of the waiting time of one-second intervals.

Shake Reduction – Mirror Lock Up

Many people worry about mirror slap. Mirror slap occurs when the little mass of the mirror “wiggles” the camera enough to blur long-ish exposure shots. Mirror slap is particularly pernicious in the 1/4 to 2 second exposure length. It may also be a problem if you have your camera attached to a delicately balanced telescope at high magnification.  How do you solve the problem?  It depends on your camera, but there are several approaches to try:

  1. Leave live-view on (which will eat batteries and may result in excessive warming of the sensor)
  2. Use the camera self-timer in mirror lock-up shooting mode. Most cameras will behave properly if your exposure length is not bulb. That is, they will move the shutter, wait for the delay to expire and then take the shot. Remember to allow a delay that is at least one second longer than the shot length plus the self timer delay. For example, let’s say you want to take as many 24 second exposures as possible but you need at least 8 seconds for mirror slap to stabilize. Set the camera to 24 second exposures with a 10 second self-timer.  Then set the intervalometer to take a 1 second(!) exposure every 36 seconds. The reason for the 1 second exposure is to allow enough time for the shutter release to be recognized while the 36 second delay allows for 10 seconds of timer, 24 seconds of shot and a 2 second safety buffer.
  3. See the Maximum Shots, minimum interval trick. But instead of 1 second delays, change the length of the exposure to the amount of time you need for camera stability + 1 second.
  4. Want to do shake reduction in BULB mode and without a self-timer?  Set the exposure length to the desired amount of time and use a short interval. With mirror lock-up on, you’ll get every-other exposure at the desired length. Note: this is the most “iffy”mode as it depends on your camera behavior.
  5. Finally for shake reduction in BULB mode WITH a selftimer, set the intervalometer as normal, but set the length of exposure longer and include the self-timer interval. For example to take 60 second exposures with a 10-second self timer, set the exposure length on the intervalometer to 70 seconds.

Variable Length Shots

While this technique seldom works well, you can allow the camera to determine the exposure length via metering.  All you have to do to make this work is to have the camera take 1 second exposures (as before) no more frequently than the longest exposure you expect to take. Some fancier devices, like the Trigger Trap and the CamRanger can even be configured to change the exposure length over time. This feature is called “Bulb Ramping”.

Extended Self Timer

Got a big group shot and no wireless remote. Not a problem. Set the camera to a short (e.g. 2 second) self-timer delay, and set the shot delay to say 20 seconds – or as long as you need to safely climb on top of the human pyramid to get that perfect shot.  Since you can allow multiple shots, you’ve all got plenty of time to change your poses, or re-architect your human pyramid.  We use this trick all the time when we’re conducting workshops. It allows us to set up our camera and walk away while we instruct. We leave enough time to set up for the shot.  Most cameras will blink or flash to let you know they are about to take a picture so everyone can time that cheesy fake smile.  Note: If using a Flash, you can lengthen the interval between shots to give the flash extra time to recycle.

Maximum Shots, Minimum Interval

When not in Bulb mode, it can be maddening to not have the Intervalometer and the camera in sync. Set the camera to 20 seconds and the intervalometer to 19 and you’ll miss about every other shot. Bummer.  Here is a trick to maximize the number of shots and not care much about the actual exposure time.  Set the intervalometer to take one second shots with one-second intervals between each.  The maximum shot-to-shot delay will be two seconds that way and it doesn’t matter what your exposure length is on the camera if it’s NOT bulb.

What if you want BULB mode? How do you configure that?

Answer: (Select the text below to reveal)
That’s the normal intervalometer configuration mode. Camera is bulb, length of exposure is whatever you need and the interval should either be 1 second, or exposure length PLUS one second depending on the intervalometer.

Astrophotography Equipment Follow Up

Steven Christenson: New &emdash; Castles on High

New Equipment vs Old

In the years since I began writing about astrophotography techniques and equipment (including review of the Polarie, pointing tips, and processing techniques) things have obviously changed for me.  For one, I’m not working at astrophotography as hardcore as I expected.  The reality of managing an informative website (this one!), creating publishing and supporting tools, conducting fairly frequent expeditions and workshops, writing and improving content for webinars *AND* having a day job means I have to temper my enthusiasm. Or to say it more plainly, have my enthusiasm tempered by reality.

However a student asked me this question and I felt it was a good topic. The question:

I read your review suggesting the Orion Astroview EQ mount with optional dual axis motors. I’ve been looking for a cheap way to do decent tracking and have considered making a homemade Barn-door mechanical tracker to something more reliable (motor driven).

On Orion’s website, I find their Astroview EQ mount (#09822) and the dual axis motors for the Astroview (07828).

Soooo, my question is this: Since you wrote that article, is that still the most bang for your buck, or have you found something better/bigger/cheaper?
— Bruce L.

As I noted in my article, there are definitely bigger and better and significantly more expensive things … though nothing cheaper that I’d recommend. The Polarie is in the same price league.  After I made my recommendation my Astroview suffered a series of blows to the declination drive that rendered the drive useless.  The first blow was that the locking nut fell off in the dark and was lost. Once I replaced the lost piece (at about $35) the next blow was quite literal and it bent the drive axis rendering the motor useless. The truth, however, is I really didn’t need the second axis at all and I’d have saved a few bucks by only buying the single drive motor to begin with.  The Astroview is just beefy enough to carry the weight of my Orion 80ED refractor and a camera.  And to be quite honest since it is lighter and not a “GoTo” mount it’s actually easier to set up and take down than it’s bigger cousin, the Sirius mount. But the Astroview is nowhere nearly as well made.  So yes, I’d still recommend an Astroview as a minimum viable solution… provided you stick with a camera and telephoto / normal lens to do imaging.  Most telescopes worth mounting on the Astroview will cross the boundary of what the Astroview is designed to carry and will be too heavy for good operation.

Automating Focus – Two Steps Forward, One Step Back

I had upgraded the focuser on my 80ED to one sold by ScopeStuff (#RNFR) – a $320 motorized focuser. That focuser proved easier to use and more versatile, but I later found it coming apart and it required some heavy tinkering and investigation to get it working again.  I also realized that the system was not that well thought out – it was designed to have the motor base mounted to the focus TENSIONING screw rather than attached to a fixed screw on the focuser.  That’s probably in part why when I got it, the tube would not travel all the way through the almost 4 inches of focus. I’ve restored it to operation but it still won’t travel in the final 3/4 of an inch… that’s fine, however as I have never needed that much in-focus – I’m usually working with the focus tube nearly fully extended.

In focus - moving the camera inward, toward the front element of the telescope, thus shortening the overall length.
Out focus (aka back focus) - moving the camera outward from the front element lengthening the apparatus.

Is A Barn Door Tracker A Good Solution?

Let me address the question about a Barn Door Tracker.  There are no places that I have found to buy barn door trackers, it’s strictly a home-built type of thing. As I explain in the Astrophotography 101 webinar, a barn door tracker is a form of an equatorial mount that has been simplified to drive only one axis (the right ascension) and with a limited tracking time.  Various designs like the double arm version improve tracking accuracy while complicating assembly. My personal bias is that even though I’m pretty handy with tools I’d rather spend $400 on a fully built system than $80 on parts and 10-20 hours of my own labor building and perfecting the system.  I suppose if someone handed me a robust kit for $100 and told me I could assemble a motor driven barn-door tracker in an hour or less, I’d give it a try.  But at much more cost in time or money the barn door tracker starts bumping into fully built solutions like the Orion Astroview and the Vixen Polarie or the iOptron SkyTracker.

One of the principle impediments with all things astrophography – and part of the reason I created the Astrophotography 101 course is that there is a LOT of language used that is foreign to most people. And, there are legion of difficult choices to make. For example, I recently bought a William Optics Telescope. It is a well built, heavier than expected, refracting telescope that features a power focuser. Perhaps as a surprise to the uninitiated the “power focuser” is not actually powered (motor driven), it is an improved version of the manual Dual speed Crayford focuser and the term “power” implies it’s ability to hold focus without slop or creep – even if the other end of the focus mechanism is a pretty substantial camera.

I had hoped my existing finder scope and guide scopes would easily attach to the new William Optics telescope, but they won’t. The fittings are all different. For the most part astronomy and astrophotography equipment is a wild west of non-compatible, non-interchangeable components.  Much like you see if you try to use a Nikon lens on a Canon camera.  Or an intervalometer built for a Sony on a Lumix camera.  The difference, at least to my way of thinking, is that the compatibility of components is much better spelled out in the camera world than the astronomy world.

What about the Polarie?

The Polarie will work well with normal lenses. When I mounted my 70-200 with a 1.4x and the Canon 5D Mark II (or 40D) on the Polarie, tracking accuracy was pretty bad – but not directly because of the Polarie. The problem is that the systems is not balanced and there are three different points around which the apparatus gets sloppy: at the connection between the ring-collar of the lens and the head mounted on the Polarie. At the point where the head is attached to the Polarie screw, and where the “collet” with it’s two thumb screws attaches to the Polarie.  Invariably one of those would become loose enough that it would slip.  I found that putting a counter weight at the end of the lens reduced slipping and improved the tracking – but it’s a hassle and highly dependent on where you aim.  A true equatorial mount is easier to balance. The Polarie system works better when there isn’t a lot of torque around those attachment points.

In summary, I like and use the Polarie because it’s compact, light, not bulky and easy to take with me literally anywhere I go. But I would not use it to take serious astro images.  The Polarie best fits Landscape astrophotography.  For example, below is a 63 second exposure using a Canon 40D at 1000 ISO, f/2.8 at 16mm.  Using the 500 rule, star streaking would become apparent at about 12 seconds.  In this small size there is nothing at all visible, but do notice how the foreground head frame at Bodie State Historical Park is blurred – that’s because the Polarie was tracking the sky at 1/2 sidereal (star) rate. The photo has been exposure enhanced (brightened) to see details, and noise reduced a bit.

B_180-002309_sm

 


I realize the photo at the top has nothing to do with any of the subjects… it was taken in daylight. But, hey I like it. In my defense, the “Phantom Ship” structure seen in the first photo is the oldest rock at Crater Lake.

Here is an exposure that is a bit more germane. Two exposures, actually. One focused for the hand-lit tree, the other focused on the stars and both were combined in Photoshop.

Heaven Bound [C_075698+701]

How to Not Lose (Much) Sleep

Save the Wonder II [C_070237]

If you want to catch the good stuff… like a meteor shower, or the Milky Way rising in Spring you have to be up in the wee hours. After midnight up to perhaps sunrise.  There are some tricks to pulling this off without collapsing – or worse, falling asleep at the wheel.  One problem with doing night photography is that motels and hotels aren’t particularly suited to the night photographer who would prefer to get to bed after breakfast and sleep until dinner – you often end up paying for two days worth of room that you only use for 8 hours!

So here are some ways you can “Store up Sleep” to support your night habit.

The No Stay Method

  • Get plenty of sleep in the afternoon.
  • Drive from home to the event.
  • Do the shooting
  • Get Breakfast
  • Nap on a cot, pad or bench
  • Drive back home, stopping to rest or nap as needed.

Obviously you can try to get to the shooting location sooner, but for most people it’s not safe to not get proper rest especially if you’re driving.  For example, if I know I want to shoot a milky way rise – I work backward from my arrival time.  Let’s say I need to be on site at 3:00 am and it is a 5 hour drive. That means I will want to hit the road at 10:00 pm. It might sound scary to drive from 10 pm to 3 am, but if you’re properly rested you may find the lack of traffic refreshing and the travel time that much quicker – I do this all the time!  To pull this off, see my “Body Clock Reprogramming” method.

Stay and Play method

  • Arrive in the early afternoon.
  • Check in to an area hotel, motel or campsite.
  • Get lunch.
  • Retire EARLY for sleep.
  • Get up EARLY (depends how far away you are from the location) Perhaps a 2:30 AM or earlier.
  • Do the shooting.
  • Get Breakfast
  • Get back to the hotel in time for at least an hour or two (or ask for late checkout)
  • Check out and go home… or stay another night.

Body Clock Reprogramming

A lot of people claim that they can’t sleep during the day. Hogwash, I say.  If I know I’m going to do a long weekend of night shooting, I can push my body clock around a little – in spite of my day job. For example, if I know I’ll be shooting mostly in the pre-dawn hours, starting on Wednesday, I’ll go to bed an hour earlier and get up one or two hours earlier. If you don’t get out of bed until 9:00 am… you’ll have to start reprogramming on MONDAY.  Do this each day before the trip – go to bed an hour or two earlier and get up an hour or two earlier the following morning.  If you normally arise at 6:30 (like I do), after two days you will find you’re easily awake at 2:30 AM – perfect!  And a day later you won’t have much trouble getting up at midnight and plowing through perfectly perky until well after breakfast.   Just remember to avoid caffeine and stimulants!  By the way, altering your body clock like this is a great way to get ready for an upcoming trip to another time zone.

If you can’t push your body clock that far, then plan to sleep or nap at your shooting location. I usually bring a fully reclining chair, a comfortable pillow and TWO sleeping bags – one very warm one, one that is only meant to take the chill off. I can then either sleep out-of-doors, or if necessary in my car.  This works well if I’m running a timelapse or star trail – the intervalometer does all the work. In fact, while I was taking the shots for this timelapse/startrail:

The Cove [C_071837-940br]

I was a dozen feet from my camera in my car out of the wind checking the progress every once in a while on my CamRanger. I didn’t have to leave the car except to change batteries or memory cards!  I didn’t have to use the CamRanger, of course, an intervalometer is just fine. There is an advantage to using a Canon for unattended operation, however. That red “exposing light” on the back of the camera can be seen from a long way off. I can easily and quickly take a look and know that the camera is doing its thing. With the Nikon, you have to watch carefully for the “green flash” as it writes to the memory card – if you have 6 minute exposures, you may have to wait a LONG time.  The CamRanger makes it a bit easier because I can also check the images, and the camera battery status, and memory card status remotely.

Leave The Gear

Oh, and there is one more way: set your camera up, leave, and come back for it. I usually aim to return BEFORE dawn because few humans bother to be out before the sun is up. My gear has been left alone in the wild quite often.  Of course I’ve already triple checked and prepared for the weather conditions and I place my camera where it’s not easily located – except by me. It’s a good idea to triple check all your settings. More than once I’ve left and upon return found I forgot a setting. For a belt and suspenders approach, I also keep track of the camera’s exact location with a GPS or by “dropping a pin” on my iPhone. Of course the downside here is you may need a huge memory card, a super strong battery, and you can’t have too much separation anxiety about leaving your gear. It won’t do you any good if you leave and DON’T get any sleep because you fear for the safety of your gear.  Trust me, your gear is braver than you are!

Sometimes when we run workshops, we take turns guarding the gear for one another, so you can also agree to leave a guard soldier behind if you shoot with buddies.  Just be sure to be kind to your guard – they will likely be grumpy.