Tag Archives: HDR

Review: CamRanger

I am always looking for the best solutions for automating my night photography. In fact, I recently reviewed a litany of products. At the time I didn’t know about the CamRanger product – my friend Rob C. told me about it.

I am now the owner of a CamRanger. Here are my first impressions:


iPhone Application

  1. I ordered from the CamRanger website, selected two day delivery. The box came all the way across the US. From Virginia to California and it arrived in two days. Woohoo! Great store and interaction.  It’s also available through Amazon, but doesn’t qualify for Prime. I figure if I’m going to pay for shipping I’ll order it directly from the company and hope they keep a bit more of the cash.  By the way I paid with PayPal. Sweet. 
  2. The packaging is reminiscent of the iPhone. Everything is nicely tucked into a little box. I was worried briefly because I also ordered two extra batteries. Thankfully they were tucked into the same box.
  3. Included were: Quick start instructions, a charger (wall wart), charger cable, USB to mini USB to connect to the camera, Ethernet cable (for upgrading the firmware), the batteries, a cigarette sized-packet with the CamRanger unit, and a carry pouch with a velcro closure and a carbiner clip.

The CamRanger is an incarnation of the TP-Link portable wireless router. It even says so on the batteries and under the case. Really clever approach! Kudos to them. Of course the firmware has been customized, and they are using the USB connector to drive the camera.  With that arrangement they can do a WHOLE lot more than you can do with a lowly intervalometer.

Essential is the CamRanger application for iPad and iPhone. They are planning to roll out other applications, including one for the PC. Since the device is a portable router, theoretically they could even provide some simple browser driven connectivity.  I loaded the app long before I received the box. You can’t get to square one without the device, however – it won’t show you any of its glorious features until it can talk to a camera. Makes some sense since what you can do depends on the camera it connects to.  I found some blemishes with the application which I’ll enumerate in just a moment.

What Can the CamRanger Do?

Before I criticize, let me first explain what you CAN do with this clever device. And this is just scratching the surface.

  • Focus stacking – let CamRanger control incremental focus for maximum depth of field with your macro (or other) shots.
  • Remotely adjust focus (camera auto-focus must be turned on for this).
  • True HDR using exposure time, ISO or f/stop increments. Up to 7 exposures are allowed.  Intervalometers with this feature can only work in low light since they can only crudely control the camera shutter.
  • Monitor “live view” and captured images. Even delete them when they suck. I am slathering at how this will improve my Astrophotography. Have you ever tried to adjust focus of a telescope pointed nearly straight up – it’s a neck breaker.

    Delete Images from Camera

  • Intervalometer functions: timelapse, and bulb exposures.
  • Complete control of settings (how complete depends on your camera). Nearly all of the settings can be changed remotely including ISO, f/stop, exposure time, metering mode, image size and type… and more.  I even moved the connection from my Canon 5D Mark II to my cohort’s Nikon D800 and had immediate control of his camera and its unique settings.
  • Some features do require manually changing the camera mode knob. For example to get bulb exposures you must be in Manual mode on a Canon 50D or in Bulb Mode on the 5D Mark II.  These peculiarities vary by camera.
  • CamRanger can do everything the EyeFi can do for sending images. EyeFi isn’t supported on CompactFlash media cameras so CamRanger is a great replacement!
  • IMG_0137Focus by touching the iPad screen.
  • Provides a Live View Histogram.
Touch the iPad to select focus point!

Landscape Mode






Portrait Mode


View images from the camera memory card

What Could Use Some Improvement

I’ve ordered my complaints according to how much they affect the way I do most of my work which is night and astrophotography.  Some of these are nitpicking, I know.

  1. There is no sub-second interval for long exposures. I’d love for them to add a “star trail mode” and select the shortest possible interval between shots based on the camera type and behavior. The company says this is a limitation in what they are able to do through the USB connection to the camera.
  2. There appears to be no way to know if a timelapse is running nor can you stop a timelapse in progress.  The CamRanger can continue to run a timelapse sequence without an app driving it.  That’s a plus. But not being able to tell if it is running or to abort a sequence in progress is annoying. CamRanger tells me they are planning to address this in an upcoming release. Yeah!
  3. The pouch for the CamRanger could be improved to:
    • Hold all the items that come in the kit. The pouch can only hold the CamRanger device, USB cable and perhaps an extra battery – not the additional cables or plug-in charger.
    • Add velcro straps so I can wrap them around my tripod leg and secure the pouch to my tripod,
    • Provide a closeable window so I can see at a glance the unit status (i.e.those LEDs which are too bright, see below).
  4. The timelapse settings use spin dials to select the number of exposures and exposure times. The keypad would be more efficient.  It would also be great if the App automatically calculated your elapsed running time based on the number of exposures and a configurable frame rate (like TriggerTrap does). CamRanger is adding the calculation.
  5. The LEDs on the device are pretty doggone bright for night work. Would be great if they were dimmable. Of course that can be achieved by putting the device in the pouch or by putting some semi-opaque tape over the LEDs.
  6. IMG_1564To interact with the CamRanger, you have to switch your iDevice to the WiFi network generated by the CamRanger. Unfortunately that means you can not use your iDevice browser to surf the internet. If there were some fast-switch way to do it, I’d like that. Or better yet, I’d like to integrate the CamRanger into an existing network.
  7. The CamRanger itself comes with a serial number sticker. I’m SURE it will come off or get lost, but you need that serial number to connect to the device. The same serial number can be found on a sticker under the battery cover, though.
  8. The Access Key to join the CamRanger network is all in upper case.  All lower would be easier to type.
  9. My buddy Rob noted that he felt like he was going go have to break the battery cover off. Mine seems to come off quite easily if you hold it correctly.
  10. The CamRanger battery is a custom lithium-ion form factor. You can charge the battery in-device, but there is no additional charger provided.
  11. Sometimes when switching functions, for example when switching to Timer it told me “must turn off live view” which seems a bit strange since it knows how to do it!
  12. I ended up with both my iPad and my iPhone attempting to connect to CamRanger. It caused a problem that was not obviously solvable (Communication Error) until I realized both of my devices were trying to get CamRanger’s attention.

As I noted, some features depend on the way your camera interacts with the USB connection. I didn’t figure out, for example, how to cause my camera to meter the scene for me so that I could manually adjust my exposure – i.e. what I’d normally do with a half-press of my shutter button.

I haven’t tested the range or battery life as yet. Claimed battery life of the CamRanger is 6 hours. There is, however, no on screen indication of the CamRanger’s current battery condition.

Now That I’ve Used it More…

The problems with not being able to see if or stop a timelapse are more than irritating.  The only way to stop a timelapse in progress is to turn off the CamRanger device and turn it back on. It takes about a minute to come back up and meanwhile since the WiFi from CamRanger goes away, my iPad or iPhone will by default switch back to another known network (my home in this case).  That means I have to remember to also switch WiFi networks or I get “unable to communicate”.  I also noticed that for bizarre reasons which are not quite clear I could start a timelapse, but the camera did nothing.  However I *could* use the Capture button.

But that’s not the end of the pain, unfortunately.

  • The Bulb and timelapse settings are not saved. All settings reset to 0 when a timelapse completes.  If you want to re-run the same program – as I do when I take darkframes after my astrophotography sequences – you have to reprogram everything. That’s tedious.
  • Apparently the interface is not smart enough to know how to do HDRs that exceed the camera settings 30″ exposure time.  On my 50D, for example, an HDR sequence that should shoot at 15, 30 and 60 seconds will not be accepted. However that sequence can easily be achieved by using bulb mode for the last shot and that does not require changing the dial on the camera – so the app could figure it out.  I even tried doing this in “Bulb” mode, but it still didn’t seem to work.
  • The biggest pain in the butt is that the “Autofocus” behavior is not preserved.  What this means is I leave the AF button on on the lens, carefully fine tune the focus, turn it to MF (manual focus mode) on CamRanger and take my shots. If, however I am forced to cycle the CamRanger power it reverts to AF mode by default so the first shot will try to autofocus in the dark – which prevents the camera from shooting.  I’d like to set the default behavior to NOT AF even though I have set AF on the lens.
  • It also appears the timelapse is not aware of the drive mode for the camera.  I often set my camera to the 2-second (or 10 second) delay for two reasons: 1. it lights the self timer on the camera so I know when a frame is about to fire, and 2. In delay mode, an Autoexposure bracket (AEB) will automatically complete from a single press of the shutter. The timelapse settings could know that the minimum delay will be the length of the camera self timer delay (plus perhaps a second).  But it doesn’t use that information.

The good news is that the biggest pain points can be fixed in the app. I suspect some of the more advanced things would require the app to know more about the camera – and are thus less likely to be supported.

The other good news is, it really does save me from breaking my neck trying to get my eye down to the view finder or to view the LCD – when objects are high overhead I’ve had to lay down on the ground to see the LCD – blecch. And it’s great fun to watch the images roll in as the timelapse runs – even from indoors while my poor equipment is out shivering in the cold.

Camera Control Devices Compared

IMG_0092 IMG_0106 Neweer_Shoot SatechiWireless._SL500_AA300_

Welcome to another investigative report on… devices to control cameras.

My readers will already know about intervalometers. No? Ok, you can read about them in this moldy old article.  Reduced to its simplest form, an intervalometer is a device that electronically presses your shutter button and releases it.  Fancy intervalometers have many other important and useful features including those described in that aforementioned article.

In this article I will compare four devices I have with one I don’t own. The devices I am comparing are all for use with a Canon 5D Mark II but most have variations that make them suitable for wider use with other cameras and brands. Here are the devices in question:

There is one obvious difference: price.  In my opinion the somewhat unreliable cheap Shoot Intervalometer is worth the price as a sacrificial device for use in a harsh environment but not something I would recommend for a critical shoot.

It is also a little unfair to compare the two smart phone based products on price alone since they require a smart phone to operate them. Both the Trigger Happy and the Trigger Trap are picky about what phones they support.  Neither supports an iPhone 3G – each requires at least an iPhone 3Gs, 4G, 4Gs or 5.  That’s unfortunate since I have an old iPhone 3G which I would gladly convert for use only as a camera control device. What I am hinting at is that you may want to consider the cost of an iPhone or Android phone to drive these devices.

If you’d rather that I just “cut to the chase” and tell you which of these devices I recommend… Here is my ranking from best to so so:

  1. Trigger Trap
  2. Satechi Wireless Intervalometer
  3. Promote Control
  4. Trigger Happy
  5. Shoot

Promote Control

PromoteControlThe Promote Control is the unit I don’t own and its ranking is based on three things: the cost (high), the features (many) and the usability. As a dedicated device the Promote Control is almost the most versatile. Indeed it is the only device I investigated that can control the camera – using a USB connection – not just the shutter.  But they bill themselves mostly as an HDR device. Watching their videos and following the many modes and button presses made my head hurt.  The smart phone based products clearly have a leg up. They can present the data more intelligently and allow more features through upgrade than the few buttons available on the Promote Control.  The Promote Control screen is reminiscent of those multi line text pagers of yesteryear.

Because it has direct camera control the Promote Control can perform several features that the others on this list can not touch. The Promote can: shoot real extended HDR shots, not only long-exposure HDR. It can also control the focus to do focus stacking.  In various modes it can do timelapse, star trail and “bulb ramping”.  And it *might* have a method to be dormant for a while and start running the configured program in the future… however it can never be as clever as the Trigger Trap which is able to take advantage of all the other goodies on a smart phone like GPS location, tilt/shift, on board cameras, and WiFi. Being this is a dedicated device, you may not have to worry about choosing between a timelapse and and important phone call.

I learned that there is another device like the Promote Control that uses WiFi to allow extended control of the camera through the USB link: the CamRanger ($299).   What is enticing about the CamRanger is that it says you don’t need to keep your i-device connected after you set up the shooting program – that would be very nice!

If you are a Nikon shooter, there is the curiously named Zesty or ZGR-1 ($70). I downloaded the ZGR-1 app – it looks like a bad hack job – especially the translation of the manaual (as they called it) from Chinese to English.  The ZGR-1 app seems pretty limited, too, but it’s hard to tell since it only connects to cameras I don’t have.


IMG_0078This device is the newest in my arsenal and is perhaps the most promising. The funny thing is that I was able to test it without having the dongle… because the TriggerTrap and the Trigger Happy dongles both work on the same principle: they attach to the headphone port of your smart phone and control the shutter button by playing sound through that port. If you have an alert, or incoming call, it may make the camera do strange things – I’ve noticed that behavior with the Trigger Happy product, and unfortunately an incoming call during my star trail test with TriggerTrap terminated the current exposure even though I didn’t do anything to the call. Indeed, selecting the home screen on the iPad or iPhone seems to terminate TriggerTrap’s signal – it doesn’t continue to run in the background like the built-in Music Application or White Noise do.

The TriggerTrap application exploits features of your smart phone or iPad in very clever ways not only can you configure it to do normal timelapses, star trails, bulb ramping and long exposure HDR shots.  TriggerTrap can fire your camera when it:

  • determines you’ve moved x meters from your previous location
  • notices movement in the smart phone camera
  • notices faces in the smart phone’s camera
  • detects that the device is moved
  • hears a sound of a configurable volume (clap, bang, whistle)
  • detects magnetism / metal (presumably using the built-in compass)
  • gets a wi-fi signal from a master – that is it can become a remote control device.

The TriggerTrap application is well done, has copious help, lots of little features, and clear definition of functions. If it lacks anything, it is the ability to save a particular camera or shooting setup. IMG_0086I really appreciate the ability to set times and duration using a slider with a pop-up spin control to fine tune the values that are hard to hit via the sliders alone. And it supports sub-second intervals, timeouts, etc.  It also calculates and displays the results of your changes on the fly so if you increase the number of photos that will be taken in timelapse mode, it shows you how many seconds the timelapse movie will last, and automatically calculates the photo interval.

It really only lacks ONE very useful feature that I would use… the ability to set an initial delay or an ending time.  I’d like to app to “sleep” until 20 minutes before moonset and THEN start my star trail sequence, or set it to end 40 minutes before sunrise, etc.  It has the built-in intelligence to know when the sun will rise or set for your current location so it’s just a small matter of code to add the delay function or the cut-off function.

IMG_0110Some functions are a little too cute. The Cable Release mode, for example, has an odd little spin-wheel to select functions. A pull down would be easier to use than the mostly useless single letters on the wheel. The area you press to start the exposure is both small and it does not light to show when it is exposing. In the diagram at the left the exposure has been started but nothing is counting down and nothing has changed since pressing the small gray “start” button.

One problem with this app, and the Trigger Happy application, is that it must be dedicated to use for the purpose it is intended to serve.  I made the mistake of leaving my Bluetooth on and with my car parked nearby my phone paired with the over-visor Bluetooth speaker in my car and could not drive the camera (but I got strange buzzing noises in the car). Turning off Bluetooth  solved the problem. BUT a phone call or pressing the home button to return to the main screen effectively ends your exposure. Oh, and the cable is short – about 1.5 feet total – so you’ll need something to hold your iPhone or iPad close to your camera. And the app spills light which may affect your shot. Oh, and an inadvertent touch may stop whatever you’re trying to do.  But it does do sub-second delays between exposures. I got mine down to 250 milliseconds between shots without missing any exposures on my Canon 5D Mark II – that’s 1/4 of the time you can do with the run-of-the-mill intervalometer.  Indeed, I set my exposures to 26.63 seconds and delays to 250 milliseconds. 45 shots took 20 minutes, 10 seconds which works out to 26.88 seconds per shot.

Trigger un-Happy

IMG_0092Trigger Happy ranks near the bottom of my list not because it is unreliable, and not because it is more expensive than its TriggerTrap cousin, which it is, and not because many people are reporting months long delays in receiving a working product. No it’s near the bottom because the iOS application (version 1.03) that was released to control it is… maddening.  It seems to have features I want (timelapse, Bulb Ramping, HDR Bracketing) but its sophomoric interface feels like it hates me.  For one thing, the many screens are all “single purpose” but you MUST select things in the order the app expects or it will both complain AND ignore you.  IMG_0100For example, you must start by setting the Interval. If you then try to set a shutter time that is longer than the interval it refuses to let you go ahead – you must go back and change the interval.  Moreover when you try to set the Shutter time, it doesn’t TELL you what the current Interval is. A better application would add a “Star Trails” mode where all you do is set the exposure length and it ASSUMES a 1 second or less pause between shots.  And a MUCH better application would either adjust or offer to adjust the other parameters for you. A good example of a better application is the TriggerTrap. TriggerTrap shows the settings together on the same screen and doesn’t divide them across screens.

IMG_0091If you switch e.g. from “Timelapse Normal” to “Timelapse Bramp” it pops up an annoying dialog box “Bulb Mode Required”. Switch the Shutter mode from “Auto” to “Manual” and guess what dialog box pops back up! Blecch.  A little on-screen reminder would have been fine, but why pop up a box I can only say “OK” to?  Thankfully it has sub-second exposure and interval lengths, but it could be made MUCH better if it asked you what camera you are using and initialized the settings for you… or if you could create a profile for a specific camera.  There are many other problems with the interface… for example in “Single Shot” mode the banner across the top on my iPad still reads “Time Lapse” what? A One shot timelapse?  The good news is that a release of a better app could dramatically improve the usability and usefulness of this device.  I have tried to persuade the makers to do a better job with their application, but the very young adults who started this project long ago on Kickstarter and apparently have had a falling out after collecting $221,000 in starter money.

Satechi Wireless

SatechiWireless._SL500_AA300_Rather than expend a lot of energy writing about it, you can read my (rather glowing) review of the device on Amazon (its the topped ranked favorable review).  One thing to note: the device I received was labeled “Young Nuo”  not “Satechi”.


Shoot Intervalometer


This devices is a cheap knock off of the manufacturers device. Like the Satechi, there are different connectors available to fit different cameras.  I bought three of them for loaners with my workshop participants and one of them developed the problem I described in the review.


Device Comparison

F E A T U R E Trigger
PromotControl Trigger
Price $ USD (3) 30 320 50 60 15
Control Type Audio USB+S Audio Shutter Shutter
Computer-less operation Yes (4) Yes Yes Yes
Timelapse Yes Yes Yes Yes Yes
StarTrail Mode Yes ? No No No
Delay Before Start No No No Yes Yes
Sub-second intervals Yes Yes Yes No No
Bulb Ramping Yes Yes Yes No No
Ease of Use (6) Great Fair Poor Good Good
Bulb based HDR Bracketing Yes Yes Yes No No
Full HDR Bracketing No Yes No No No
Focus Control No Yes No No No
Android Compatible (5) No Yes No No
iOS Compatible Yes No Yes No No
Battery Life (7) ? (7) Months Months
Flash Control Yes ? No No No
Wireless use (2) (1) No No Yes No

(1) Can use WiFi with Master/Slave for remote control.
(2) Theoretically all audio jack based controls COULD be operated via a BLUEtooth audio device.
(3) Includes the cost of an application and a cable or cables to connect to the camera.
(4) Computer and USB cable required to upgrade the firmware, but not for programming/use.
(5) The android application has fewer fancy controls, but the timelapse, bramping, and star trails work fine.
(6) My subjective evaluation of ease of use.
(7) I ran both the Trigger Trap and the Trigger Happy applications on my older iPhone 4. Each ran for over 4 hours and consumed less than half of my battery – and that was with all phone functions left on (WiFi, Bluetooth, and cellular).  Of course your battery life may vary.  I did not test the battery life of the Satechi in Wireless mode.

 Yet More Control Ideas

  • DSLR Remote (Homebrew Hardware)
  • CamRanger ($299). Wireless (WiFi) control with USB support. Allows you to view photos like you can with the EyeFi card but you can also control focus, and much more.
  • Zesty or ZGR-1 ($70, Nikon models only)
  • Timelapse+ ($210) In development – also a Kickstarter Project.  Currently only shutter control, but it looks like it may be a serious competitor to the Promote Control with USB support *and* an iPhone application to control it.
  • Rubberband. Yep, rubber band. Set the camera in continuous exposure mode and hold the shutter button down with a rubberband. Works in a pinch – trust me!

Graduated Neutral Density Filters

In a Flickr discussion, a poster asked whether he should get a hard stop graduated neutral density (GND) filter or a soft one.  But wait, perhaps you would first like to know what a GND is so that I can explain to you why you probably DON’T need one.  Here is a concise article, I’ll wait for you to come back.

In a nutshell, let’s dissect the words: Density means darkening – the denser the darker. Graduated means the amount of darkening changes from top to bottom. Neutral means that while darkening, the color is unchanged.  A neutral density filter is one that darkens the scene to allow a longer exposure – e.g. of a waterfall or ocean to get the “silky water” effect. A good neutral density filter will not distort the color in the scene. The Cokin GND I’ve used, for example adds a purple cast (hue) to the captured image.  Usually photographers employ a GND to darken the sky in a daytime scene so that the sky brightness is not so significantly different from the landscape. By darkening the sky a single exposure can capture sky details (e.g. bright clouds) as well as details in the landscape.

All that’s left now to describe is the difference between a HARD and a SOFT GND. If you read the linked article you already know, but if you didn’t, here is an easy way to disentangle the words: hard is ABRUPT while soft means GRADUAL.  That is, a hard filter has an sharp transition between the dense area and the clear area while a soft filter has a smoother transition.

Can you use a GND at night? Yes!  But normally you will end up using it in the opposite way of the normal use:  e.g. to darken city lights at the ground but leave the night sky undarkened.

Here is an example where you might think of using a GND

Mary Avenue Circular Motion

The lights on the bridge deck and towers are very bright compared to the night sky.  A GND in theory could be used to mask the lower portion of the bridge to control the brightness. And while it will work, it will not work well because somewhere there will be a transition between the darkened part at the bottom and the sky above. If there were no tower, the GND could be used to knock down the lights on the fences and deck with a relatively minor sacrifice.

This scenario repeats itself in daylight situations too. Imagine a lovely tree in your daylit scene instead of a tower and it quickly becomes clear that nature affords very few situations where there is a linear and sharp distinction between the dark area and the light area… the ocean being one clear possibility or perhaps a landscape in a flat-as-flat-can-be field in Kansas.

Here is a better candidate for use of a GND – but still far from ideal:

Incoming [5_034817-5138brPS]  Star Trail

A GND could knock down the excessive city lights. But it would also darken the mountain.

While it is certainly desirable to knock down the excessive city lights there is no orientation for a GND that won’t also knock down the brightness of the mountain or a portion of the sky. A triangular GND – if it existed could control the overbright part but since every scene is different the chances of getting a well matching GND are slim.

90% of the time using bracketed exposures and High Dynamic Range processing techniques makes more sense than using a GND. Also by not using a GND there is no additional opportunity for glare, flare, reflections or color cast – and nothing additional to carry lose or break or spend money on!

But before I completely pull the plug on GNDs, here are a few extra tidbits you can employ to get the most out of a GND that you may have:

  1. You can turn a hard GND into a soft one, by moving it up and down while shooting. For this to work, you need a longish exposure and you must be careful not to shake your camera. You also won’t be using the filter holder.
  2. A lower tech approach that works is black carding. Instead of using a neutral density filter you use a flat black card. You hold it for a time (keeping it moving a bit) over the light part of the scene and then remove it. This is exactly analogous to the “dodging” and “burning” process used long ago by Ansel Adams when he wanted to tone down (or up) an area of a photographic print.

The effects of the GND can be duplicated on the computer – and better yet, without the tell tale darkening of things like trees and mountain tops that cross the transition area of the GND filter. Tools like Photomattix and Adobe’s Photoshop Merge-to-HDR can automate the merging of exposures, but to my eye the result is usually somewhere between bizarre and odd looking.  A more effective process is to hand merge your HDR as described by Harold Davis in his book The Photoshop Darkroom 2 or his latest book dedicated to HDR processing – which begins shipping July, 2012.

In Summary

GNDs work, but seldom does one find a bright area separated from a darker area by a straight line – whether gradual or otherwise. Trees, hills, mountains and man made things like to poke up into the sky and look “weird” when darkened via a GND.

The advantages to bracketed HDR photos are many, the drawbacks are few – and it’s one less filter, filter holder, and pouch to take along and one less source of additional reflections, flare, vignetting, or color problems.

In fact, I’m not really sure where my GND is anymore, or the holder for it which was a beast to manage.

More Resources


I did NOT use a GND on the Mary Avenue Bridge picture!  I used a technique that will be covered in an upcoming webinar on Photo Manipulation for the Night Photographer.  The very next webinar on photo manipulation is June 7, 2012.

Easy (HDR) Blending with Stacking Software

I’ve been teaching a “Catching the Moon” webinar approximately monthly. The focus of that course is to teach how to properly expose for the moon, how to catch the moon aligned with your favorite landmark, and how to determine the optimum light scenarios.  The webinar is based on my Alignment 1 and Alignment 2 articles with a healthy dose of additional material including some private material for students only.

One of the most difficult aspects of getting a moon alignment is that there is a pretty small optimum time window for getting an exposure.  Shooting earlier or later makes the foreground illumination and the moon illumination all but impossible to get both exposed properly in a single shot.

Here is an example of a single shot where the lighting was pretty close to perfect (though you can see the moon is a bit over exposed).

A Perfect 10 [5_057646]

However later that evening the sunset occurred quite a while before moon rise, so the sky and foreground were much darker.  The photographer faces a conundrum. Expose for the foreground or expose to preserve moon features.

On the left is a 30 second exposure prior to moon rise (though a tiny bit of the moon is in fact visible). On the right a 1/25th of a second exposure. Both taken on a tripod at f/9, ISO 250, 444mm effective focal length.  The problem is that a longer exposure renders the moon as a white featureless blob or streak (see below for an example). However exposing for the moon as on the right renders the foreground all but invisible.

What to Do?

There are a couple of simple alternatives. One is to bring both images into Photoshop. Make both images layers, the moon on top of the background and combine the two images using “Lighten” blending mode.  That will work very well and it’s essentially what happens when using the StarCircleAcademy Stacking Action. But that action, and even Photoshop are overkill for this situation.

Free Solution!

Fortunately Markus Enzweiler offers a free solution called StarStax that runs on Windows, Linux and Mac that makes it trivially simple to combine these two exposures – assuming they were taken on a tripod and the zoom, focus and direction does not change between shots.  StarStax is tailored to stacking star trails, but it does the same operation that Photoshop (and Image Stacker and StarTrails.de do).

And fortunately you can make it do a little more with almost no extra effort… as in this example. When the first image was taken it was quite dark and required a long exposure to capture foreground details.  Then all the moon images were taken with identical settings using an intervalometer.  It’s interesting to note how the moon darkens and deepens in color as it sinks in the atmosphere.

Project Impact [5_057573-615br]

So how do you create the simple or “stacked” motion images?  Easy.

 And here is the result.

Obviously to create a descending or ascending moon sequence you merely need to combine exposures taken at the appropriate interval. What is that interval? The moon travels roughly its diameter in two minutes. About 2 minutes, 14 seconds to be more precise.  I recommend taking exposures twice or four times as often as that, however and just use every-other or every fourth shot.

Since I took a simple approach to blend the images I also elected to go simple in presentation. Rather than fight the many different colors inherent in urban night scenes, I used Picasa3 to convert to monochrome, crop and frame the combined image – here using an earlier shot than the “Golf Ball on a Tee” shot above.

In the Evening [5_057775+92]

Here is one last example of a descending crescent moon combined using Photoshop. Here I didn’t wait a full moon diameter time between images because it was a crescent moon:

Mamma Glows, Baby Shines

 This also illustrates why taking more frequent exposures gives more creative latitude.