Pentax K-5 Time Lapse Guide

Overview

The Pentax K-5 is an extremely competent camera, and offers an APS-C sensor with best of class low light performance.   As is typical with Pentax, there are many in-camera processing and shooting features which can be used in combination, maximizing the flexibility of the K-5.   The K-5 includes 3 axis image stabilization, in camera HDR, flexible bracketing, in camera LCA and geometric distortion correction when used with Pentax lenses.   It makes an excellent instrument for time lapse work for a number of reasons, but it also presents some difficulties which can make it somewhat more difficult as well.   The aim of this guide is to cover these features broadly and how these fit into the usual aspects of time lapse.

Timing – Free Running

The K-5 offers a Lo speed continuous shooting drive mode which will actuate the shutter at a rate of about 1 – 2 frames / second.   After the initial in camera buffer is filled up by the first few shots, the speed of shooting is limited by the write performance of the card, and by whatever in-camera processing you choose to do.   Continuous shooting does not work with many modes, including HDR, so you may still need a external intervalometer.   But for short period time lapse, covering period up to 4 hours, I almost always use this continuous shooting mode.

You don’t want to sit there holding the shutter button for 4 hours.   But for $2.95,  you can create a plug which does that for you.  The K-5 has a wired remote port.   It accepts a standard 3/32″ stereo headphone jack.

We short the tip and the ( common ) ring leaving the middle ring unconnected.

 

Set up the camera as desired, shove in the plug, and you are shooting.   This same “bulb plug” can be used for CIF ( catch-in-focus ) shooting popular with birders, or if you want to make your K-5 into a high quality game camera.

If you want more precise timing, longer period, etc., any dry contact timer can be used to construct an intervalometer using the above info.   A photo transistor could be used to start shooting when there is light.

Limitations of Continuous Shooting

There are, regrettably, a number of limitations using the continuous drive modes.   First, the camera is free running and so there is no guarantee about the frequency of the shots.   I don’t find this to be an issue, as the K-5 is generally limited by the speed of the memory card.

In-camera processing, like CA and geometric distortion correction, or HDR, adds a very reliable, fixed per-frame overhead which yields a more constant frame rate.   Continuous shooting is not appropriate for long period shooting, where you will run out of storage.

Many of the more interesting features cannot be combined with continuous shooting, including bracketing, stacking, HDR, and so on.   For those situations, you will need to use normal drive mode and a wired or IR intervalometer.

Wired vs IR Intervalometers

You may be thinking, all things being equal, why would you use an IR intervalometer?   The K-5 has a significant advantage over other cameras in terms of weather resistance.  An IR remote allows you to keep the camera completely sealed.   If you want / need to use a wired remote, It is possible to modify the plug above to include a gasket to seal the jack, but with an IR remote you add no additional risk.

I have had good luck with the Gentled Auto.   Its small, simple, easy to weatherproof, and very reliable. If you already have an Auto for a different camera, you can use it along with a wired phototransistor and the stereo jack to rig a “wired” timer.

The small set screw on the front sets the interval.   An easily accessible jumper on the inside sets the range from short to long periods.  Frankly, I’ve never needed to use the long period setting.

Special Drive Modes

Assuming you use an external timer of some sort, you can use the K-5′s various drive modes for time lapse work.

In camera HDR is very nice and does a good job.   The only problem with the HDR mode is the extensive processing time – which limits the frame rate.   If you can get away with 1 or 2 frames / minute, HDR will work perfectly.   If you want to do HDR at a higher frame rate, use bracketing and do your HDR in post.

Breaking the Rules

I’ve been told there are many rules to time lapse photography.  I’ve never been that good with rules.    Lets go through a bunch of them

Rule 1 – Fixed Aperture

To the extent possible, use a fixed aperture and let the camera adjust ISO and shutter speed.  Changes in aperture result in changes in vignetting.   Constant vignetting can be corrected in post if it is annoying, and normally is it not.   Adjusting the aperture on any lens changes the vignetting and this can be noticeable, and as the camera does this, it can be noticeable on your finished videos.  Depending on the lens, aperture adjustments can also defocus your shots.

You can see an example of the effect here, where the changes in aperture impact the far field focus.    As always, expecting this effect and planning around it will save your time lapse series.  To avoid this issue, set your focus with the lens wide open, then when the camera selects different aperture values, they will generally be well focused.


Rule 2 – Fixed Focus

Unless you really trust your camera, or are a masochist, use manual focus.   This avoids wear and tear on the focus mechanism, jitter in the focus solution, and the unknown…   If that nasty bird flies by, or whatever, you know the camera will do what you want.   The K-5′s magnified live view can be used to get very sharp focus.   You can then change the aperture to test the focus.   If its well focused over the range of aperture values you’d expect to see, you will have a much better series.

 

Rule 3 – Fixed Exposure – Not!

It is often necessary to use automatic exposure for time lapse work.  Many avoid this because of the potential for flicker.   The K-5 has a fairly stable exposure program and will produce relatively flicker free results when you use center weighted average metering.   Unfortunately, the K-5 does not have a full frame “average” metering mode like some cameras, notably Fuji.   The larger the average, the less jitter in the metering.

Rule 4 – Always Oversample

Many people approach time lapse by shooting the minimum number of frames they need. Don’t. Shoot at least 4x the number of frames as you think you’ll need. You can use every N frames and toss the rest. But you cannot re-shoot if you under estimated, or if you find a section which is overly fast of for which you want a slower speed vignette. The extra frames are not wasted. You can stack them, which inherently reduces flicker and noise. You can pick the best frame of a set and use it. For example, if a big crow decides to fly in front of the camera, you can omit that frame without it showing in the final video.

Oversampling also goes for pixels too. 1080p video requires only 2MP stills, but if you shoot 6MP stills, or larger, then you gain several advantages. You can pan / scan full crops from these without fat pixel zooming. Downsampling acts like or is pixel binning, so there can be an advantage in terms of noise.

My strategy is to figure out how many frames I’ll need and ensure that every byte of my memory card is filled by the end, shooting more / larger / higher quality frames. Then you have a lot of flexibility in post production.

Rule 5 – Memory Rules!

Use the biggest memory card you can afford. Format it in the camera prior to the shoot. And always use the largest / best quality stills you can given the number of frames you want to shoot. I usually use the 6MP *** setting on the K-5. This gives about 9000 frames / 32GB card.

Rule 6 – Use User Modes

If your camera provides user modes, for God’s sake use them!   The K-5 will allow you to save most settings into a user mode.  This allows you to build a time lapse mode(s) ahead of time.   If you need to stop and resume a shoot, its much easier to do so when most of the settings are dialed in.

Rule 7 – Disable Image Stabilization!

Always, always, always disable any image stabilization features. These are designed to stabilize a single shot, and are not repeatable from shot to shot. That is to say, you will actually introduce shot to shot variations when the OIS is enabled either in camera or the lens. You can see an example here. With OIS disabled, the images are rock solid even with an enormous zoom, see here.

You have to assume your camera will be stolen or damaged if you leave it exposed.   You may come up with a clever way to protect it.   But the best way is to ensure you have control over the location.   Locked roof tops, locked vehicles, locked enclosures will make you eel more secure about leaving your camera out for long series and expand the range of your work.

In Camera Interval Mode

The K-5 has a built in interval timer.   Its basically useless for anything serious as it is is limited to 999 shots, and does not work with many of the useful features of the camera – like HDR and so on.  But it is free, and does work.   It also has the advantage of acting like an alarm clock, where the K-5 will basically fall to sleep between the shots and wake up to take the next.

 

Auto Exposure – The EV 0 Issue

The K-5 implements a hard limit on the minimum exposure it will compensate for.   This limit is around EV 0 for whatever lens you are using.   I have a huge problem with this design. Its not consistent with other makers who will easily dig far deeper and try to convert any scene into daylight, with perhaps a cap placed on the length of the exposure.   With Fuji, this is usually 4 seconds, and the Pentax Z series will actually let the shutter run out to 8 seconds.   This makes the K-5 far more difficult to do day into night transition time lapse work, and it, by far, its biggest issue for time lapse. Based on EXIF data, the K-5 does, in fact, meter the scene far below the limit, but chooses not to go there.

Live View vs OVF

When using OVF and / or using phase detection focus, the K-5 has to actuate its flip mirror each time the camera takes a shot. In a long series, this can be thousands of actuations. To reduce wear and tear on the camera, it might be appealing to force it to lock up the mirror for the entire series.

Unfortunately, the K-5 does not allow you to perform this very basic function while in continuous shooting mode. Instead you can use Live View mode with contrast detection focus. This will allow the mirror to stay locked up so that only the shutter ( and perhaps the lens motors ) is being actuated during shooting. This should greatly extend the life of the flip mirror. Using fixed focus and aperture, similarly, reduce the amount of stress you place on the camera.

Live View

As mentioned, Live View has the advantage of saving your flip mirror some abuse.   It also will meter a couple stops below where the OFV metering will give out.   For example, given the same scene, the OVF metering might give 1600 ISO, F3.5, 1/12″ exposure.   The Live View might give 1600 ISO, F3.5, 2/3″ which is to say a full 2 stops greater.

Using Live View with Continuous Shooting will not vary the exposure.  It will be fixed to the exposure solution computed when you take the first shot.   This is a major disappointment when you get caught by this issue.   This is fine if you want fixes exposure, but use manual mode instead.

Since Live View can provide additional operating range for the AE program modes, and reduced wear, you may want to use it with an intervalometer.   Then you have these benefits.

OVF

The OVF, when used with Continuous Shooting will re-evaluate the exposure for each shot down to approximately EV 0.   This is necessary for scenes with variable lighting conditions.  The disadvantage is the actuation of the flip mirror for each shot taken.   I don’t know how worried to be about this.   If worried about this, use Live View and an Intervalometer.

In Camera HDR

To me honest, you can get some nice effects from the in-camera HDR.   However, this is not available for continuous shooting.   You can use an external intervalometer with a longer period ( 30 – 60 seconds ) and let the camera do the processing for you.

Power To The Camera!

A fully charged battery will, when you avoid in camera processing, last almost 4 hours!   I got more than 9000 shots on a single charge.  But what to do when you need more?  You can buy the K-5′s AC adapter and then power that some how.   Or if you are cheapskate risk taker like me, you can build your own which runs on any DC source, like a car battery, solar pattery, or 12V AC supply.

A DC-DC supply, as described in the post, is ultimately much more efficient, and hence requires far less solar panels or batteries, plus its a lot less expensive.

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