Pixel Shift & RawTherapee 5.1

The major downside with Pentax’ Pixel Shift technology has been issues and artifacts produced when we have a scene with motion. Even when Motion Correction is activated in camera these unwanted effects occur. However, the people involved in the Open Source project RawTherapee, which is an advanced raw converter, have now come up with a solution in version 5.1 of the program.

We will in the following have a close look at several images shot with the Pentax K-1 set to Pixel Shift and compare how RawTherapee and Lightroom handle the files. I do not have access to other raw converters. We will also show how the Pixel Shift functionality is activated in RawTherapee.

The first image is a waterfall image shot by Chris Williams – the image is used with permission. The Gorge is located along the Columbia River just outside of Portland Oregon. A waterfall, depending on its size and power, will always cause some movement in the foliage closest to it.

The image is raw prepped in RawTherapee and edited in Photoshop. A fantastic shot by Chris – well balanced with a great comp and sharpness all across.

waterfall pixel shift.jpg

First we will check out how Lightroom handles the motion in the foliage and water:

Lr pixel shift.PNG

And this is how RawTherapee translates the file:

RT pixel shift.PNG

The difference is striking – I don’t think any further comments are necessary; the images speak for themselves. Kudos to the developers at RawTherapee!

There was almost no wind when I shot the following image an afternoon in January. The image is edited in RawTherapee 5.1.

Cabin pixel shift.jpg

Even though it was very quiet there was some movement in the foliage. As seen in the following close crop (4:1) Lightroom introduces this weird checkerboard pattern:

Lr pixel shift cabin.PNG

RawTherapee yields a much cleaner result, but some minor color fringing remains around the branches.

RT RT pixel shift cabin.PNG

A faster shutter speed would have preserved more details in the branches – solely my mistake. It is not unlikely that less blurry edges would have made things easier for the motion correction algorithm like seen in the waterfall example where well defined edges resulted in a perfect outcome with no color fringing.

The final example image has some light wave action going on (ripples). The scene is shot both with and without Pixel Shift. With Pixel Shift activated I shot one image with Motion Correction off and one with MC turned on.

The scene:

The scene

Lightroom – MC off (crop is 2:1):

Lr MC off.PNG

Lightroom – MC on:

Lr MC on.PNG

It seems to me that Lightroom handles the files in the same manner. In addition to these color shifts there are also weird patterns in the water.

Pattern (crop 3:1):

Pattern.PNG

RawTherapee – MC off

RT MC off.PNG

RawTherapee – MC on:

RT MC on.PNG

Whether Motion Correction is turned on or off RawTherapee produces an almost identical outstanding output for the two raw files. For both files edited in RawTherapee I set False Color Suppression Steps to 5. That seemed to give the best result.

And finally a close up of the non Pixel Shift image (Lightroom):

Not PixelS.PNG

This final crop shows without a shadow of doubt what a terrific job RawTherapee does with Pixel Shift images.

After this post was published I have learned that shooting all these exposures for the last example most likely was a bit redundant. It seems that I would have managed with one exposure set to Pixel Shift and MC on. MC and PS could then be turned off for the rest of the examples. Have of yet found out how this can be done…whether it is done in camera or in software.

How to turn on the Pixel Shift functionality in RawTherapee: Open the Raw tab (shortcut: Alt-r) when in the Develop/Editor module. Then under Demosaicing set Method to Pixel Shift:

Raw demosaicing.PNG

As of yet I have almost exclusively used Automatic to render the Pixel Shift images, and as seen in the example images the algorithm does an outstanding job when it comes to motion correction. The software also offers a Custom option which I played around with in order to see if I could get rid of or reduce the color fringing in the example image from the cabin scene.

I cannot see that RawTherapee’s motion correction algorithm in any way reduces the benefits of Pixel Shift which among other things is a tremendous boost of dynamic range.

RawTherapee 5.1 can be downloaded here and RawPedia is crucial for understanding how to use the software. I only have a few hours of experience with RawTherapee so currently I do not have the full overview of everything the program offers. Some claim RawTherapee has a steep learning curve, but my experience is that reading the instructions made available in RawPedia while playing around with the various sliders do wonders for learning how to use the software. It is of course possible to export the motion corrected image as an uncompressed tiff file and continue the editing in a software with which one is familiar.

Disclaimer: The scope of this article is not to provide an exhaustive array of examples on Pentax Pixel Shift images edited in RawThereapee, and it is by no means a scientific article, but hopefully it can give the reader an idea about what is now possible to achieve in regards to motion correction with Pentax cameras set to Pixel Shift.

Under the Stars

Ever since I got my first camera I have wanted to shoot the night sky and notably the milky way. This desire awakened in me after seeing many amazing images which in various ways portrayed the part of the milky way which stands out from the rest of the MW – the density of stars, gasses etc are much higher along this “band”. I believed I had to travel to the southern parts of Europe in order to shoot the milky way. Great was my joy when I one late August evening soon two years ago discovered it right over my head.

Moonlight Shadows.jpg

A setting moon casts a golden glow across a very still lake. This is a pano from four horizontals. I panned my camera upwards in order to capture as much of the sky as possible.

Where I live approx 60 km north of Oslo, Norway, the MW is very visible from around the middle of August until early winter. In August around 11 pm it is positioned along the south/north axis before it slowly turns westwards. I always shoot the MW towards the south or west as it is most distinct in those directions.

Our days are not exactly 24 hours – they are actually 4 mins short of being 24 hours. In other words, if the MW is seen towards the south around eleven in the evening in the end of August it will be seen towards the south 60 days x 4 mins = 240 mins (4 hours) earlier two months later.

I always carry the following equipment when doing night photography: Headlamp plus spare batteries and a regular torch, a cloth to wipe off damp from the lens if necessary, tripod, spare camera battery, camera and a fast wide angle lens. What is a fast lens? Lenses that are designed to offer apertures of f2.8 or lower are usually considered fast lenses or fast apertures. If you would like to learn more about aperture make a Google search and you’ll find plenty of resources.

Since full frame cameras or medium format cameras have larger sensor surfaces than crop cameras they will collect more light and hence yield a better result. A crop camera or aps-c camera will also produce more noise with less details at the same iso settings as a full frame camera. However, none of this should deter anyone with a crop camera from going out and enjoy the magic. And with the rapid advances in sensor technology we have seen the past years these differences between sensor sizes are not so pronounced as they used to be. You can read more about FF vs crop here.

Streams-3.jpg

A composite image – the waterfall and the MW are shot at different times and then blended in Photoshop.

But, how on earth do I compose my images when it is utterly dark? First of all, I drive to locations with very little or no light pollution so that the MW stands out clearly in the night sky. With some practice it is easy to locate. Next I push up the iso to max and shoot exposures at only a few secs to nail the comp. When I am happy with my composition I set the camera to around 25/30 secs. Longer exposure times than this will produce star trailing since the earth and the stars move relatively to each other. And I shoot with my lens wide open. For my lenses it means f2.8. In daylight I have tested where infinity is on my lenses so that I know where to set the focus ring. Auto focusing in the dark is not an option. The lens or camera (Pentax) has to be set to manual focusing. The next step is setting the iso. I try various iso settings until I have something that gives me a relatively even histogram. It is vital for me to check the histogram after each shot.

A decent straight out of camera histogram:

Decent histogram.PNG

But what if it is impossible to achieve a relatively even histogram? The histogram shows no clipping of the highlights but on the left side there is huge bump which starts as a straight line – no nice curving at all at that end. If you know your way around photoshop and know how to blend exposures you shoot one extra exposure for the shadows at for instance two minutes. If you want even more shadow detail you can for example set the aperture to f4 and reduce the iso and perhaps shoot a four minute long exposure for the shadows.

Trying to overly push the shadows in post when having shot at a high iso usually never yields a good result (see my end notes). There are magenta color casts all over the place and excessive noise. I am not very fond of images where the shadows only are a black ocean of nothingness, in other words, silhouettes. So for me it is vital to produce night images which offer a decent level of shadow detail. The Pentax K-1 comes with a timer in Bulb mode so making long exposures is a breeze. With my former cameras I always had to keep track of the time myself and that was an added stress factor for one who now and then is plagued with fear of the dark.

In my beginning days of shooting the MW I found that shooting it wasn’t particularly difficult. The tricky part was finding out how to edit these night shots. I spent numerous hours in front of the computer trying to find ways to make the MW stand out, to give it pop, contrast and so on. All my efforts have resulted in this tutorial.

Image straight out of camera:

Under the stars sooc.jpg

The finished image:

Under the stars finished image.jpg

The image is from the middle of Sept 2015 and the MW had turned quite a bit towards west.

Stellarium is a free program which can be downloaded to your desktop, and it shows the whereabouts of the MW at any given day and time of the day.

Turning on and off the headlamp all the time doesn’t exactly help our night vision so knowing where all the vital buttons on the camera are is a relatively good idea. And if you are shooting with others the light must be turned off save times when no one is shooting. Ruining others’ images because we haven’t done our homework isn’t very nice, to put it like that.

I have arrived at that shooting a pano of the MW this far north is a tad pointless. Firstly, one third of the MW is hidden from view. However, that part is visible for those living further south on this globe. Secondly, up here the MW is very “high” in the sky whereas for the southerners it is hanging much lower, something which of course simplifies things in regards to shooting panos. When that is said, it is of course possible to make panos like this:

Under the stars pano.jpg

End of sept 2016. Five 15mm verticals handblended in Photoshop. We had some aurora that evening as seen to the far right (north).

Shooting at a high iso is detrimental to the image quality. Both luminance and color noise are introduced liberally to our dear efforts at night photography. Lightroom offers a good raw noise reduction algorithm. The problem is that noise reduction softens the image and details become blurred so it is always a balancing act between noise and detail when we edit our night images.

There are of course a few workarounds. We can shoot our shadow exposure before it becomes too dark at a narrower aperture and much lower iso. Then we wait until it is sufficiently dark to shoot our sky exposure. But, if the luminosity values are too wide between the two exposures the blending can turn out to be a very painful affair. What I mean is that the shadow exposure will have highlights that are way too bright and we face fringing and weird artifacts along our blending lines. In other words, not a bad idea to have a third exposure that bridges the gap.

Shooting verticals can be a great way of capturing a larger portion of the MW:

Lodging.jpg

A second method of increasing the quality is using star tracking devices. They make it possible for the camera to follow the motion of the stars so that we can shoot much longer exposures than 25 secs for the sky and hence reduce the iso considerably. As mentioned in my Astro Tracer blog post the camera sensor is linear whereas a wide angle lens creates a curvature so that we may get star trailing in the corners (when shooting wide angle). The Pentax K-1 is equipped with an in-camera star tracker which enables the sensor to follow the motion of the stars.

The greatest enemies of night photography are clouds and the moon. Even a half moon washes out the milky way so that it becomes more or less impossible to shoot. So keep an eye on the moon phases.

I have of yet not tried focus stacking in the dark since that is a pretty time consuming affair. Instead I make sure that my tripod is fully extended so that I can achieve infinite focus (hyperfocal distance) from around 2,5/3 meters (distance from my camera/lens) when shooting f2.8 and 15mm. An object around 3 meters from my camera should then be in focus. There are several hyperfocal distance apps that can be downloaded to our cell phones. I haven’t tried any of these.

I always shoot auto white balance at night and adjust the WB in post. When it is iso 1600-3200 dark the sky is very blue and beautiful in my raw files, but as it becomes increasingly darker colors become washed out and the raws often get this yellow tint. To put it like this; things aren’t exactly static when doing night photography and that is one of the reasons why I prefer auto white balance.

Some end notes:

Some claim they getter a better result if they expose to the right. In other words, they boost the iso so that the histogram is pushed to the right. More light to the sensor they claim yields a cleaner image. Then we have this thing called iso variance. A camera with great iso variance can achieve better results at a lower iso setting than what the histogram suggests we should use. This means that we increase the exposure in post but yet achieve a very good end result.

For example if I get a balanced histogram at iso 6400 I opt to shoot iso 1600 and then push the exposure two stops in post. If the camera has good iso variance I will in many ways achieve a better result than shooting iso 6400. Notice that doubling the iso is the equivalent of one stop of light. Since a camera’s dynamic range suffers dramatically at high iso levels we will also achieve a better dynamic range at lower iso settings, and we preserve our highlights. Anyway, we have to experience on our own to find what works best with the gear we have.

From dpreview: “The K-1 is as close to being ISO Invariant as we’ve seen, meaning there’s no cost to shooting at ISO 100 and pushing the files later, rather than using a higher ISO. This means you can keep the ISO down and protect multiple stops worth of highlight information that would otherwise be pushed to clipping by the hardware amplification.”

The following image is pushed two stops in post. Exifs: Pentax K-1, Pentax 15-30, iso 3200, f2.8, 15mm, 30 secs.

Under the stars pushed.jpg

We will end this blog post with my very first MW shot ever – I haven’t bothered editing this particular image:

Under the stars first ever.jpg

Color Enhancement in Lightroom

An image pleasing to the eyes is a combination of many factors of which colors in my opinion are a major piece of the expression. Lightroom, Photoshop and many other editing programs come with many color enhancing tools. We will in this brief article have a look at two color enhancing techniques I apply frequently and which can be carried out very swiftly in Lightroom. Contrary to the HSL section in Lightroom these enhancements won’t leave any harsh transition lines between colors. The transitions are smooth and pleasing.

My favorite time to shoot is during the golden hour, that is, sunsets or sunrises. Sunrises are in the middle of the night this far north during summer, and since I am not a morning person I prefer sunsets during that season. The approaches we are to have a closer look at are perfect for golden hour images.

The image we will be working with (shot with a Nisi cpl):

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Below the HSL section in Lightroom we find the Split Toning section which is divided into two separate parts, Highlights and Shadows, which target different tonal values in an image.

After having adjusted the tonal values in Lightroom so that I have no clipping in either end of the histogram I open up the Highlights’ color picker in the Split Toning section. Click on the rectangular box and a new pop up window appears in which you can move a color picker around choosing whichever color you please. Here I will pick a warm color that accentuates and enhances the warm colors already present in the image. Be careful to not overdo it – clipped colors or over-saturated colors aren’t exactly very pleasing to the eye.

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Next I head over to Shadows and do the same as over save that I now will pick a cold color for the shadows, usually something bluish. Here I just add a very modest tint of the color of my liking, and I try to find colors in both sections that work together, that is, which are as complementary as possible.

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Very often what we do in the Highlights section will wash out the beautiful blues we have in the highlights, that is, in the sky or water. And usually we do want to restore our blues and not leave them too faded or warm looking.

This is easily achieved in the Camera Calibration section in Lightroom where we find four various sliders. I am only interested in the one at the bottom – the slider named Blue Primary. Push it to the right and see what happens.

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Not only does it give the image a pop, it adds contrast, enhances colors and restores the blues in the highlights. Again, try to avoid overdoing it. Now and then our highlights might become clipped when we have pushed the blue slider to the right which means we have to readjust the tonal values in the image with the help of the Highlights, Whites or Lights sliders in the tonal value sections in Lightroom.

It is at this point I may turn my attention to the HSL section in Lightroom and make small adjustments to hue, saturation and luminance – very gingerly to avoid transition lines – I usually zoom into the image after making adjustments in the HSL section to see if I have produced unwanted “artifacts”. Usually I also push the Vibrance slider a tad to the right.

I do a lot of midtones work in Photoshop and use various masks to target specific tonal values or colors which always result in a color boost so that my personal preference is to hold back on the above mentioned adjustments in Lightroom.

On the Bulbous Side of Things – Review of the Nisi 150mm Filter System

Obtaining good filters for lenses with bulbous front elements has often been a challenge for me (and many others), but that was until I came across Nisi Filters which does not only produce “regular” 100 mm filters, but also offers very good 150 mm filter system solutions for a wide array of lenses which do not take regular filters, like for instance my Pentax 15-30.

We will in the following first have a look at the filter system itself before we move on and review some sample images. The review is not meant to be an in-depth scientific treatment of the filters. The point of view is more on the daily use side of things for the average photographer, as it were.

Pentax 15-30 and the 150 mm system filter holder:

20170429_104123

Attaching the filter holder to the lens is a very smooth affair which only takes a couple of seconds. A screw on each side of the filter holder secures it to the lens:

20170429_104029

It is actually possible to stack three filters in the filter holder:

20170429_055936

The built quality of the holder is outstanding. “NiSi 150mm filter holders are made from aviation-grade aluminum with single element processed by CNC machine with Matte black frosted finish on the surface. The screw accessory are all made of copper and with black nickel plating. It’s durable and will reduce the influence of stray light on the imaging.” (Nisi Filters Australia)

The filter holder and a 0.9 soft filter:

20170429_055236

The filters come in these protective and beautiful pouches (unfortunately the filters do not grow on trees ;)):

20170429_104428

The four filters I have tested:

  • 10 stop – long exposures for beautiful skies.
  • 6 stop – long exposures (notably when dusk has set in and I haven’t time to wait for 2-3 mins long exposures) and waterfalls.
  • 0.9 soft – balancing the exposure, that is, darkening the sky so that it is possible to capture a high dynamic range scene in one exposure. We usually use a soft filter when we do not have a very defined horizon line.
  • 0.9 soft reverse – balancing the light during a sunset/sunrise when we have strong highlights around the middle of the frame.

One stop of light is doubling the exposure time. In other words, if my exposure reading in camera for instance is 1/20 sec and I then insert a 6 stop filter I will calculate the needed exposure time in the following manner: 1/10 – 1/5 – 1/2 – 1- 2 – 4 secs. The Pentax K-1 comes with a histogram in Live-View mode so that my math is at times a tad superfluous. 0.9 means that the filter can even out the light with approx 3 stops if necessary. Soft means that the filter gradually goes from 0 to 3 stops starting from approx the middle of the filter. A hard filter on the other hand will have a very defined “starting point” and is used for example when we are shooting an ocean scene which usually has a very clear and defined horizon line.

The three following sample images are only given some basic adjustments in Lightroom.

150 mm en

Sunrise Tyrifjorden, Norway. Pentax K-1 and Pentax 15-30. Nisi 10 stop and Nisi 0.9 soft at iso 100, 15mm, f11, 110 secs. Neither the 10 stop filter nor the 6 stop filter produce any color cast. They may warm the image a tad, but that may also be the camera’s auto white balance. The 0.9 soft filter did its job perfectly and the raw file was very well balanced in terms of light – the image was shot just before the sun was about to emerge on the far left. Worth mentioning is that this was a very high dynamic range scene. Some cloning work may be necessary around where the sun is about to emerge (those more whitish spots to the far left).

Zero color cast is of course of great importance to the photographers who prefer jpg. For those shooting in raw that is perhaps of less interest since the white balance can be adjusted in post.

I always insert the graduated filter (0.9 soft) when the camera is in Live View mode so that I can see how the filter impacts the scene and how far down I have to push it to obtain the balance in light I would like.

The same scene without any filters – shot immediately after the 110 secs exposure:

150 mm to

What is plain evident here is that there are several parts in the top left corner that are clipped and we lack highlight detail notably along the beautiful cloud in the very top left corner of the frame. In this instance exposure blending would have been necessary to rescue those highlights which means shooting extra exposures and blend those in for instance Photoshop. Exifs: iso 100, 15mm, f11, 1/10 sec.

Due to advanced nano coating flare is incredibly well controlled by the Nisi filters. Let’s have a look at an image shot after the sun had risen.

150 mm tre

Nisi 0.9 soft and iso 100, 15mm, f22, 0.3 secs. First of all, the scene is very balanced in terms of light. Secondly, the only flare I can see is a red curved line at the end of sun’s bottom right spikes which shouldn’t be too difficult to clone out. That flare may just as well be produced by the lens or by dust on the lens or filter. A couple of notes: For a scene like this I would also shoot an exposure at for instance f8 or f11 to use as a base exposure in order to eliminate diffraction caused by the narrow f22 aperture. I would usually also shoot one exposure with a finger or several fingers covering the sun to have one flare free exposure which I blend in where necessary. This was, btw, a few minutes past six in the morning and we are in the end of April.

Using filters and capture everything in one exposure have several advantages: We can manage with less shots and hence save space both on memory card and hard drive. Post work is simplified considerably when we can omit exposure blending. And perhaps most importantly; many who shoot raw only use Lightroom for their editing so that exposure blending is outside their reach.

There is absolutely no vignetting when using the 150mm filters. Nada! It is possible to purchase 150mm polarizers to the system. In order to achieve desired polarization the filter holder has to be rotated (which is a part of its design) and that means that the use of a polarizer more or less cancels out the use of a graduated filter.

What about sharpness and details? Let us have a look at two very close crops from our first two sample images. As mentioned those images are edited in Lightroom and only basic raw sharpening is applied. The top cropped image is Nisi 10 stop and Nisi 0.9 soft. The bottom cropped image is without filters.

150 mm fem

150 mm seks

There is no loss of details and sharpness when using the Nisi filters (which perhaps is easier to see on my computer than on this blog site).

Nisi Filters is a China based company which produces high end filters to a reasonable price. The company has engaged a host of profiled photographers as ambassadors for the brand as a marketing strategy, but also as a way of receiving feedback on their products. What strikes me is Nisi’s drive to continually be in the forefront of things and the developers willingness to take into account feedback from the ambassadors and adjust things accordingly.

The filters are produced in high quality optical glass made in Japan and Germany. A well known fact is that glass is far more scratch resistant than for instance resin – after a year’s use my filters are still scratch free. Furthermore, the filters have various nano coatings which make them water repellent, finger prints are very easy to remove, flare resistance is outstanding and infra red light is prevented from reaching the camera sensor.

We will finish the review with an image shot with the Nisi 0.9 soft filter (150 mm) – the image is edited in Photoshop:

150 mm fire

An overview of which lenses that currently are 150 mm system compatible is found here.

Pentax K-1 & Pixel Shift

The Pentax K-1 comes with many unique, practical and handy functions of which one is Pixel Shift. When the camera is set to Pixel Shift it takes four subsequent exposures at one pixel increments. One of the benefits is a huge dynamic range boost to a camera which already offers stellar DR. Four exposures provide more light to the sensor than one. Pixel shift is also supposed to produce greater sharpness and increase the level of detail. You can read more about Pixel Shift at DpReview and Imaging Resource

It is important to note that this function works best when there is no wind or motion even though the K-1 comes with a motion correction setting which output is best handled with Ricoh’s bundled software; SilkyPix. A tripod is a must when shooting in Pixel Shift mode.

We will in the following have a closer look at an image shot with the Pentax K-1 set to Pixel Shift and no motion correction since it was very still that evening. I will chiefly let the sample images do the talking. A Pentax 15-30 lens is used.

The raw file straight out of camera:

Pixel shift straight out of camera

Lightroom’s interpretation of the raw file’s luminosity values:

Pixel shift histogram sooc

The image after raw prepping in Lightroom:

Pixel shift edited in Lr

The histogram after raw prepping:

Pixel shift histogram Lr

The finished image after being edited in Photoshop (this image of the cabin has never been published before):

Pixel shift edited in Ps

Histogram after Photoshop:

Pixel shift histogram ps

The image below is a very close crop of an often problem area with my former cameras, that is, noise and artifacts along the right edge and top right corner of the cabin’s wall. Note that no sharpening or noise reduction are applied in Photoshop. That area is now incredibly clean in Photoshop and Lightroom, but a bit less so on here due to jpg and image compression:

Pixel shift close crop ps

It is also important to note that since the sensor receives so much light it is vital to underexpose the image quite a bit to avoid highlight clipping and loss of highlight detail. The K-1 is a beast when it comes to picking up shadows without adding grain, noise or artifacts. I exposed this image at -3EV using average metering (Pentax K-1 language: Multi Segment metering).

This was a very high dynamic range scene with pretty strong highlights from a setting sun and shadows were well in to dusk, to put it like that. Yet, the Pentax K-1 offers a very clean image with plenty of highlight and shadow detail – and that from a single raw file. In other words, no need for exposure blending which now and then can be a challenge with trees reaching into the sky.

Rules in Photography

Disclaimer: The images added to this blog post are just images – they are not meant to illustrate anything at all.

It is not unlikely that I am a bit childish when I have this strong negative reaction when a newsletter arrives in my inbox where the heading for instance reads: “5 rules to follow when composing an image” or something similar.

I have a lot of personal preferences when it comes to photography. However, I try to avoid making rules or laws based on what I prefer.

floating rock tyrifjorden

Sunrise Tyrifjorden, Norway. Pentax K-1, Pentax 15-30

In my thinking photography is a creative way of expressing how we see things or a way of mirroring our personality with its likes and dislikes. And none of that can be contained within the boundaries of various rules. I honestly don’t think it is healthy to legislate taste or create a framework on how things ought to look.

I would have been far more positive if the heading read: “10 approaches to consider when composing a landscape image”.

When I am out shooting I solely work on intuition based on what my eyes see through the viewfinder, and how what I see impacts me. Do I get a sense of harmony and balance, or does what I see create a sort of disharmony in me? I notice I have a tendency to gravitate towards the golden rule or divide things into thirds, but far from always.

Jevnaker kirke pentax

Jevnaker, Norway. Pentax K-1, Pentax 70-200

I also notice that I prefer simple compositions and often try to avoid complexity or compositions with too many disturbances. Sometimes I like lines – at other times lines do not work at all. Quite often I like to have strong foreground elements that work as anchors or balance things or add visual interest to a scene. However, that is not either a rule I follow simply because it may not be possible to find a foreground that works, or that I omit it completely for other reasons.

Admittedly, I have deleted thousands of raw files which for various reasons didn’t look as appealing on the computer screen as they did out in the field. At other times the opposite is true. And sometimes I know I have images on my memory card that will be deleted, but I shot them anyway just for the fun of it.

When all this is mentioned I have no problems admitting that “rules” can be of help in the beginning helping people towards a sort of structure while they work towards carving out their own way. For my own part I cannot draw conclusions or make rules based upon the complex interactions between eyes, brain and emotions – usually it is impossible to articulate why something works in my eyes or why something doesn’t work. I can only to a certain degree articulate what I notice about myself.

Full moon rising

Full moon rising – our house is approx 500 meter straight ahead.

First Impressions Astro Tracer

The Pentax K-1 comes with an inbuilt astro tracer function which makes it possible to extend the exposure time during night shots considerably. In other words, we can reduce the iso and get cleaner shots with less noise. Pentax’ floating sensor technology makes this possible – the sensor follows the movement of the stars. I have only been out testing the feature once, and I merely shot wide angle, that is, 15 mm.

The astro tracer did its job perfectly after I had followed the guidelines and calibrated the inbuilt GPS. However, it cannot counter wide-angle distortions. In other words, the center of the frame is pin sharp whereas the extreme corners show trailing. 60 seconds seemed to give the best result using such a wide angle lens as I did.

Rising Up

The finished image from that evening.

I am not a physicist but have read that since the sensor is linear whereas the wide angle lens yields a curvature these effects of trailing are bound to occur. If we narrow the focal length to for instance 24mm or even 50mm the star trailing in corners will more or less be cancelled out even when increasing the exposure time. To put it like this: the narrower the focal length the longer the exposure times without having trailing in the corners.

If we prefer to shoot wide angle a fix can be as follows: Shot 60 seconds or longer for the center and shoot one regular exposure at 25/30 secs for the extreme corners and blend the two in Photoshop. With the milky way in the center of the frame we can have a pin sharp and very clean MW whereas the corners will be a bit more soft since they will require more noise reduction due to a higher iso.

Samle images (Pentax K-1 and Pentax 15-30):

15mm iso 1600 90 secs f2.8 center:

15 mm 90 secs center iso 1600

15mm iso 1600 90 secs f2.8 right corner (I was shooting north west) – star trailing is well controlled:

15 mm 90 secs right corner iso 1600

15mm iso 1600 90 secs f2.8 left corner (not sure why there is more trailing in the left than the right corner – see last samle image for a possible explanation):

15 mm 90 secs left corner iso 1600

15mm iso 1600 60 secs f2.8 center:

15 mm 60 secs center iso 1600

15mm iso 1600 60 secs f2.8 right corner (less star trailing than 90 secs):

15 mm 60 secs right corner iso 1600

15mm iso 1600 60 secs f2.8 left corner (again more trailing in the left corner – Worth mentioning that this was in the middle of January just north of Oslo, Norway. An unverified theory I have is that the earth’s velocity relative to the stars is bigger towards the south than towards the north that time of the year this far north, and this may explain the difference between the corners – remember I was shooting north-west. The lens is, btw, not the guilty part in this – it is not askew in any way):

15 mm 60 secs left corner iso 1600

Further tests will be carried out as soon as I get a chance and then I will direct the camera towards the south.

A touch of Aurora

Northern lights are most common in the northern parts of Norway, but at times the sun activity is so strong that the lights are visible also where I live, that is, 60 km north of Oslo. On April the 22nd the Aurora forecast suggested kp 6 or 7 during the night/evening, which meant that the aurora might be visible pretty far south. I was anxious to further test out the Pentax K-1 and what it could deliver after dark had set in, so I headed out.

After waiting for about 1 1/2 hour it was sufficiently dark around 23.30 to actually see the greens coloring the northern horizon and I began shooting. Sky/highlights were 30 secs at iso 3200 and iso 6400 as it became increasingly darker. 30 secs turned out to be a tad too much since that resulted in slightly stretched stars in the corners at 15mm. 25 secs would have been better. My exposures for the shadows were at iso 3200 and 90 secs. All shot wide open, that is, f2.8. According to various reviews the Pentax 15-30 is one of the sharpest lenses out there wide open. At f2.8 it even beats the renowned Nikkor 14-24.

Have to admit I had a great time out there in the dark shooting various comps for almost two hours, and my at times bothersome fear of the dark was forgotten as I was embraced by the moments.

The next day I reviewed the raw files and as far as I can tell the Pentax was definitely on par with my Canon 6D which has been lauded for its very good high iso performance. Noise and color noise were very well controlled by the Pentax and it yielded images far more detailed than what the 6D delievers. My shadow exposures were crisp and clean, that is, no magenta color cast appeared in dark areas when bringing up the blacks and shadows sliders in Lightroom. I was also impressed by the dynamic range the Pentax offered at the two aforementioned iso settings.

The first image I have edited from that night (a blend of two exposures – under the tab “Learning” you find a link to how I blended the two):

NL pentax

Note: Only basic raw sharpening and noise reduction are applied to the image in Lightroom.