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Article in VK

Inger Nilsson, reporter at the local news paper Västerbottens-Kuriren (VK) in Umeå has written an article entitled ‘Teknikintresset gav framgång’ about me and my brother Jonas. The article (only available in Swedish) can be read online at VK’s website.

Länk till VK’s artikel

Creative fun with tilt-shift lenses

Tilt-shift lenses are not that common and give the photographer more dimensions to work with. They are really flexible and can be used to modify image perspective and control the focus plane. A common opinion among tilt-shift users is that they are a little bit challenging to use and require more time, knowledge and practice to master.

Köln Hauptbanhof captured with Canon TS-E 24mm f/3.5L.

This article starts by explaining the basics, followed by common examples where tilt-shift lenses can be used, some example-images and finally some personal opinions and tips on how to use tilt-shift lenses in your daily work.

Tilt-shift mechanics

A tilt-shift lens is a lens where you have at least two additional controls. Usually you are able to adjust the tilt amount, shift amount, rotation angle relative the images sensor plane and sometimes the rotation angle between tilt and shift axis. On the lens there are four knobs and one or two small lock-buttons to release the rotation. Two knobs control tilt and two knobs control shift. One knob is used to lock the tilt axis and the opposite knob is used to control the tilt amount. Perpendicular to them there is one knob to lock the shift amount and one to control the shift amount.

Shifting the image plane

By moving the lens horizontally or vertically in front of the sensor it is possible to select what part of the image circle that will illuminate the sensor. This has not only a cropping effect on the image, by realigning the camera different perspective adjustments can be done. This is often used in architectural photography where the vertical lines in an image need to be straight. When shooting buildings from street level they appear to fall backwards which is not really nice. Adjusting the perspective will not only straighten the image but also align the focus plane with the building face.

Tip: This effect can be created with any camera without using a tilt-shift lens by using half the sensor area and cropping away the other half of the image, with the obvious drawback that the resolution will be lower. To do this just shoot the building with the horizon in the central focusing point. Note that this requires a much wider lens.

Shifting and stitching

To create a high resolution image by stitching multiple exposures together is very easy using a tilt-shift lens and a stable tripod. This is done by having the camera in manual mode and taking photos while shifting the images plane. It will be really easy to stitch the images together into a larger image to get more pixels and a wider coverage. The stitching process will be really simple because all lines in the image will render correctly, as we do not move the lens. Instead we just slide the sensor.

Tip: This can be done without a tilt-shift lens by taking a panorama sequence. Just have a longer lens and capture multiple shots adjacent to each other. The drawback with this method is the larger distance to the object that may be needed to avoid too large perspective-artifacts because the camera has to be repositioned between each image. In complex scenes or scenes with objects close to the camera some editing might be needed. Read more here about how to create panorama-images and how to stitch multiple exposures together.

Pro tip: Shifting the lens can be very useful when making a front photo of something with a flat mirror surface without having the camera visible in the image. Just move the camera off center from the mirror so the reflection excludes the camera and then shift the lens until the mirror frame looks good.

Tilting the image plane

When tilting the lens, the focus plane is not aligned any more with the sensor and this can be used to optimize the focus of an image.

Either the focus can be extended into the scene to allow for an image with a larger focus range or it can be used to minimize the amount of focus in the image. Extending the focus is often useful for product photography or macro work. The focus can be placed along a front panel of a device or to fit some printed text in the image. Minimizing focus is used to isolate an object or to remove unwanted details.

Tip: This can be done with a normal lens and photo stacking, i.e. merging of multiple images with different focus distance into one image.

Pro tip: Combining stacking and tilt can be very convenient to avoid error in the stacked image along edges not aligned with the focusing plane.

Details from Cologne Cathedral, focus has been limited by tilting the focusing plane using a Canon TS-E 24mm f/3.5L

In my work the tilting effect is most valuable and I normally use this effect to limit the focus in the image to the important part. A bad scene with a lot of distracting elements may look very nice if the focus is reduced to only the critical detail.

Tip: This effect may be created at least partially with Photoshop or similar programs. Usually the effect is more easily to control in software even though a perfect tilt shift image requires a depth map (z-information). In most simple cases you will not be able to see the difference unless you study the image carefully. For advanced tilt-shift filters a depth map is required and may be drawn by hand if the scene is simple and mostly contains objects that can be separated from the background.

This effect can also be used to shoot with a larger aperture than normal and still having two different object distances in focus in low light conditions, enabling faster shutter speed to be used.

Drawbacks with tilt-shift lenses

The main drawback with this lens type is that the effect is somewhat difficult to control compared to if the effect is added in post-production. In that case there is a much larger chance that the artificial focusing plane can be placed to achieve the best result. The amount of defocus is controlled by the F number and this has also to be decided on when taking the image. If you have a camera-lens combination with some focus mismatch the area in focus will be on a different spot in the recorded image. This can be really annoying and can be avoided by using live view to check the focus.

Tip: It might also be a good idea to have an image without blurring in case the results are not as expected.

A tilt-shift lens is also both heavy and bulky, and takes up valuable space in the photo bag, but when used correctly on a suitable target the effect is mind-blowing.

I do not like the lens-baby kit. That toy lens just creates unsharp images – 1 out of 100 exposures might be good. If used right a true tilt-shift lens is something completely different. The main problem with the lens baby is the crappy optics. You can see a tilt-shift lens as a lens baby with much better optical performance.

Fontain in Koeln city captured with Canon 24mm f/3.5L

Overview of Canon tilt-shift lenses

  • Canon TS-E 17mm f/4L
  • Canon TS-E 24mm f/3.5L now replaced by Canon TS-E 24mm f/3.5L II
  • Canon TS-E 45mm f/2.8
  • Canon TS-E 90mm f/2.8

Canon TS-E 17mm f/4L is a very special lens, the widest tilt-shift-lens on the market and mainly designed for landscape work.

Canon TS-E 24 f/3.5L is the most common tilt-sift lens because it has a very useful focal length and has been sold in higher quantities due to the L quality label. The most important improvement between TS-E 24 f/3.5L and TS-E 24 f/3.5L II (except for sharpness) is the ability to rotate the lens between the tilt and shift mechanics. This is new and a good improvement compared to the old one that requires to be taken apart using a small screwdriver or sent to a Canon service center to do the change. The old version was only able to be configured in two predefined positions perpendicular to each other, while the new can be independently rotated.

Canon TS-E 45mm f/2.8 is probably the most universal tilt-shift lens. It is also an extremely good 45mm lens with spectacular sharpness and optical quality. This lens is very useful for medium sized product photography. Here is a product photo of another lens captured with Canon TS-E 45mm f/2.8.

Canon TS-E 90mm f/2.8 is best for product photography of smaller objects or macro photography. It is probably the tilt-shift lens with highest optical performance.

If a branded tilt-shift lens is out of reach try to rent one or buy a cheaper one, for example the Samyang T-S 24mm f/3.5, which is made in China by Rokinon but the build quality feels good and the price is half compared to other well-known brands.

Prototype of Samyang tilt-shift lens T-S 24mm f/3.5 on dispay at Photokina, a cheaper alternativ made in China by Rokinon.

Best practise

It is very tempting to use especially the tilt effect in every other image. This is the most common beginner’s mistake, but not every image gains from being partially blurry. The perspective correction is more subtile and works very well on non-human objects. But again, do not over use it.

While tilting the lens the image quality in the enlarged part of the image will suffer slightly, because the active part of the lens is closer to the border of the optical circle. Technically both tilting and shifting the lens lowers the quality of the image. This is very clear on the TS-E 24mm lens where even some of the scales on the lens have been painted with red color to make sure the user has a really good reason to go so far out towards the optical edge of the image circle. A good recommendation is to not tilt or shift the lens into the red area unless you know what you are doing.

Focus has been limited to make this Koeln ambulance image more dramatic, Canon TS-E 24 f/3.5L

The automatic metering does not work with this lens. You need to do test shots to get the measurement correct. Another method is to measure in neutral position but that is very awkward, because it is difficult to go back. The exposure between the measured and the actual light level might differ up to two full stops. This is not a real problem, unless you are using the full automatic mode which I do not recommend on any tilt shift lens. Canon extenders seem to be usable with the different tilt-shift lenses even though I do not see the point of trying that. Note that the focal length and aperture is not reported correctly in this case. Extenstion tubes can be used on tilt shift lenses but the tilt effect will behave differently than without the exension tube and the tilt amount might not be enough. For macro it is better to use a high quality standard lens and a bellow with tilt function.

Using the control knobs can sometimes be a little bit cumbersome as they are really small and it is easy to forget that the axis has been locked with the lock knob. A common concern with this lens is broken tilt and shift knobs. Never use force while working with this lens because it might break, and remember to put it back into locked neutral position before packing it into the camera bag.

The tilt effect (narrow focus) has to be aligned with the light and spot on the important thing in the image, otherwise the result will look strange. That is the reason that tilt shift lenses tend to require a tripod and a careful operator.

Conclusions

If you are uncertain on which tilt-shift lens to buy and you do not know exactly what you are going to use it for, I think Canon TS-E 45mm f/2.8 might be the best choice. It is the most versatile tilt-shift lens and also an extremely good (manual focus) standard lens. When not shifted or tilted the huge image circle and extra-large optics create an extremely good normal image. There are not that many copies sold, so it is more unusual on the second hand market compared to the TS-E 24mm f/3.5 which is one of the sharpest 24mm lenses on the market.

Remember that focusing is manual, and that tilt-shift lenses are more useful on full frame cameras. Since an APS-C sized sensor only covers the central part of the image, full format tilt-shift equipment does not work that well.

I recommend tilt-shift lenses to anyone that is interested in photography. Remember that using a tilt-shift lens requires some training and not everyone will love it immediately. I have to end this article with a miniature style tilt-shift image that is not created with Photoshop, but with a true tilt-shift lens.

Munich city center, tilt-shift style miniature effect created with a Canon 24mm f/3.5L lens.

Photo tips: Reminders for professional photographers

Probably most of the following tips are known but a reminder is always good.

Do not ruin your photos in post-production, use Photoshop with care

This is a very common mistake by inexperienced photographers, applying too heavy Photoshop filters to finalize the image. Sometimes even the most experienced photographers apply too many and too strong adjustments while trying to fix a hopless image. This mistake is also very easy to make when working on a temporary workstation with a bad computer monitor that suffers from bad gamma or contrast. It is also something to be careful with while working in locations where it is difficult to see the results on the screen due to too strong ambient light.

One of the most common mistakes is to apply too large adjustments to the dynamic range on an image. Most images need some contrast to look natural, just applying aggressive gamma curves, local tone-mapping or heavy dodge/burn operations without thinking of natural light sources in the image may easily ruin even a decent image. It is very common now to see images with extremely flat contrast that has been heavily processed by a careless operator. Too much color is also common but usually not that bad if the color noise is under control. Over sharpening is also common but as long as the image is kept at high resolution this artifact is less visible. Web images with low resolution are much more prone to the very typical black and white halos created by different high pass filters.

New house in Markt Schwaben. The right image has too flat gamma curve due to heavy processing in Photoshop, the left is more normal.

Use high ISO to avoid blurry shots

Now with equipment with high sensitivity and embedded signal processors that automatically removes much of the annoying noise it is a good idea to use higher gain (ISO) when shooting under low light conditions. Noise is often possible to remove but a blurry shot will be blurry even after normal sharpening has been applied. Using strong sharpening may save a party shot for web usage but the image quality will be reduced which limits the usage of the image. Sometimes a blurry effect might be good to give impression of movement, but usually it is a problem.

Clean the sensor

Remember to clean the sensor now and then, a dust free sensor saves you a lot of post processing work. Especially for macro work and landscape images it is a good habit to clean the sensor before each major assignment.

Gerlos, Zillertal Arena, blue alm. To keep the foggy feeling, the contrast has to be keept low.

When traveling, bring some light

Remember to bring some light on location, this is usual the difference between a professional shot and a common image. Professionals tend to bring better light equipment and know how to use the light to create the perfect atmosphere. Just by adding a small amount of light in people’s faces the image will look much better. When the face is well-lit add some back projected light to add glowing edges around heads. This usual improves the contrast and makes the image look more dramatic. By adding your own light to the scene, you control the outcome of the photo session instead of relying random luck.

Think about your scene

Take some time and think about the photo: what will be the most important part of the image, make sure this part is clearly visible and a fair part of the image. Add light to guide the viewer towards this spot in the image. Light is the most powerful tool you have.

Don’t shoot bad scenes

It is no use to shot bad scenes. Even if you keep trying the scene will not improve. Stop, think and be creative, perhaps you need to leave the scene for something better. Rubbish will not look nice independent of angel.

Use tripod and a remote release device

A steady camera is really something useful, it enables long exposure and helps you holding your camera in the right position while working on the scene. The remote helps you firing the camera without moving or shaking it and thus avoiding unnecessary blurring of the image. This is crucial for macro work with high magnification. Do not cheat with this. Carry a tripod and always have a remote relsease device in you bag.

Shoot more people when shooting in public

After working with photography professionally and the limiting rules which restrict the use of people in commercial images it is easy to end up with too few people in images from public places. Try to return to the good old habit of having local people in the scenes. It is a problem when you sell images to stock archives but many times it is allowed to publish images with unknown people. Always remember that people are much more interesting than things.

Remember to backup

Make backups of your photo files and store them in separate location. Usually you need a three level backup strategy:

  • A fast and simple backup that is used while moving files around, for example cloud-storage or a dropbox account.
  • Scheduled backup that runs every night or at least weekly.
  • Off-site backup that moves your work to a different site, weekly or monthly

Use more than manual mode, and don’t forget your mobile phone

Sometimes it is easier to take photos using full automatic mode – when appropriate use it. Even a decent mobile phone may capture nice images if zoom is not required and the scene is well lit.

Kitzbuhel mountain view. Successful iPhone 5 snapshot using full automatic mode.

Avoid too many shots of the same thing

Save some time (and your camera) by not capturing hundreds if identical shots. It is just a big waste of time to compare and delete a lot of identical files. On location, shoot the required images, maybe one or two extra depending on how difficult the shot is and then stop. It is better to find a new angle or subject than continuing working with an identical setup.

Plan your work

Avoid being at the wrong place when the important thing happens. As a photographer you need to be in the correct spot and with the equipment ready then things occur. Usually some shots can be postponed while some can’t. Prioritize! When working on events make sure you know the planning, ask for a small brief of what’s going to happen. Study scene-light, and prepare some camera presets. If suddenly the light situation starts to be difficult you might need to leave manual mode to avoid accidental over and under exposure.

Challenge yourself with new equipment or methods

It is important to always continue to improve your photographic skills. One way is to add new types of lenses to your photo bag which enables new technical skills. Another way is to test new type of photography, to expand the aesthetic side of your work. A third method is to work experimentally within a familiar area. But always remember to work structured but still stretching your limits to learn more and widening your offerings. A good way to do this is to end every assignment with a couple of more experimental shots, bring in some unexpected props or equipment. Try to produce 10 different kind of images from the same scene. It is a very challenging task.

Remember to shoot friends and family

When working with photos every day it is easy to forget to capture photos of your closest friends and family.

Keep working!

Advancements in camera technology at Embedded World 2013

Embedded World is a trade show that is dedicated to embedded systems and everything needed to develop them: circuits, debugging tools, compilers and a lot of off-the-shelve pre-fabricated circuit-boards for embedded usage. The vast majority of attendees to this exhibition are developers and industry people doing business in this field.

Embedded world 2013 in Nürnberg

How about camera technology at such an event? Every modern camera is an advanced embedded system with a large amount of on-board software and algorithms that are used to control the system while images are produced. How will the camera of the future be affected by the exciting things that are shown at this exhibition? To be able to answer this, it is important to identify both new and improvements to existing technologies. An interesting but still unknown part of this show is the cohosted Electronic Displays Conference, the largest display conference in Europe. This conference is the reason why there are so many great embedded displays to view and so many display experts in Nürnberg this week.

Opening of the Electronic Displays Conference 2013

Display technology is now moving extremely fast and we are just in the beginning of a shift from full HDTV towards 4K also called Ultra HD (UHD). The largest consumers of embedded displays are the mobile world with its handsets. They are in the forefront of what’s technically possible with the highest resolution per area and the smallest, brightest and best pixels.

Camera displays are expected to follow (or on some cases lead) the mobile screen developments. Soon we will see scatter-free mobile phone displays. This might not be that important for the camera industry but the trend is clear, new materials in the screen will enable thinner and lighter screens that will consume less power.

The next screen trend will be cheaper, flexible and more accurate touch interfaces. This will soon be standard on many cameras, just like the screen on your mobile phone. Touch accuracy will be much better and hopefully the built-in camera software will be improved to use the touch more cleverly. Hovering will be possible to detect and the touch function shall actually be disabled in some situations… E.g. I don’t want to have my nose accidently changing settings or deleting images on the memory card while I’m using the viewfinder. Viewfinder screen technology is somewhat unique; no other devices require screens with that amount of pixels per square mm. This is also a new expensive part of the camera that is expected to grow in importance with the popularity of mirrorless cameras.

Another revolution will come in a couple of years when the flexible screen technology is mature. At that time the screen can be bent around any curved surface and even bent over an edge for an impressive display that can do many simultaneous functions and still be one piece. This will enable new designs of the camera back and reduce the cost because multiple screens can be replaced by on part bent around the edges. It will also be possible to have a significant larger rollable display that can be used to preview images.

Improvements in lightning technology enable intelligent flashes with an option to produce more light in smaller cameras. Light with different wavelengths will be possible to produce by the flash. This means that the light can be tuned to the available scene color. Built-in electronics can easily measure scene light and suggest a scene adaptive light solution. We have already seen a video camera from Sony with built-in projector but I do not see the use of that function.

Texas instruments at Embedded World 2013

Embedded processing power will continue to grow according to Moore’s law and enable much more advanced onboard camera software. If more powerful CPUs are combined with the possibility to download and install applications from an appstore a small photo revolution may occur. This enables new in camera editing and processing functions, earlier only seen on computers, to be done already in the camera. This will in some cases replace post-processing and the image will be ready for immediate use, without any publishing delay. The embedded CPU will of course be used for much more than editing apps, see my earlier article about computational photography.

The future of digital cameras is looking very bright, but the current advancements in mobile communications may be bad for camera manufacturers as a lot of potential point and shoot camera users will buy a mobile phone instead. And photo dealers will lose not only many equipment customers to online stores but also the majority of the print customers because online publishing will replace the traditional physical photo. And even though we consume more photos than ever, many photographers will have difficulties to stay in business.

Winter in Bavaria

Winer landscape, captured a sunny day in Bavaria

Sunny spring day outside Markt Schwaben, Bavaria

New gallery: Street Art Vancouver

© 2012 Stefan Lundberg

A collection of images of impressive paintings located in a narrow alleyway not far from the gas town clock near Woodwards and the Harbour centre. It is a very well performed and beautiful piece of graffiti covering the complete passage between Richards and Cambie. Ongoing work performed by the artist collective Cold World Media, 2005.

New gallery: Woodward’s

Woodward's

© 2012 Stefan Lundberg

A gallery from Vancouver featuring the Woodward’s building which is located downtown Vancouver, not far from the Gastown steam clock. This historic retail store was built 1903 by Charles Woodwards in the middle of Vancouvers retail district.

Nokia 808 pureview camera review

This review is focused on the camera capability of Nokia 808 pureview mobile phone. If you need information about how this device works as a phone, or whether Symbian is a good option for a smartphone, please look for a more in depth phone review somewhere else.

Redefine mobile photography

The camera integrated in this phone is the most groundbreaking mobile phone camera ever. When news about this 38 megapixel camera started to make headlines all over the industry I was really interested in trying it out. I wanted to play with it and investigate what this type of very different camera sensor is capable of and how it can be used for real photography. I think this phone from Finland is the most interesting 2012 technology achievement. It is a remarkable combination of a super-high-resolution sensor and custom made optics served by custom designed hardware to deliver superior mobile phones images.

Nokia 808 PureView for extraordinary mobile Photos

When this phone began to ship it was the highest resolution sensor in a mobile phone, and in fact this still is the highest-resolution sensor of ANY consumer and semi pro camera! You need to buy a medium format camera or similar to beat this mobile phone when it comes to pixel count.

Sensor

The secret behind this camera sensor is a really small 1.4 um pixel 1/1.2″ sensor that delivers 7728×5368 pixel in 4:3 aspect ratio. The sensor itself counts 41 million pixels but the additional pixels above 38 megapixels are only used in the 16:9 mode thus a 41 megapixel image can not be stored. According to Chipworks the sensor in this phone is 140 square mm large, called HES9 and manufactured by Toshiba.

Even more impressive than the sensor is the dedicated processing hardware designed for this phone to enable real time oversampled imaging. In the phone there is a novel solution that is built to process almost 41megapixel sized RAW images and convert them down to 3, 5 or 8 megapixel. This is done at an impressive rate which makes this phone feel faster than a professional medium format camera. This down conversion is clever and is used to cover one of the bigger drawbacks with so small pixels: noise. Oversampling and digitally scaling down while optimally removing noise is a good way to reduce the impact from small pixels. This oversampling can be traded against zooming and the available zoom range depends on selected output mode. In 5 megapixel mode the zoom ratio is 3x which is much less than super zoom cameras but better than nothing. Image processing is done on BCM2763 a Broadcom multi-media processor according to Chipworks which has made a teardown of this product.

Nokia 808 is running Symbian

This camera is designed to run in 3, 5 or 8 megapixel mode, using oversampling and with this clever construction this makes sense, the delivered images are really crisp and good.

Dynamic range

The delivered dynamic range is slightly low compared to other point and shoot cameras and this may be a drawback due to the small pixels used. It is easy to detect clipping in white even for moderate scenes without overexposure and this may be a serious problem. White clipping can be decreased but not completely avoided by using the built in bracketing.

When capturing in 38 megapixel mode visible noise will be the main issue, even in full daylight the typical full well noise can easily be seen in a blue sky. There is a built in function to lighten the darker part of the image but in many cases this makes the image look flat. Luckily this function can be reduced by the contrast slider.

Noise

The noise level is even more visible when less light is available, indoor, dusk or dawn. Unplanned night time photography is very difficult to do because the bad placement of the home button, it is very easy to reach and press it by mistake while trying to keep the camera still against for example trees other steady objects.

It is impossible to do studio photography or other creative projects where exposure time control is needed. A true manual mode with selectable exposure time would be very useful. I have not managed to sync the flash to anything in the studio, crazy stuff happens with the exposure. If you plan to play with this camera in the studio do not forget to use the contrast control – I can’t explain what I have seen. I suspect some sort of contrast enhancement or wide dynamic range algorithm ruins the image. If you manage to control 808 in the studio please write a post here how it was done.

There is a spring-loaded clamp from Nokia which can be attached to any camera tripod for shoots with longer exposure time. When comparing this camera to other larger cameras like DSLRs it is easy to forget about the lower stability due to the smaller mass and lack of good grip.

Lens and built-in flash

The lens is a Carl Zeiss 8mm fixed iris f/2.4 lens (28mm equiv) with 5 aspherical elements, mechanical shutter with ND-filter and one LD glass element. The built-in Xenon flash is small but works very well in normal phone flash photo range – read ‘one to five people portraits’. The lens aperture of f/2.4 combined with a large sensor creates nice out-of-focus blur when capturing close-up portraits.

41 megapixel Toshiba sensor and Carl Zeiss lens

The contrast based autofocus works like expected very similar to other camera phones. Focus time is below one second most of the times and which acceptable accuracy. The built in AF illuminator works well and is enabled automatically. Shutter delay depends mostly on the autofocus delay. The built-in white balance is good but the manual white balance is really strange and I do not understand why. The camera lacks a manual white balance setting for really warm light, but I think this might be difficult due to the white clipping issue which is a dynamic range problem. The dynamic range of this sensor may limit the usable white balance range, a warm light setting may generate too much blue noise.

My list of drawback in priority order

  1. Limited dynamic range, white clipping
  2. No real manual mode, exposure time control is missing
  3. No lens protection
  4. Limited white balance
  5. High noise penalty in 3, 5 and 8 MPixel modes while zooming
  6. Day time noise in the sky
  7. Three seconds processing time after each 38 megapixel image

Predictions

I expect future pureview cameras to improve the dynamic range by using multiple exposure merging or dual pixel structure. This may also improve the white balance. Upcoming camera phones will also include faster processing but not necessary higher pixel count. This camera phone will not sell in high volumes due to the obsolete Symbian operating system.

Conclusions

This is the best camera phone currently available and is is usable down to ISO 1600 for smaller output formats. This camera delivers images with a very natural unprocessed look. I recommend this camera to photo interested people. Remember that this camera does not replace a DSLR. It should be compared to a pocket camera, even if this camera under ideal conditions may generate images with higher resolution than a professional DSLR.

Bryce Bayer has passed away

The Bayer pattern color filter was invented and patented 1976 by Bryce Bayer, working as a scientist for Estman Kodak . The pattern was first described in Bryce Bayer’s notebook (29th May, 1974) as a solution to provide color in a camera using a photo sensor array. Bayer passed away at the age of 83 the 13th November 2012 in Bath, Maine. This clever and still simple pattern mimics the human eye’s structure by using double amount of green pixels compared to blue and red.

U.S. Patent No 3,971,065

Image sensor world has more information and an image of the notebook here.

4x4 Bayer pattern

Four times four Bayer pattern patch

New gallery: White Lines 2012

White Lines 2012

© 2012 Stefan Lundberg

This gallery contains images showing the results of the initial learn to know assignment for arriving LTH students. This great campus-wide installation, made primary of white string, was made during one autumn week 2012.

My first gallery with similar theme can be found here:White Lines

Halloween greetings

Halloween pumpkin 2012

Wish you a very scary Halloween by posting an images of our pumpkin.

New gallery: Rock Labyrinth

Luisenburg-Felsenlabyrinth, Germany

Images captured during a half day tour at the Luisenburg Felsenlabyrinth, a Rock Labyrinth near Wunsiedel / Fichtelgebirge, Germany. The labyrinth is formed by weathering and erosion over a long period of time leaving large granite blocks randomly placed forming a very special forest covered landscape. A great place which offers hiking on trails of varying difficulty.

New gallery: Devil’s cave

Devil's Cave

Devil’s cave near Pottenstein in Oberfranken, Franconian Switzerland, Germany.

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Review of Soloshot automatic panning head

Soloshot is a new outdoor video production helper for YouTube-enthusiasts, who need help filming outdoor sport action. Using this new motorized tripod and a video camera of your choice, it is possible to make surf/bicycle/racing shots without the need of someone assisting with the video camera. Unboxing of this new device is really exiting, the build quality looks good and the weight is lower than expected. Personally I think the design of the base station is a little dangerous as the general design message from orange tripod-mounted devices means water seal rugged professional equipment, which is not completely true in this case. The product is divided into two parts, base station to be stationary on the beach and the remote to be carried around. The base station can be charged with the included transformer/wall plug which is 110V/220V compatible but needs a wall plug adapter in Europe. The base station also works as a charger for the remote, but it is tricky to fasten the remote for charging due to the design.
The manufacturer claims 2.5-3h charging time which sounds reasonable and more than 5 hours of battery time which is very good and more than enough for most actions.

Soloshot

Soloshot automatic panning head

The base station has been designed to carry a camera load of 5 LBS or 2.2 kg which is sufficient in most cases but the adjustable tripod mount on top of the Soloshot that is used to attach the camera is not very stable, and will only be usable with lightweight pocket camcorders. It is not a good idea to use this tripod with video capable high end DSLRs like Canon 5D. The 5D can be mounted but the mounting fails when anything but a really light weight lens is attached. The included tripod is of lower quality than most of my other tripods but I think is ok for this type of equipment. A typical user has to be somewhat careful when working with the base station, both the panning motor and the adjustable antenna feels a little bit fragile. The base is not easy to detach from the included tripod, looks like a small hex tool is needed (not included).

The base station setup is really easy, place the tripod on stable ground facing the sea/playground, mount the camera, level the device using the built in leveler or simply by turning and looking through the camera viewfinder.

Both the base and the remote have to be powered on followed by a long calibration delay, you need to wait 8-15 minutes before the actual pairing can be done, this procedure has to be done each time the system is started. The instruction manual included both images and descriptions about the procedure but fails to include a simple single-page chart that really explains has to be done. My first pairing failed due to some unknown error and everything had to be powered off with another 8 minutes delay. I believe that the remote shall be kept still hanging on the base station during this procedure but there are no notes about this in the manual.

Finally when pairing has been completed the fun begins. Just walk away from the base, toward the center of the scene, look back for the strong red narrow light beam from the base station and press the pairing button again, the light turns green and the camera starts following the remote. The camera movement is smooth and the generated video is very usable. This is important for good video footage.

How does this product work, and can this equipment be used legally outside US ? Very common questions among people buying radio equipment from US. Unfortunately this is not explained anywhere on the manufacturer web page or anywhere else on the Internet. The first thing that has to be check before using this stuff in Europe is to understand the radio communication between base and remote. Luckily all radio equipment sold in US has to have a FCC ID which has to be printed on the device. Searching for this FCC ID enables us to download some of the documentation sent to FCC prior to approval. In this case the documentation is really bad and only tells us the this device receives and transmits on the same wavelength as IEEE 802.15.4, using the MRF24J40 transceiver IC. IEEE 802.15.4 is the physical layer and media access control used by low-rate wireless personal area network and uses ISM Band at 2400.0-2483.5 MHz which is used by ZigBee and other standards. ZigBee is approved world wide so I think this product is legal to use in Europe.

Now to the other question, how does this unit work? It is obvious that this equipment does not use radio frequency tracking or another method where the receiver transmitter angle is measured with some sort of directional antennas. I’ve got the feeling that it is the manufacturers wish that the exact method is not directly disclosed. My analysis of this equipment tells me with high confident that it is based on one GPS receiver that uses a digital radio channel to communicate the absolute position of the remote back to the base station on 2.4 GHz. In the base station the digital position signal from the remote is received and compared to the known base station position stored during the calibration. Based on this information a micro controller computes the angle and the panning head is moved to the correct position. This is the reason why this equipment does not work indoors and requires 8-15 minutes of “calibration and warm up time”. This time is needed for the GPS unit to find enough satellites.

I recommend this equipment to everyone who plans to film outdoor sport action themselves because the price is right and the device works. I hope the manufacturer updates the manual and web to include at least the enough information to help customers understand why the device needs some time prior to pairing and what restrictions that apply.

New iOS game to celebrate Martin Gren

New iPhone and iPad game


Check out this new platform game created to celebrate Martin Gren’s 50th Birthday. A game for all children ages 4-92 where you roll a ball over platforms. Before hitting the target on each level you need to pick all the stars and avoid any mines. Practice the precision of dragging your finger over the screen to rotate platforms so that the ball moves at the right speed to perform its tasks without colliding with a mine on the way to the target.

Available as MG50 in the Appstore

This game is featured in this article about Martin Gren turning 50 by Sydsvenskan (The largest newspaper in south part of sweden). Congratulations Martin as you celebrate 50 years today, and please enjoy your new custom made App!