JOBO LensTRUE – proportional correction of perspective distortion

Those, who already made pictures of a building and pointed the camera upwards, have surely recognized that the building on the picture looks different from reality. We talk about converging lines which are created when these lines are not in parallel to the imaging plane (film or sensor). One photographic mean to solve this problem in objects or architecture photography is by using tilt-/shift-lenses or a view camera. JOBO, a company located in Gummersbach, Germany, now offers the LensTRUE System, a new technique to solve this problem by correcting the perspective distortion in post-processing. This new approach is what I would like to present here.

DieserBeitragInDeutschThe challenge: Proportions and converging lines

Photographers know what I am talking about: Taking pictures with small focal lengths from a high or low position or perspective by swiveling the camera down or up creates converging lines and the proportions of the photographed objects change. The objects look distorted, e.g. buildings look like as they would tilt back and people have e.g. a head which is too small or too big in comparison to the rest of the body. Let me illustrate this with two examples I found in my image archive:

Blick vom Altstädter Rathaus auf Teynkirche
Prague, View on Church of Our Lady before Týn from tower of Old Downhill
Mallorca 2013, Capdepera, Carrer Major
Mallorca 2013, Capdepera, Carrer Major

The picture from Prague with the view from the tower of the Old Tonhall shows the the converging lines when looking at the buildings at the left, where the houses tilt towards the photographer. The picture from Capdepera, Mallorca shows that the camera was swiveled in three axis, in Y-axis so that the imaging plane was not in parallel to the facade, in Z-axis so that the left building corner was in parallel to the left edge of the sensor and by this the camera was clearly moved from the horizontal and additionally swiveled upwards in the X-axis to capture the entire building. This results in a clearly visible backwards tilt of the right corner of the house.

Let’s stay with these two images and have a look on what e.g. Lightroom can do to correct these two types of distortion using „Upright“, a feature which has been added to Lightroom with version 5. The picture from Prague was processed with the Upright function „vertical“ and exported from LR without cropping the withe parts. Below both pictures, original and Upright-corrected as a direct comparison:

The left part of the image now shows that the facades auf been vertically corrected which is valid for all vertical lines except for the building at the right edge of the picture.

The gallery below shows the picture from Mallorca in the original version (left), processed with LR-Upright „vertical“ (center) and LR-Upright „full“ (right):

This series of three pictures clearly shows that LR-Upright „vertical“ is only correcting the converging lines and completely ignores the proportions. LR-Upright „full“ is correcting the picture in a way that tries to apply a view from a central perspective which means to show the object in a way as if the photographer was standing at the center in front of the building. This has two downsides: First is a greater loss of image parts when applying the optional image cropping like shown in the following pictures cropped down to an aspect ration of 1:1:

Cropped in Lightroom to aspect ration 1:1

In addition to a loss of image information there is a loss of image quality. This is not visible on the left edge of the house because here the amount of pixels was reduced, but it is easily visible in the right part of the image e.g. with the upper and lower window which are now much bigger than in the original image and the missing details had to be added by interpolation. The enlarged view of the image shows that Lightroom is not doing well on this and that this is something to be verified with JOBO LensTRUE System.

In the box

DSC02191So, let’s have a look on the LensTRUE System of JOBO. The LensTRUE System is delivered in a fancy box which contains the LensTRUE meter that is mounted below the camera, a printed quick guide and a small USB stick that contains the LensTRUE Visualizer software and a pdf manual. The USB stick works as a license dongle when the LensTRUE meter is not connected to the computer. A cable for the USB connection of the LensTRUE meter and one to connect the LensTRUE meter to the PC sync socket (multiUSB-connector for the Sony mirrorless) are also included and not shown in the following gallery. A small remark on this: The cable to connect the LensTRUE meter to the PC-sync socket is meant to grab the shutter signal from the PC-sync socket (usually used to trigger studio flashes) in case the the socket for cable release is used. Owner of a Sony mirrorless now have a small problem when shooting from a tripod with a cable release connected tot the multiUSB connector. The Sony mirrorless cameras do not have a PC-sync socket – maybe for reasons of body size – and the multiUSB port is used by the cable release. One way now is the connection of the sync cable through a hot shoe flash adapter having a PC-sync socket. The ideal solution would be a multiUSB-adapter which could connect the cable release and the LensTRUE meter to the camera at the same time. Owner of supported A-mount cameras are not affected because e.G. the Sony alpha 99 has one of these PC sync sockets.

The most important feature of the LensTRUE Systems surely is the correction of converging lines while keeping the proportions of the object up to a swivel level of 35° (shift lenses for example only support up to 11°). The correction of pincushion and barrel distortion of the lens, the integration of a RAW converter and the manual, individual adjustment of a correction are further features of the LensTRUE visualizer.

The price of  990 € incl. VAT (european sale) is pushing the expectations – so let’s have a look on the performance of this combination of hard- and software. The comparison to Lightroom is something I would like to focus on, because Lightroom contains the Upright functionality since version 5.

Architecture

Example 1: The Tommy-Weisbecker-House, Wilhelmstraße, Berlin

One of the first pictures I took with the Sony alpha ILCE-7RII was made with the LensTRUE system connected. I like this motif because the sun peaked through the gap between the Tommy-Weissecker-House and the house on the right just at the moment I was standing in front of the building – this is the original exported from Lightroom with lens correction profile appllied:

Original + Objektivkorrektur
Original with LR lens profile applied

The automatic mode of LensTRUE Visualizer creates the following result as full view and cropped version:

 

Although the LensTRUE Visualizer correctly used the shots.txt which I copied into the folder with the pictures to make use of all tilt values of the camera – the intelligent assignment of shots-txt entries and images works brilliant – the house still slightly tilts to the right. This is not an optical illusion, denn wenn applying the grid you can easily recognize that the house is not really fully aligned as shown in the following screeshot:

DSC00003_Screenshot_Auto
Screenshot LensTRUE Visualizer

The following results were created by manual adaptation of the transformation values (X +0.6, Y -1.4 and Z -0.2):

So now let’s compare this image with the result of Lightroom Upright „vertical“ and a manual adjustment of vertical +18, horizontal -4 and rotate +0.2) and a final crop:

At a first glance both results look the same. A closer look shows that the proportions of the right part of the house are not correct in the Lightroom result. I tried to manually fine tune this in Lightroom but this is somehow impossible because one of the proportions remains wrong – may it the car on the right edge or any of the corners of the house. In the end the result coming out of LensTRUE is the best in my option and therefore I took this version to develop the final image:

Tommy-Weisbecker-Haus, Wilhelmstraße
Finale image, corrected in LensTRUE, developed in Lightroom

Example 2: old gantry Anhalter rail station, Stresemannstraße, Berlin

I used a motif from architectural photography which requires extreme corrects due to the short distance to the object and the heavy tilting of 23,7° as a second example:

Original + Objektivkorrektur
Original with Lightroom lens profile correction

I applied the same steps like in example 2 – so let’s have a look on the automatic correction of LensTRUE Visualizer in full view and cropped:

Due to the very short distance between camera and object and the strong tilt the correction of the converging lines requires a heavy crop which would make the picture sort of unusable without adding pixels to the image. I therefore manually adapted the transformation by +15 on the X-axis to reduce the correction and the loss of image elements:

The reduction of the correction brought back the converging lines a little bit but the effect on the tip on the top of the front column is reduce and now looks less dominant. The following are the results created by Lightroom using Upright „vertical“ in the first step and shown as full view and cropped:

The next two images compare the partially cropped fully automatic results from LensTRUE Visualizer and Lightroom Upright:

I prefer the automatic correction results from Lightroom with this motif, the extreme point of view and strong tilting because the LensTRUE result creates a very dominant and huge roof tip on the top of front column, although LensTRUE respects the proportions and the Lightroom result is wrong when it comes to proportions. So let’s compare the two results of LensTRUE and Lightroom with manual adaptation of parameters by +15 with LensTRUE on the X-axis and -9 vertical in Lightroom, first looking at the Lightroom results in full view and cropped and than comparing the final cropped versions of both, LensTRUE and Lightroom:

There are two reasons why I prefer the Lightroom result with manual adaptation of example 2:

  1. The proportions may not be mathematically correct but they don’t look that exaggerated like in the LensTRUE visualizer version.
  2. The result from Lightroom keeps more image elements (see above right border next to the front column) although the converging lines are less recognizable (see last column left image border)

Example 3: Virtual change of perspective

This example is to show a special feature of the JOBO LensTRUE system: the virtual change of perspective. This can be used to show the main object in the image the way as if the photographer was standing in a central position in front of the object or building like in this case – meaning in central perspective. This can be very useful in the case where the central perspective can’t be used by the photographer for different reasons like buildings that are in the way – like in the case of the following picture:

Original
Original

The LensTRUE visualizer auto correction creates the following result in full view and cropped:

The virtual change of perspective is done by applying a manual change of transformation of -12° in Y-Axis which almost creates a view from a central perspective:

The cropped images look like this:

Lightroom Upright offers a similar functionality with Upright „full“. This is the comparison of the cropped versions of LensTRUE and Lightroom Upright:

On the first view both results look similar or even identical but on a closer look Lightroom Upright shows some weaknesses. The Lightroom Upright correction still shows some converging lines at the borders of the image and the roof edges show minor errors. I tried a manual adaption in Lightroom but quickly gave up. The virtual change of perspective is paid with an enormous loss of image parts in both results.

Especially the second and third example made two things clear to me: On one hand architectural photography with correction of converging lines always requires to plan the image the way that there is enough room around the main object when cropping afterwards – especially when applying the both, correction of perspective distortion and the virtual change of perspective using LensTRUE visualizer. On the other hand I am very surprised that a rather „cheap“ software solution like Lightroom Upright can do the job as well to a certain extend. This is mainly due to the fact that Lightroom Upright can make use of the vertical and horizontal lines in these examples which makes the correction a lot easier. The following couple of examples show motifs from the portrait photography where Lightroom does not necessarily find the help of these lines and where LensTRUE visualizer may have an advantage by using the data recorded by the LensTRUE meter.

Portrait photography

I was very curious on the results of portrait photography and have stolen 10 minutes at the beginning of a already very tight plan of a Tf?-shooting to shoot a few frames with the LensTRUE meter attached to the Sony alpha ICLE-7. Some remarks upfront: The strange camera position tilted to one side and slightly upwards for some frames is intentionally and useful to clearly show the ways how LensTRUE and Lightroom Upright apply the correction. A overexposed background is also intentionally as well as the soft bokeh to make it more difficult to Lightroom finding vertical and horizontal lines and structures for the correction. All images within one example are developed with the same settings in Lightroom – differences may show due to the development of RAW and TIF-images.

Example 1

This is the time to apologize the first time to the model because we start with a really bad portrait: The camera was tilted horizontally and the the shot was taken holding the camera up by -3.5°.

20151004_DSC03105_ILCE-7
Original, focal length 35mm, tilt -3,5°

The LensTRUE meter recorded the tilt values and LensTRUE visualizer used these parameter to create the following auto corrected image:

The cropped images shows the same mistake of the photographer like with the examples of architectural photography. The right hand of the model is cut off – I was still not used to work with the LensTRUE system and to leave a lot more room around the main part of the image. Well, the comparison of the auto correction results of LensTRUE and Lightroom upright is a lot more interesting as shown in the next two images:

This clearly shows the strength and advantage of LensTRUE over Lightroom when it comes to the correction of perspective distortion. Both cropped images show almost the same parts of the original image but the Lightroom result is missing the correction of the proportions of the head – which is not acceptable – and the torso although the later is not that obvious.

Example 2

This example should be a bit easier for Lightroom because there is plenty of information, although partially blury, on the ground and in the background which could be used to detect the camera tilt. The pictures was shot with a focal length of 55 mm and a tilt of 5.8° which creates a slight top view.

Original
Original, 55 mm, tilt 5,8°

Again the comparison of LensTRUE auto correction in full view and cropped and the comparison of the the cropped versions from LensTRUE and Lightroom Upright „auto“:

The differences in correction between LensTRUE and Lightroom are quite obvious: Where LensTRUE can rely on the recorded data of the LensTRUE meter Lightroom Upright can only try to find an orientation on the vertical and horizontal lines and structures in the image, which are sufficiently available. This leads to the fact that the columns in the background are straight in the corrected version. The Lightroom result looks like if the head of the model is a bit smaller which could be related to the crop. Effectively I would say that the model looks pretty normal in both versions. Let’s have a look on the comparison of original, the LensTRUE and the Lightroom Upright corrected versions with a matching crop:

I put these three images into one picture and added some red lines to have an optical assistance to better analyze the proportions because the original and the corrected versions look very much the same on the first glance, although the background show some minor difference which are not of importance for a portrait:

Vergleich_Original_LensTRUE_Portrait2

This clearly shows what is not visible when switching through the images of the gallery: LensTRUE and Lightroom Upright do changes to the proportions which is visible when looking at the head and the length of the legs. Lightroom Upright can do this by making use of the great amount of lines which is almost like a grid and is almost creating a result which is very close to the correct proportions of the JOBO LensTRUE system.

Example 3

Up to here the LensTRUE system not only looks like a solution to solve problems in the classical architectural photography and can be used to replace tilt-/shift lenses but also makes a lot of sense in people photography, especially because it can be used free-hand without tripod. Example three is going for the extreme now and was shot with a tilt level of -23.4° point the camera upwards. The intention was to create a souvenir picture with the church spires in the picture.

20151004_DSC03167_ILCE-7
Original, 35mm, tilt -23,4°

Of course, idea and pose are questionable but this is only to see what LensTRUE and Lightroom can do with it. Like before the results of LensTRUE auto correction in full view and cropped first and then the comparison of LensTRUE auto correction cropped and the correction of Lightroom Upright „vertical“ in the cropped version:

This is the moment when my apologies to the model are almost too late, because where the original picture still was a nice souvenir of a day in Cologne in front of the cathedral both corrected versions turn out to be images of a beautiful woman with almost bizarre body proportions and this although the tilt limit of 35° for the LensTRUE system was not passed. But such is live: You can’t have it all and sometimes it is better to stick with the original and accept the the Cologne Cathedral has converging lines – at least the spires are still shown in the picture.

Verdict

My verdict is absolutely pro JOBO LensTRUE. It is an absolute must have where an error free, proportional correction of converging lines matters because the correct reproduction of proportions is not really possible with Lightroom „Upright“ and impossible without supporting lines and structures. A correction of converging lines and a correct virtual change of perspective is only possible with lots of fine tuning and with luck. But be aware – our usual perceptions are presumably affected by the daily flood of pictures that way, that we are not used to correctly reproduced proportions in images and may cause that some people may find the images corrected by Lightroom  more pleasing. I personally think that a solution like the LensTRUE system is absolutely mandatory for high class real estate, interior design and exposé photography.

LensTRUE is also recommendable for portrait photography because wrong proportions are easy recognizable in a face and are not really pleasing for the depicted person. Yet the area of using LensTRUE ist not universal and I would define the tilt-level limits in portrait photography even a bit tighter than 35° which should not be a problem in the field since portraits are rarely shot with these extrem tilt levels. Lightroom Upright can keep up in some situation like shown in example 2 with the many horizontal and vertical lines. The interesting part is to see how Lightroom will perform in the case these supporting lines are missing in the background – I will deliver some examples for this in the near future.

The idea of the proportional correction of objects and converging lines is fabulous and currently unique in the market with the JOBO LensTRUE system. The software in version 1.8.5 is running very stable. It could be a feeling a bit quicker but which software is fast enough.
Smaller weaknesses and missing functionality will surely be corrected and added shortly. I personally find the dimensioning of the crop frame a little bit difficult to use and a function to define the biggest possible crop is missing which is valid for a comparing view of an automatic and manually adapted correction as well. The definition of the values for a manual adaption of the correction is reacting a bit slow; especially when working on RAW files it is recommended to reduce the preview size to 512 pixel in the view settings. Another downside is that the manually adapted transformations are valid for all images. Removing the hook from the option resets all values which are then lost and need to be inserted manually. Some settings are sort of hidden like e.g. the selection of the target folder for the output files. A quick option in the main screen to store the output files in the input folder would be a good option, especially to integrate the output files into the Lightroom workflow if required.
Last but not least an important detail: The LensTRUE visualizer is currently only available for Mac; Windows users are out of the game.

What remains is the question if the JOBO LensTRUE system is worth the price tag of 990 € incl. VAT on which I can’t give a general answer. This system is definitely valuable for the professional photographer whose customers require a correct reproduction of the proportions of objects and products. Taking the list of supported cameras and lenses as a reference, this is definitely the target audience – a big applause on this list of supported camera and lenses at this point because this list is exemplary!

I personally would recommend JOBO LensTRUE to some of the portrait photographers because recently I realized that quite a few commercials I saw in the street show heavy faults in the the correct reproduction of proportions of shown models – something I started realizing since I started working with LensTRUE and on this article. Amateurs and hobby photographers with an affinity to technical devices in photography but also the real estate agent, architect or interior designer which may use cameras with APS-C sensor are currently out of the game as well because LensTRUE is only supporting cameras with full frame and medium format sensors (Pentax 645) which is understandable since the effort to create sensor and lens profiles for the multitude of APS-C systems and combinations of cameras and lenses is tremendous.

The LensTRUE system is not only good to replace tilt-/shift lenses with any prime or zoom lens but is also able to dramatically extend the tilt level from 11° with tilt-/shift lenses to 35° with these more flexible lenses. The economical added value is obvious when considering the cost of one tilt-/shift lens from Canon or Nikon at about 1,500 € and when taking into consideration that there are no Sony e-mount tilt-/shift lenses available.

You can find all further details on the JOBO LensTRUE system and the steadily growing list of supported cameras and lenses on http://www.lenstrue.com. The complete set can be ordered for 990 Euro incl. VAT (Europe) via the Online-Shop of JOBO or rented for 50 € for the time of 10 days.

More example pictures which I shot and corrected afterwards using the JOBO LensTRUE system can be found in my new blog category JOBO LensTRUE System.

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