Shift-Lenses vs Software: some examples (TS-E 4/17mm L)

RokkorDoctor · Joined: 27 Nov 2021 Posts: 1267 Location: Kent, UK

Well, arguments have been put forward from both sides, and everyone will have make up their own minds as to which is going to work better for them. In any case, I hope that some members at least have learnt something new from this discussion re. use of shift lenses vs PP in software.

Regardless of whether someone prefers to do perspective correction in the field using a shift lens, or in PP using software, some of the thoughts of Keith Cooper in the below video may be of interest to anyone hoping to work for architectural clients:

https://youtu.be/bl48-fyBsp4

He does go over some of the points brought up in the above discussion, and I know Ian will therefore disagree with some of Keiths findings (fair enough, Ian), but I would like to draw attention in particular to what Keith has to say at 6:50 onwards in the video, and again at 11:10, regarding the desirability (or not) of correcting converging vertical lines in architectural shots, in particular his experience of talking to the people in the marketing dept. of his architectural clients vs. those in the finance dept. This dilemma is irrespective of what methodology is then used for correcting perspective distortions, either using a shift lens or PP.

He also expresses some thoughts re. the predictability of the results, and the ability to assess in the field what a final shot will look like when utilising a shift lens.

Ultrapix · Joined: 06 Jan 2012 Posts: 551 Location: Italy

Phalbert · Joined: 17 May 2009 Posts: 359 Location: Namibia

Very very interesting thread. Thank you all. We've learnt a lot about different ways to straighten a certain type of picture (I believe things are very clear now). Nicely spiced up by different personnalities. Let's be thankfull we're all different, and let's learn from each other more more about photographic possibilities.
Now where was I...

RokkorDoctor · Joined: 27 Nov 2021 Posts: 1267 Location: Kent, UK

stevemark · Joined: 29 Apr 2011 Posts: 3754 Location: Switzerland

iangreenhalgh1 · Expire: 2014-01-07

Cut the bullshit and point out exactly what is 'crooked' in that image:

It's not perfect, it's not a natural rendering either, because it's been altered.

But to say it is 'crooked' and 'has gout' is just childish bullshit.

RokkorDoctor · Joined: 27 Nov 2021 Posts: 1267 Location: Kent, UK

OK; I'll leave it to Stephan to explain his issues with the image, but I'll point out the distortions my eyes are seeing in this image. However, you will have to excuse my "bloviation" since you asked me to explain exactly where I am seeing issues. I've drawn a few of my own lines over it to help explain:

First the bottom half of the tower, green lines. I have drawn these parallel to the top of the "The CLOCK TOWER" sign as well as the base of the archway foundation blocks, both of which you would expect to be level in a building. The slight convergence to the right of both green lines suggests a vanishing point for the bottom half of the facade far to the right. This is consistent with the image having been taken slightly from the left of the center-line of the tower, as also evidenced by the way in which the archway and actual doors are not lining up. The effect is subtle, but it is the top-half of the tower where things get more obvious.

For the top half of the facade, I have drawn some blue lines through a few architectural features that should also be level, and on-line images by other people & Google street view show to be level indeed. These lines implies a vanishing point for the top half of the facade some distance to the left of the tower, which would be consistent with having taken the image slightly from the right of the center-line of the tower.

Having an apparent vanishing point to the left for the top half of the tower, and one to the right for the bottom half of the tower, makes the tower look twisted. Again, other on-line images of this tower show this not to be the case. This type of inconsistency would not occur with use of either a rectilinear UWA lens, or shift lens.

The yellow lines show a problem with the domed roof section of the tower. There is foreshortening of the clock face, evidenced by the perfectly round yellow circle I have drawn around it. A shift lens, used with the appropriate amount of shift, would render this clock face perfectly round. In fact, not only vertical shift (rise) would be required, but also a modest amount of horizontal shift as the image was taken slightly to the left of the center-line of the tower. Which brings me to the final issue; the foreshortening of the clock face is not just pure vertical, but at a slight diagonal (I have indicated this with the yellow off-vertical line), opposite to the direction of foreshortening that would normally occur with the image taken standing to the left of the center-line of the tower. This, together with the corresponding lopsided distortion on the domed roof, again gives the tower a "twisted" feel.

With more work this could possibly be fixed in PP, but with a shift lens, an appropriate amount of diagonal shift that would take maybe 30 secs to do, would render the facade exactly as an architectural client would expect it to be, and this could be checked in the field whilst taking the image. And whichever look you may prefer (there is some argument for maintaining a level of foreshortening), there is no point arguing with the client holding the pay-cheque...

iangreenhalgh1 · Expire: 2014-01-07

Look, Stephan is being a childish swine, instead of any attempt at creative criticism, he does his usual mocking.

As for the distortion you see, well, you seem to ignore the fact that I wasn't standing directly in front of the clock tower, but several feet to the left of it (there's a statue in the way) so what you're complaining about is perspective, not distortion.

Also, you bloviated about how much you hate PP, so I did the least possible amount of PP on that image, only for you to turn around and moan about it's imperfections - which could so easily have been removed by just a little more PP! Make your mind up, to PP or not to PP - you can't have it both ways!

So we have an image that I stated was 'quick n dirty' that was literally thrown together using the barest minimum of time and effort, akin to a throwaway comment. It is literally the bottom rung of the ladder of what can be done, but for various reasons, I never even began to show what else is possible. Maybe I should show you some of the stitched images from one of my exhibitions, several of those have sold for four figure sums as huge prints 3 metres wide and challenge youto find the perspective issues, distortion and stitching errors you moan about.

All I've learned from this thread is that it is far too annoying and counterproductive to attempt to have a serious discussion with quite a few people.

and to think, I only bothered to post in this thread because it exists in order to personally attack me by an obnoxious blowhard who I have zero respect for.

Seems like a long time ago now that this was a good forum, before it became dominated by alpine egomaniacs with far more arrogance than ability.

King Arthur · Joined: 26 Feb 2023 Posts: 1

Please excuse me in advance that my English is not perfect.

What I read from you was the reason why I signed up.

I don't want to say anything about your bad upbringing. But about your photography: If your free view of the bell tower was blocked by a statue, then nobody prevented you from taking an undistorted photo. From your point of view, too, it was possible to take a direct shot at right angles without the slightest problem.

In my eyes, you're a self-righteous talker who takes himself a little too seriously without knowing what you're talking about.

Forgive me for being so direct.

Ultrapix · Joined: 06 Jan 2012 Posts: 551 Location: Italy

Returning to the technical aspect, eventually the topic became confusing, because two different issues were intertwined: on the one hand, the correction of falling lines, which is within the reach of any software, without any relapse in terms of distortion, but only with a decrease in image sharpness due to pixel stretching; on the other hand, people started to disquisition about stitching, which is not necessarily related to the straightening of falling lines, but can also be just an artifice to increase the framed field.
This procedure via software is always invasive, because it leaves a wide margin of interpretation of the subject, both to the photographer and to the software, and can almost always be recognized at a glance by those with experience and geometric sensitivity.
It also has other downsides: if there are moving subjects in the image, it is not possible to capture them naturally; if there are objects such hedges or fences in the foreground, there will always be some element to be adjusted; if it is windy, the trees will never be in the same position in the various shots, etc. These are all problems that do not exist by shooting with dedicated lenses. It should also be said that the best stitching is done precisely with shift lenses: if you have the foresight to attach the lens to the tripod, and shift the camera body (there are heads dedicated to this procedure), the nodal point of the optic does not move, and the overlay is perfect even with complex three-dimensional scenery.
In favor of the stitch procedure remains, of course, the possibility of increasing the file size at will, which is very useful, for example, to reproduce life-size paintings of square meters in size, without loss of quality, which professionally I have done quite often. Then, of course, there are those situations where the required amplitude of field leaves no choice, and so one must accept the limitations in order to benefit from the advantages. Ultimately there are no wrong techniques, only wrong uses of a given technique.

RokkorDoctor · Joined: 27 Nov 2021 Posts: 1267 Location: Kent, UK

RokkorDoctor · Joined: 27 Nov 2021 Posts: 1267 Location: Kent, UK

stevemark · Joined: 29 Apr 2011 Posts: 3754 Location: Switzerland

Here are a few sample taken with the Canon TS-E 4/17mm L. All these images have been published in large high quality books ("Sakrales Zürich - 150 Jahre katholischer Kirchenbau im Kanton Zürich" by Markus Weber and "S. Maria dell'Anima" by Franz Xaver Brandmayr).

Let's start with the oldest buildings. The church of "S. Maria dell'Anima" in Rome (close to Piazza Navona in the mst beautiful part of ancient Rome) was built around 1500, as a home for pilgrims from the north (mainly from todays Netherlands). Later on - around 1650 - the Austrians took over, and up to these days they are responsible for the church, the adjacent seminary, and quite a few buildings surrounding both the church and the seminary.

The church itself is famous for its excellent acoustics (among the best in Rome), but it is quite hidden, and difficult to capture on a photo. There's a small narrow alley where it's belltower is visible, and I toook this image for the back cover of the large book (24x32 cm / 10x12.5 inch). The image was composed so that its right side could be used as a "neutral" background for some writing. The contrast was pretty high, and it had to be reduced drastically to make it printable. In addition I had to "remove" some cars to make it look better.

Using a tripod, taking the image was pretty straight-forward. Compsing the image without a shift lens would have been a nightmare.

Here's another one, from the same church. It's the altar of the "Capella del Margravio", with the main image, a masterpiece of the Florentine painter Salviati (1510-1563). The 17 mm superwide results in a beautiful "3D" image of the marblework surounding the image. The natural light was pretty scarce (and had a strong color cast due to the colored windows), but after some less-than-convincing trials with artificial light we decided to use available light. Careful post-processing did the rest, and the result is quite convincing.

Again a complicated and difficult setting, and the shift lens was indispensable.

S

simple.joy · Joined: 30 May 2022 Posts: 437

iangreenhalgh1 · Expire: 2014-01-07

At the end of the day, this whole thread and debate has been pretty damn stupid and only came about because one idiot has a hugely inflated ego and actively seeks out things he can troll people about.

Nothing new in this, similar arguments arose in the past about HDR with the luddite crowd insisting it was rubbish and always produced horrible, garish results, today it has become an accepted and widely used tool, as it should be.

Same thing with stitching and software correction of perspective - it is just another tool and a sensible person would see it as such and welcome it - the more tools we have, the more work we can produce.

stevemark · Joined: 29 Apr 2011 Posts: 3754 Location: Switzerland

Here are a few more samples from the 640 p book on catholic churches in the Canton of Zurich.

Zurich was - along with Geneva (then part of Savoy) and Wittenberg (in todays Eastern Germany) - a hotspot of the Reformation.
Between 1524 and 1807 any catholic worship was completely forbidden, and the remaining catholics were expelled. Only in 1868
the catholics were allowed to build their first "new" catholic church in the Canton of Zurich. Back then, most catholics in Zurich were
workers for the newly established industrial enterprises in Zurich and Winterthur. They came from the catholic Central Switzerland,
from southern Germany or from Italy. They mostly were poor people, and building new churches for them was a though and difficult
undertaking. Usually they were constructed in the suburbs, with very little money, and therefore they are of limited architectural
or artistical value. Nevertheless these days much more praying and worship is going on in these poor catholic churches, than in the
ancient and beautiful (pre-reformatoric) protestant churches (former cathedrals and monasteries).

Taking meaningful images was pretty difficult. Not only the poor architecture, but also the dull light of Northern Switzerland was a challenge. Here are some examples.

Winterthur - the first "new" catholic church built in 1868. Neo-gothic style, surrounded by apartment buildings. This image was stitched
from two handheld photos taken with the Canon TS-E 4/17mm L (due to rapidly changing light). The final image was improved
by some post processing (reducing the contast). Published also in a large size calendar (40x60cm). The image also was used for the
cover of the first volume of "Sakrales Zürich".

Now another neo-gothic church, this time from Bülach:

The image above was not only used in "Sakrales Zürich", but also as a cover image for a separate booklet about the church and its
history. As you can see, I had to compose the image with enough "empty" space for a title and undertitle. Works much easier with a
shift lens, for sure! Again the light was changing rapidly, and I was really happy to have the shift lens with me (which allows not only
for precise, but also for fast work). Handheld, no tripod.

And here's an image from the choir of the Bülach church. Not something of outstanding artitistic value - but simply an expression of
faith and devotion from around 1900. Luckily the entire original altar and the paintings were not "purified" (=removed & destroyed)
during the 1960s when the neo-gothic style was considered to be "outdated" (more on that later on).

Now a really "crazy" image - only possible with a superwide shift lens. If you look at the upper part of the image, you will see that it was
taken shifting the 17mm L "too much", and pointing the camera slightly downwards. In fact the large frescoe in the choir of the church
cannot be seen "correctly" by the naked eye: Either the saints (at the bottom of the image) or godfather (at the top of the image) will
look completely distorted since the fresco is painted on the inside of a semi-cupola (see here on wikipedia: https://de.wikipedia.org/wiki/Fritz_Kunz#/media/Datei:Hottingen_-_Katholische_Kirche_St._Antonius_-_Innenansicht_2011-08-19_14-19-30_ShiftN.jpg). While some of the figures still are visibly distorted (especially Jesus in the center), the over-all impression of the entire large fresco is much better than with any photo previously taken - and believe me: many were taken professionally during the last 100 years, since these frescoes are from the most eminent Swiss fresco painter of the 1900s.

Composing such an image would have been completely impossible using "stitching" ans software.

Here's another sample taken with the TS-E 4/17mm L. The church Zurich St. Joseph (neo-baroque, and finished just at the
beginning of WW I) was built in a (then) industrial district of Zurich. The church - as most others in town - is surrounded by pretty high
buildings, and thus difficult to shoot even with my Zeiss 2.8/16-35mm "non-shift" lens. This image was taken on a cold winter morning
with exceptionally clear light (unusual for Zurich). To display not only the church itself, but also its surroundings I did include the
appartment buildings, but also the street with its zebra crossing and the traffic lights. Again, the shift lens was extremely useful for
composing the image (that would have been pretty much impossible with stitching), and for getting the work done quickly.
As I said, such a beautiful light is rare in Zurich, and I was happy to take pictures in quick succession at other locations as well.

This last image was taken wide open (f4), using a Manfrotto carbon tripod with 410 head (head made specifically for architectural work).
Why wide open? The TS-E 4/17mm has a strong vigetting at f4 when shifted (about 3 EV). This helps to "reduce" and darken both the
sky as well as the traffic lights to a nice color. Since the lens is shifted, the lower part of the image is more or less in the center of the
its image circle, and thus not underexposed. The resolution of the 4/17mm was completely sufficient even at f4 and in the
shifted state (not much detail in the upper corners).

visualopsins · Expire: 2025-04-11

Although probably expensive filters may be required to sift there is much here I've learned.

We are extremely fortunate to have such a broad range of people's educations and experiences being shared.

Not really related as architecture tends to move slowly most times, Raspberry Pi lets you have your own global shutter camera for $50:

https://www.engadget.com/raspberry-pi-lets-you-have-your-own-global-shutter-camera-for-50-104547026.html

stevemark · Joined: 29 Apr 2011 Posts: 3754 Location: Switzerland

simple.joy · Joined: 30 May 2022 Posts: 437

Thank you very much for the additional information - that explains what I was wondering about! I think the image looks great on the cover with the additional text etc. and it really seems incredible important to take the space around your main subject into consideration when it comes to architecture! Very interesting to hear those explanations and have some examples shown to, particularly for someone like me who has never tried shooting any architecture. I really appreciate it!

Ernst Dinkla · Joined: 30 Nov 2016 Posts: 378

Suppose I would make a fixed shift lens with Sony FE mount. Aiming at hand held, FF portrait takes of max 12 meter high houses, me standing at the other side of a 12 meter wide street. That is a narrow as you encounter in older cities here, less is even more unworkable, for wider I can step forward. Retrofocus SLR lens to have more back focal distance. Eye height 160cm. For a kind of snapshot architectural photography, facades mainly.

Which focal length to use, how much shift needed ?

RokkorDoctor · Joined: 27 Nov 2021 Posts: 1267 Location: Kent, UK

RokkorDoctor · Joined: 27 Nov 2021 Posts: 1267 Location: Kent, UK

Ultrapix · Joined: 06 Jan 2012 Posts: 551 Location: Italy

Ernst Dinkla · Joined: 30 Nov 2016 Posts: 378