Sassan Sanei, The Blog of

Perspective control with the new Canon TS-E 24mm f/3.5L II tilt/shift lens

2009-06-13T22:44:00.007-04:00

Have you ever found yourself pointing your camera upward to take a picture of a tall building?

If so, chances are that your picture turned out something like the one below, which I made using a 24mm wide-angle lens on a Canon EOS 5D Mark II full-frame camera body:

24mm lens pointed upward

See how all the vertical lines converge upward, even though they are parallel in real life? The building seems slanted, like it is about to topple over. This might be fine for the Leaning Tower of Pisa, but it makes for a very strange picture of an office building!

You can get rid of the bizarre angles by pointing your camera straight ahead, perfectly perpendicular to the building. This eliminates the converging lines. Unfortunately, this also causes you to lose the top of the tall building, as you can see in the next picture:

24mm lens pointed straight ahead

The obvious solution is to use an even wider lens. This is often an elegant solution to the problem, as long as you have an interesting foreground to work with, and don't mind the building becoming a background element instead of the principal subject of the image. The lens must also be wide enough to take in the top of the building.

The following picture is an example of what not to do. None of those three criteria are met in the following picture. The foreground is vast and boring, the buildings have been relegated to the background, and the top of the tall building is still cut off (although just barely). This is taken with a Canon EF 14mm f/2.8L II USM lens on a Canon EOS 5D Mark II full-frame camera:

14mm lens pointed straight ahead

Admittedly, I could have changed my location to make that picture work better, but I really just wanted a picture of the building and its immediate surroundings.

Is there a way to take a decent picture of tall buildings? There must be; after all, professional architectural photographers do it all the time. What technique do they use to control perspective?

The answer lies in the magic and wonder of... the tilt/shift lens.

Actually, there is nothing mysterious or exotic about this lens. Photographers have been tilting and shifting lenses on large-format cameras for well over a century. These days, the soaring popularity of digital cameras -- and the ability to quickly "fix" mistakes in Photoshop -- has created an expectation of convenience and instant results. Tilt/shift lenses are considered a specialty item; it takes skill and patience to use lens movements effectively, and many think that it is becoming a dying art.

Using a shift lens, it is possible to point your camera straight ahead, then move the lens upward until your image includes the top of the building. Since the lens is no longer centred on the camera, the image is off-centre too. You take in the top of the building, while vertical lines remain parallel since the camera is not tipped upward. The following picture shows how this works. This image is straight out of the camera -- no Photoshop needed. It's a perfect solution!

24mm tilt/shift lens shifted upward by 11mm

This picture was made with the new Canon TS-E 24mm f/3.5L II lens. I already had the original version of this lens, but the improvements in the new version are well worth the upgrade. The new lens completely eliminates chromatic aberration (colour fringing), which was a problem with the original version. I also like the ability to change the direction of tilt relative to the direction of shift -- with the original version of this lens, I had to take the lens apart, turn half of it around, and put it back together. There are several other worthwhile improvements as well.

Unfortunately, the lens is manual focus only; like all tilt/shift lenses, it does not have an autofocus motor in it. The Live View mode with 10X magnification on my Canon EOS 5D Mark II camera makes manual focusing much easier than using the viewfinder.

Keep in mind that I am using the 24mm lens on a full-frame camera. Canon has also launched a new TS-E 17mm f/4 tilt/shift lens, which provides a wide angle of view on a crop-sensor camera like the Digital Rebel series or the EOS D30/D60/10D/20D/30D/40D/50D. Of course, either lens can be used with any Canon EOS camera, depending on your needs.

Perhaps the biggest drawback to tilt/shift lenses is their price. In Canada, Vistek has the best deal going right now, offering the 24mm lens at $2399 and the 17mm lens at $2699. This is slightly lower than U.S. prices, even at the current exchange rate, but it is still a lot of cash to fork over.

Fortunately, there are a couple of ways to eliminate converging lines without buying an expensive shift lens.

The first method is to take a wide-angle picture and crop it off-centre. Take a look again at the image from the 14mm lens, below, and compare the cropped area to the shift lens picture above. They are exactly the same. The difference is that you lose a lot of resolution. The original image is 21 megapixels, while the cropped area is only 7.2 megapixels. This represents a huge loss of detail.

14mm lens pointed straight ahead, then cropped off-centre to resemble a shift lens

The second method is to take a picture with your camera pointing upward, then correct the perspective in post-processing. In the past, when I used a darkroom to make prints, I would tilt the enlarger base to do this. Today, perspective correction is much more easily done using Photoshop!

24mm lens pointed upward, with perspective later corrected in Photoshop

This method actually produces surprisingly good results, and the stretching process does not cause any noticeable loss of image quality. In fact, vignetting (darkening of the corners in the sky) is improved. The only drawback is that the lower corners of the image are cut off, so you must anticipate this when you initially compose the image.

This presents an unusual dilemma: buy the Canon TS-E 24mm f/3.5L II tilt/shift lens and correct perspective distortions at the time of image capture, or the Canon EF 24mm f/1.4L II lens and correct perspective distortions in Photoshop? The latter costs less, has autofocus, and has a much faster aperture, which makes it more useful in most situations. Therefore, I would not expect most photographers to choose the tilt/shift lens over the f/1.4 lens unless they have a specific need for lens movements.

Incidentally, you might be wondering why buy a 24mm lens at all if you already have a zoom lens that covers that focal length. The difference is in the image quality. Unfortunately, the 24mm setting on my Canon EF 24-105mm f/4L zoom lens suffers from chromatic aberration and barrel distortion. While it is useful for everyday photography, I do not find it acceptable for architectural photography.

The Canon TS-E 24mm f/3.5L II lens also offers a tilt mechanism, which is completely separate from shift. Tilting means changing the plane of focus so that near objects on one side of the image are in focus, while far objects on the other side of the image are in focus. The rest of the image is blurry. This is used to follow focus along a slanted line, like railway tracks receding into the distance, or a clump of flowers in the foreground against a treetop in the background. It can also lead to some very creative and unusual effects.

In the following image, I tilted the lens to the left until only the front face of the tall building was in focus, while the rest of the image went to blur. This has the effect of drawing the eye to the office tower, making it the dominant subject in the picture, even though it is in the background. Notice how some of the trees are also in focus; this is because they happen to fall along the tilted plane of focus. This picture uses both shift and tilt together to bring a fresh look to a fairly ordinary picture.

24mm lens shifted 11mm upward and tilted 8.5°left

Here is another image in which I tilted the lens downward. This allows the tree to become blurry at the top. (Unfortunately, this effect is lost on a small image on the web, but it is readily apparent on a print.) I did this because the image is about the contrast between the gnarled roots of the maple tree and the hard angles of the building. The top of the tree provides only context, and I did not want it competing with the building for the viewer's attention. Without tilt, I would simply have a picture of a sharp tree against a blurry building, which would draw attention to the tree instead of the juxtaposition of forms. This is one of the first images I made with the new lens.

Here are a few more images that I made while getting acquainted with this new lens:

There are many other creative uses for this lens. You can use it to exaggerate perspective, selectively focus on one part of the image, and make dramatic environmental portraits.

Keep in mind that while wide angles are useful for architectural photography, Canon makes tilt/shift lenses in several focal lengths: 17mm, 24mm, 45mm, and 90mm. I frequently use the Canon TS-E 90mm f/2.8 tilt/shift lens for product photography -- a purpose for which the 24mm lens is far too wide. The 90mm lens is useful not so much for shifting, but for controlling the zone of focus through tilt.

Tilt/shift lenses are the ultimate tool for controlling every aspect of your photograph. The process is slower and more methodical than with other lenses, but that is well worth the sense of satisfaction you get from creating an image exactly your way.

The first set of images were made at the Sun Life Financial headquarters in Waterloo, Ontario, Canada. All the images are straight out of the camera without any adjustments. The last seven images were made at various locations in Waterloo, and have had local adjustments applied to colour, exposure, and dynamic range. All images, except the third, were made with the Canon TS-E 24mm f/3.5L II lens on a Canon EOS 5D Mark II camera. You can click on any picture to see a larger version in a new window.

Canon EF 14mm f/2.8 L II USM lens - first pictures

2008-11-26T10:24:00.004-05:00

While many photographers prefer shooting with telephoto lenses that get them closer to their subjects, I've always had a preference for wide-angle lenses that let me capture a vast expanse in a single frame.

I've enjoyed using panorama stitching software to achieve wide angles of view, but this process has its drawbacks. It's inconvenient to set up, a tripod must be used, it takes work to stitch the images together, and stitching does not always respond well to images that contain moving subjects.

I've also owned a couple of wide-angle lenses over the years: the Sigma 14 mm f/3.5 lens and the Sigma 12-24 mm f/4.5-5.6 lens. Both of these lenses easily captured the wide angles of view that I was after, and were a lot of fun to use, but they simply did not have the optical quality needed to maintain image sharpness across the frame. I felt that there was too much vignetting and that the image corners were not very sharp.

Canon has offered a 14 mm f/2.8 lens for many years. I tried one once, and it was a fine performer, but I did not feel that the improvement over the Sigma version was dramatic enough to justify the higher cost. I decided to continue using my existing tools while waiting for something better to become available.

So you can imagine my excitement when Canon introduced an updated version of their 14 mm lens last year, which they claimed delivers "higher image quality overall including superior peripheral image quality." Could this be what I'd been waiting for all these years? It certainly sounded promising, and I put it on my wish list.

Finally, I took the plunge and acquired this magnificent chunk of optical glass for my very own. I was very excited! I put it on my Canon EOS 5D, which has a full-frame sensor to take full advantage of wide-angle lenses, and took it for a quick spin to try it out. I was not disappointed. At last, I am getting both the angle of view and the image quality that I was after. While a 14mm is not an everyday lens, it has quickly become one of my favourites.

Here are my first pictures, taken in and around the University of Waterloo. (You can click on each image to enlarge it in a new window.)

While these are just some quick shots to try out the lens, I'm looking forward to unleashing my creativity with the use of dramatic wide angles!

Is this joke funny or not funny? You decide.

2008-09-30T07:25:00.002-04:00

Q: Why did the cricket have trouble falling asleep?
A: Its cicadan rhythm was off.

("Nine months and that's the best you can come up with?")

That one with the red thing

2008-02-24T12:11:00.004-05:00

I decided to let Ryan watch a little TV this morning. Usually we try not to do this too often, but I thought he might enjoy it. Ryan is three and a half years old -- an age where the "and a half" is still relevant. Communicating with young children can be a challenge, because sometimes they don't use the best words for getting their idea across, and that leads to confusion and miscommunication. Come to think of it, it's that way with a lot of adults too.

Sassan: Ryan, would you like to watch Mickey Mouse Clubhouse?
Ryan: Want to watch Mickey Mouse!
Sassan: Okay, we'll watch one episode. Which one would you like to see?
Ryan: The one with the rocket ship!
Sassan: Sorry, I don't think we have that one. Let's see what we do have! We have Mickey's Treat, Pluto's Best, Donald the Frog Prince, Daisy in the Sky, Goofy the Great, Minnie's Birthday, Donald's Big Balloon Race, Pluto's Puppy-Sitting Adventure, Sleeping Minnie, Donald and the Beanstalk, Goofy's Bird, Goofy the Home Maker, Mickey Goes Fishing, A Surprise for Minnie, Mickey's Treasure Hunt, and Minnie Red Riding Hood. Which one of those would you like to see?
Ryan: Umm, umm, that one, the one with the red thing.
Sassan: The red thing???
Ryan: The one with the red thing! The one with the red thing!!! That one!
Sassan: What red thing?
Ryan: The red thing! The red thing! Umm, umm, Goofy's Bird.
Sassan: Oh, that red thing!
Ryan: That one! With the red thing!
Sassan: Okay.
Ryan: What Daddy didn't know what Ryan meant for?

No way out

2008-01-16T21:37:00.000-05:00

I'd sure hate to be stuck in this traffic jam! (Click on image for a larger view.)

Sorry I don't have the original source to credit the image.

I'm not sure what to make of this question

2008-01-12T09:30:00.001-05:00

My three-year-old son Ryan just asked me:

How come sometimes Daddy doesn't know everything more than Mommy?

Is that a good thing, or a bad thing? I don't know.

The 10 tastiest foods on this, or any other, planet

2007-12-20T12:43:00.000-05:00

Here is a list of the 10 tastiest foods on Earth and elsewhere. (This is different from my list of 10 favourite foods that I previously posted, because a favourite food isn't necessarily the tastiest food, or vice-versa.)

10. Pepperoni stick
9. Buttered popcorn
8. Orange creamsicle
7. Old El Paso cheese dip
6. KFC
5. Earl Grey tea
4. Blue bubble gum ice cream
3. A&W Cream Soda
2. Nutella
1. Reese's peanut butter cups

Hello Blogosphere. I have NO IDEA what this means. Any suggestions??

2007-12-07T21:36:00.000-05:00

I found this word list in an unsent message in my Drafts folder. No recipient, date, or subject line. I have no idea what it's doing in there; all I know is that I must have written it at some point. I'm going nuts trying to figure it out, and would appreciate any suggestions! Thank you!

Denim
Clorox
Alimony
Mentholatum
Argot
Linoleum
Xerox
Polonius
Masonite
Pandemonium
Steponum
Kryptonite
Latrine

Life after BlackBerry

2007-12-02T17:10:00.000-05:00

I've decided to leave my job at RIM and become a full-time, stay-at-home dad to my two young children, Ryan and Megan.

It's a life-changing decision, and people react predictably to this news. If they have children of their own, they are generally very supportive. They say something along the lines of "You're doing a wonderful thing! They're only this age once, and they grow up so fast. It's great that you can take this time to do it."

On the other hand, those who do not have children of their own invariably ask, "What are you going to do with all your free time?" I forgive them the absurdity of this question, because they clearly have no idea what it's like to be around two very busy little kids all day long. They go non-stop, and they don't take breaks. The concept of free time went out the window a long time ago. But thanks for asking.

Leaving work wasn't easy. I started working at RIM in 1996, before there was even a BlackBerry. As an electrical engineering student, I was intrigued by the idea of wireless data communication, which was still in its infancy. I knew that RIM was on the verge of something big, and I wanted to be part of it. The entire company consisted of about 50 people when I joined. Today, it has grown to more than 7,000 employees, including some of the best and brightest minds in the field. The company measures annual sales in the billions of dollars, and has made BlackBerry a recognizable brand name around the world. By any measure, RIM is a huge success story.

I have had an amazing time at RIM. I truly enjoyed working with the people and technology that make the company great. It was a difficult decision to give that up and spend every day raising my kids, who are too young to understand or appreciate the value of what I am doing for them, and who often behave in a thoroughly unpredictable and irrational manner. It isn't the fun and games some people think it is. There are tantrums and unreasonable requests, and a good night's sleep is a thing of the past. It makes me cranky sometimes. But parenting is all about challenges and sacrifices, and this the life I have chosen for myself.

So now that my parental leave is over, I've left my position indefinitely. Tomorrow morning, and every day after that, instead of throwing my laptop bag over my shoulder and heading into work, I'll be at home, changing poopy diapers and teaching the ABC's. Of course I'll miss going into work. But I also know that if I went, I would be missing something even better.

There is no right answer to this question

2007-10-31T19:20:00.001-04:00

"Are you going to share your Hallowe'en candy with your sister?" our neighbour asked Ryan while trick-or-treating, referring to his 7.5-month-old sister Megan.

Rap lyrics translated

2007-10-28T00:05:00.001-04:00

This is awesome.

Rap lyrics translated

Which Friends character are you?

2007-10-27T22:53:00.000-04:00

Fun little quiz...

Which Friends Character Are You?
	You are Ross. You're intelligent and adored by your parents. However, your lack of social skills causes you to talk too much and try too hard. While your friends pick on you for your nerdiness, they better watch our for your rage.
Find Your Character @ BrainFall.com

To the other people waiting in line with me at the passport office

2007-09-20T10:15:00.000-04:00

To the other people waiting in line with me at the passport office, I would like to share a few things about my three-year-old son Ryan:

1. Telling me to "control your child" as he breaks loose from my grip and runs off assumes, incorrectly, that I am unaware of what has just happened or that I could easily have prevented it. It further suggests that it's any of your business. Wrong again.

2. A nicer word for you to use might have been "precocious."

3. Actually, he's saying "Fun! Fun! Fun!" You did not hear what you think you may have heard.

4. Yes, I do plan to take him onto an airplane; that's usually why one obtains a passport. I am also aware that it is an even more confined space than the passport office. Painfully aware.

5. I too would like to harness half his energy!

6. I know it's not a toy. But it looks like fun. Thank you for your heartfelt concern.

7. He's THREE. I'm tired. Give me a fucking break.

Sassan and Janet Simpson

2007-09-15T16:16:00.000-04:00

This is awesome!

Toronto skyline pictures

2007-09-01T20:46:00.000-04:00

I was in Toronto this week and pointed my camera's sights on one of my favourite photography subjects, the downtown Toronto skyline. This is the city I grew up in, and even though I no longer live there, in many ways it still feels like home.

I used Canon's 24 mm shift lens for the first two pictures, and the 70-300 mm diffractive optics lens for the last three. All the pictures, except the fourth one, used the high dynamic range technique that I previously discussed here and here, to have good detail and colour in both the dark and light areas of the image.

You can click on any picture to open a larger view in a new window.

Montreal pictures

2007-09-01T19:41:00.000-04:00

I was in Montreal two weeks ago and took some time for photography. Here are some of my favourites.

The first one is the interior of Place des Arts metro (subway) station. To get a wide view, I used a Canon 24 mm shift lens to take three pictures: one shifted left, one centre, and one shifted right. Then I combined the three pictures into one frame. (It's like doing a spin panorama, except that the camera remained stationary and the lens was shifted instead, which means that there is no perspective shift from one frame to the next.) I also exposed each frame three times: one normally exposed, one underexposed, and one overexposed, then combined the three exposures into one frame; this allowed me to retain detail in both the shadow and highlight areas of the image. So the following picture is made from a total of nine exposures.

The next picture is of the Chalet du Mont Royal. This was a tricky picture to make, because the ceiling was very dimly lit, while the view out the window was bright and sunny. So again, I made three different exposures (one for the shadows, one for the midtones, and for the highlights) and combined them into one. The camera was on a tripod so that the three images line up properly. This was a large, expansive room, and I used a shift lens (shifted up) so bring in more of the interesting ceiling and less of the boring floor. (Why shift? I could have simply tilted the camera upward, but then the vertical lines would not be parallel. See here for more information on perspective correction lenses.)

Outside this chalet is a lookout over the city, called the Belvedere Kondiaronk. This has always been my favourite spot to take pictures of the city. I took two pictures here, one a traditional image and the other with exaggerated perspective that adds a bit of drama.

Back now to where we started, Place des Arts, where the Montreal World Film Festival would begin just a few days later, and also where the Musée d'art contemporain (Museum of Contemporary Art) is exhibiting the works of Bruce Nauman. These pictures were also combined from several different exposures.

You can click on any of the pictures to bring up a larger view in a new window.

Miss South Carolina says Americans need more maps

2007-08-27T23:01:00.000-04:00

This defies comment.

Question: Recent polls have shown a fifth of Americans can't locate the U.S. on a world map. Why do you think this is?

Answer: I personally believe that U.S. Americans are unable to do so because some people out there in our nation don't have maps, and I believe that our education, like such as in South Africa and the Iraq, everywhere like, such as, and I believe that they should, our education over here in the U.S., should help the U.S., or should help South Africa and should help the Iraq and the Asian countries, so we will be able to build up our future for our children.

Patriot Acts: Then and Now

2007-08-10T09:13:00.000-04:00

This brilliant cartoon comes to us from Propaganda Matrix.

A walk in the park

2007-07-27T09:09:00.001-04:00

These pictures are from a walk in the park by my house (Anndale Park) on June 10. Ryan enjoys nature!

(You can click on each image to open a larger view in a new window.)

Amazon coupon codes!

2007-07-27T08:20:00.000-04:00

Here at the world headquarters of Sassan Sanei, The Blog of, we are busily working to save you some hard-earned money. Our loyal blog readers deserve it!

We are proud to announce an exclusive partnership with the good people at Amazon to save you lots of money on your online purchases. Just go to their web site (that's amazon.ca in Canada, amazon.com in the U.S., and amazon.co.uk in the United Kingdom of Great Britain and Northern Island and Various Other Places, etc.), buy lots of things, and enter the following coupon codes at checkout.

You can combine codes for even more great savings!

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Hurry, these coupons expire at 11:59 pm on !

Don't give your phone number when returning an item to the Please Mum store

2007-07-26T10:16:00.000-04:00

Don't give your phone number when returning an item to the Please Mum store. Our number ended up on their marketing telephone list, and we received an automated call (phone spam) where a computer told us about the "grand re-opening" of their store, a promotion that we could not care less about. For a store that sells baby clothes, they should know that parents of babies sleep strange hours (i.e. when we can) and causing a disruption like mass automated phone recordings is a great way to make sure that we never shop there again.

Ham and cheese

2007-07-22T12:46:00.001-04:00

I like buying a footlong ham sub at Subway because it's $5.69 and with tax it comes to $6.49, so when they ask for "six forty-nine" I feel like I've won the lottery.

Sitefeeds, a la cat

2007-07-16T08:23:00.000-04:00

I love this LOL Feeds site that provides "Cat macros for every occasion." It takes headlines from any site that provides a news feed (including my blog) and turns them into captions for pictures of cute kittens.

Here is what mine looks like:

http://lol.ianloic.com/feed/sassansanei.com/atom.xml

Enjoy, and have a caterrific day!

Flower pictures

2007-05-02T13:51:00.000-04:00

These pictures are from Ryan's first trip to the Toronto Zoo, on July 24, 2006. (I'm a little late posting.) Most people take pictures of animals at the zoo. I took a lot of pictures of flowers. I played around heavily with them in Photoshop to achieve various effects, just to have fun. Now that spring is in the air, it's nice to see flowers again. Here are the results... enjoy!

(You can click on any individual image to open a larger view in a new window.)

Nice Hummer

2007-04-08T13:48:00.000-04:00

So some guy you know just bought a Hummer H3, because there is no more profound public declaration of "I don't give a shit about anybody else but myself" than driving around for the sole purpose of destroying everything around you.

How do you properly congratulate them?

"A Hummer, eh. I figured you more as a Dirty Sanchez type of guy. But whatever yanks your crank."

"You got the H3! Wow. So... you couldn't really afford the H2 huh. That's okay. I'm sure things will pick up for you eventually."

"That's the civilian version, right? Not quite the same as a military Humvee now, is it. But I guess you take what you can get. Congratulations!"

"Making up for a lack of something? Haha."

"You bought a Hummer? OMG, that is so 2004."

"What's the mileage like in that thing?"

"What'd that beast set you back? Twenty, twenty-five thou?"

"Wow, nice Jeep!"