Canon16x35LIIGuide - Johan Eickmeyer

 

-Canon 16-35L II Guide-
 

Subjects covered in this guide:

  • Testing A Lens
  • Best Apertures
  • Lens Flare
  • Filters
  • AF/MF Back Button Focus
  • Focus Breathing
  • Reducing Condensation/Fogging
  • Cleaning
  • Lens Hoods
  • Night Photography

 

OVERVIEW

        If used properly, the Canon 16-35L II can be an incredibly versatile camera lens for landscape photography. The following guide shows how to get the most from the 16-35L II. Much of which also applies to the Canon 17-40L and other ultra-wide angle lenses.. Some of this information may also apply to different types of photography other than landscapes.

One of my favorite photos taken with the Canon 16-35L II

 

 

TESTING A LENS

        Make sure your lens is performing as it should when buying a new copy or going on a long trip with your current gear. I have received new lenses in the past which have been out of alignment and were returned for replacement. It is also possible to have a lens go out of alignment due to an impact.

 

Testing Infinity Focus

        It is important for a lens to achieve infinity focus when manually set using the distance scale. This will ensure that you can take nighttime star photos with minimal guess work. Testing for infinity accuracy can be done by setting the camera on a tripod and pointing the lens towards a far distant object. While in Live View mode, zoom in 10x for maximum magnification and set the lens to infinity focus. Check to see that the image is as sharply focused as possible by manually adjusting the focus back and forth around infinity. If you find true infinity focus to be far off from where shown in the distance scale, then your lens may have issues. As seen below, my current copy of the 16-35L II does well when set at exactly the infinity marking, but there is a very tiny amount of sharpness gained by adjusting the lens slightly away from the infinity marking. I do not know how much variation can be expected from copy to copy of the 16-35L II, but mine is within acceptable accuracy of the infinity marking.

 
Canon 16-35L II Infinity Focus Test 16mm 200% crop, No Sharpening
 
 
 

Canon 16-35L II Infinity Focus Test 35mm 100% Crop, No Sharpening

 

 


Canon 16-35L II Infinity Focus Scale Shift

 

Testing Centering

        Sometimes the glass elements inside of a lens can be out of alignment brand new or after an impact. It is actually quite surprising how many lenses are decentered and the users don’t realize the issue exists. A decentered lens can be identified when one or more edges or corners of the frame look much softer than other edges or corners This is due to not all of the glass pointing in a straight line down the lens barrel. Testing for lens centering is very easy. Go outside on a day with consistent light, such as clear skies or solid overcast, and avoid partly cloudy days as they can make for inconsistent lighting. Find an object 40 or more feet away, which has fine details and sharp contrast. Vehicle license plates work very well for this test. Using a tripod to steady the camera, point the test object perfectly into the center of the frame and manually focus the lens so it is perfectly in focus. Now, making sure to not move the focus and zoom rings on the lens, rotate the camera on the tripod head and take 4 different shots at f8 with the test object perfectly in each corner of the lens. Then open those 4 shots in Photoshop and cut out the corners of each shot which contain the test object. Take those 4 cuts and paste them into the same file. Place them into a 2x2 grid and compare the results. If they are all close in sharpness, then your lens is OK. If one or more are noticeably less sharp than the others, then your lens is decentered. Do this centering test for at least the 16mm and 35mm ends of the zoom range, as sometimes zoom lenses can be decentered at one setting and not at another. If you suspect your lens is out of alignment, then perform the test at least one more time to replicate the results and to ensure it is the issue. If your lens is new, return it as defective for a different copy. If your lens is not new, then the manufacturer should be able to fix it. My lens looks to be doing pretty good as far as centering goes. All four corners look equally bad, haha. :) (Note: if you are testing a sharper model of lens that does better in the corners wide open, then test it wide open at f2.8 or whatever aperture is widest.)

Canon 16-35L II Centering Corner Test 100% Crop

 

 

BEST APERTURES

        Sharpness is an important factor in printing landscape photos. It is crucial to know what apertures your lens performs the best and where compromises should be made for increased corner sharpness and added depth of field. The 16-35L II produces results that work well with landscape photography.

 

Corner And Center Sharpness

        The following tests show sharpness levels at various focal lengths, apertures, and areas of the image frame. For the most part, f8 seems to be a good compromise between center and corner sharpness. If corner sharpness is most important, then f11 - f16 look best, and if center sharpness is most important, then f2.8 - f8 look best. I am not going to show every focal length and aperture, but this is indicative of over-all performance.

Canon 16-35L II Sharpness Test 16mm Center

 

 

Canon 16-35L II Sharpness Test 16mm Corner

 

 

Canon 16-35L II Sharpness Test 35mm Center

 

Depth Of Field

        The following test shows where the best compromise may be made for maximizing depth of field between an object 4 feet away and another object 3/4 mile away with the lens set at 16mm. I feel this is a good average distance to show the differences. It is important to note that an object closer than 4 feet may require an f stop of f16-f22 or more to bring the background into better focus. In the test below, it is obvious to me that f11 may be the best compromise between depth of field and diffraction. Apertures of f16-f22 start blurring in-focus areas of the image due to diffraction. At f22 the background is gaining more focus, but losing much detail due to diffraction. In this scene, f22 would be a poor choice. For a single exposure, f11-f16 would be a best bet. While f16 may work well for a single exposure, f8 may be a little better if you plan on taking multiple shots, focus stacked at various distances.

 

Canon 16-35L II Depth of Field Test

 

 

 

LENS FLARE

        Whenever you have a bright source of light shining into the camera lens, there is a potential for some flaring artifacts. Landscape photographers tend to avoid or limit lens flare, as it can pollute an otherwise clean photograph.

 

Managing Flare With Blending

        I often like shooting the Sun as a Sun star, where the lens produces intense rays of light at f22. One problem is that it also allows for some unsightly flare artifacts to also creep into the photograph. To get around this issue, I shoot one photo with the Sun blocked using my fingers, and then another shot at f22. The two images can then be combined in Photoshop for a cleaner final image. There are more complex methods for removing further artifacts near the Sun, but this example should give a good idea of the concept. More info on capturing techniques and post-process image blending can be found in my Landscape Tutorials.

Canon 16-35L II Flare Control With Blending

 

Managing Flare With A Lens Hood

        Lens hoods are often underrated for their effectiveness in improving image quality. Even a super wide and shallow lens hood, like the one found on the 16-35L II, can be effective in maintaining image quality. They can sometimes do a great job of reducing flare from sources of light that are just outside of the camera frame. The sample below shows one instance where the lens hood has produced an image with better contrast and less lens flare. It is also advisable to use your hand for blocking light when using 4x6 filters or any other instance where a lens hood is not possible.

Canon 16-35L II Flare Control With And Without Lens Hood

 

 

FILTERS

        Filters are an essential part of the creative process for landscape photography, as it is important to control the type and amount of light entering the camera. They are also useful for protection in some cases.
 

Screw-on Safety Filter

        I have a super-cheapo glass protective filter I use on the 16-35 L II when not mounted to the camera. Since my camera bag gets rolled around a lot, I have had issues in the past with lens caps coming off the lens creating a potential for scratching the front glass element. The glass filter is there under the lens cap to make sure this does not happen. I avoid using a protective filter when shooting with the lens. I keep a lens hood mounted for added protection during storage.

Canon 16-35L II Safety Filter

 

My Lee Filter Setup

I currently only use Lee filters in the 4x4 and 4x6 formats. Here is the list of my filter collection.

- Two – Lee .9 (3 stop) ND soft grad 4x6 filters

- One – Lee .9 (3 stop) ND hard grad 4x6 filter

- One – Lee .9 (3 stop) ND solid 4x4 filter

- One – Lee linear polarizing 4x4 filter

- One – Lee magenta grad 4x6 (protective filter)

- One – Lee 3.0 (10 stop) ND solid 4x4, “Big Stopper”

- One – Lee filter holder with wide angle 82mm adapter

 

Please have a look at my Lee Filter Guide for more info on using filters.

 

 

AF/MF BACK BUTTON FOCUS

        While many landscape photographers use manual focusing for the majority of the time, there are cases when a properly set-up camera can make good use of auto focus.

 

Benefit Of Back Button Focusing

        I currently use a Canon 6D with my 16-35L II. The 6D has the option of customizing the controls so that the camera does not auto focus when pressing the shutter button, but may be activated when the AF-ON button is pressed. The benefit of setting up like this is that you never need to manually switch the lens from auto to manual focus modes.

Canon 16-35L II AF-ON Back Button Focus

 

When To Use Auto Focus And How

        I have found that auto focus in live view mode is rather slow, but very accurate. If I need to have my attention centered on something else, like not falling into a pool of water, then I use the auto focus instead of manually focusing. If you need more precision on the focus location, try zooming in during live view mode and then performing the auto focus on a smaller area.

 

 

FOCUS BREATHING

        Focus breathing is when a lens changes its field of view based on how near or far the focus is set. If you take a photo at infinity and another at minimum focus distance, the two photos will appear to have been taken with slightly different focal lengths. This happens with most lenses except for the super expensive cinema lenses used for movies, which can cost tens of thousands of dollars each and are often much larger and heavier.

Canon 16-35L II Focus Breathing 16mm
 
 
 

 

Canon 16-35L II Focus Breathing 35mm

 

What To Consider When Focus Stacking

        When shooting landscapes and utilizing focus stacking, it is important to know how focus breathing will affect your final image’s field of view. When a focus stack sequence is aligned on the computer, your final image will only be as wide as the narrowest image taken in the stack. The image below shows the wider field of view caused by the closest focus distance (darker outer portions), with the narrower field of view caused by the furthest focus distance (brighter). The dark border of this image will need to be cropped when focus stacked together. Note that I darkened the close distance image for illustration purposes, and is not indicative of any darkening that happens when focus stacking.

Canon 16-35L II Focus Breathing Crop Factor

 

Using The Distance Scale For Focus Stacking

        While the focus distance scale on the 16-35L II is limited in detail and size, it can still be used to make focus stacking go quicker and easier. It doesn't really matter if you start at infinity focus or minimum focus, but I usually start at infinity where the field of view is the narrowest. This makes it easier to frame the shot and know exactly what field of view the final image will have. If shooting f11 and 16mm, it is possible to shoot at every distance marking (feet, not meters) and at every halfway point between markings, in order to achieve a sequence of photos with everything in focus from minimum to infinity. Usually it is best to just make sure each object in the scene has a focus shot, which can sometimes eliminate the need to focus at distances where nothing is visible. Faster f stops like f2.8 - f8 require more shots to gain full focus when combined in a focus stack, as well as using a longer focal length like 35mm.

Canon 16-35L II Stacking With Focus Scale

16mm and f11

 

REDUCING CONDENSATION/FOGGING

        Gear temperature and condensation can be large issues for landscape photography in cold or varying conditions. I find it important to keep the 16-35L II as warm and dry as possible to prevent damage and image degradation.

 

Hand Warmers, Rubber Bands, and Cloth

        Chemical hand warmers are absolutely perfect for keeping a lens and camera warmer than the outside air, which is important for preventing a fogged front lens element. I keep a cotton cloth in my camera bag for general use, but also for wrapping and insulating the lens from the cold. I usually open two hand warmers and shake them until they are warmed up. I then use one or two rubber bands to secure them to the lens with the cloth covering everything for heat retention. This will keep the lens warm inside of the camera bag for hours, and will also keep it just warm enough outside of the bag to prevent the front element from fogging up, which can happen in cold humid conditions when the lens drops in temperature. Manual focusing is still possible just by rotating the whole setup at the rubber band.

Canon 16-35L II Using Hand Warmers

 

Cold To Hot Condensation

        The most likely cause of condensation on your gear is when you are outside for a long duration and then enter a warm room or vehicle. The cold camera will cause moisture to condense on the outside and may result in damage or fogged optics. As long as the camera lens is not removed, there is little chance of condensation actually forming inside the camera, as the air trapped inside is the same temperature as the camera itself. The camera would have to be placed in front of a strong source of heat to cause internal condensation. I have personally found that a good padded camera bag, if left closed shut, works perfectly for keeping a camera free from condensation even when going from below freezing to a fully heated vehicle. I personally find that placing the camera in a plastic bag for temperature changes is not necessary. It is important to NOT zoom or focus a lens when it is cold and placed into a warmer environment. Doing so will result in warm air entering the lens and camera, which is an almost guarantee to get internal condensation. You never want that to happen!

 

 

CLEANING

        A dirty front element can increase flare and ghosting, as well as degrade image sharpness. One of the worst cases is when doing ocean photography where the salty mist can build up into a thick layer over the front of the lens. Small dust particles are often not an issue until they build up into a thick layer.

 

Brushes, Zeiss Wipes, and Headlamps

        For dust and other non-sticky particles, I purchased a cheapo blower brush from Fred Meyer. I removed the blower portion and just use the brush to flick away particles. Be gentle and it will never scratch your lens or coatings. I have been using these for nearly 20 years without any issues. Just make sure to not handle the bristles themselves, as oil from your skin may adhere to the brush. With the dust and other “dry” particles removed from the front element, I then use a Zeiss wet wipe designed for optical glass. These can be purchased just about anywhere, even Walmart. With the wipe fresh out of the package, give a gentle but thorough cleaning over the entire surface of the front element. There will still be some streaks left over from the wipe, so let the wipe sit unfolded out in the air until much of the cleaning fluid has evaporated and it remains just slightly damp. Now do a final wiping of the lens starting from the center of the lens glass and circling outwards to the edge. The drier lens wipe should leave no streaks. I recommend using a strong LED head lamp in a dark room to check for any further dirtiness or leftover streaks. For some reason this can show leftover debris that can otherwise not be seen in regular lighting conditions. One box of these can last me several years.

Canon 16-35L II Zeiss Cleaning Wipes

 

 

LENS HOODS

        In my opinion, lens hoods are an essential part of maximizing the effectiveness and protection of camera lenses. They block out stray light for added contrast and help prevent lens flare from sources of light outside of the camera frame. Lens hoods are highly effective for preventing scratches and other damage to the front lens element. Lens hoods are also very effective at preventing rain from falling on the front element, but this can vary depending on the focal length of the lens, which determines how deep the hood is made. A deeper hood on a telephoto lens will keep more rain out than the shallow hood of the 16-35L II.

Another way to help keep the 16-35L II safe from glass damage, is to keep the lens set at 28mm when not in use. This moves the front element back into the lens to its furthest position back and helps keep it safe from harm.

Canon 16-35L II Lens at 16mm and 28mm

 

 

NIGHT PHOTOGRAPHY

        While the 16-35L II lens is highly versatile, it does have a considerable level of nearly 3 stops of vignetting when shot at f2.8 and 16mm. This means the center of the image will have almost 8 times as much light as the corners, which will be much darker as a result. For some people, they may not mind the vignetting or even favor it. I personally like an evenly lit sky for night photos.

Canon 16-35L II Corner Vignetting Test

 

Fixing The Problem

        To correct for vignetting, I will often use two methods. The easiest way is to use the vignetting removal tool in a raw image converter which digitally brightens the corners to even out the brightness. The only issue is that the corners will now exhibit more visible noise. The more advanced way is to stitch a few images together which have a 2/3 overlap between each consecutive shot. The stitched output will use only the inner 1/3 of each image and the extreme dark corners will be discarded.

 

 


 

 

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