TRY TIME EXPOSURES FOR ETHEREAL EFFECTS

When we think about taking long exposures with a camera, night time images usually come to mind. Only dark conditions generally call for slow shutter speeds, right?

True-but there is a way to take time exposures in broad daylight...with surprising results.

So the first question that comes to mind is: how do you take a long exposure in bright light? Won’t the camera try to set a fast shutter speed to ensure that the exposure is correct, regardless of how small the aperture is set?

Then there’s the other question: why would you want to take long exposures in daytime, anyway?

OK - a long time exposure (keeping the camera’s shutter open for a long time – from seconds to minutes) will occur when:

• Light level is very low
• A very small aperture is chosen, and
• ISO is set to the lowest value that the camera will allow.

So, to answer the first question, you need to simulate low light conditions by giving your camera dark sunglasses. The device that will do this is an inexpensive thread-on piece of glass called a neutral density (ND) filter. These filters come in a wide variety of grades and are either specified in ‘stops’ or ‘times’.  They are also available as variable grade versions, often referred to as Fader NDs. Be sure to buy one that has the same filter thread diameter as your lens.

A one-stop (or two times) ND filter, with aperture and ISO remaining the same, will require that you force the shutter to stay open twice as long to get the same exposure as you would without the filter. Similarly, a two-stop filter will require slowing the shutter by four times, since a stop means a factor of two in exposure. For the kind of images I’m proposing we take, you will need a ten-stop filter in order to get exposures that are minutes long. This is equivalent to increasing exposure by a factor of 1024 times, but is usually referred to as a 1000 times filter.

Why minutes? Well, in answer to the second question above, anything moving (water, clouds) will take on a foggy (in the case of waves) or streaky (in the case of clouds) look. As long as you have stationary elements in the scene, such as rocks, ground and a tree trunk in the sample shots shown in this post, the viewer is confronted with a paradox that doesn’t appear ‘natural’. This makes for a more interesting image than if you had captured the same scene with a shutter speed of, say, 1/250^th of a second. While these images were shot in colour, I converted them to black and white, since they tend to look more dramatic that way.

And now for the practical considerations. You will need:

• A stable tripod
• A remote shutter release that plugs into your camera, since you can’t hold down the shutter button on your camera for minutes without jarring it. You can also get an intervalometer, which allows you to set a specific time interval without having to manually time the shutter.
• A camera with a Manual mode that will allow you to set the shutter to ‘Bulb’, or one that has a dedicated Bulb mode.
• A day with calm winds, so that your tripod doesn’t get buffeted during the exposure.

Look for a scene that has a combination of moving and stationary components. Getting the right exposure is definitely going to take some experimentation. As a starting point, set your camera’s ISO to the lowest value it provides. This is typically 100. Do NOT use Auto ISO. In Manual / Bulb mode, set the aperture to a value anywhere in the range of f/16 to f/22. This will depend on whether it’s an overcast or sunny day. You should get exposures in the range of 2 to 4 minutes. Use the histogram to confirm good exposure and tweak the time (or aperture) as needed to get perfect exposure or desired motion effect.

With digital SLRs, a practical consideration is the heating of the sensor during long exposures. While it won’t damage the camera, this heating tends to amplify what are often referred to as ‘stuck pixels’. Every camera has them, and they appear as unexpected bright spots on the final image.

To combat this, DSLRs generally have a long exposure noise reduction setting which can mitigate this annoyance. Unfortunately, it requires that the camera will make you wait twice as long to see your image, since it takes as long again as the exposure time to process out the stuck pixels. This could result in an 8 minute wait until you take the next shot. While this technique is effective, I prefer to take my chances and fix the spots after in either Lightroom or Photoshop.

By way of a summary, here are the steps I take:

1. Set up the camera on the tripod and compose the scene with the chosen lens.
2. Ensure ISO is at its lowest setting, and choose a small aperture to help force a long exposure and to give me the depth of field I want.
3. Plug in the remote shutter release or intervalometer (and set it to the exposure time I want).
4. Thread on the ten-stop ND filter, being careful not to disturb focal length or focus settings.
5. Cover up the eyepiece if the sun is behind me, to prevent light leak onto the image (it has happened to me!)
6. Check my image and histogram, rinse and repeat until I get the right exposure and effect.

It’s a slow process that requires patience. At the end of it though, you will get images that will be set apart from the ordinary.

USING SPEEDLITES FOR BETTER RESULTS

Speedlites , simply stated, are accessory flashes that attach to the hot shoe of your DSLR. By raising the light source above the camera, the speedlite produces a more pleasing effect than the harsh head-on shadow cast by the camera’s built-in popup flash.

But there’s more to speedlites than that. Most have swivel heads that allow you to “bounce” the flash off a ceiling or wall to provide a more diffuse light source. This has the effect of softening the shadows behind the subject and more evenly filling in shadow areas on the face. Because the flash head is now well separated from the camera body, you can also add light modifiers such as a collapsible softbox. As the name implies, it softens or diffuses the light, allowing you to aim the speedlite directly at the subject rather than depending on a bounce surface. Outdoors in daylight, these are often used as a “fill” light to overcome the harsh shadows cast on the face by mid-day sunlight.

Better yet, speedlites have their own internal battery supply, so they can be separated from the camera and used in the same way as studio strobes. By mounting them on light stands and firing them with inexpensive radio triggers, you can have studio lighting anywhere, without the need for AC power. Add lightweight bounce umbrellas to diffuse the light evenly, and you can have as many light sources as you like filling an area with even, soft light.

So how do you configure this portable studio? Most of the small stuff can be bought on eBay much cheaper than at local retailers, but bulky items like light stands and umbrellas, in my humble opinion, can be sourced locally for not much more than overseas online pricing. And you have the benefit of not having to wait 2-3 weeks for product.

When it comes to speedlites and radio triggers, however, I would like to make a recommendation. While I want to stress that I have no affiliation with the company, I have found products made by Yongnuo of China to be well made and very cost effective. Just be sure that when you make a purchase that the models you choose are designed for your specific DSLR model. In some cases, their triggers are also compatible with camera manufacturers’ speedlites, but why not buy a speedlite that works as well at a third of the price?

So what is a radio trigger? If you decide to use a speedlite off-camera, you will need a means of making the flash fire when you press the camera’s shutter button. The transmitter mounts on your camera’s hot shoe and sends a signal to the receiver, which you mount on the light stand. The receiver has a hot shoe built onto it, so you simply attach your speedlite to it. Some triggers, like the YN-603, are actually transceivers, so you can use them as either a transmitter (when mounted on the camera’s hot shoe), or a receiver (when the speedlite is attached to it).

Now, there are two types of speedlites that you should be aware of: manual (such as the YN-560 III) or full ETTL (such as the YN-565 EXII). ETTL stands for Evaluative Through The Lens, meaning the camera and speedlite work together through connections on the hot shoe to ensure that the light output from the speedlite gives optimal exposure.

YN-560 III in off-camera configuration

A manual speedlite, however, requires that you set the light output on the speedlite itself by either trial-and-error or by using a flash meter. Studio setups are typically all manual. The YN-560 III has a very nice feature: built in radio receivers that are compatible with the YN-603 trigger. This means that you only need a single YN-603 on the camera’s hot shoe, rather than also attaching one to each of the speedlites to act as receivers. One feature of a manual flash is that its hot shoe connection is comprised of only a single contact point. This makes it compatible with a wide range of cameras, as opposed to an ETTL speedlite that has an arrangement of multiple contacts that are specific to a camera brand. This is why you must buy an ETTL speedlite specifically for your camera.

 

 

Yongnuo also makes an ETTL radio trigger called the YN-622. Two of these transceivers will allow you to trigger a compatible off-camera ETTL speedlite like the YN-565 EXII in full ETTL mode, meaning you don’t have to manually set the speedlite output. The camera reads the light from the speedlite through its lens and sends commands to the speedlite over the YN-622 radio link to adjust its output. You can also control groups of speedlites with these so that each has a different output level, but still controlled by the camera.

YN-565 EXII operating ETTL through a YN-622

Another benefit of using the YN-622 and a compatible speedlite on the camera is that you can use that speedlite in ETTL mode while simultaneously triggering a manual flash with a second YN-622 off-camera. That way, you can quickly move from a studio setup with two lights to a roaming subject using the single ETTL speedlite on your camera (such as in a wedding reception). The YN-622 simply attaches to the camera’s hot shoe and the speedlite attaches to the YN-622’s hot shoe.



Stacked YN-603 on a YN-622

While the Yongnuo product line is great value for money, however, I get the sense that the company doesn’t have a uniform design vision. For example, the built-in trigger receiver in the YN-560 III doesn’t exist in the YN-565 EXII. Where this becomes an issue is if you want to use the 560 and 565 together in a setup (with the 565 set to manual mode) and trigger them both from a single YN-603 trigger on the camera. Also, you can’t mix and match YN-603 and YN-622’s in a setup because they’re not compatible. You can, however, stack one on top of the other on your camera’s hot shoe and have each trigger their respective receivers.

By doing a little research, you can configure a professional lighting setup for well under $500. Just be sure that you are buying product that is 100% compatible with your camera make and model

New Digital SLR Photography Book for 2014

"Digital SLR Photography Demystified" is my new venture in the world of photography instruction.

Originally conceived as a reference for students taking my Digital Photography for Beginners course, it also serves as a standalone guide for those who prefer self-instruction. Written in the same way as my easy-to-understand teaching style, it includes ten practice exercises to reinforce the concepts presented.

The content goes beyond the "Beginners" course by covering panoramic, high dynamic range (HDR) and night photography. Also included is a comprehensive Glossary of Terms and a Quick Solution Guide.

While no one book can explain the functions of all camera makes, a generic model is used to help the reader locate a button or menu item on their own camera, using industry-standard icons where applicable.

Currently, the book is available as a 96 page paperback from Lulu.com for $14.95 CDN + shipping (slightly less in $US). In the coming weeks, it will also become available on Amazon and Barnes & Noble websites under the ISBN 978-1-312-03258-3.

Use the QR code below to review the book on Lulu.com.

WINTER EXPOSURE

Have we had enough of cold and snow yet? Unfortunately, it doesn’t look like it’s going away any time soon.

So – if you have the itch to get out and take some photos anyway but are disappointed with the results, the problem may be with exposure. The photographic kind, that is. The camera meters (measures) the light coming through the lens and tries to ‘average’ the exposure to a mid-grey (referred to as 18% grey).

With Evaluative (Canon-speak) or Matrix (Nikon-speak) metering, the camera reads the light over several zones in the viewfinder. If a bright scene covers most of these zones, the computer in the camera will calculate the exposure based mostly on these bright zones. In winter scenes – guess what – snow tends to dominate the scene and the camera tries to expose it to a mid-grey. So, if your winter shots are a little dark, that’s the reason.

There are two fixes for this: spot/partial metering and exposure compensation. I find the latter is the easiest solution so I’ll address it first.

 
Exposure compensation is a means of overriding the camera’s metering, by allowing you to over- or underexpose by an amount chosen by you. It’s normally controlled by pressing the +/- button and turning the command wheel on the camera. As you do, a bar graph (depends on the camera) will indicate by how many stops you are changing the exposure.

Since the snow caused your camera to underexpose, you need to dial in some overexposure or + exposure compensation. I typically use about one and two-thirds stops, but you may need to use something different depending upon how much of the scene is occupied by snow. Just don’t forget to dial it back to zero when finished, because it won’t go away when the camera is turned off.

 

Partial or Spot metering relies on something that has a mid-grey tone (although it can be a colour like facial skin) centred in the viewfinder. It effectively ignores all the white snow around it and exposes based on the face or mid-grey object.

I hope this helps, because there’s nothing I can do about the weather. If you need a little more help,  check out my photography courses at www.filmscapes.ca

PERFECTING THE PANORAMIC

It’s getting easier to make panoramics with today’s cameras. Some will actually do the stitching together for you without the need for software. But unless you take control of the process, you may be selling yourself short on results.

Here is a checklist you can follow in preparation for shooting your panoramic. It may look a little daunting, but it will become old hat with a little practice:



• Arrive Early   In order to get through this checklist, you’ll need the extra setup time before the light changes!
• Use a Tripod   A panoramic is comprised of a series of adjacent photographs stitched together in software to form a single wide-angle image. In the stitching process, the software does its best to match adjacent images seamlessly, but there is usually a bit of twisting required to match them perfectly. This requires cropping the final panoramic. Unless the individual images are shot with the camera absolutely level, the twisting and subsequent cropping may get to the point where much of the scene is lost.
• Level the Tripod and Camera  I have a bubble level on the base of my tripod which I use to get the legs levelled up first. I also use a bubble level that slips onto the camera’s hot shoe, which I use to do fine levelling adjustments. The reason for using both is that uneven legs may give me the impression that I have a level camera at one position, using the hot shoe level. But as I pan, I would likely see the level drift off centre. Once you have tweaked both the legs and the pan/tilt head, try panning through the intended range of your panoramic to ensure you have optimized both.
• Set the Camera to Manual (M) mode   Imagine you’re shooting a panoramic made up of photos that have dramatically different light content. In any mode but Manual, each photo would be exposed differently because the light metering system built into your camera tries to set the exposure automatically to an average 18% grey level. In this scenario, the panoramic wouldn’t look right because the inherently darker scenes would be forced to look lighter compared to the others, resulting in a patchy-looking result. Sure, you could try matching the exposures in software before stitching, but it’s easier to get it right in the camera. I pan the entire scene first, using the digital meter to set a shutter speed/aperture combination that averages a normal exposure. As a result, some shots will be over-exposed slightly, others under. As long as the histograms for all photos don’t show any clipping at the black or white points, you’re OK.

  

  The camera's digital light meter. Zero is optimal exposure.

  

 

 

 

 

 

 

•  Set the Camera ISO setting to a fixed value  Some cameras have Auto ISO setting. Per the last point about exposure, ensure you choose a fixed value (eg. 200) rather than Auto.
• Set the Camera to manual focus  Most SLR lenses have a switch allowing you to disengage the motor that automatically focuses your lens before you take a shot. For panoramics, set it to manual focus (MF). The reason for this is that as you pan to take each of the shots, the camera may refocus on something close in or far away, especially if there’s an object in one of the shots that is prominent. That could result in uneven focus across the panoramic. Pick one focus setting that works for the whole panoramic and leave it there.
• Take the Camera out of Auto White Balance  Similar to the argument in the last two points above, you don’t want the camera to change the colour balance as you pan because of changing content. Choose one of the presets instead of Auto. For instance, if shooting on an overcast day, use the Cloudy Bright setting. If shooting an indoor scene under fluorescent lights, use the Fluorescent setting. If you have access to a photo editing program that allows white balance adjustment, don’t worry about what preset you choose, because you can correct all the shots by the same amount if the preset you chose results in wonky colour.
• Overlap the Photos  Panoramic software uses artificial intelligence to look for similarities between adjacent shots then join those features seamlessly. In order to provide those reference points, you need to provide overlap in content between adjacent shots. I typically overlap by 25%. If I start my panoramic on the left end then take subsequent shots by panning left to right, this means that my second photo contains the rightmost 25% of the first photo. I’ve made marks on my tripod head that tell me how far to pan before taking the next shot while allowing 25% overlap. I have marks for both landscape format and portrait formats. But, of course, those marks only work for one focal length, which brings me to the next point….
• Use a “Normal” focal length  For a consumer digital SLR with an APS-C sensor, normal focal length is about 33mm. Anything shorter is considered wide angle. The wider you go, the more barrel or pincushion distortion will be introduced. This may make it harder for the stitching software to match the photos without twisting the photos to counter this effect. The more twisting, the more cropping of the final panoramic you’re likely to have to do. Of course, you could use a longer focal length without this concern, but remember that depth of field reduces with focal length.  I use a 35mm prime lens for panoramics, adapted from an old film camera.
• Choose the Right Content  I like shooting sky panoramics. I found out the hard way that sometimes the stitching software will not work properly with some content – particularly soft images with few hard edges. Some sunset clouds fit that description. Sometimes, it helps to include some hard edge detail (like treetops) to assist in the stitching. You can always crop it out later.

• Choose the Right Software  I find that the ‘premier’ photo editing package gives too many choices when creating panoramics. You have to try them all to find out which one works best, but my experience is that I generally don’t like any of the results. On the other hand, a cheap and cheerful package sometimes works better and with less fuss. I particularly like ArcSoft’s Panorama Maker, which came bundled free with my point-and-shoot camera.

 

 

3 overlapping images stitched together, before cropping. Note how the software has to distort the images to make them match up.



As you can see, the process of shooting panoramics like a pro is very manual. If you’re shooting a scene with moving clouds, set up marks on your tripod so you can rapidly make all your shots before the clouds change position and shape. And finally, resist the temptation to use more than 3 or 4 shots in a panoramic, because you’ll end up with a long, skinny picture sitting in the middle of your print that will look silly.

NEW LIGHTING COURSE IN 2013

Many people have taken my Digital Photography for Beginners course to overcome their reluctance to take their camera out of Auto mode and take control of exposure and depth of field.

For those who are starting to feel comfortable with their camera's creative modes and now want to take portraits or product shots aided by low cost lighting equipment, this 3-hour course should fit the bill.

Dubbed 'Lighting for the Beginner Photographer', the course provides plenty of hands-on practice using equipment the student may not yet own. All that is required is to bring along a digital SLR and to have an understanding of the basic concepts in the Digital Photography for Beginners course. You can also bring a hot-shoe flash if you have one.This is taught in my home in London, Ontario.

To register for the course, please visit http://filmscapes.ca/html/photography_courses.html

Here is an outline of the course (subject to change):

1.       The Camera’s Creative Modes

a.       Review of Aperture Priority, Shutter Priority, Program and Manual Modes

b.      When to use these modes in available light

c.       When to use these modes with fill flash (built in to the camera or external)

d.      Taking control of light and depth of field in the studio with Manual mode

e.      Flash sync and its relationship to maximum shutter speed

PRACTICE: Using fill flash in various creative modes. Observing shutter speed limitations with flash.

2.       Light Sources and Exposure

a.       The meaning of colour temperature and its relationship to outdoor and artificial light

b.      Selecting white balance for the light source (outdoor light/flash/indoor lighting)

                                                               i.      Preset vs. auto white balance

                                                             ii.      Custom white balance: when to use and how to set it

c.       The hot-shoe flash vs. the built-in flash

d.      Strobes (optional)

e.      Continuous (hot) lights

f.        Guide Numbers and Watt-Seconds

g.       Use of the light/flash meter (optional)

h.      Camera metering modes

i.         The histogram as an exposure tool and the meaning of 18% grey

PRACTICE: Experimenting with White Balance presets. Setting a custom white balance. Shooting without flash using various metering modes and comparing results in the histograms.

3.       Remote Triggering of Flash/Strobe

a.       Radio triggers and adapters for flash mounted on light stand

b.      Optical triggering

c.       Controlling the flash in manual mode

d.      Controlling the strobe output (optional)

PRACTICE: Setting remote flash output. Triggering from camera with radio trigger or optically from camera’s flash.

4.       Introduction to Light Diffusers and Reflectors

a.       Umbrellas

b.      Soft Boxes for strobes and hot-shoe flash

c.       Reflectors and Absorbers: outdoors with/without flash; in the studio

d.      Diffusers for harsh daylight

PRACTICE: Take a portrait shot/object shot with remote flash, with and without umbrella Repeat using available light and reflector, then diffuser.

5.       Basic Portraiture Methods

a.       Background stands

b.      Choice of material and colour for the type of shoot (including green screen)

c.       The role of depth of field and lens choice

d.      Using natural light

e.      The single light setup

f.        The two light setup

g.       Balancing sources for intensity

h.      Mixed light sources and the importance of custom white balance

PRACTICE:

-          Portraiture/object shoot using window light and choice of background (try black then white)

-          Portraiture/object shoot using window light, reflector and/or absorber and choice of background

-          Portraiture/object shoot using window light and single hair light (custom white balance)

-          Portraiture/object shoot using single light in studio setting (custom white balance)

-          Portraiture/object shoot using two lights with umbrellas/soft boxes in studio setting (custom white balance)

-          Experiments with other combinations

Size matters – in sensors, that is.

When digital SLRs started to come into the market, they essentially replaced the 35mm film camera. In most cases, the lenses that fit your 35mm camera could now be used on the new digitals (from the same manufacturer, of course) without the need for any adapters. Sweet.

Those who made this transition noticed something right away. The 50mm focal length lens that gave a ‘normal’ angle of view on their film camera now acted like an 80mm lens, or slight telephoto, when attached to the digital SLR. In other words, the image was now magnified compared to using the same lens on the 35mm camera.

In some ways this was a benefit, because it meant that the telephoto lens you bought for your 35mm camera now reached a bit further on the digital SLR– about 1.6 times further. The downside was that the wide angle lens that used to work beautifully for landscapes on your 35mm wasn’t so wide anymore on the digital.

This difference is attributable to the size of the sensor in the digital camera. Most consumer SLRs use an APS-C size sensor, which is 22mm x 15mm. Compare that to 35mm film at 36mm x 24mm. Given the same lens projecting the same ‘image circle’ on the digital sensor  and the 35mm negative, the digital sensor only captures part of what the negative captures. Essentially, the digital image is magnified (by 1.6 times) since it’s like zooming in on a small part of the image circle.

For years now, professionals who could afford it have been using full frame digital SLRs (example – the Canon 5D) which use a 36mm x 24mm sensor, just like the 35mm negative size. While the manufacturers could have stuffed more pixels into this bigger sensor (and did so to an extent), the big benefit is that they can now make the pixels bigger.

Why? The bigger the pixel, the more light it can gather, meaning the camera will yield less ‘noise’ in the image in low light situations. Overall, the image is cleaner and yes, at a somewhat higher resolution. In fact, Nikon recently introduced the full frame D800 with an astonishing 36 megapixel sensor. Compare that to the Canon 5D’s 22 megapixel resolution or 18 megapixels on most consumer SLRs. Of course, file sizes bloom with higher resolution.

All of this is significant because the prices of full frame camera bodies are starting to slide below the $2000 price point. While APS-C and other similar size sensors kick-started the digital photography revolution, affordable full frames will eventually bring it full circle. The smaller sensors won’t disappear for a while yet, but those of us who came up through the film world will once again be able to shoot the way we used to – only with the immediacy of digital and a moderate size hole in our pocket.

Are Point-and-Shoot Cameras Really That Good?

As someone who shoots stock images using SLRs, it may seem strange that I find it necessary to have a digital point-and-shoot in my possession.

Not so strange when you consider that the lenses, resolution and exposure modes are starting to catch up with their big, interchangeable lens cousins. Besides, sometimes a small no-fuss camera, due to its portability, is available to capture images we would otherwise miss because we left our clunkier gear at home.

But can they really compete on image quality? I decided to pit a Canon Rebel XTi SLR against a Panasonic Lumix FX500 point-and-shoot, each claiming 10.1 megapixel resolution. I shot the same image outdoors on each camera in rapid succession, so the light was consistent. The Rebel was set to record in JPEG only (instead of RAW) so that it matched the Lumix method of recording. Each was set to aperture priority and f/8. Shutter speed was 1/40th to 1/50th for each. Both were set for auto white balance.

The fundamental difference between the two cameras, of course, is the physical size of the sensor and the technologies used. The Rebel uses a CMOS sensor, while the Lumix uses a smaller CCD sensor. To be accurate, it should be noted that the Lumix creates a 10.1 megapixel image when in 4:3 mode, while in 3:2 mode (to match the Rebel's aspect ratio)the image size is actually 9 megapixels.

Examining the zoomed-in crop of each image, it's apparent that the little CCD can't compete with the larger CMOS, both in terms of sharpness in transitions from white to red, for example, and in colour saturation in general. Also, the CCD appears "grainier" amongst the blades of grass, and falls short in latitude (or dynamic range) when compared to the Rebel image.

The results may seem obvious, given the smaller size and lower cost of the p & s. So why bother?
Well, I wanted to gauge just how far apart the quality levels were. In my opinion, while the p & s is not up to pro standard, it's still amazingly good. I'm going to use it to take test shots of scenes that I might want to return to later and shoot with the SLR. Besides, how many times have we jumped in the car and wished later that we had grabbed a camera?