cornicello

What does that modifier look like?

I had a few spare minutes yesterday (New Year’s Eve), so invited a friend and her daughter over to make some photographs with a variety of light modifiers. Here are the results of the 28 configurations we tested.

All photos lit with an Interfit Photographic Honey Badger strobe head. All photos metered to f/6.3. Subject seated about 2 feet in front of white seamless paper. All lit with the single light with no reflectors or fill light. Camera was set to “daylight” white balance (yes there is that big a difference in skin tone between them) and the only post-processing on the images was to crop them to a square.

Here is the list of modifiers used and some notes:

  • Interfit 48-inch deep parabolic softbox with both diffusers in place

  • Interfit 48-inch deep parabolic softbox with only the inner diffuser

  • Interfit 48-inch deep parabolic softbox with no diffusers (open face)

  • Interfit 48-inch deep parabolic softbox with 20-inch black foam-core disk blocking the middle of the light (looks like a ring light)*

  • Neewer 36-inch parabolic softbox with CheetahStand focusing rod with the flash head pulled all the way in to the softbox

  • Neewer 36-inch parabolic softbox with CheetahStand focusing rod with the flash extended to the opening of the softbox

  • Neewer 36-inch parabolic softbox with CheetahStand focusing rod with the flash extended to the opening of the softbox and a 20-inch black foamcore disk blocking out the middle of the light*

  • SPSystems 28-inch folding octabox with both diffusers in place Light boomed over camera on axis with lens

  • SPSystems 28-inch folding octabox with only the inner diffuser

  • 22-inch Speedotron beauty dish centered over the camera with diffusion sock

  • 22-inch Speedotron beauty dish without the sock

  • 20-inch metal dish reflector centered over the camera

  • 20-inch metal dish reflector with a diffusion sock on it

  • Interfit Deep Zoom reflector at camera left

  • Interfit Deep Zoom reflector with its diffusion sock

  • Interfit Deep Zoom reflector with 10-degree grid

  • Interfit Deep Zoom reflector with 10-degree grid and diffuser to show that the diffuser negates the effect of the grid

  • 7-inch metal dish reflector

  • 7-inch metal dish reflector with one sheet of #261 diffusion

  • 7-inch metal dish reflector with two sheets of #261 diffusion

  • 7-inch metal dish reflector with 10-degree grid

  • Interfit 2x3-foot softbox pointed directly at the subjects

  • Interfit 2x3-foot softbox feathered in front of the subjects

  • Interfit 2x2-foot collapsible softbox (which comes with the Honey Badger and has a recessed front panel)

  • 2x2 softbox with a flat front (old and apparently yellowed with age)

  • Interfit 65-inch** Silver Parabolic umbrella with the head pushed almost all the way into the umbrella

  • Interfit 65-inch** Silver Parabolic umbrella with the head pushed in (focused) and a 20-inch black foam-core disk blocking the center of the light

  • Interfit 65-inch** Silver Parabolic umbrella with the head mounted on a separate light stand about 5-feet in front of the umbrella

    * see the photo below
    **measured across the opening, other companies call this a 7-foot or an 84-inch as they measure around the back arc of the umbrella

The black foam-core disk was used in an attempt to make the lights act something like a defocused Broncolor Para. The sliding focusing arm in the 36-inch para was for the same reason. But looking at the photos, I think that I like the big 48-inch Interfit Parabolic Softbox in any of its configurations (2 diffusers, inner diffuser, no diffuser).

Some photos for clarification

Strobe head mounted on a separate stand 5 feet in front of the Interfit 65-inch Silver Parabolic Umbrella

Strobe head mounted on a separate stand 5 feet in front of the Interfit 65-inch Silver Parabolic Umbrella

Black foam-core disk blocking the center of the deep parabolic softbox

Black foam-core disk blocking the center of the deep parabolic softbox

Cheetah “Chopstick” lets you position the flash head inside the softbox, sliding it closer to or farther from the back of the softbox to focus the light

Cheetah “Chopstick” lets you position the flash head inside the softbox, sliding it closer to or farther from the back of the softbox to focus the light

What information lurks in the shadows?

Only the Shadow knows.

And he has something to say! Shadows are a very important piece of our photographs. Shadows help define our subject. They help set the mood of the photograph. They can hide things we don’t want to show. They can tell a story about how a scene was lit. And that’s what I am talking about today. What can we see in the shadows?

Here are my descriptions for the 14 images on the right (click on the image for a larger version):

  1. Standard 7-inch metal dish reflector
    Notice slight double-edge to the shadow due to the flash tube being slightly brighter than the surrounding reflector.

  2. Standard 7-inch metal dish reflector with one layer of diffusion material
    Contrast is lower from light bouncing around the room, shadow edge is more homogenized by the diffuser. The shadow edge is the same, no extra softening from the diffusion, just a brighter shadow.

  3. Standard 7-inch metal dish reflector with two layers of diffusion material
    Very similar to #2 but needing more flash power. Extra diffusion did warm up the color. Still has the same edge with no additional softening.

  4. Standard 7-inch metal dish reflector with 10-degree grid
    Narrow beam of light doesn’t hit walls, ceilings, etc. (environment), so more contrast. Still has the same shadow edge quality, just a darker shadow and restricted coverage on the background.

  5. Standard 7-inch metal dish reflector with 10-degree grid plus a layer of diffusion
    Brings us back to what we had in #1 or #2, but required 5 more stops of light power to maintain the same exposure. Don’t put diffusion in front of a grid! It negates the effect of the grid at the cost of a lot of your flash power.

  6. Deep Zoom 11-inch reflector
    Narrower light been from the deep reflector gives a darker shadow, somewhat similar to the grid in #4, but like #1 the shadow edge is doubled because of the difference in efficiency between the light direct from the flash tube and the light bounced off the walls of the reflector. Diffusion would help homogenize the shadow, but will also take away some of the contrast.

  7. Deep Zoom 11-inch reflector with 10-degree grid
    Even less environmental bounce producing a darker shadow.

  8. 1x3 strip box in vertical position
    Narrow modifier produces little shadow along its long dimension (up/down here) with much more shadow along its shorter dimension (left/right here).

  9. 1x3 strip box in horizontal position
    Rotating the narrow box moves the shadows. The left/right shadows are a little bit tighter while we now have up/down shadows. This is especially noticeable on the light stand holding the silhouette. In #8 it casts a wide shadow, while in #9 the wide pattern wraps around the narrow object and there is virtually no shadow.

  10. 2x2-foot square softbox in close at 3-feet
    This softbox has both an inner and outer diffusion panel. Shadow transition is soft

  11. 2x2-foot square softbox backed up to 6 feet
    The box gets smaller in relation to the subject when moved back.The shadow gets a harder and more defined edge. The background brightens up slightly (depth of light, inverse square law). More light bounces around the room picking up some warmth from the wooden floor.

  12. 2x2-foot square softbox at 6 feet with an extra layer of diffusion
    Shadow quality remains the same, but image picked up some warmth from either the wood floor bouncing in or from the diffusion material (or both). Requires more flash power.

  13. 46-inch Photek Softlighter umbrella WITHOUT the diffuser
    Large, round light. Even shadows all around. Background is brighter than #14 due to longer light path and depth. Although the umbrella is 36 inches from the subject, the light path is from the flash to the umbrella (24-inches) and from the umbrella to the wall (36-inches) so the distance of light is like having a forward facing light at 5-feet away instead of 3-feet, as you would get with the front diffuser (see #14).

  14. 46-inch Photek Softlighter umbrella with the diffuser
    Adding the diffusion cover has a slight effect on lightening the shadow density. Background is slightly darker as the light source (the diffusion panel) is closer to the subject. The closer the light is to your subject, the darker the background will be.

All the photos were metered to give the same exposure. In most cases the aperture remained the same (f/4.0) and the flash power was adjusted to maintain correct exposure. The exceptions are the exxamples with the Deep Zoom reflector, as it was very efficient and I could not lower the flash power enough so I had to stop down the lens to f/7.1. 

The main take-aways from this lesson is that the shape of your modifier determines the shape of the shadows and the size of the light as seen by the subject determines the size of the shadow width or the quality of light, that is hard or soft. Diffusion, along with the environment, controls the shadow density or contrast. Adding diffusion directly to a light, where it doesn’t make the light any larger, does not soften the light. It is a very subtle, but important concept. Diffusion does homogenize the light, making it more even across its field. And, depending on the environment, fills in the shadows making them less dark by bouncing off the walls, floor, ceiling, and other surroundings. Don’t confuse contrast with quality.

As I said, the difference can be subtle. Here we have three photos to compare. The first (A) was lit with a standard 7-inch diameter silver metal dish reflector. It casts a hard edged deep shadow. Next, I taped a sheet of diffusion material over the reflector (B) and you can see that the edge shape and transition (quality) has remained the same. What changed was the depth or darkness of the shadow (contrast). The diffusion spread the light around the studio and made the shadows lighter in tone, but the edge didn’t change because the light size didn’t change. For the third photo (C) I switched to a 20-inch diameter light modifier without diffusion and you can see here that the edge got softer and the transition got wider as the light was able to “wrap” around the subject for a softer light quality.

contrast-vs-quality.jpg

Now let’s look at what happens when we keep the same small 7-inch diameter reflector but add single and double diffusion. The first sheet of diffusion material makes the shadow brighter and also homogenizes the shadow edge so there is no longer a double-shadow (from the flash tube and the reflector not being equal in brightness). Adding the second layer of diffusion slightly lightens the shadow, but not appreciably. It does not in any way soften the light.

multi-diffusion.jpg
triple-diffusion

I can anticipate a comment and question. That’s all well and good for diffusing a small light. I am using a Photek Softlighter and want to double (or triple) the diffusion on that. What happens there? Let’s take a look! Here are four examples starting with the Softlighter umbrella on its own without the diffuser. Next is with the diffuser. Then for double diffusion I hung a roll of diffusion material in front of the Softlighter to double-diffuse it. Then I doubled that up to make it triple-diffused (see the photo on the right). Adding the diffusion panel to the bare umbrella actually limits the spread of the light and makes the shadow a bit darker. Adding additional layers of diffusion on top of that brighten the shadows ever so slightly and start to add some warmth to the color. But again, no change in the quality/softness of the light from extra diffusion. The size of the light remained the same.

This environmental bounce can also cause color casts if the room isn’t neutral in color. In a larger studio, or in a studio with black walls, ceiling, and floors, or in an open field the changes in contrast on the subject with or without diffusion and grids will be much less noticeable.

 

 

Well, this brings us to the close of another year. 2018 has been quite a year for me. The biggest event was the passing of my 98-year-old mom, Rose, in August. Thanks for everything you have done for me and for all the support for my taking my own direction in life. I could not have had a better mom. Rest in peace.

So, here is looking to a bright new year with new challenges and accomplishments. I wish you all a Happy New Year! Stay safe and be well.

Cheers!
John














Light as a feather

What does it mean to “feather” your light?

The first thing many people will say is that it makes the light softer. But is that really true? Let’s take a look. To feather the light means that you turn the light so it isn’t pointing directly at your subject. As we should all know, the softness of the light comes from the size of the light in relation to the subject. A big light in close gives a soft light with its size allowing light to reach the subject from multiple angles and filling in its own shadows. That same light backed up farther away becomes smaller as seen by the subject. Light comes in from more restricted angles and the shadow edge quality gets harder.

What happens when you take a softbox and rotate it away from your subject? The height of the box remains the same, but the width gets narrower (smaller) as you turn it away, making it look more like a strip light to the subject. As the height remains the same the up/down shadows (under the chin, under the nose, under the eye sockets) will remain the same. But side-to-side shadows (the side of the nose) will get slightly harder. If you don’t make the light source larger, it will not get any softer.

OK, if feathering doesn’t soften the light, what does it do?

Feathering gives you control. You get to place the edge of the light from your softbox and you get to control the balance the intensity of light on the cheeks of your subject. Let’s take a look.

For this series of images I used a flash meter at the point marked in the upper left image to measure an exposure of f/4 (ISO 100, 1/125 sec.) and I varied the flash power between each image to maintain the same f/4.0 reading on all five images. The inset diagrams show the lighting setups from above and the second row of photos shows the setup from the side. There were no fill cards or fill lights used. All images are straight out of camera with no exposure or color adjustments. The light, an Interfit Photographic Honey Badger was modified with the 24x24 popup softbox that comes with the light. Both the inner and outer diffusers were in place and it was 18-inches from the nose of the mannequin in the middle image. (FCC Warning: that is an affiliate link, I may be compensated if you purchase something there using code “cornicello10” at checkout—and you get 10% off!)

Pay close attention to the nose shadows in the photos above. They stay pretty much the same throughout the series. What changes is the exposure balance between the two sides of the face. Pointed behind the subject the cheek closest to the light is much brighter than the other cheek. As the light is turned towards and then beyond the subject the highlight moves across the face. At first the two cheeks come closer to each other in brightness. Then finally with the light pointing away from the subject and towards the camera the other cheek gets slightly brighter than the cheek on the side with the light. The power on the light had to be brought up quite a bit on the last image because it was pointing quite a bit forward, lighting up more of the environment in front of the subject, causing a bit of a change in color, too. My last blog post was about environmental bounce. Check it out if you get a chance.

Distance matters, too. As you move your light back farther from your subject the light pattern grows and transition area gets larger. This can help when photographing groups of people with a single light. By backing the light up and pointing the light across the front of the group you can get even coverage across the group. Here is a group photo of the staff of PCNW in Seattle. It is lit by one large umbrella slightly to the side and slightly feathered across the group.

Click on the image to enlarge it

To answer some questions that might come up…


What is the difference between using a softbox with a recessed front panel versus one with a flush front panel? The recessed panel with its miniature barn doors gives more control over where you place the edge of the light and has quicker fall-off with darker shadows. Here is a set of comparison images lit with the same size softboxes with and without a recessed front diffuser. For the third row I added a white foam-core bounce board as a fill light.

beauty-direct.jpg

Yes, you can feather up and down to control the balance of light from the forehead down to the chin. It is not uncommon to have your light look like it is pointing at the ground in front of your subject or pointing up into the air above your subject to get the desired pool of light on your subject’s face so that the forehead is not too bright compared to the nose and chin. Your light might end up looking like it is not pointing at your subject at all. The important thing is what the light looks like on your subject, not what the actual light looks like.

Yes, you can feather an umbrella or a hard reflector or a beauty dish. WIth an umbrella or beauty dish be careful to not turn the light so far that the bare flash can be seen by the subject, hitting them with harsh direct light from a small light source (the flash tube).

What are your questions about feathering light?

Cyber Monday with creativeLIVE and DPReview

Creating Portraits at Home

I recently had the honor of being invited by creativeLIVE and DPReview to be part of the DPReview Live Cyber Monday event to talk about making portraits at home.

Caitlin

Caitlin

Shawn Barnett (former Features Editor for DPReview) and I talked about a range of options for setting up your home portrait "studio" that might fit various budgets. We started with window light then moved to fluorescent lights. Then we worked with a speed light (on and off camera) and then used a studio strobe light. You can watch the segments for FREE any time on the creativeLIVE

I just wanted to do a little follow up here on the blog to talk a bit more about what we did, show the photos we took, and give the settings information. The camera I was using was the Canon 5D mkiii and the lens was the Canon EF 85mm f/1.8 for all shots.

We started out using a frosted window for a nice diffused light that didn't cost anything. To fill in shadows we added a sheet of foam core from the dollar store (around 18"x24"). A piece of white poster board would also work. The exposure on this shot was ISO 800, camera in AV (aperture priority) mode, f/4, and +1 exposure compensation. This gave a shutter speed of around 1/80 of a second. I chose the +1 exposure compensation because I was metering off of a light-skinned model. Caucasian skin reflects around 30-36% of the light that hits it. As our meters are looking for an average around 12-18%, if I used the actual meter reading the images would have been much too dark. +1 stop fixed that.

White balance was set to Cloudy to add some warmth to the skylight coming through the window. Most likely, your windows at home are not frosted. In that case, you can hang a translucent white shower curtain over the window to diffuse the light. I suggest a cloth shower curtain in case you later try to use it to diffuse other light sources. Plastic might melt in front of a hot light.

I selected the f/4 aperture because I wanted to make sure to get both of our model Caitlin's eyes in focus. When filling the frame with the head of a portrait subject the depth of field is very shallow. I would actually prefer to shoot at f/8 for this, but that would have pushed my shutter speed too low to hand hold. Even at 1/80 I noticed that these images are not tack sharp from motion blur (the model moved a lot) and camera shake. I did not want to shoot the portrait at higher than ISO 800. I could have opened up to f/2.8 to get a higher shutter speed, but then might have had more focus issues as the model moved forward and backward in the chair. As with everything in photography, you have to make compromises and decide which aspects of the situation are most important to you.

When shooting portraits I like to work with a specific white balance. It can be a built-in preset (as we did here, selecting Cloudy), or it can be a manually set Kelvin temperature. I don't like using Auto in this situation because different framing of the scene (more face or more background) could alter the WB settings. As the light wasn't changing, having a specifically set WB would allow me to make batch changes to the WB setting during editing in Adobe Lightroom. Auto WB might have me having to make individual changes to each shot from the session. For ultimate control you would need to calibrate and profile your computer monitor and camera and use a gray card to set your white balance, but that is beyond what we are presenting here. Just remember that accurate color is not always pleasing color. We often want to warm up images of people.

Here are some of the window light images with various post processing effects and attempts at getting better color out of the JPG files... 

dpreview-window.jpg

Next we moved over to a studio style set up where we had a gray seamless paper backdrop and a continuous fluorescent lamp set up. Again we used a piece of white foam core as a fill card. As photographic fluorescent lights are supposed to be daylight balanced, I set the camera to daylight. The images out of camera at this setting were a bit too green and too warm (yellowish) for my taste. I changed them as best as I could for a JPG in Lightroom. A gray card test and a calibrated system would really help with fluorescent lights. A raw file would have been much better to work with, too. 

As with the window light, I went with f/4 to try to keep most of the face in focus. Even though the light fixture had 8 or 9 bulbs in it, it still wasn't very efficient, so I kept the ISO at 800 and the exposure compensation at +1. This gave a reasonable shutter speed of 1/160 second. With all that, I still wasn't happy about the overall sharpness of the images. Our model was still rocking back and forth a bit (perfectly normal for a nervous photo subject) and the eyes were often soft. Again, I would have preferred to go to f/8 for the images. Here are some of the images from that segment...

dpreview-fluorescent.jpg

Next we moved to using a speed light. For the first image I left the camera in Aperture Priority mode (f/4), but brought my ISO down to 200. In this mode the camera selected a shutter speed of 1/4 second, which led to a very blurry image. It was time to switch to manual exposure mode where I set my shutter speed to 1/80 (no particular reason, anything from 1/60 to 1/200 would have looked the same) and left my aperture at f/4. The flash was in E-ttl mode (automatic). As expected, this gave an image with a heavy black shadow behind our subject, showing why we don't want to use on-camera flash straight on to the subject.

To soften the light (which is accomplished by making the light bigger), I added a Gary Fong diffuser to the on-camera flash (a Canon 420-EXii) and pointed the flash 90-degrees to the side pointing at a shall sheet of foam core that Shawn held in place. This made a dramatic change in the image as seen here. You could do something very similar if you were to set up your portable studio in the corner of a room with white walls and ceiling and point the flash at the wall instead of having to hold the foam core up in place.

Next, I took the flash off the camera via the Canon Off-camera Shoe Cord 2. I also added a large Rogue FlashBender with diffuser. I attached the flash to one side of a Black Rapid double strap. I would normally attach the camera to the other side and use this for event photography, but I forgot to bring the lug for the bottom of the camera. This allows me to put the flash where I want, within arm's reach. Here are the images from the speed light session...

dpreview-speedlight.jpg

Our final set up was using a studio flash (in this case a Speedotron Force 5 monolight, but just about any studio strobe light would work. Popular brands are Alien Bee, Paul C. Buff Einsteins, DynaLite, Photogenic, Profoto, and more). This was placed in a 46" Photek Softlighter II, which is a combination of umbrella (for ease of set up) and soft box (for control). I mentioned that the 60" version of the Softlighter is my "go-to" or "desert island" flash modifier. 

For this setup I was able to lower my ISO to 100. The camera remained set to Manual exposure mode (as there is no way to use automatic settings in this situation) with a shutter speed of 1/80 (again, not very important with a studio strobe, it just needs to be fast enough to not let in ambient light to show shake and slow enough to sync with the flash). To be somewhat consistent with the previous photos, I chose an aperture of f/4.5 and dialed the power on the strobe to give me a good exposure. White Balance was again set to daylight.

The background for this set up was changed to be a Westcott X-Drop stand with a dark patterned backdrop they call Eminence (they offer around 30 different backdrops for the X-Drop system). The light was place in close to the subject, slightly forward of her so the light would feather or skim across her face. Instead of the foam core we use the white side of a 52" 5-in-1 collapsible reflector on a light stand.

During this segment (photos below) we talked a little bit about light direction or short/broad lighting. The basic thing to remember from that is for flattering short lighting have your subject point their nose somewhere between the camera and the main light. This works for most subjects. We quickly showed broad light (nose points away from the light), but with our beautiful model it wasn't as dramatic a difference as it might be on other subjects.

The final image was done using a "clamshell" set up with the large light overhead pointing down and a white foam core reflector below the model to fill in shadows. Here the light source is on axis with the camera, but large and diffuse to cast as little shadow as possible. If we had a little more time I would have tweaked this set up a bit more bringing the overhead light a bit more forward (towards the camera) to get more light in Caitlin's eyes.

dpreview-strobe.jpg

With that we finished up our segment. I know we only touched lightly on some topics (light placement, posing, lenses). For more information about those you can tune into creativeLIVE for more in-depth classes from a variety of instructors. I also have two classes that cL sells from Photo Week on the Basics of Lighting and Basics of Lenses that you might want to check out on my creativeLIVE course list. A lot of this is also covered in previous blog posts, so please look around the site.

Also feel free to ask questions here on any of the things we discussed in the presentation.

 

Thanks!
John 

Do you still think it is the lens?

Photographic Lenses, Perspective,
and Distortion

Yes, another in the series about lenses, perspective, and distortion. This time it is about wide angle lenses used up close. For example, if you photograph a group of people with a short lens and fill the horizontal frame with the group you will find that the people on the right and left appear to be stretched out.

Pop quiz! Why does this happen? Do you think it is the wide angle lens causing the situation? Or is it the distance between the camera and the group of people?

I think the popular answer is going to be "the lens," but I also think that with a few photographs I can show that the lens is NOT the issue. In these photos, the (full frame) camera was stationary with a 16mm lens on a tripod. I photographed the mannequin head straight on, then I moved it to the left and right sides of the frame, still facing straight forward. I then combined the three in Photoshop. The images are layered straight over each other, with no cropping or other manipulation.

perspective_1.jpg

You can clearly see the distortion of the mannequin head when moved out to the far edges of the frame. And, of course, our first inclination is to blame the use of a wide angle lens. But is the lens to blame? Let's look at another set of images...

perspective2.jpg

We start with the same image that ended the first series of photos for reference. Then we see a photo with a PRINT of the original photo in the same position as the head on the left. Take note that the head in the print does NOT show the "wide angle" distortion that the actual head shows.

This shows us that the distortion is not from the lens. The reason we see the distortion on the three-dimensional head is that we are so close to those people on the edge of the frame and at such an acute angle that the lens is seeing both the front and the side of their heads at the same time. The 2-dimensional print, in the same position as the head is rendered straight--there isn't a side of the head to show in the print.

This is something you can easily try for yourself. Hang a photograph on your wall. Put your widest lens on your camera. Position the camera straight on to the wall with the photograph centered and take a photo of the photo. Then move laterally to the left or right so the hanging photograph is on the edge of your frame. Make sure the camera is still positioned straight on to the wall and take another photo. Repeat the same with a 3-dimensional object (a lamp, a statue, etc.). Do you see the same amount of distortion in the 2-dimensional photo as in the 3-dimensional item?

If I was to keep the same 16mm lens on the camera and backed up to a suitable distance I would not be at that strong of an angle and would only see the faces straight on. The distortion would be gone, but the people in the image would be much smaller with a lot of empty space around them. The fix for that? Use a longer lens, which will magnify the people more to fill the frame. The longer lens doesn't fix the distortion we saw with the short lens, it just magnifies the scene when you are further away from the subject by providing a narrower angle of view.

So..., what do you do if you are in that situation where you have a group of people to photograph and you can't move back? Have the people on each end of the group turn in towards the other subjects so that they are more straight on to the camera. It won't be perfect, but will help. Next time try to arrange to take the photo in a larger space that allows you to back up.

This goes back to the basics of perspective in photographs. The camera to subject distance determines the perspective (the relationship between items in the photo) and the lens focal length determines the magnification or how the subject fills the frame. One of the best descriptions of how this all works is in a book from the 1930s called Pictorial Composition in Photography by Arthur Hammond. A good read if you can find a copy. Check out Chapter V  on "Linear Perspective."

Here is a list of some of my previous articles on lenses and perspective:
Seeing Ourselves In Photos
Seeing Ourselves Part 2
Depth of Field
Lens "Compression"
Aperture and Depth of Field
Aperture and Portraits

Thanks!
John

 

Shutter Speed and Flash

How Shutter Speed affects studio flash

What are your settings?

That's the question that disheartens so many photography instructors. The settings are particular to the situation. I know that many photo magazines list settings along with the photos. But until the digital age with that information in the EXIF data, I'm willing to guess that 50% or more of the "settings" listed with a photo were a guess. I was there. I never took detailed notes on my photos while making them. If someone asked me about the settings used on an image from a week/month/year ago I would have had to guess. I think most others would have too.

But enough of that rant. The question is still going to be asked. So, lets talk about one of those settings. Shutter Speed when using flash in a studio situation. When doing a workshop I often get to hand over the flash trigger to a student and give them some settings to get started. The important ones are ISO (how sensitive the film/sensor is) and Aperture (how much light the lens lets through).

Then there is shutter speed.

A difficult concept for some is that within a range, the shutter speed doesn't much matter in the studio when using flash. You have the ISO, the Aperture, and the power of the flash. There's your Exposure Triangle for the studio. You can usually set your shutter speed somewhere between 1/30 and 1/125 of a second and be good to go.

But what about blur? Won't my image be blurry from camera shake or subject motion if I shoot at 1/30 of a second? In most cases the answer is No. A studio setting is usually dark enough that even at 1/30 nothing will be recorded. The duration of the flash becomes your "shutter speed." While the shutter is physically open for 1/30 of a second, the flash duration may be 1/500 of a second or faster (depending on the particular flash you are using). Yes, in a bright studio or if you are working at a high ISO and at a wide open aperture you might experience some motion blur. You can do a quick test to see what's up. Set the ISO and Aperture for the flash exposure and take a shot WITHOUT firing the flash. In most cases the image will be black. That's good. That's what we expect. If there is something recorded, you can go to 1/60 or 1/125 of a second.

But my camera manual says it syncs at 1/250 of a second. Well, yes. It will do that with a dedicated speedlight/lite. The flash duration on those little things can be really fast and work at 1/250. But when you go to studio strobes you have to give a bit on the shutter speed. For example, the Canon 5D MkIII (used for these tests) specs say that its X-Sync shutter speed is 1/200 of a second. But on page 104 of the manual you will find some additional information:

Using Non-Canon Flash Units
Sync Speed
The camera can synchronize with non-Canon compact flash units at 1/200 sec. and slower shutter speeds. With large studio flash units, since the flash duration is longer, set the sync speed within 1/60 sec. to 1/30 sec. Be sure to test the flash synchronization before shooting.

That's good advice. Test for yourself. That's what I did this afternoon and here are the visual results. Next to each image is the Shutter Speed (SS) used (80=1/80 sec.) and the info reading for the spot on the shoulder identified in the first photo. You will see that at 1/80 to 1/125 sec. the image is pretty clean/similar. But at 1/160 and 1/200 sec. the bottom of the image starts getting darker. At 1/250 sec. there is a clear black band across the bottom of the image.

cornicello_photography_sync_speed.jpg

It might be easier to see the comparison side-by-side. Here are the images that were taken at 1/125, 1/160, 1/200, and 1/250 sec. to more easily see the shadow of the shutter curtain starting to impinge on the bottom of the photo. The image at 1/200 sec. is also starting to be darker overall.

cornicello_photography_sync_speed_2.jpg

In many situations you might not notice the darkness on the bottom of the image (or on the side if holding the camera in vertical orientation) at these faster shutter speeds. But it is there. And it may be troublesome if you have taken the time and energy to create an even background light on the scene and then find one side of the image is darker when you get the file into your computer for editing.

If you are using a wireless flash triggering system with your Canon or other compact flash gun you may also be limited to slower shutter speeds. I don't have such a system to test with. If you do, please let us know your test results in the comments section below.

What happens if you go slower than 1/30 sec? A few things might happen. If there is enough ambient light in the studio you might pick up some color variation and a bit more exposure as the ambient light will then be adding to the overall exposure. Here you can see images taken at 1/60 sec. and 1/8 sec. at the same ISO, Aperture, and flash power level. The image at 1/8 is slightly brighter and a little more yellow from the tungsten modeling lamp in the flash.

cornicello_photography_sync_speed_3.jpg

So, when in a controlled studio setting using studio strobe units you should heed the warning in the camera manual and work at around 1/60 sec. to sync the camera and strobes.

When outside doing syncro-sun flash the shutter speed becomes more important. But that's for another article.

Creating a collage in Lightroom

I've had a few people ask how I put together the image collages in my blog posts. I create them in the Adobe Lightroom Print Module. Here are the steps I use to do this.

UPDATE: My friend Laura Shoe just posted on her blog with a chapter from her video training series that goes into more detail about the Print Module.

First, create a collection of the images that you want to place in the collage. This can be a Quick Collection or a regular collection. Go to that collection in the Library mode.

Next, switch over to the Print module. You will see the images in your collection at the bottom of the page. Over in the Layout Style menu on the right side select Custom Package.

lightroom_printmodule_screenshot.png
In the Rulers, Grid & Guides section I set my Grid Snap to Cells and turn on the Image Cell guides and Dimensions.

In the Rulers, Grid & Guides section I set my Grid Snap to Cells and turn on the Image Cell guides and Dimensions.

In the Cells section I check the box for Lock to Photo Aspect Ratio so the images don't get distorted if I resize them.

In the Cells section I check the box for Lock to Photo Aspect Ratio so the images don't get distorted if I resize them.

In the Print Job section I select Print to: JPEG file.

In the Print Job section I select Print to: JPEG file.

I set the File Resolution to 125 ppi (I find 125 an easy number to work with as you will see later when setting the custom file dimensions)
Print Sharpening is set to Standard/Glossy (I actually haven't tried any other settings, feel free to experiment)
JPG quality set to 80

Now comes the math part. Don't worry, it is easy math that even I can do. This is where the File Resolution set to 125 comes into play. The range for PPI is 72 to 1200. I want my image for the blog to be 500 pixels wide, so I set the custom file dimensions to 4.00 in x 12.00 in. 4x125 = 500 pixels. I selected 4 inches because my files are 2:3 and I wouldn't have to resize two images set side-by-side. I told you the math part is easy. The tall dimension (12 in here) will change, depending on the content of the collage. It will usually end up being shorter, but this gives me room to spare while setting up the collage.

Now that the page is set up you can drag in images from the bottom of the page. Simply drag an image onto the layout and then drag it into place and then drag out a corner to size it appropriately. As the images from most dSLR cameras are 2x3 inches the horizontal images will need to be resized up to fill the width but tall images should come in without needing any adjustment (refer back to 4 inches by 125ppi). If your camera gives you files with a different aspect ratio or if you crop your images to other ratios than 2:3, you may need to adjust the file resolution and file dimensions to fit your images. A little bit of experimentation with numbers should get you there.

Things can get a bit tricky/hairy here. If the page is taller than you need you can adjust the tall dimension smaller, but if you go too small it will shift all the images on the page so they might overlap on each other. You can make the page taller again, but that won't fix the affected cells, you will have to go back and drag the image cells back to where you want them. It is better to have too much white space at the bottom than to make the page too short and have to re-do the layout. You can bring the JPG file into Photoshop and trim off the extra white space if necessary.

If you want to do a bit more calculating, you can figure out the exact height you need. Add up the heights of all the images on the page. In this case there are 4 at 2.667 inches and one at 3 inches. 4x2.667 = 10.668 + 3 = 13.668 inches, which you can type into the custom dimensions. Again, this is all based on using 2:3 aspect ratio images. Your mileage may vary if using other aspect ratios.

If you have an identity plate set up in Lightroom you can put it on the image as a watermark.

lightroom_print_page.png

Here I have selected a PNG image and set the size and opacity. Uncheck Render on every image unless you want each cell to have the watermark. Simply drag the identity plate to where you want it to appear. You can also drag the corner handles to reset the scale (size) of the watermark.

lightroom_print_watermark.png

Alternately, if you don't have an identity plate set up in Lightroom you can open the JPG in Photoshop after exporting/saving from Lightroom and add a watermark using your favorite method.

I set the color profile to sRGB for the web and use perceptual intent.

Once everything is in place you can click on the Print to File... button in the lower right corner and select where to save the file and give it a name. It will take a few seconds for Lightroom to render all the images to size and create the print job.

Here is the resulting image from the above settings...

Thanks, Mom, for letting me use my photos of you!

Motion

Seattle Performance Photography

I am often looking for ways to give back to the photographic community. One of the ways is by volunteering to assist instructors at Photo Center Northwest. For this semester I am helping out in Patricia Ridenour's class on motion.

This past weekend we had a field trip to photograph aerial artists at Versatile Arts studio here in Seattle. I am friends with the owner, Bev, and a number of her students and instructors, and have photographed in their space before. I was going to a comfortable location with friends. There are a few different spaces to work in here, so selected the dance studio to try some stroboscopic techniques with the students in the photography class.

motion_stroboscopic_photography.jpg

As you can see in the lower left corner, I tested some things out on my self before the class started. And next to me is my dear friend Courtnee who was our host for the evening. Courtnee helped direct the aerialists, changed out rigging as needed, and was also a model for the photo students. Thanks, Nee!

The technique I selected for this series came about when I was looking at the spec sheet for the Speedotron Force 5 monolights. They claimed 4 flashes per second at its lowest power setting. So, I set up two of these units with gridded reflectors. A 7" with a 40-degree grid on one side and an 11-1/2" with a 35-degree on the other side. They were set up in sort of a cross pattern, skimming across the model and red silk. They took some finessing to keep the lights from spilling onto the walls of the space. This was further complicated because one of the walls is all mirrors.

The next challenge was going to be triggering the strobes. Pocket Wizard Multi-Max to the rescue. I went online to take a look at the manual for the PWs and quickly found the settings (*/menu > A > C) where I could set the interval between flashes (I chose .35 seconds) and how many flashes (I set it to 6) on each trigger. This info is on page 36 of the manual if you need additional information.

Exposure was somewhat trial and error. I took a guess at about ISO 100, F/8, and 2 seconds (to accommodate the multiple flashes) and that worked pretty well. What was nice for the class is that this is one situation where we could have multiple photographers working at the same time. Normally, I ask that only one photographer work at a time to have a clear interaction with the subject. But these were going to be more abstract images and I could count down 3..., 2..., 1..., and everyone could open their shutter and take advantage of the multiple pops of the flash.

I started out with my camera on a tripod, but quickly ditched that for more "creative" control. For some images I spun the camera around during the exposure. For others I zoomed the lens during the exposure. For most of these images we left the strobe units' modeling lamps on, but turned down, to help with focusing. We had them set low so as not to add much to the exposure. On some images you can see warmer (more orange color) streaks between the flashes. This is most obvious in my self-portrait in the lower left where I had the modeling lamp turned up brighter.

And before you ask, the photo of Courtnee was lit with a 12x50 strip bank light, not with the reflectors and grids used on the other photos.