focal_lengths

I was going to write up a forum post about lens lengths, but I figured this would be a good topic for here instead.
I shoot with 3 lens focal lengths, 35mm, 50mm, 85mm. If shooting on a crop sensor, to emulate this setup, you'd need a 24mm, 35mm, and 50mm lens. These correspond to moderate-wide, normal, and short telephoto. What do I mean by this? Normal means that size ratios line up with what our eyes are used to. Put a person 3 meters in front of a known object like a fire-truck, or a door, and the ratio of the two in how the lens renders them on the camera's 2d plane will look just as our eyes see. Wide means now that far object will look a bit smaller than it should, but since 35 is only moderate wide, you can kind of get away with it. In many situations with a person in the frame, 21/24/28 will look distorted and unnatural. I personally don't like them, but many do. Short-telephoto means that the ratio between objects will slant the other way. The firetruck would look slightly too large, for example. This can be used to one's benefit as well with very long telephoto lenses, keeping the moon huge behind a person, or compressing landscapes, but I find short telephoto gives the affect the way I want it. Off, but not too off as to mis represent reality.
The reason I keep to 3 primes like this, rather than a zoom that encompasses them all like the 24-70mm 2.8, or on a crop, the 17-50/55 from tamron/canon (both good), is because first and foremost, I routinely shoot in lighting situations where I need the extra light. All 3 of my primes are sub f/2 and useable at max aperture. The 35 on my 5D is f/1.4, the 50 and 85 both 1.8. My X100 is 35mm f/2. I find 2.8 too slow for many situations. Secondly, I like having the space between focal lengths. It makes the decision making easier. Expanded, normal, or compressed perspective? With a zoom it's more of a spectrum with lots of choices. Many people like that, but I don't. Creatively I only ever want one of those 3 settings, and having them in set steps helps me focus. In addition, having an out of focus background becomes more difficult the wider your lens goes. So while an 85mm F/2.8 can still give you a headshot with a blurry background, a 35mm f/2.8 at normal viewing distances doesn't really. 50mm 2.8 is kind of mixed bag depending on distance from you to the subject whether you will get background blur or not, but at any distance, F/1.8, 1.4 or even 1.2 will give you much more.
Now for some examples:
35mm

35mm really allows you to get a sense of this space. 50 or 85 would have compressed it too much. You would have only gotten a small edge of the front flower box with 50, less of the branches at the top, and the white area in the back would have been projected physically larger in relation to him, making it more of a middle or high key shot instead of this smoky dark look. Backing up to make 50 work would have made him much smaller and it would no longer really be a portrait. 85 would have made all these issues worse. 35mm gives you a sense of setting.

50mm

This one needed a lot of size ratios going on, and it was already unrealistic and surreal to begin with, so I didn't want to muck with perspective at all, hence the 50mm. 35mm to keep him this size and the front bench would curve away, and the back benches would be very small, and the path wouldn't look very deep or three-dimensional. 85mm would not have shown the side-most benches at all, and the background would look very large and tunnel like. In order to get the whole bench in, I'd need to back up a lot from where I was with the 50, and that would require him being much smaller in the frame.

85mm

This one, the background was very important to the shot. That far building over his right (our left) shoulder is the Dom Cathedral in Cologne, Germany. With a 50 or 35mm, it would have been projected incredibly tiny, and the darker areas around him of the less populated residential area of Cologne would have shown more, making it a less bright and less city-ish feel. He was also on a cramped balcony and I was inside the apartment shooting out. A 50mm might have allowed me to still get all of him without showing the door frame or other parts of the balcony, but the 35 definitely would have unless I got so close as to make him look very distorted.

I chose these three shots specifically because I had decided on the lens focal length before even getting to the location to shoot (or from the original location scout) but they were specifically picked for their affect on perspective. Also because all three relied on fast, sub-f/2 apertures, as all 3 were shot at the widest aperture, either to let in enough light on the 2nd two, or the provide a bit of background blur on the first. Could I have shot these same images with a zoom and had them look very similar? Possibly, but my creative process doesn't work that way, and I like the freedom that this limitation actually brings creatively.

Noise Reduction

I wanted to share my noise reduction techniques. I don't personally like a lot of noise reduction, because noise can imply sharpness, but there are a few times it's necessary because of how extreme and attention drawing it can be. Above is the final image after denoising. Here is the original:

In order to really show the steps, I've cropped in to the center area so I can show you the results at 100% 1:1 pixel ratio. Here is the original image with no luminance noise reduction. I like Lightrooms color noise reduction, and leave it on 7 for up to ISO 800, and up it to 12 for ISO 1600 (your camera will require different settings, slide till the color noise becomes un noticeable).

Next, I duplicate the entire layer, and use Filter > noise > reduce noise and slide it to maximum affect, with sharpening at zero. The image is a bit mushy but has a lot less noise.

Next, I use the layer itself to mask it's visibility. Complicated, but I will try to break it down:

1. I copy that de-noised layer into the clipboard. (ctrl+a for select all, then ctrl+c for copy).
2. Then, I add a layer mask, see here for more, and alt+click on the mask so I am "inside" the mask, it will be all white.
3. I use paste (ctrl+v) to paste the image into the mask. Now you have a black and white version of the layer in the mask. Masks work by showing the rgb of the layer when the mask pixels are white, and hiding when black, with opacity varying by the shade of grey. The problem is that when you paste, it will show the dark areas and hide the light areas, and we want the reverse.
4. Hit ctrl+i to invert the mask.

What this does, is it reveals the denoised layer in the shadows, and hides it in the highlights. The image itself controls the masking. The reason this works is that properly exposed areas (the light areas) tend to show detail better and noise is less offensive. De-noising these areas kills details. However at high-ISOs shadow areas tend to lack detail and have lots of noise, so denoising these areas tends not to have as much of a blurring affect. By using the image itself to mask the noise, you get a perfect light to dark transition of full noise reduction in the shadows, to none in the highlights. You can even paint further into the mask with a brush, or use curve/adjustments for fine tuning the cutoff of noise reduction.

Better, but the dark areas still have too much noise, it's especially evident in the background blurry areas from using a large aperture lens. A normal gaussian blur destroys too much detail, so I use a smart blur. This will vary per image the values you need, but you want to blur to the point all the noise in the smooth pools of solid color disappear, and adjust the other settings to that the details and hard lines of the actual sharp areas remain.

Smart blur however leaves too hard of edges for what we want, so then I do a gaussian blur with a small enough value to just smooth those hard edges created by the smart blur. This results in an image completely devoid of noise, but much less blurry than using plain gaussian blurring to obscure it.

Next, I use the "blend-if" layer blending option to reveal this noise-free layer only in the darkest areas. I covered blend if earlier on the blog. The settings I used are below, but you can easily adjust to taste.

I duplicate the noise free layer a second time, and remove the blend if options so everything is showing, add a mask, and invert so that nothing is showing. Then using my judgement, I use a 40% opaque brush, and remove noise in areas that are glaring in the image. Just look at the whole thing and see where your eyes go to noise wise, and paint into the mask on those areas until it's acceptable. Most of the times it's the areas that are large areas of solid color.

Next, I proceed with my standard sharpening procedures to get the final result.

alejandro_lighting_dissection

I really loved the newest Lady GaGa music video (what gay man didn't?) but beyond the tight bodies and amazing costumes and dance moves, was some really phenomenal lighting. After the 4th or 5th watch through I started trying to figure out some of the lighting setups.

First scene that intrigued me was this tight framing of her face toward the beginning. The razor sharp shadows tell me it's a tightly controlled spot light, and it's aimed perfectly so it doesn't hit her head. This gives attention and lighting to her face, but lets the crazy head gear lighting show, as well as the background lighting create a framing device. It gives it a very otherworldly feel by using light in the main portion, then shadow framing it, then light again framing that. Most lighting schemes either leave the subject lit and background unlit, or the subject unlit and the background lit. The times when it is lit > unlit > lit, the ratios are much closer, creating volume but not this level of contrast. The other thing to note, is while the goggles leave a jet black shadow, the nose doesn't leave any. This requires very precise positioning, because if the light was moved up or further to the right, you'd get a very black very hard edged nose shadow from it. This probably also means her face is very, *very* heavily powdered to prevent any specular shine on her skin.

The scene I liked the most, however, is the above. Very difficult lighting to pull off on a scene this size with so many subjects. My best guess is a huge softbox, large enough to cover the entire stage area, probably 10x20 meters, and potentially gridded or with barn doors to prevent spill (the floor going quickly to black is what makes me think this). I think it's a large softbox because of how soft the shading is, and how even it is on each person and no matter how they move throughout the space of the scene.

What is very likely is the size of the space being huge to prevent light leakage from illuminating the background. One thing that gives these scenes their signature look, is the soft overhead lighting, on a pure black background. This is most likely a stage in a large hanger or warehouse. By having the background being far away in all directions, you don't get any bounce contaminating the shadows on the subjects, and you don't get any light on the background, allowing it to go to black.

I liked this look so much I decided to try it out myself.

This is my 1.5 meter softlighter directly over head. I have lowish ceilings or I would have put it higher, which would have resulted with similar levels of shading, but less falloff from head down to feet. Because I also have a small room I was working in, the background is actually a black paper background. The setup is similar though, in that it's a soft, overhead source, large enough to cover the subject, but controlled so it doesn't hit the background.

I think again this is a brilliant lighting decision in the original GaGa video, because it's the type of lighting we don't normally get to see. The most often occurring soft lighting is on overcast days, but it then comes from all directions, and backgrounds are also hit, ensuring everything is soft. Sometimes we get soft window lighting in houses with dark interiors, but then that lighting is from the side. It's only in controlled lighting environments that you can get soft overhead lighting, but with dark backgrounds. This gives it a highly elevated distinct look, separating it from the lighting achievable from most music videos without unlimited budgets.

Magazine advert dissection

Time for another dissection. I saw these in a local magazine and loved them. They're from a prominent fashion label, and I assume these are corporately sponsored shots that are disseminated to smaller magazines. What I like is the simplicity. I think if most photographers tried something this simple, it would end up looking far too garish and ugly, whereas here I think it's stunning.

Setup shot:



I am positive it's a single light source. What I'm unsure of is the shape of the light and what kind of modifier was used. I do not think it's barebulb, the shadows are far too soft for that. It could possibly be a large beauty dish, but it's more likely an octobox or softbox, with a grid. The shadows are still quite hard for most shoots, so the light was definitely further away. The grey wall provides just a bit of bounce. You can see it open up the shadows of the guys face. It's possible there is some kind of bounce or reflector at the front of this room, angled so it doesn't add much to the wall (leaving the dark shadows intact) but keeping the clothing from going completely black. I'm unsure of this aspect though.

Great shoot, stunning images. I definitely want to try something like this in the future.

Striplight

I built a striplight using one of the many DIY guides on the internet, and wanted to try it out. It's best used when you want to light a cylindrical shape/object. The light comes out evenly from a long, thin softbox. Had I used an umbrella (round light source) in this same way, the "raking" of the light would not have been the same.

Here are the setup shots:



Settings:
2 Vivitar 285hv
main flash at 1/4 power,
at telephoto zoom,
through a striplight (20x90cm),
Striplight was at 2.5 meters height,
directly overhead subject.
background flash was at 1/16 power,,
wide tele zoom setting with fresnel diffuser,
light stand was at 1 meters height,
directly behind subject,
aimed up at background.

The goal for this kind of setup, was to create rake lighting on a body. Rake lighting is where the light comes from an extreme, near-perpendicular angle to the details, so that they are revealed by light and shadow. This is one reason that on camera flash is so ineffective. It lights the details from a parallel angle, hiding shadows.

This goes back to my lighting video. The lightsource affects the object based on it's size and distance. You have to imagine a sphere, it's center on the subject, and it's radius the distance between the subject center, and the surface of the light. The size the light takes up on the surface of that sphere will dictate the light's look.

On this shot, I wanted to reveal muscles. With a less harsh light, I wouldn't look nearly this defined. An umbrella would have put a lot more light coming from further forward, filling in the shadows, and ruining the rake affect. This lighting setup would also be very affective for a reclining pose, since the light would run along the length of the body. It's best to think of striplights as better for lighting cylindrical shapes, when you want to reveal volume evenly.

This example image should show the difference in how a round light source behaves compared to a long thin light source.



And one more from the shoot:

Light modifications

This post is going to explain the various light modifications that I use in my portrait photography. This will serve to illustrate what mods I mention in posts, as well as to show how you can modify a small studio strobe.

First off, bare bones flash with skyport wireless trigger. This is the foundation, where everything builds off of. The skyport triggers the flash wirelessly, the front of the flash can accept gels (there is a 1/2 CTOrange gel in it in this photo), and the head can zoom from wide, normal, and telephoto.



Next, is a "bare bulb" emulation mod. This is just a white frosted container that scatters the light in all directions, like a real bare light bulb would do. Normally the flash is directional, but with this mod, it works like an omni-directional light, sending light off in all 360 degrees. Useful for lighting small places, hiding inside a real lamp, car interiors, etc.



Now I've attached a Dave Honl 1/8" gridspot. The flash head is zoomed out to telephoto as well. This mod throws the light in a very tight, very narrow beam. Useful for isolating the light to a single area.



This is a Lumiquest Softbox II. Normally the flash "size" is exactly the dimensions of the flash head. This gives a very hard light that is not very flattering for a front light. By increasing the light's apparent size, you get a softer look. This small softbox doesn't blow over in the wind like my umbrella does, and allows for a great feathering affect that's harder to achieve with an umbrella. I'll demonstrate the feathering affect in my next portrait post. I am in the process of building a snoot for this softbox, which will give me a soft, isolated light.



This one brings the juice. It's the 285hv cranked to full power, with a small slave flash velcroed on top. The 285hv has a GN of 120, and this slave flash a GN of 80. This gives me a GN of 144 (thanks for the math Jasphoto) brighter than the high end canon and nikon flashes. The flash only has 2 settings, high and low, but I leave it on high, and set it to slave, and it's triggered when the main flash it's on top of goes off. The same velcro that I attach the soft box to, holds my skyport slave on the side of the flash.



This is that same setup, aimed into a silver umbrella. Right now the handle is choked up on, but if I extend the umbrella all the way, this really packs a punch of soft light. Great for groups, or if the light has to be out of the frame on a wide angle shot.



Now I've attached a white nylon sheet. This is just white rip stop nylon from a fabric store, with grommets for the umbrella tines to go through. It has a slit to the middle for the umbrella shaft, and then had fray-check (a sort of fabric glue) to keep the slit from fraying. This setup is incredibly soft, and extremely powerful. With the slave flash velcroed to the 285hv, it can really pump out the light. The reason I like this better than a white shoot-through umbrella, is that this provides a 43" flat white soft light, rather than a rounded one that curves away from the subject. It makes a difference in the wrap around light.



In the future I'm planning to build a small card for the honl grid to further restrict the light to a tiny area, a snoot for the softbox, and a snoot for the white nylon'ed silver umbrella. Being able to "not light" is almost as important as being able to light. Control is the artist's tool.

Sync-speed explained

Max sync speed. It's an important term, but it can seem hard to understand. It's the maximum speed at which your camera can take a photo and still get the flash to hit the entire sensor.

Here is an example image to help explain:



Most modern DSLRs have two shutter doors, a top and a bottom one. When you press the shutter button, the top one starts to raise, and then the bottom one starts to follow, till they both meet, closed, at the top. The speed you set your shutter will determine the time between when the top door starts moving and the bottom door follows (your camera make/model also can affect this).

Your max sync speed is essentially the setting at which the top door has reached the top of the sensor before the bottom door has started moving. It provides an entirely unobstructed view of the sensor for the flash to come in. A flash's duration is around 1/4000 or faster, so it will always be fast enough to hit the sensor for only a fraction of your shutter duration.

If you set your camera to faster than max sync speed, say 1/320 of a second, when your flash fires, the bottom door will already have started upward, and will be blocking a portion of the sensor from getting flash. This will cause a black bar at the bottom of the image. If you go too fast, say 1/1000, you will get a black bar from both the top door and bottom door. At this speed, the opening of the shutter is essentially a small slit moving across the sensor. The bottom door starts moving almost immediately after the top door starts. This will give you a black bar on top and bottom of the image.

Some point/shoot cameras, like the Canon g9, have electronic shutters, meaning that rather than using a physical door, the camera merely shuts off the sensor. This results in being able to sync around 1/4000. There is no door in the way of the flash.

Ambient is unaffected by this property. That's why most flash photographers start their camera at their max sync speed (1/200 or so), get the flash value correct, then start lowering the shutter speed to allow in more background light. I mentioned that the flash duration is only 1/4000 of a second or faster, so it will hit the sensor the same at 1/200 as it does at 1/5 of a second. Only ambient will be affected by this change in time.

When shooting with both flash and ambient, you get an opportunity to balance the flash intensity with background intensity.

For example:



This shutter speed is 1/125. If I changed it to 1/200, the sky would be darker, and the sunlight on his right cheek would be a bit dimmer. If I changed the shutter speed to 1/60, the sky would be much brighter, and the sunlight on his cheek even brighter. The flash fill on the left of his face would be unaffected by the shutter speed change.

You can see how this gives you power to alter your light ratios, background to foreground values, and overall scene control.