Showing posts with label artistic. Show all posts
Showing posts with label artistic. Show all posts

Friday, April 24, 2009

How To: Shoot Silhouettes - And a Bit About Dynamic Range


Before I start, I want to take a few lines to apologize for my upcoming blog post sabbatical. As I mentioned in an earlier post, whenever I'm at home, my limited internet access prevents me from doing much blogging. I'm currently sitting in Savannah, GA. and will be catching a flight back home to Virginia tomorrow morning (Sat. Apr. 25th). Instead of being back at work on Monday for more blogging, I will be taking my vacation next week. I'm headed to the Wyndham Nassau Resort and Crystal Palace Casino in Nassau Bahamas! I've read that internet access isn't free at the hotel, which blows my mind. What year is this?....1998? Anyways, I'll likely be shooting photos, relaxing on the beach, scuba diving, or finding some nightlife. I'll be back to work Monday, May 4th. Expect a new post shortly after with photos from my trip, and oh!....I'm also attending the Langley AirPower over Hampton Roads air-show this upcoming Sunday! Expect a blog post about how to photograph an air-show sometime on my return week as well.

As for my upcoming posts, the majority of the basics have been covered and I'll now be posting more specific how-to type posts. We'll start today with how to shoot silhouettes.

What is a silhouette? - A silhouette is a view of an object or scene consisting of the outline and a featureless interior, with the silhouetted object usually being black. The term was initially applied in the 18th century to portraits or other pictorial representations cut from thin black card. The term has been extended to describe the sight or image of a person, object or scene that is backlit, and appears dark against a lighter background. Because a silhouette emphasises the outline, the word has also been used in the fields of fashion and fitness to describe the shape of a person's body or the shape created by wearing clothing of a particular style or period. - Source: Wikipedia

In terms of photography, the italicized bold text in the paragraph above describes a silhouette perfectly.

An important term when referring to a silhouette is dynamic range.

Dynamic range is the ratio of light to dark that the cameras "eye" can see. The greater the dynamic range, the more details you'll get in both the highlights and the shadows. Unfortunately the cameras dynamic range is nowhere near that of the human eye. The human eye can see a considerably larger amount of details in highlights and shadows of a scene. While this can cause a lot of problems with getting a photo to look the way you want it, it works very nicely for silhouette images.

All you really have to do for a silhouette is set your exposure for a bright light source behind your subject. The limited dynamic range of your camera will automatically lose all or most of the details in the shadows and retain all the details in the light source, or the highlights.

With that said, a great light source to use for silhouettes is a sunset or sunrise. This is because the colors are very dramatic, and if you have a lot of clouds in the sky, you'll get even more visual interest in your photo. A sunset or sunrise, however, is not required. You could stand your subject in front of a window on the inside of the building, expose for what is outside of the window, and your subject will be silhouetted against the background. (See the flip-flop photos below)

So let's break this down into steps:
  1. Look for or create a subject with a strong visual interest. In other words, use something that will be very recognizable just by it's outline or shape alone.
  2. Place your subject in front of a light source so that there is a lot of light behind the subject, and as little as possible falling on the camera side of the subject itself.
  3. Ensure there isn't a lot of other items in the frame of your shot that will distract from the main subject or clutter the photo excessively.
  4. Set your exposure so that the background (light source) is properly exposed and not blown out (a term for losing detail in the highlights) or underexposed (a term for losing detail in the shadows). With the proper exposure on the background and no light falling on the subject, the subject itself should be underexposed which will give you the silhouette you're trying to achieve. Remember...exposure is set by varying aperture, shutter speed, and ISO.
  5. Once you're photo is properly exposed, focus the camera on your subject. This will ensure the subject has a nice crisp outline, and isn't blurry. On occasion, there may be times when you want the background to be in perfect focus and the silhouette to have a blurry outline. For example, I had a shot of my pug, Fez, looking out the window at a girl on the street. I exposed for the girl on the street as well as focused on the girl in the street. I wanted the focus on the girl so you could tell what Fez was looking at. I framed the shot so both the girl and Fez were in the viewfinder and snapped the photo.
  6. Once you've achieved your desired focus, and have framed the subject nicely, press the shutter button to take the photo.
  7. Thanks to the digital camera age, you now have instant results on your cameras LCD screen. Review your shot and make any adjustments to exposure, focus, and subject framing as necessary and continue shooting. With a few repetitions, you'll find that you can now confidently shoot a silhouette image.
A few tips:
  • Try using a wide array of aperture settings to see the different results. First try a very small aperture (large F number) so that the subject has a crisp outline, and the background is in focus as well. Then try a large aperture (small F number) so that your subject is crisp and the background is a nice smooth blur of color. Thinking back to an earlier post, if you change your aperture, you'll need to change your shutter speed to compensate for the addition or subtraction of light. This will keep your photos exposure the same, but change the artistic effects associated with aperture.
  • Angle the camera a considerable amount to give your photo an unusual perspective and add interest to the photo. (See the photo at the top of this post)
  • Don't use flash. By using flash, you'll light the subject even if the background is properly exposed. This is obviously the exact opposite of what a silhouette is.
When I first started this blog, I mentioned that the posts would be geared towards shooting photos in full manual mode. If you happen to be using a point and shoot on automatic mode, you can still shoot silhouettes. Although I won't go into the extra details, I wanted to provide a link to a site that does describe how to create the effect on automatic mode: Easy Ways to Shoot a Silhouette

Below is an example pertaining to dynamic range:


You'll notice in the first photo, the shoes are properly exposed, but the details in the background are completely blown out. If it weren't for the second photo, you'd have no idea such a vibrant background existed. The second photo is exposed for the golf course and water in the background. You end up with a silhouetted image of the shoes, but you lose almost all detail in the subject. The reason for this is because of the cameras poor dynamic range. When I say poor, I mean in reference to the fact that as I looked at the shoes against the background with my eyes, I could see the detail in both the shoes and the golf course that lay behind. In comparison to what you can see with your eye, a camera has a poor dynamic range. Getting both the shoes and water properly exposed in the same image would require either adding a light source to the shoes so it is more closely matched with that of the background light source, or a number of post processing techniques such as exposure blending or HDR (high dynamic range). We'll get into these techniques at a later date.

I'll close this post with one more silhouette shot that I've taken. The photo below is of a PT6 turboprop airplane engine against a setting sun. I shot this photo en-route from Fayetteville, Arkansas to Indianapolis, Indiana back in December of 2008.

This has been how to shoot a silhouette "From the Ground Up!"



View the full post here...

Friday, March 13, 2009

Aperture & Shutter Speed (A Beautiful Relationship)

So today I want to hit a bit more on aperture and shutter speed.

As I said in the last post...

Aperture = Size of hole in the lens. Bigger hole equals more light. Smaller hole means less light. Bigger hole means shallower depth of field (less in focus in front of and behind your subject). Smaller hole means larger depth of field (more in focus in front of and behind your subject).

Lets add a bit to what we've already learned. The size of the aperture is referred to as an F-stop.

This is the confusing part... This will be tough for many people to wrap your heads around. I know it was for me at first

The larger the F-stop number (ex. F/22), the smaller the hole opening.
The smaller the F-stop number (ex. F/2.8), the larger the hole opening.

Let's lay this out in a table of sorts:
  • Little number, Shallow DOF, More light
  • F/2.8
  • F/4
  • F/5.6
  • F/8
  • F/11
  • F/16
  • F/22
  • Big number, Large DOF, Less light
if you set your camera to manual and read the instructions on how to change aperture...
scroll through the numbers by changing the aperture. you'll notice there are other numbers between these that I have listed. i didn't list them because the numbers above are 1 full stop of light each. just know that you can change the F/number in smaller increments perhaps 1/3 a stop by using one of these other numbers.

So now what is a stop or an F stop?
A stop is how we measure how much light is being allowed to hit the sensor through the cameras aperture.

So lets say we shot a photo and it was really bright and overexposed. One way of fixing this is changing the size of the aperture, perhaps reducing it one stop of light (meaning a bigger F/number). This would in turn reduce the size of the aperture opening allowing less light to reach the sensor.

Shutter Speed - Length of time the shutter is open allowing a given amount of light to pass through the aperture opening to your cameras sensor. Slower shutter speed means more light. Faster shutter speed means less light. Slower shutter speed blurs movement. Faster shutter speed freezes the movement.

Again with the confusing part. When referring to shutter speed, a seemingly large number (1/1000) is actually a lesser amount of time than a seemingly smaller number (1/15). One one thousandths of a second is a very short period of time whereas one fifteenth of a second is a considerably longer amount of time. Keep this in mind.
  • Small Number, Shorter period of time, Less light, Freezes action
  • 1/1000 of a second
  • 1/500
  • 1/250
  • 1/125
  • 1/60
  • 1/30
  • 1/15
  • 1/2
  • 1 second
  • Bigger number, Longer period of time, More light, Blurs movement
again each number in the table above represents one full stop of light. your camera settings will likely show numbers between these numbers but they are in increments of 1/3 of a stop.

So how does aperture and shutter speed relate to each other. It's rather genius really...

To keep a set exposure, but change the artistic effects, you can change either the aperture or shutter speed to reach the desired effect. If you change either of these things you will throw your exposure off soooooo: If you reduced the aperture by one stop to get a desired effect, you can increase the shutter speed by one stop to maintain the proper exposure. So what you do to one, you have to do the opposite to the other!!

Lets say you have a photo where you've nailed down the exposure. It's really great. The only problem is that the photo is blurring the movement and you really want to capture that car moving by freezing the action:

Sample Settings for desired exposure: 1/30th second & F/11
If you refer to the above table you'll see that you change your shutter speed to something more suitable for a moving car say... 1/250th of a second. That's 3 stops of light. You must then drop the F/stop down by 3 stops. The trusty table above will show the appropriate F/number to maintain your exposure is F/4.

We've just changed the artistic effect without hindering our desired exposure.

Another example:

You have a portrait and you'd like the background to be blurrier or more out of focus (OOF).
Current settings: 1/30th second & F/8

We want to make the f-number smaller or the hole larger (don't forget that trickery). To do this we may stop down the F-number to something like F/4. Conveniently F/4 is exactly 2 stops of light less than F/8. To maintain our desired exposure we should then increase the shutter speed by two stops. Trusty table above says 2 stops of light difference would be 1/125th of a second.

So again we've changed the artistic effect without changing our shutter speed.

it should also be noted that since your camera allows you to choose stops in 1/3 increments as mentioned above....three clicks of the wheel in either direction would adjust your setting 1 full stop. so if you want to decrease you're aperture one full stop you'd click the aperture wheel 3 clicks to the left. in turn, you'd click the shutter speed wheel 3 clicks to the right to maintain that desired exposure.

To wrap this up, let's take a glance at a few examples of the artistic effects available with aperture and shutter speed.

Desired Effect: Blur everything closer than and beyond our focal point (the little knob sticking out of the tree). We need a large aperture opening to gain the desired effect aka a small F/number.
F/4, 1/80th second

Desired effect: Subject (people) and background in focus. We need a small aperture opening (large number) to gain this desired effect.
F/22, 1/100th second

Desired effect: Freeze the action. We need a fast shutter speed.
F/2.8 1/4000th second

Desired Effect: Blur the movement. We need a slower or longer shutter speed.
F/4.5, 1/25th second


In conclusion: Whatever you change in either aperture or shutter speed, you must then change the other in the opposite direction to maintain a desired exposure.

This has been aperture and shutter speed "From The Ground Up!"
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