Neutral Density Filters

Neutral Density (ND) Filters are used when you want to use a very large aperture to get heavy background blur, or to use a slow shutter speed to get motion blur in very bright light. Here’s a quick guide so you can find the right filter.

*There are also Graduated ND Filters that affect only one half of the filter to balance out the exposure in scenes like landscapes where the sky is much brighter than the ground (sunsets). 

Tutorial #4: The Basics of Photography

In this tutorial, I aim to demystify the seemingly complex technical aspects of photography. If you delve deep enough, yes, there are some very complex formulas that go into shooting a photograph, but with today’s camera technology it’s not necessary (but can be very useful) to know about all that stuff. Still, you want to be able to control the look of your photos, and learning how to use manual settings is the best way to do that. Be aware that not all cameras will have fully manual controls (M mode), and if this all seems like beginner stuff keep reading anyway. There will likely be some stuff you don’t know – even if you already shoot with manual settings.
 
My point here is to get to the essence of photography – which can be broken down into balancing the three most fundamental components utilized in achieving a proper exposure: Aperture, Shutter Speed and ISO. The very first thing you need to learn is how to control the balance between the three, and what their different settings mean in relation to the resulting effects produced in photos.
 
Before I start to delve too deep into the mechanics of exposure, you need to become acquainted with the three variables through which you will set your exposure. [For more on the mechanics of exposure see my previous post Explaining Exposure] First, I’ll go over aperture.


Use of Aperture:
The larger the aperture, the better the light can enter to reach the film or sensor. The size of the aperture is one of the variables that determines the Depth of Field (the other’s are focal length and focus distance). The Depth of Field is the area that appears sharp in an image. The larger the aperture the more this narrows. This means you will get more blurry (bokeh) areas and will be able to shoot in lower light. Small apertures widen the depth of field so that parts of both the foreground and the background will appear in focus, but this also lets in less light and you will need to compensate by changing your Shutter and ISO settings. You can set your camera to Aperture Priority (AV) so that you determine the aperture and the ISO, while the camera decides the shutter speed to use. This is useful for getting quicker shots while maintaining control over the depth of field.


Use of Shutter Speed: 
Slow shutter speeds will capture elapsed time in low light (or with Neutral Density Filters). Faster shutter speeds freeze motion, and by using the Reciprocal Rule you can avoid camera shake as well (more on this here: The Reciprocal Rule in Photography). On a normal lens (around 30-50mm) a shutter of 1/60 or faster  will be enough to freeze motion, while 1/30 will capture motion blur. For longer focal lengths you will need faster shutter speeds to hand hold the camera. Even if you have your camera set to Aperture Priority you still want to pay attention the shutter speed, OR set it to Shutter Speed Priority (TV). In this setting, you select a shutter speed and ISO while the camera determines the aperture. This is useful for maintaing control over motion blur and for freezing action.



Use of ISO:
While it is ideal to use the lowest ISO available in order to achieve the greatest image quality, using a higher ISO will increase the depth captured in a photo – particularly coupled with the use of a flash. The reason for this is that a high ISO picks up more ambient light so you get the most detail out of a low lit scene. It will also help balance the flash and ambient light in low light situations, AND use less powerful flashes so there is less recharge time. This is a good technique to practice when shooting events or on location in low ambient light situations where you want to capture as much background detail as possible to avoid flatness from the use of a flash. Just be aware that using high ISOs will increase file size due to increased noise. The more noise there is, the more variation in pixels. The more variation in pixels, the more stuff that needs to be recorded.
 
The Key is Balance:  
To get a correct exposure, you will usually have to make a compromise unless you have completely controlled lighting. If there isn’t enough lighting even at the highest possible ISO and largest aperture, you will just have to use a longer shutter speed. If there is too much light (and there is never really too much light) you can purchase Neutral Density (ND) filters that will allow light to pass through without affecting the balance of lights and darks and  take your exposure down as many stops as the filter indicates. This allows using large apertures in very bright light so you can get very shallow depth of field.
 
If you haven’t already read my post Explaining Exposure you should probably do that right now. It has more information that you can use in conjunction with the knowledge in this tutorial.

Explaining Exposure

Now, I’ll talk a bit about your camera and exposure. For any given light situation metered, there is an ideal exposure value (0) with it’s corresponding aperture, shutter speed and ISO settings. By default, a camera’s light meter will seek to expose anything being metered to appear as 18% gray, or Zone V in the Zone System [I'll later be posting some info on the Zone System]. To your camera, a perfect exposure is making everything look like 18% gray.

 
Meaning, that if you point your camera at something primarily dark, or spot meter on something dark, the camera will give you a reading that makes those dark areas appear 18% gray. This will over-exposure your photo, blowing out whites and losing all detail there.

 
The same is inversely true for metering on something primarily white in a scene. The entire photo will be under-exposed with a lot of detail on whites, but with those white areas appearing as 18% gray. All detail in dark areas is then lost.

 
 Essentially, what is happening is this:

For this reason, 18% gray cards exist. Metering on an 18% gray card will give you the most ideally balanced amount of detail possible that your sensor or film can capture at both the dark and light ends of the spectrum. The exposure you are aiming for is likely to be something like this:

That is the ideal shot. Artistically, you may want to shoot high or low key over-exposing white or under-exposing darks respectively.
  
  
In any case, if you don’t have an 18% gray card and you seem to be getting photos that are way too dark or too bright you need to pay attention to the scene you’re shooting. Is it primarlily light or primarily dark? Are you spot metering on something that deviates far from a middle gray? If that is the case, there are faster, easier ways to compensate for it than to pull out an 18% gray card for every shot. Your camera has a EV scale that looks something like this:
 

 
You’ll need to do some Exposure Compensation. If your photo is too dark then you need to over-expose from the camera’s “correct” reading. so adding one [+1] or two [+2] stops might help.
 
If your photo is too bright then you need to under-expose from the camera’s “correct” reading by stopping down one stop [-1] or more.
 
If you plan on doing post processing, on digital you may want to under-expose the photo a bit [-1/3] and for film you may want to over-expose a bit [+1/3]. If you want to know more on why you should do this refer to my previous post [Film vs Digital Tidbit: On Exposure].

Tutorial #3: Shooting Fireworks

Introduction: Fourth of July is right around the corner, so obviously that means fireworks and the photographing of said fireworks…There a few things you need to know to shoot some fireworks photos like these:
 
Fireworks 01  
Supplies: The first and most important thing you need (other than a camera) is a sturdy tripod, and a good location to shoot. If it’s a big public fireworks show you’ll want to do some research on exactly where the fireworks will be and arrive extra early to get a good spot. For SLRs the lens you choose will depend on your location. If you are shooting from afar then you can use a telephoto lens. If you are up close or want shots that include the surrounding landscape you might want to opt for more of a wide angle. If you’re shooting on an SLR you can purchase a remote shutter release so you can shoot without creating any camera shake. Otherwise, you can just use the timer function on the camera – of course this gives you less control of when you can start an exposure because of the wait time.
 
Shooting: Once you have properly planned your location and are all set up, you’ll need to adjust your camera’s settings. Manual settings (M) are really the only way to shoot good fireworks photos, so check to see that your camera allows for the following settings.
A low ISO, such as 100 is ideal coupled with a slow shutter speed of 2 seconds. On an SLR, if you use a remote shutter, you can opt to set it to bulb and you determine how long you leave the shutter open. This may be useful if you want to suddenly close the shutter and take a new exposure because something more interesting has just popped up. Either way, 2 seconds is a good amount of time to capture a firework from the explosion to the time it disperses.
 
You will also want to set  your camera/lens to manual focus. Focusing on infinity will work on some lenses, or you can wait for one of the fireworks to go off, try to auto-focus on it and then switch the lens to manual focus to lock it. Just be sure to not accidentally change the focus later.
 
The trick is to listen for the firework pops as a sign to start your exposure and end it when the sparks have dispersed. Practicing with different start times for the exposure might give you some interesting results…

http://farm4.static.flickr.com/3231/5768268200_161f694985.jpg

This is what happens if you press the shutter right when the burst is almost done dispersing.

It might take a bit of practice, but following these tips will give you the fundamentals for shooting some great fireworks shots.

Film vs Digital Tip: On Exposure

When you plan on post processing your photos there is a trick you can use to get more detail in the lights and darks in one exposure. For digital, underexposing a bit [up to -2/3 of a stop] is best for retaining details in the highlights. It’s not difficult to pull detail from dark areas in digital photos with an image editing program, but blown out highlights can’t be recovered. For film, overexposing [+2/3 of a stop or even more] works best for capturing and retaining details.

The reason comes down to the way each format captures images (and how as well, don’t rule out film as irrelevant just yet). If your capturing negatives, then the area that the light hits on the film turns dark. These dark areas on the film are actually the highlights when transfered as a positive print. Exposing it longer captures more detail throughout and there is more to work with than just clear film. The opposite is true of digital because it’s not capturing a negative. The area the light hits is corresponds to the highlights. Overexposing will lead to less detail to work with.

In addition to that, digital sensors don’t have the ability to capture a wide range of values in the highlight end of the spectrum. Negative film is special in that it is able to retain remarkable amounts of detail even in somewhat extreme overexposure. Details can later be recovered when printing or converting to digital. A white digital image is basically the same as a clear negative…if that all makes any sense…

So why should you care about this? No more washed out skies in landscape photos! :-)

140_IMG_0673

Tutorial #2: Tips for Shooting in Bright Sunlight

Introduction: The start of Summer means the likely-hood of extra free time, and yeah, that also means taking photos of all the fun you will be having with all that extra free time. The problem is you just can’t seem to get good shots in that harsh, bright spotlight/heat-lamp that is the Sun. Well, here are some things you might want to know for shooting some great portraits AND landscapes in bright sunlight. You will likely need to have a copy of your camera’s manual to know how to change everything for your specific camera, and really you should always have a copy of your manual with you. Personally I always keep a PDF copy on my phone…just in case.

*If you’d like to see a larger view of any of my photos, just click the photo. They link right to my flickr page.

Tip 01: If you’re using a camera that has manual exposure control and you want to try getting away from using those auto settings then you might want to use the Sunny 16 Rule. The Sunny 16 Rule is basically this:
 

 You choose an ISO setting and your shutter speed will be the nearest reciprocal of that number. Meaning that if you choose an ISO of 100, then you should set your shutter speed to 1/100 [100/1 = 1/100]. The nearest whole step shutter speed to 1/100 will be will be 1/125 if you’d like to stick to only whole values. The aperture setting will depend on the lighting conditions as shown in the chart. 
 
Tip 02: For Shooting Portraits, this might seem like the most obvious thing; seek out open SHADE! Find some trees to stand under…ANYTHING that shields the direct sunlight.
 
In the Shade
  
It may seem like the more light the better but the angle of direct midday sunlight will create some unpleasant shadows on the subject’s face. With shade you avoid all of this:
 
In the Sunlight
 
Tip 03: In direct overhead sunlight or backlit situations in which you don’t want a silhouette, you can always use a fill flash. That is just a fancy way of saying turn the flash on to fill in the shadows from the harsh overhead light or to compensate for back-lighting. The results will be something like this:
 
With Fill Flash
 
Much. Better.
 
You can use fill flash in shade as well. You may notice in the first photo that the sky in the background is washed out, but if you expose correctly for the sky your subject will be too dark.


Exposed for the Sky

That is because there is a limited dynamic range of lightness and darkness values that can be captured in one shot by a camera’s sensor or film. By adding a fill flash, both the foreground and background get correct exposure.


With Fill Flash in the Shade

Tip 04: An important thing to consider is the ISO setting. Be aware of your ISO setting! That setting determines your camera sensor’s sensitivity to light. Keep it at a setting like 100 or even lower if available on your camera. If you’re still using film, for some reason, then you’re stuck with whatever ISO film you’ve purchased. High ISOs aren’t very useful in bright light and will only result in noisy photos. (There are times when a high ISO and flash combination will be useful, such as a low-light situation, but i’ll go into that some other time.)

Tip 05: For shooting landscapes, a major problem is often washed or blown out skies. There are a number of things you can do to fix that, but if you don’t plan on doing any photo editing AND you own an SLR you might want to invest in a circular polarizing filter. A polarizing filter will make the sky a darker blue and remove harsh reflections from shiny surfaces.


Before Filter ReflectionsWith Polarizing Filter No Reflection

Before & After

No Polarizing FilterWith Polarizing Filter


They’re like polarized sunglasses for your camera. Just be sure to get one that fits the diameter of your lens. They aren’t very expensive, around $20 for a 58mm filter that would fit on most kit lenses.

Polarizing Filter

Again, if you’re using a camera with more advanced settings you might want to go manual for those landscape shots. Definitely apply the Sunny 16 Rule here. Again, keep your ISO as low as possible and use a polarizing filter if available. To get greater depth of field, so that you have as much of the foreground AND background in focus as possible, you might want to look into calculating the Hyperfocal Distance for the settings you’re using (I will later be making a tutorial on how to do this).

http://en.wikipedia.org/wiki/Hyperfocal_distance

You can likely skip the tripod in the bright light but you MIGHT still want to use one to make sure the photo is perfectly level. If you want to know a bit more about when you should use a tripod refer to my previous post, The Reciprocal Rule in Photography.

That concludes the basics you need to know to get better control of the available natural light so you can take shots like this too…

The Church Ruins

The Reciprocal Rule in Photography

This might be a lesser known tidbit about when to use or not to use a tripod. It all depends on the focal length of your lens. As a guide, you should be sure that your shutter speed is at or faster than the reciprocal of you focal length – otherwise use a tripod to be safe and avoid camera shake.

So…if the focal length on the lens is set to 50mm AND you’re using a full-frame (such as a Mark II) or 35mm film camera, then you would need a shutter speed of 1/50 or faster [50/1 = 1/50]. If you’re camera has a crop factor like the x1.6 crop on most Canons or the x1.5 crop on Nikons then you multiply the focal length the lens is set to by the crop factor number and THEN use the reciprocal of that number [50mm: 50 x 1.6 = 80 = 80/1 = 1/80].

Tutorial #1: Bokeh Shapes

Tutorial #1 Bokeh Shapes: Introduction Tutorial #1 Bokeh Shapes: Supplies

Tutorial #1: Bokeh Shapes, a set on Flickr.

…and my first tutorial is officially completed. read it. Follow it. Take cool pics. You’re welcome. In the future, i hope to cover tutorials for some of the more unexplored shooting techniques…i just need to do some research and organize a list of what’s NOT out there – which isn’t much – but MAYBE I’ll have a slightly better [more entertaining] approach. :D

The format I chose for this tutorial is in the form of a Flickr set. I’m planning on making all the future tutorials in the same format (with accompanying images). So…just click on the top photo or the link above for the full tutorial.