Tag Archives: tutorial

Tutorial #10: Motion Blur & Panning

These colder months mean shorter days with less light and more opportunities to use slower shutter speeds without needing ND filters, so this is a good time to go over this topic…

Motion Blur and Panning both illustrate movement in a still image. Not unlike Futurist painter Giacomo Balla’s Dynamism of a Dog on a Leash seeing the image trail shows the position of an object elapsed over a period of time. In the case of a photo that time frame would be dependant on a slow shutter speed.

For some reason anytime I think of motion blur this painting always comes to mind.
Dynasim of a Dog on a Leash 
  
The faster an object is moving the faster of a shutter speed you can get away with using while still capturing motion blur. Anything 1/30 and slower is a good place to start. Something like 1/10 is ideal – especially if you aren’t using a tripod. Just remember there’s a difference between camera shake and motion blur. At least one thing in the photo must be in sharp focus otherwise the blur in your photo is just undesirable camera shake.
 
If your lens has some sort of image stabilization and you’re using a wide angle you can get away with using pretty slow shutter speeds and no tripod. The image below I shot handheld with a shutter speed of 1/4.

17th & Beaumont
  
If a scene is fairly well lit it’s possible to show down the shutter speed just enough to capture motion by closing up the aperture as much as possible. I shot this carnival ride in late afternoon light at a shutter of 1/15 with the aperture stopped down to f/22.

Carnival Ride
  
In some cases you can use a flash set with a second curtain shutter to get a trailing effect and a sharp well lit image. What a second curtain shutter does is make the flash go off right before the exposure ends rather than right after the shutter first opens. Doing this makes the trails appear to drag behind the subject in movement rather than through it.
 
Ambulance
Panning:
 
The other way to depict movement in an image is a technique called Panning which involves the camera following the object in movement so the background is blurred rather than the subject. It can be tricky to get the speed in which u swipe the camera to keep up with the moving subject, and the only way to really master it is practice and a lot of trial and error.
 
I panned the image below at 1/5 on a tripod by just swiveling the tripod to follow the ambulance as it passed by.
 
Ambulance Pan

This pan I shot handheld with a shutter of 1/40. The shutter was a bit fast so the background blur is very subtle but the subject still pops in comparison.
 
Cat Walk

There’s a lot to be explored with motion blur whether it’s adding a sense of movement to something that doesn’t move or using it to isolate a the subject just as bokeh does. Just be prepared to take a lot of shots without expecting them all to even be usable.

Tutorial #9: White Balance

White Balance is getting neutral colors such as whites and grays to appear neutral in a photo by compensating for the temperature or tint of available light. Often the color temperature chosen is based on an artistic decision. It’s important to know how to set it so you have control over whatever it is you want. Shooting in RAW will allow you to adjust the white balance in ways that aren’t possible with jpgs. In the days of film, you had to use film specifically designed for certain temperatures of light or filters to correct white balance.
 
The hotter the light the bluer it appears, but according to color theory, artistically choosing for it to appear golden or red gives a feeling of warmth whereas making it blue makes it appear cold. This color association is why typically food will be shot in warmer temperatures – it’s more appetizing – and things like ice will look best cooler.
 

  
Shooting:  
 
You can always shoot using one of the camera presets. In most situations these or Auto White Balance [AWB] will work fine, but custom white balance is always the most accurate. Even if you want to adjust it later when editing it’s best to get it right when shooting.
 
The typical presets are: Auto, Daylight, Shade, Cloudy, Tungsten, White Fluorescent Light, and Flash. I’ve made this chart with the Kelvin measurement for some typical light situations:
 

 
If you want more accuracy use the “Custom White Balance” setting. You will need something white like a sheet of paper to photograph a sample from. Some higher end cameras will let you choose the actual temperature number like in the chart above. Here’s is what you would do on a Canon. I used a Rebel T1i in the example.


First, you will need to take a photo of something completely white under the lighting conditions you will be shooting in.

Press the menu button, go to the second screen and select Custom WB.
Then you’ll need to select the photo you took of something white.
Then when you press the “Set” button to select OK it’s set.
It will remind you to set the White Balance to Custom.
You can do that in the White Balance Menu. On the Canon Rebels it’s the up arrow labeled WB

Post Processing:

There are 2 variables to adjust: Temperature and Tint. Temperature determines how blue [cool] or red [warm] the whites appear. Tint is the balance of green and magenta – similar to color balance settings on a tv. Different types of light sources produce different tints and temperatures of light. Most fluorescent lights produce a green tint, daylight has a cool temperature, and incandescent bulbs produce very warm light.
To edit in Camera Raw you adjust the the sliders for Temperature and Tint as desired. It’s a pretty intuitive interface.


Although the best way to edit white balance is to shoot and edit in RAW, you can make adjustments in Photoshop by using “Hue/Saturation” to adjust tint if the photo is too green. Sliding “Hue” to the left will add more magenta hues and sliding to the right will make it greener.

Image > Adjustments > Hue/Saturation
shortcuts: ctrl+alt+U or cmd+option+U
For non-destructive editing use:
Layer > New Adjustment Layer > Hue/Saturation…
To adjust the temperature the easiest thing to do is use “Photo Filter.” Select the desired filter and adjust the density until you get the result you want, or even use a custom color to use as a filter.

Image > Adjustments > Photo Filter…
For non-destructive editng:Layer > New Adjustment Layer > Photo Filter…

The Results:
  The images are in order of warm, neutral, cool.

Tutorial #8: Calculating Hyperfocal Distance

Shooting at your camera’s Hyperfocal Distance will allow you to capturing the maximum depth of field possible for any given aperture. This is most useful for shooting landscapes or any scene where you want as much of the foreground and background in focus as possible in one shot. For every camera film or sensor size and aperture combination, there is a distance at which you must focus your lens on to achieve this maximum depth of field. It is the closest distance at which you can focus while still keeping objects at infinity appearing to be in acceptable focus.
 
:( The Math Stuff:
 
Of course there are all sorts of calculators and apps that will do the math for you, but in case you’re ever stuck in a position where that kind of tech isn’t available it’s always good to know how to do it yourself – even for someone who hates math as much as I do…
 
The formula is fairly simple:
 


Let’s use the example of shooting at a focal length of 17mm with an aperture/f-stop of f/8 on a Canon with an APS-C sized sensor. Take the focal length and multiply it by itself [square it] then divide it by the product of the f-stop number and the circle of confusion number and add the number of the focal length. The circle of confusion depends of the cameras sensor size The chart above contains the most common sensor types, but with a bit of research you can find the circle of confusion for even point and shoots and phone cameras. The result that you get will be in millimeters so you will need to convert that to something that is usable such as meters or feet. Just move the decimal 3 spaces to the left and round it off. You will get about 2 meters as your hyperfocal distance.That’s about 6 1/2 ft.

((17 x 17) /( 8 x 0.018)) + 17 = 2023.94mm = 2.02m = 6.63ft

Shooting Tip 01:
Some lenses have markers for showing focus distance (many Sigmas lenses). However, these markings can become unreliable under different temperature conditions that can cause the parts of the lens to expand and contract. A quick trick you can use is to either measure (if you want to be very precise…) or make an educated guess of the hyperfocal distance you’ve calculated and find an object to auto focus on at that same distance. Once focused, switch the lens to manual focus to lock it.

Shooting Tip 02:
Keep in mind that shorter focal lengths and smaller apertures increase depth of field so using these can get you shots that appear in focus from close in the foreground all the way to the farthest parts of the background.

The Results:

Notice how the stuff up close is just as sharp as the stuff furthest in the back.





…mainly religious imagery not intentional lol…I just found these to be the best examples because the statues are close in the foreground…and I’ve shot quite a lot of local landmarks for work…i guess there are not really many non-religious statues around here now that I think of it…

Tutorial #7: Macro Photography for Under $10

Macro lenses are expensive, so good thing there are cheaper ways to do macro photography. I’ll go over Reverse Lens Mounting and a bit on using extension tubes.
 
Supplies: First, I’ll go over the things you will need and some you might want to have…
  
01. A tripod (optional)

02. An SLR camera with a kit lens or any lens 50mm or wider.


 
03. A reverse mount ring (optional but recommended)

 
04. AND/OR An extension tube


 
Shooting Tip 01: Aperture Size & Depth of Field
The results will have a very shallow depth of field, so you will need a small aperture to increase the depth of field enough to have a decent amount of the image in focus rather than just a couple of millimeters. You will want to set the aperture to f/11 or f/16. You might not be able to see much when composing the shot if there isn’t a lot of ambient light, but it can mean the difference between this:
 

 
and this:
 

 
Shooting Tip 02: Manual Aperture Hack
If you’re shooting Canon and the lens you’re using doesn’t allow manual aperture control there is a “depth of field preview” button right underneath the lens release button. This button temporarily sets the aperture so that you can preview the depth of field by closing up the aperture to the setting of your choosing. Normally, the aperture is set to the max aperture [wide open]. I don’t really see the difference in its intended use, but it has a much more useful purpose.
 

 
Just set the aperture in the camera’s settings and press the DOF button while removing the lens. It will hold the aperture setting once removed.
 
Shooting Tip 03: Lighting
The lack of light from using a very small aperture will likely cause you to need more light and even a higher ISO to avoid camera shake. A flash can come in handy. Sometimes, you can get away with using a built in flash if you can figure out how to bounce the light just right, but you will probably need an external flash or some other light source. It could even be something you already have lying around like a desk lamp…
 
Shooting Tip 04: Focal Length & Magnification 
The wider the angle (the shorter the focal length) the more magnification you will get. My favorite focal length to use when shooting bugs is 35mm. Using an ultra wide lens will produce some extreme macro shots like the ones i posted below taken with the 10-22mm lens.
 
The Camel Logo on a Cigarette
Camel
 
Eye Shadow

 
 Shooting Tip 05: Focusing 
You will need to manual focus each shot. It helps to physically move the lens [and yourself] back and forth to focus once you have the focal length and the focus set. Once you try it out you’ll get a feel for the limitation of how it the lens is able to focus. You will need to be so close you are nearly touching the subject – especially with shorter focal lengths [18mm] 

 

Method 01: Free-lensing
Reverse Free-lensing is probably the cheapest method. It’s possible to do it with just the kit lens, and no extra attachments need to be purchased. In this method all you do is hold your kit lens reversed in front of your lens-less camera. You will also get a tilt-shift effect depending on how you hold the lens. There are a few drawback such as, dust getting into the camera and lens and light leaks. Here is a photo I took with a 10-22mm wide angle lens of my hair. You can clearly see my terrible split ends. :-/



Method 02: Using a Reverse Mount Ring
A Reverse Mount Ring can be purchases anywhere online for anywhere between $4 & $8. It’s probably best to purchase a common size like a 58mm ring and just get step up or step down rings for any other lens sizes. To use it, just attach the ring to the filter end of the lens and then attach to the camera. I find this to be the best way to get good macro shots. I don’t have to worry about light leaks or dropping the lens. Dust (and other things) can still enter the open end of the lens. I once had a jumping spider jump right into the lens! D:

I eventually got the spider out… This guy, actually:



Method 03: Extension Tube
Using a 50mm lens and an extension tube can give you similar results to reverse mounting, but extension tubes can cost $10 or more. It simply attaches between the lens and the camera to increase the focal length, but it doesn’t do much to increase working distance. You still need to get extremely close to focus on a subject.

Method 04: Combination
You can go on to combine the extension tube and a reverse mount ring to get even more magnification, but it still wont increase working distance and the depth of field may become too shallow. But of course, you can experiment with that if you like…
The Results:
I find that my best shots were taken with the reverse mount ring method.




I even shot some stereoscopic 3D macro shots, so you can get pretty creative with this stuff. [Cross your eyes until you see the 3D effect]



and to give you a better idea of the scale of some of these things…


If you want to see more examples, check out the Flickr Set with all my Reverse Mount Macro Shots.
http://www.flickr.com/photos/life-in-edit/sets/72157627268955398/with/5753211296/

Sure, a real macro lens will give you some good working distance, but the point here is really to have fun doing macro photography for under $10. You get what you pay for, sort of…

Tutorial #6: HDR Photography

High Dynamic Range Photography is fairly easy to do with a tripod and some HDR software and an image editing program. I’ll go over several ways to do it.

Dynamic range simply means the range of values between lightest and darkest visible tones. The idea behind HDR Photography is similar to the Zone System. I think of it as an extension to the Zone System and one of the modern applications of it in digital photography. It’s not just about making cool almost surreal photos, the goal is to capture tones in every zone. For more info on zones and tonal values see my previous post: [Tutorial #5: The Zone System]
 
For this tutorial, I’ll be using both Photomatix to quickly create HDR images and Photoshop to create them manually. First I’ll go over Photomatix. It’s reasonably priced at $99 for the pro version and $39 for the light version. http://www.hdrsoft.com/ Anyone can use the trial version which never expires but does watermark images made with some of the advanced features.
Photoshop CS5’s new feature is not very good…it really REQUIRES raw files for actual HDR images…and just gave me an error message about my images not being the same size…so converting to JPG or shooting in JPG will result in a terrible image.


no, not ok, adobe. :<
It once even rendered a completely black image. Not very HIGH in dynamic range at all. :-/

Step 01: Shooting
 
If you want to do HDR the right way, you will need to Bracket. This means taking anywhere between 3 and 5 different exposure values of the same image. One correct exposure and then over and under exposed by 1 and 2 stops. I would strongly recommend using a tripod and shooting in RAW. If you take your photography seriously you should always shoot in RAW – even if right now you aren’t using or editing those files.
When shooting try to work quickly and shoot with similar lighting which may be difficult with landscapes if it suddenly becomes overcast or sunny. Clouds and plants also move pretty quickly on windy days. When putting the images together later it will cause ghosting from the different objects not being in the same place in each photo. That’s why the tripod is important. There may be similar difficulties with motion blur and ghosting on longer exposures. You want each of the 5 images to be as identical as possible so they line up properly.
 
Step 02: Pre-Processing
 
It’s definitely a bit tedious if the image is made from multiple shots, but it is possible to create them from one correctly exposed RAW file so you don’t have to worry about ghosting from any moving objects. You wont get all the dynamic range you can get from shooting multiple images but you can still get a similar effect.
When processing the RAW file export an image at the EV values of -2, -1, 0, +1, +2. For more on this see my previous post [Explaning Exposure]

EV -2EV -1EV 0EV +1EV +2
For demonstration purposes i’ll be using this one exposure method.
   
Step 03a: Processing in Photomatix
 
The first thing you do is load your bracketed photos [3-5 photos].


If the different photos were made from one file the meta info will have the same exposure value recorded for how it was shot. You will need to manually fill in the exposure value and the increments at which they were adjusted to. I did them in whole stop increments from -2 to +2.
 

 
When you press “ok” it will give you a few options for automatically dealing with several things, such as alignment and ghosting. I didn’t need to check any of these since I did mine off the same image.



It will then composite a preview image that you can adjust. The screen will look like this:

[click image to enlarge]
 
There are several detailed settings on the left and the filmstrip along the bottom contains various presets that you can apply and then fine tune on the left panel. You can use the loupe to magnify details. The top bar has all the zooming/viewing options, and there is a histogram toolbar as well.
 
The settings you decide on will depend on your taste. Some people love the “painterly” look and some hate it because it starts to look more like a painting than a photograph. Reducing the “smoothing” setting will increase the effect while increasing it will reduce it. The rest of the settings are best explored depending on the photo and what look you’re going for.
 
Step 03b Processing in Photoshop:

This step is more advanced. You need some familiarity with layers & blending modes and layer masks. First, open the correctly exposed image [EV 0]. Then “Place…” the underexposed images over the the original layer and place the over exposed images on top of those. If you need to adjust the alignment you can do so as you place each image by reducing the opacity of the placed layer and moving the layer until it matches the one under. ghosting elimination will come later.

        
You can play around with different layer orders and opacities – even blending modes – but i recommend setting any underexposed images to “Mulitiply” and overexposed images to “Screen.” Mulitply blends only the dark values into the final image composited and Screen only blends in the light values. this way your correctly exposed base image is being enhanced by the values in other images.
 
You can get even more tones values by using other filters such as “Diffuse Glow” and a Layer Mask to hide and reveal dark and light parts of each layer.
The Diffuse Glow settings I used are below, but yours may vary. You just want it to have a a soft glowing effect on the highlights. The final touch for this layer is to set it to screen mode and adjust the opacity as desired.
 

 
I added a bit of a vignette by using a copy of EV -1 layer in multiply mode over the screened layers and then using the layer mask to hide the center of the layer with a large brush in black.


 

The Results.
[click images to enlarge]
 
 The images that are done manually aren’t as detailed and simply have an HDR effect, but it is possible and actually more time consuming in comparison… After trying Photomatix i highly recommend it. I know a lot of others do too.

I’ll do a proper HDR image later on to show how color can be exaggerated, and how the results from multiple images differ and are ultimately better.

Angle of View & Focal Length

Use this chart to determine what focal length you should use depending on the horizontal angle of view you need to capture. The longer the focal length/narrower angle of view, the more flattening that occurs in the image, meaning that objects that are at a distance from one another appear to be in much closer proximity and within a flatter space than on a wide angle/short focal length. A wide angle lens will increase perceived spacial depth and at the same time increase distortion.

*The following is for full-frame/35mm cameras. You will need to do some conversions if you shoot with a different sensor size such as a Canon with a X1.6 crop factor or a Nikon with a x1.5 crop factor you will need to multiply the focal length indicated on the lens by the crop factor before referring to the chart [50mm x 1.6 = 80mm]. There are ways to convert for other image sensor sizes. Another popular one is for the Four Thirds System. The Four Thirds website lists the 35mm equivalents of all their lenses here: http://www.four-thirds.org/en/microft/lens_chart.html

Tutorial #5: The Zone System

The Zone System is a method used to take a scene as it appears to the eye and create an image to reflect the artist’s vision of it by controlling the exposure of lightness and darkness values. It’s a great method for achieving the highest dynamic range possible in one exposure, or to determine the proper way to composite an High Dynamic Range (HDR) image from multiple exposures. This will allow you to achieve correct, ideal exposures. It can be applied to film or digital in black & white or color.  
 
Use the following scale for guidance in differentiating between the different values. Each zone is an increment of one stop.

In order to apply the Zone System, you must look carefully at your scene and decide what objects fit into the middle value, Zone V. Figure out what Zone you are metering on. To your camera, anything you meter on will be considered Zone V and the meter will give you settings for that. The point is to match what you visualize in the scene as belonging in Zone V with what the camera will capture as Zone V, or middle gray. You want the objects in the scene to fall into their designated zones as follows:

Zone 0:  Darkest Shadows, night sky

Zone I:  Very dark shadows.

Zone II:  Pure black/dark surfaces, first instance of detail.

Zone III:  Dark shadows, dark surfaces with textures: cloth, plastic, paper.

Zone IV:  Blue sky, dark green foliage, shadows on dark skin or dark surfaces.

Zone V:  Gray card, dark skin, green foliage, shadows on light skin & surfaces.

Zone VI:  Average skin, yellow foliage, light stone.

Zone VII:  Very light skin, soft shadows on white surfaces.

Zone VIII: White surfaces with textures: Paper, Sand, Snow, Cloth.

Zone IX:  Pure white surfaces in direct light. On the digital scale this zone is synonymous with Zone X and appears pure white.

Zone X:  Reflection highlights, direct sources of light.

For example, if you meter on a dark object that falls into Zone III, then you will have to compensate the exposure by stopping down by two [-2] stops. The reason being that the camera will give settings that will shift the Zone III objects into Zone V and cause over-exposure. To correct this, and move the Zone III objects back into Zone III you must adjust your settings to be 2 stops darker [Zone III - Zone V = -2 stops]. If your camera were exposing for Zone VII tones then you would need to adjust the exposure by two stops [Zone VII - Zone V = +2] to avoid under-exposure.

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].