Aperture & Depth of Field

In this post, I’ll be talking mainly about how your camera’s aperture setting affects “depth of field,” the portion of your image which appears to be in focus.  Those using SLR cameras and the right lens really have it quite easy, while point-and-shoot users are a bit more limited.  And for those of you with P&S cameras without any manual or semi-automatic options, controlling depth of field is even more tricky, but it can still be done.  Lots to talk about, but first a little background information.

Your camera’s aperture, or f-stop, is a relative number.  In other words, it’s a ratio of two other numbers, and that ratio only means something for your particular camera, lens and settings.  Only relative comparisons can be made between different cameras and lenses.  This aperture ratio is simply the focal length of your lens divided by the diameter of the aperture (the opening that lets light into your camera).  All right, had enough?  Here are the things you need to know:

  • f/4 = f4 = F4 (same thing, written three different ways)
  • Lower f values = larger openings = more light (and “shallower” depth of field)
  • Higher f values = smaller openings = less light (and “deeper” depth of field)

Simple, isn’t it?  Here’s are two examples showing a page in an old (1936) Webster’s dictionary.  These shots were taken with a P&S, using macro mode and no zoom.  I focused on the phrase “To misconduct oneself” at the bottom of the page.  The photos capture about 7″ of the page, from bottom to top.   I set the aperture at two different values and let the camera choose a shutter speed.  Nothing else was changed between the two shots.

Can you see the differences?  First, compare the hinges (upper left corner).  Notice how the f/2.8 shot is kind of soft, while the f/8.0 shot is better defined.  Next check out some individual words.  In the f/2.8 shot, the word farthest up the page (in the middle column) that can be read is “mis-comfort,” and that’s about 1-1/2″ up from the focal point.  The f/8.0 shot gives us an image that can be read all the way up to the word “mischief-making,” about 3-1/2″ up.  That’s quite a difference!  So which one is better?  Neither!  That’s right, it just depends on what you’re trying to accomplish.  But now that you see the kind of impact a simple change in aperture can have, let’s talk a little about how to make it work for you.

First, check out your camera to see if it has an “aperture priority” mode (or “A” or “Ap” or “Av” mode or something like that).  If it does, lucky you!  Now, find your user manual and learn how to use it.  It’s really quite easy.  Experiment a little bit, do some tests like I did above, and see what works best for your product and the type of image you’re trying to produce.  Along the way (just for fun), pay attention to the relationship between aperture and shutter speed.

So why would you want an image with a shallow depth of field?  Well, if done properly, it can certainly give the photo a more “artistic” look.  It can also be helpful if you’re trying to highlight one particular item, or even part of an item, in the composition.  Or maybe your background is just plain ugly and you want to hide it!  Whatever the reason, a shallow depth of field can make your photos a bit more special.  See for yourself — here are two pretty cool examples from Etsy shops erinf115 and KaelinDesign.

But what if your camera doesn’t have the aperture priority option and you want an image with a shallow depth of field?  Don’t worry, all hope is not lost.  Regardless of what you’re shooting, you can trick your camera into selecting a low aperture value by putting it in “Sports” or “Action” or “Kids&Pets” mode (whatever mode your camera has that’s supposed to be for moving subjects).

Besides varying the aperture, there are a number of other shooting tricks that allow you to control depth of field, but that’s an entirely different discussion best left for another day.  Meanwhile, see what you can do with your aperture adjustments.  I’d love to see some of your results!

Until next time … Happy Shooting!

An Apology, a New Look and a Vase

The Apology

I know everyone is overwhelmed with all sorts of different electronic communications, and I certainly don’t want to unnecessarily add to that load.  This past weekend, as I was playing around with a new look for this blog, I think I may have inadvertently sent out email notifications of a new post.  The subject line may have been something like “[New Post] 411” or something similar.  Sorry about that!

The New Look

Well, what do you think?  Good, bad, indifferent?  Really, I’d like to know.  Is the white text on the black background okay?  Do you like the previews of multiple posts with the “Read more” option?  Please send me a quick note with your thoughts using the “Contact Me” form on the right, send me an email at “greenpixmail [at] gmail.com” or simply reply to this post with a comment.

Besides the new look, I’ve added a feature I call “Nice Folks, Nice Things” along the left sidebar of the Home page.  You’ll notice that clicking on these images will open a new window with a link to that person’s Etsy shop.  Would you like to be featured in this section?  Just make sure that you’re an email subscriber to this blog, and that you contact me with the URL of your shop, website or blog, and I’ll do my best to work everyone in at some point.  No promises and no guarantees, but I’ll try to be fair!

The Vase

As I’ve said before, sometimes a photo just looks “right.”

This one, from Wil Morris Pottery, shows a green Ikebana vase in a very simple setting.  The (almost) pure white of the foreground transitions beautifully through many shades of gray to the nondescript darker background.  If you’ve read my previous posts, you know by now that I’m usually not a big fan of shadows.  But in those examples, the shadows were distracting and inappropriate.  In this photo, the shadow adds some dimensional and tonal interest to an otherwise muted scene.  It’s also a great complement to the unlit opening in the top of the vase.  Nice job Wil!

And that’s all I have to say (for now).  Until next time … Happy Shooting!

Ott or Not

Back in May of this year, I did a few posts on the benefits of using natural lighting for your photo shoots (check the archives if you haven’t seen these yet).  But what about shooting with artificial lighting, say in a light tent or a light box?  Or how about just adding some supplemental lighting to your tabletop or floor setup?  Choosing the right lights can make all the difference in any of these situations.  So today I’m going to give you some lighting basics, help you to be a smarter shopper and even give you my recommendation.  To keep things as simple (and as brief) as possible, I’m only going to be covering “Compact Fluorescent Lamps” (CFLs) today.  These bulbs have become pretty popular, and they’re nice for photography because they’re cool enough that they won’t set fire to your light box like a halogen or incandescent bulb can!

What’s a Watt?

Don’t worry about it!  Seriously, a watt is nothing more than a standard unit of power, just like a second is a standard unit of time.  In terms of choosing lights for your photography, it’s pretty much meaningless unless you’re trying to save a few pennies on electricity.  A watt is a measure of how much electricity a bulb consumes, and it has nothing to do with how much light is produced or what that light looks like.  The only thing you need to know is that generally, for a particular type of light, “more watts = more lumens.”

Lumens?  Huh?

Want to compare different lights?  The first step is finding the “lumens” rating on the packaging.  You don’t need to know this, but a lumen is a measure of “luminous flux.”  That’s a measure not of how much light is emitted by a bulb, but rather how much of that light makes it to a specific target.  Need more details?  Just ask – I’ll be happy to oblige.

But all you really need to know regarding lumens is that “more lumens = brighter light.”

What Does “Color Temperature” Mean?

Simple…

Lower temperatures = more yellow = warmer look

Higher temperatures = more blue = colder look

Here’s a pretty picture saying the same thing:

So what’s a “Daylight Bulb”?

There’s really no such thing!  Think about it.  Look at the color temperature graph above.  Look at the difference in color temperatures at different times of day.  Now confound things even more with different times of year and different weather conditions.  Think about it some more.  Picture yourself outside at the beach at sunrise or sunset versus mid-day.  Or just go outside right now (if it’s during the day) and look at the sky in several different directions.  Does it look the same?  No way!

The best a bulb can do is to provide light at a specific “correlated color temperature” (CCT, for short).   The CCT is simply an approximation of the color temperature as our eyes perceive it.  So a 5500K bulb can only be a “daylight bulb” at a particular time of day, during a particular time of year, under a particular set of weather conditions.

But it’s a start!

Full Spectrum Bulbs Are Good, Right?

Absolutely!  If you can figure out what that really means.  “Full spectrum” means all the colors of the rainbow, plus a little infrared and ultraviolet.  Sunlight is full spectrum, as this spectragraph shows:

Are there any lights that actually match this spectrum?  NO!  That’s a pretty straight-forward answer, right?  Okay, let me expound on that a little bit.  Umm … NO!  Sorry, that’s all I got.  Some lights do cover a wide range of wavelengths (colors), but unless you can find a spectragraph for those lights, you really have no idea what you’re getting.  Seeing “Full Spectrum” written on the label is not enough!

What the Heck does “CRI” Stand For?

CRI is short for “Color Rendering Index.”  It can be important when you’re shopping for light bulbs for your photography.  It’s an old and somewhat obsolete standard, geared more toward video production, but it’s the best information we have available right now that represents how closely a light can reproduce colors in comparison to an “ideal” (whatever that means) light source.

Don’t pay too much attention to CRI values, other than these two considerations:

  • All else being equal, a higher CRI is better than a lower one, and anything above 90 is good for our purposes.
  • The difference between a few CRI points is meaningless, so don’t get hung up on comparing between values like 89 and 91.

Are “OttLite” Bulbs Any Good?

Well, yes and no.  There’s really nothing wrong with them; it’s just that they’re not the brightest bulbs in the chandelier.  Literally, they’re not.  Nor do they claim to be.  By the company’s own admission, “brighter isn’t always better.”  You see, they’re talking about reading and task lighting, not photography! Yep, OttLites are designed for “reduced glare, less eyestrain, and low heat.”  Sounds to me that they would be more useful in creating your craft rather than photographing it.  Who started this whole thing about OttLites being great for photography, anyway? Look at the “Shop by Lifestyle” section of their website.  See anything about “Photography?”  Me neither.

Although the OttLite website isn’t very informative, and their packaging and labels are pretty useless, I did manage to get my hands on some data for the three CFLs that they offer.  To save you all the trouble of searching for the information, here are the specs for their “brightest” bulb, the 25EDP2R.

  • Luminous Flux – 1300 lumens
  • CRI – “Above 90”
  • CCT – “Between 5000 and 6000”

I see two issues with the above.  Firstly, 1300 lumens is not a lot (not very bright).  And this is their brightest bulb!  When you listen to someone telling you to go out and “buy an OttLite,” without providing any specifics, you may very well end up with the 750 lumen model.  Not good!  Secondly, the specs for CRI and CCT are a bit vague.  Now that you know what these numbers mean, wouldn’t you like to know their specific values?  I sure would!

I also asked the OttLite folks for a spectragraph on these bulbs (to see how they compare to natural light), but they told me that the information was proprietary. Oh well.

Okay, So What Do You Recommend?

  1. Get unstuck from the “brand name” mentality.  Buy based on what the product does, not what it’s called.  Generic acetylsalicylic acid is a better bargain than Bayer aspirin, right?
  2. Learn what’s important about what you’re buying (luminous flux, CRI and CCT) and compare that information between bulbs.
  3. If you can’t find this information on the packaging or the website, don’t buy the light.  Period.
  4. Make your own decisions based on what you learn – don’t blindly take someone’s word (not even mine) on this, or any, subject!

Luckily, there are a lot of options.  Just remember … more lumens = brighter light.  And we all know that more light makes taking great photos a whole lot easier.  Spend a little time shopping and you can find plenty of less expensive alternatives.  Just look for bulbs that have specs like these:

  • A high luminous flux (above 2000 lumens)
  • A high CRI rating (90 or higher)
  • A known CCT – not a range (5500K is pretty common)
  • A reasonable price

Here’s a 45 watt bulb that I like, made by Alzo digital.  It’s rated at 2800 lumens, and has a CRI of 91 and a CCT of 5500K (I even have the spectragraph if anyone is interested).  Put a couple of these bulbs in 10-1/2″ aluminum reflector clamp lights like these (available at just about any hardware store) and see what they do for your photos!  You can get these  bulbs directly from the manufacturer, from Amazon.com, or from any number of other retailers.  Or, if you decide against Alzo, there are plenty of other options.  You just need to do a little research, compare some specs, and make sure you’re getting the most for your money.

One Last Thing

I know this post may be a little confusing to some of you, not because of your intellect but because of my attempt to jam so much information in a relatively small article.  So if you have any questions of any kind, please feel free to ask.  After all, I’d like you to be both a better photographer and a smarter shopper!

Until next time … Happy Shooting (and Shopping)!

Macro Mode – Know When to Say No

By now, most of you know that the majority of point-and-shoot cameras have something called a “macro” mode.  And most of you know that it’s set with that little flower button or menu option.  And you know that in just about every forum on improving Etsy product photos someone always says “make sure that you use macro mode.”  Well, that’s a crock!  Yes, macro mode is a very powerful and useful tool.  But that doesn’t mean you should use it for every shot you take.  Under the right conditions, and with the proper preparations, it can give you some remarkable photos.  But it also makes it easier to end up with a really, really bad photo.  So today I’m going to talk a little about when you should, and shouldn’t, select the little flower.

Just for fun, here’s an image (click to zoom) that I took using macro mode on a now-obsolete Nikon Coolpix back in 2003.  The camera itself was a 2000 model, so it’s got some pretty old technology by today’s standards.  The photo shows a drop of sap leaking out of a branch on a Fraser Fir Christmas tree.

As I said, if everything goes just right, you can get some really cool shots.  Can you see my reflected eye?  How about a few needles?  And the stretch marks up near the top?  I admit, I got really lucky with this shot, especially since the camera was hand-held.  But sometimes things just work.

So, when should you use macro mode?  And are there any tips for getting great macro shots?  Of course there are!

  1. Look in your user manual for the recommended distance range for your particular camera.  For example, I just checked an online manual for a Canon PSA480, and here’s what it says: “The possible shooting range is approximately 3-50 cm (1.2 in. – 1.6 ft.) at maximum wide angle … and approximately 25-50 cm (9.8 in. – 1.6 ft.) at maximum telephoto,…”.  Look for this information in your own manual, and keep a ruler or a tape measure handy if you’re not good at estimating distances.  By the way, in P&S cameras, these distances are usually measured from the end of the lens.
  2. Don’t think that you have to get closer than 1.6 ft. just so you can use macro mode.  Compose the image first.  Get the field of view that you want, then decide whether you should use macro mode.
  3. Don’t be fooled into believing that macro mode is going to solve all your problems.  More than ever, you’re going to need a good setup and good technique.  This means sufficient lighting, probably a tripod (along with the camera’s self-timer) and precise focusing.
  4. Speaking of focus, when you use macro mode, the depth of field is greatly reduced.  That means that the range of distances over which your subject will be in focus is pretty small.  If you know how to use your camera’s “aperture-priority” or “manual” modes, you can get a little increased depth of field by shooting with a smaller aperture (higher f number).  Regardless, make sure you’re focused on your intended subject, and not some unimportant background piece.
  5. Mix it up a little bit.  For Etsy listings, you’ve got five photo slots right?  So (if appropriate for your item) take a few shots in “regular” mode (whatever that’s called on your camera) to show the item while in use or in some kind of interesting setting.  Then take a few more in macro mode to show the detail of what you’ve created.
  6. If you decide that macro mode is right for the situation, that still doesn’t mean you have to be right on top of the subject.  Back up a little bit.  It’ll improve your odds of getting a good shot.  Remember when I talked about cropping and how few of those precious pixels are really needed?  If you missed it, you can check out two different posts here and here.  Remember, it’s okay (and even encouraged) to crop!
  7. If your camera has a viewfinder, unless it’s “electronic” (it probably isn’t), don’t use it to compose the shot when you’re using macro mode.  Use the display screen instead.  Otherwise, your eye and the lens may be looking at two different things.

As always, I hope that you learned something today, and that you can use what you’ve read to improve your photography skills.  Keep learning, keep practicing, and until next time … Happy Shooting!

Perfect Colors (Part II)

Last time I told you how to use a “gray card” to set your camera’s “custom” white balance.  Way down at the bottom of that post I mentioned that there was another way to use a gray card, but during editing rather than set-up.  This second approach will really come in handy for those of you who don’t have a camera with the “custom” white balance option.  All you need is editing software that has some type of “neutral color picker” or “white balance selector” or something like that.  Just check the help section of your software to see if this feature is available to you.  Chances are pretty good that it is.

My wife, Patti (click here for her Etsy shop), volunteered one of her dolls and a dress for this shoot.  It’s has some pretty basic colors (black, white and one particular shade of pink).  We set the doll on a table with Savage white (this is important) seamless background paper below and behind.  I placed a gray card up against the dress and “accidentally” left my camera’s white balance set to incandescent, even though there were no lights on at the time (I wanted an extreme example).  Here’s the result:

Wow!  That’s not at all what it looks like.  But do you see that rectangle down in the bottom right corner?  That’s a little section of my gray card.  In my editing program, I simply selected my white balance eyedropper tool, clicked somewhere in the gray card part of the image (it doesn’t matter where), and got this:

Yeah, that’s the ticket!  Don’t want the gray card in your photo?  Just crop it out, and continue along your way.

Now, remember what I said earlier about the “white” background?  Often you’ll hear that it’s just as effective to do this white balance adjustment using “something white” that happens to be in your photo.  The problem with this is that what you really should be looking for is something neutral, not white.  Want to experiment?  Feel free to download one of these photos, and try doing the adjustment for yourself using other areas of the image.  Try the white in the dress.  Luckily, it’s pretty close to what I just did using the gray card.  But what if you don’t have a bright white like that in your composition?  Well, you can try the white background, right?  Sure you can.  Go ahead, pick a point somewhere on the background and give it a shot.  What you get is an image that looks fine – until you compare it to the real thing.  Here’s where you have to trust me … the dress and the doll don’t really look like that!

So what are you waiting for?  Go get yourself a gray card already.  They’re inexpensive, easy to use,  and readily available at a variety of shops selling photography gear.  You can even pick one up in the “Supplies” section of my Etsy shop.

Until next time … Happy Shooting!