Nick Carver Photography Blog

Photography Tips, Tutorials, & Videos

CONTACT
 

Photography Tips: Understanding DSLR Lenses

Skill Level: Beginner

If you've ever shopped around for a lens, you know that the titles of lenses can get pretty lengthy and confusing. With all the different abbreviations, numbers and labels, the name of a lens can look more like a complex algebraic equation than a product title. So that's why I've decided to put together this blog post to help bring some clarity to the convoluted science of naming a lens.

Here are 2 examples of what a lens title might look like:

I mean really...it's a little ridiculous how complicated those titles are. I'm sure they make perfect sense to the marketing geniuses who came up with all these fancy titles, but to the average person, it's practically a bunch of meaningless letters and numbers. So let's break the names down and look at each part of it individually.

1. Lens Focal Length Range

Starting with the core of the lens title, we have the lens focal length range. The lens focal length is always measured in millimeters and it basically indicates how "zoomed in" the lens can go. Higher focal length numbers (e.g. 300mm) mean the lens will zoom in further, whereas lower focal length numbers (e.g. 20mm) mean the lens will have a wider view. For instance:

On the left: 28mm. On the right: 70mm (full-frame camera).

If the lens has a range of focal lengths, like 55-200mm, then the lens can zoom from 55mm all the way out to 200mm. Lenses that don't zoom are called "prime lenses" and they will be indicated with just a single focal length number - like the Canon 50mm f/1.4 USM.

2. Maximum Aperture

After the focal length range, the title will have an aperture number or a range of aperture numbers. This indicates the lens' maximum aperture. In other words, it tells you what the widest available aperture is for that lens. For instance, on the Canon 50mm f/1.4 USM, the widest aperture you can use is f/1.4 (remember that the smaller the f-number, the wider the aperture).

But then what's the smallest aperture you can use? Well, you'll have to dig a little deeper into the lens specifications to find that out. The minimum aperture for a lens (that is, the smallest opening) is never indicated in the title. Only the maximum aperture is. That's because the majority of customers don't care what the smallest aperture is. Most people want lenses that let in more light, not less. Only us landscape photographers care about the smallest aperture a lens can use.

Alright, now it gets a little tricky, so stay with me...

Some lenses have a range of apertures indicated after the focal length, like the Nikon AF VR 80-400mm f/4.5-5.6D ED lens. In this case the maximum aperture for the lens is listed as "f/4.5-5.6". When you have a range of apertures like this, that means the available maximum aperture will vary depending on how zoomed-in you are. The first aperture in the range indicates the maximum aperture for the short end of the zoom range. The second aperture in the range indicates the maximum aperture for the long end of the zoom range. This is called a "variable maximum aperture."

So in this example, the maximum aperture of the lens when you're set at 80mm will be f/4.5. But when you zoom the lens into 400mm, the maximum aperture decreases a bit to f/5.6. Having a variable maximum aperture like this allows the manufacturer to make the lens more compact and less expensive.

If your lens has a zoom range, but only 1 aperture listed, that means the lens' maximum aperture will be the same throughout the entire zoom range. For instance, on the Canon 70-200mm f/2.8L IS II, the lens can open all the way up to f/2.8, regardless of whether the lens is at 70mm or 200mm.

3. Features and Other Fancy Marketing Terms

All the other letters and abbreviations in the title of a lens will indicate features, quality and other marketing terms. For instance, if the maximum aperture has an "L" after it on a Canon lens - like the Canon 70-200mm f/2.8L IS II - then the lens is classified in its professional line of lenses. That means it'll most likely be weather sealed, the glass will be better quality, the image quality will be top-notch and the overall build will be more rugged.

There are a ton of different labels indicating all sorts of features and specs. Nikon especially has a very convoluted, over-complicated set of designations. Since there are so many, I won't bother defining all of them here, but I will address some of the most common ones. For a complete list of Nikon lens labels, check out this great article at DPanswers.com. For Canon's, here's a good article over at BobAtkins.com.

CANON

  • EF - "Electronic Focus" - This is the designation for all lenses fitting modern EOS bodies
  • EF-S - Same as "EF" except the lens is specifically designed for and will only fit APS-C format DSLRs like the 60D, 7D and Rebel series cameras (in other words, it won't fit full-frame cameras like the 5D or 1Dx)
  • USM - "Ultrasonic Motor" - This is what Canon calls their ultra-fast and ultra-quiet auto focus motor. USM lenses focus quickly, quietly and will typically have full-time manual override
  • IS - "Image Stabilization" - These lenses have built-in optical image stabilizer to help combat camera shake
  • L - This will come after the maximum aperture and it designates Canon's line of professional-grade lenses
  • DO - "Diffractive Optics" - This is a technology Canon uses in a few of its lenses that allows them to make telephoto lenses much more compact
  • Macro - A true macro lens will allow you to focus closer than a non-macro lens - good for photographing close-ups

NIKON

  • Nikkor - This is just Nikon's brand name for their DSLR lenses
  • AF - "Auto Focus" - If the lens has "AF" only (not "AF-S"), then the lens auto-focuses using the AF motor built-in to the camera. In other words, the lens itself has no AF motor. It relies on the camera body to drive the focus. Some Nikon cameras don't have a focus motor in the body, so they can't auto focus with these lenses.
  • AF-I - These lenses autofocus using an internal (that's what the "I" is for) AF motor built in to the lens instead of into the camera body as described above
  • AF-S  - The "S" indicates that it utilizes Nikon's current "Silent Wave" motor to auto focus. This type of AF motor is quieter and typically faster than the older AF-I motor
  • VR - "Vibration Reduction" - These lenses have built-in optical image stabilizer to help combat camera shake
  • D or G - It's kind of complicated. Check out this explanation at DPanswers.com
  • DX - This indicates that the lens is designed for and will only fit Nikon's DX "digital format" DSLR cameras
  • FX - This indicates that the lens will work on full-frame Nikon DSLRs as well as digital format DSLRs
  • ED - "Extra-Low Dispersion" - Indicates that the lens utilizes some special glass to help reduce chromatic aberration
  • IF - "Internal Focus"  - This means that the lens focuses by moving elements inside the lens barrel instead of moving the front element. As a result, the front of the lens won't extend out or rotate when focusing.
  • Micro - Nikon's indication for a macro lens

Photography Tips: Off-Site Image Backup

Skill Level: Intermediate

I want you to imagine something for a moment. Imagine that your computer's hard drive fails. It just dies. You go to turn on your computer one day and...nothing. Every last file and photo on your computer has been wiped clean simply because your system's hard drive decided to up and die on you. There's no explanation why it died, it just died. After all, it's not if your hard drive will fail, it's when. All hard drives will fail eventually.

So imagine losing every single thing on your computer. All your work documents, all your music and, of course, all your thousands of photos. The documents and music might not be a huge issue in the grand scheme of things. But the photos...that would be devastating.

This is why a regular system backup is not only wise, it's just plain stupid not to do it.

Ah, but wait. You do a regular system backup. In fact, you back up your computer to an external drive every night. Actually no, every hour. And it's to 3 different backup drives. And a server in another part of the building. So you're covered, right?

Well, what if the building burns down? Or what if there is a flood, or an earthquake, or a hurricane, or a tornado? Or what if someone just breaks into the building and snatches all the computers and hard drives? If, God forbid, any of those things were to happen, all the backups in the world won't do you any good so long as all the backups are under the same roof.

This is why having an off-site backup drive is such a good idea. And in this post, I'll show you how I do it.

Off-Site System Backup Box

On-Site Backups

In addition to the original, I have a total of 4 backups of all of my photos and 2 backups of the rest of my computer (work documents, music, videos, etc.). This is on a total of 5 hard drives - most of them external drives. All of these backups are on-site. In other words, they are in the same room as my main computer.

Time MachineMy main system backup is performed automatically every hour. This is done through Apple's built-in backup software called "Time Machine." It comes on every Mac and it is truly awesome. It backs up your system in the background every 60 minutes, allowing you to continue working uninterrupted. It also allows to "go back in time" to specific dates and recover individual files from that date. This has saved my bacon many times from accidentally overwriting a file I didn't mean to. With Time Machine, I can simply go back to before I overwrote it, and recover the original file like it never happened. You can learn more about Time Machine here.

I'm not a PC guy, so I'm not real savvy on the backup offerings for Windows, but here is a list of the Top 10 Backup Apps for Your PC by makeuseof.com.

As for my image backups, I do those at the beginning and end of any photo-editing session. So anytime I load new photos in to my computer, make adjustments or move images around on my hard drive, I run a backup of my images. I use Aperture (by Apple), which has a great built-in image backup tool called "Vaults." A Vault is basically a backup of your entire Aperture library, including all its settings, keywords, adjustments and everything else. With the click of a button, the backup starts and writes all your new files and changes to the backup vault. This is an excellent feature and is one of the many reasons I'm an Aperture user. You can learn more about Aperture here.

Aperture Vaults

I know Lightroom allows you to backup up the catalog, but I don't believe it has a built-in backup tool for the images themselves. I may be wrong on this, but you can always just back up your images with a regular backup tool like the ones here.

Off-Site Backup

Now for the absolute worst case scenario: a fire or earthquake destroys my computer, both my system backups and all 4 of my image backups. After all, they are all in the same room. This is where an off-site backup drive saves the day.

The key to a good off-site backup drive is that it's kept very far away and it's well-protected against damage. You take it home/to the office every week or so, run the backup software, then take it right back to its remote, off-site location for safe-keeping. For me, I keep my drive at my girlfriend's place about 20-30 miles away and just take it back to my place to run a backup every week or two.

If you have a computer at home and at the office, keep an office backup at home and a home backup at the office. Or keep your backup at a friend's house, at work or in a climate-controlled storage unit. Just get it far away from the original drive, but still convenient enough to fetch it every week.

My hard drive of choice for this is a LaCie 500GB Rugged Triple-Interface portable hard drive. I've had a few of these over the years and I love them. They are reliable, fast and are built to withstand drops better than most hard drives. It has USB, FireWire 400 and FireWire 800 connections, too, which means it can connect to pretty much every computer around.

For added protection against dropping, jostling and water damage, I keep this hard drive in a Pelican 1120 case. Makes for easier transport and gives me a little more peace of mind against damage from being dropped accidentally. Using Pelican's customizable foam insert, I created a space for the hard drive and its cable. The whole package is solid, sealed and very well-protected from potential damage.

Off-Site System Backup Box

Off-Site System Backup Box

Off-Site System Backup Box

ChronoSyncThe backup software I use for this off-site external drive is called ChronoSync. It's a really extensive backup application with lots of customizable options. I don't use Mac's Time Machine for this off-site backup because Time Machine can only be used on one external drive (which I already have set up). So every week when I take this drive back to my workstation, I just plug it in, run ChronoSync and voila! My system is backed up and ready to return to its secure off-site location.

Online Backup

Just as a quick note, there are online backup services like Carbonite, which back up your system to a remote server and allow you to access your files from anywhere. It's a really great idea and isn't very expensive, but I tried it once and it just took too damn long to backup my 275+ GB. The initial backup would have taken weeks or months with my computer running 24 hours a day. But they offer a free trial, so give a try if you like.

Photography Tips: Do I Need a Full Frame Camera?

(Updated April 2013)

I've had many students approach me and say something along these lines: "I'm trying to decide whether or not to upgrade to a full-frame camera" or "once I upgrade to a full-frame camera..." or anything like this that seems to hint at a full-frame camera somehow being better than a standard digital format (APS-C) sensor. So the real question you should ask yourself is "Do I need a full frame camera?"

The answer is simple: No. No you don't.

"But what if I want to-"

No. Still no.

Regardless of what kind of photography you are doing, you don't need to upgrade to a full-frame camera. In fact, even using the word "upgrade" when you talk about full-frame is not quite accurate. "Upgrade" implies that a full-frame camera would naturally be better than an APS-C camera. Well they are more expensive after all...

Do I Need a Full Frame Camera? ^ A full-frame sensor has the same
dimensions as a piece of 35mm film:
24mm tall by 36mm wide.

APS-C Sensor Size ^ An APS-C or "digital crop" sensor has the same
dimensions as a piece of the short-lived APS-C:
size film: 16.7mm tall by 25.1mm wide.

Do I Need a Full Frame Camera? ^ Overlay the APS-C on top of the full-frame sensor
and you can see how much a digital crop sensor
will crop the image. But does that mean
it's inferior to a full-frame?

The thing is, though, that a full-frame camera is not necessarily any better than a digital format camera. Take the Canon EOS 7D and EOS 5D Mark II cameras for example - two cameras that were on the market at the same time. The 5D is a full-frame camera and cost about $2500 when it was new. The 7D, on the other hand, has a digital crop sensor and cost about $1700 new. In my opinion, the 7D is a far better camera than the 5D Mark II for several reasons.

First, the 5D's auto focus system pales in comparison to the 7D's. The 7D also has an electronic viewfinder that can pull up a grid on demand. The 7D has an electronic level, a much faster frame rate and a more advanced metering system. The list goes on. And that's not even addressing the $5000 Canon EOS 1D Mark IV. That camera isn't full frame, but it has many advantages over the 5D including one of the fastest frame rates of any camera, a longer-lasting shutter, weather sealing, a better AF system and dual memory card slots. Again, the list goes on.

So a full frame camera is not an "upgrade" necessarily.

But then what's all this talk about getting a full-frame camera? Well, first things first: look at who makes a big deal about getting a full-frame camera. That mentality usually comes from beginner photographers, gear reviewers, and internet forums. (Which, by the way, you might want to stay out of internet photography forums. They are absolutely saturated with false information. In fact, read this blog post titled "5 Quick Bits of Advice for Beginning Photographers.")

So don't listen to what beginners have to say about camera recommendations. That's the blind leading the blind. Any professional worth his salt will tell you that it really doesn't matter that much what camera you have. And not coincidentally, the first question out of a real pro's mouth will never be "what camera do you use?" Why? Because pros don't care and pros know it ain't the camera. It'd be like asking a painter what brushes he uses.

As a professional with tons of experience, let me tell you why I use a full-frame camera and why they get a reputation of being better.

I use a full frame camera for 2 reasons that actually really boil down to just one: I used to shoot film. I shot film for about 5-6 years before switching completely to digital. In that 5 or 6 years, I got used to certain focal lengths looking a certain way. In other words, 16mm looked a certain way to me because I was used to the "full-frame" film view of it. Had I put that 16mm on a digital crop sensor (which I could have), suddenly 16mm on my lens wouldn't match up with 16mm in my mind. It would have been more "zoomed in" than I'm used to.

So if you shot extensively with film before getting your DSLR, then you might want to look at a full-frame camera. But if you started your photography adventure on a digital crop DSLR, then all is fine in your world. 16mm looks a certain way to you and that's all that matters. Your 16mm won't match my 16mm, but who cares? We're not going to compare mental image pictures to see who's is more zoomed in. But for me, I didn't want to have to "re-learn" my focal lengths. That would be a lot of habits to break and I didn't want to throw that kind of wrench in my gears, so I went with a full-frame.

Then there's the argument that full-frame cameras are better for wide-angle shots (like landscapes) because the sensor doesn't crop the image and, therefore, you get a wider view. Well, that is technically true that you get a wider angle image on a full-frame camera with the same lens. For instance, if you put a 16mm lens on a full-frame camera, you get a field of view measuring about 108 degrees wide. Put that same 16mm on a digital crop camera and that angle shrinks to somewhere around 84 degrees. That's a pretty big difference.

Advantages of a Full Frame Camera^ The blue border indicates the image as it would appear on
a full-frame sensor with a 16mm lens. The green border indicates
the image on a digital crop sensor with the same 16mm focal length.

Digital Crop vs. Full Frame Sensors^ This is the image at 16mm on a full-frame.

Digital Crop vs. Full Frame Sensors^ This is the image at 16mm on a digital crop sensor.

This used to be a problem in the early, early days of DSLR cameras because the widest lens available was about 16mm (before getting in to fisheye). So if you wanted that full 108-degree angle of view, you couldn't get it on a digital crop sensor. But the thing is, that doesn't matter anymore. It doesn't matter because Canon and Nikon were smart enough to come out with wide angle lenses compatible only with digital crop sensors that now go all the way to 10mm. And, wouldn't you know it, 10mm on a digital crop sensor gives you a field of view measuring (drumroll please) 108 degrees wide.

That's right. A 10mm lens on your digital crop DSLR will give you the exact same view as 16mm on my full-frame camera. So the "wide angle argument" is null and void.

Digital Crop vs. Full Frame Sensors ^ 16mm on a full-frame will give you the same angle of view as a
10mm on an APS-C sensor (or 11mm on a Nikon digital format).

Digital Crop vs. Full Frame Sensors ^ 16mm on a full-frame or 10mm on a digital crop sensor
- either would give you this same image.

Another argument for full-frame is that full-frame cameras perform better at higher ISO's. That is true with all things being equal. If you try to cram 21 megapixels into a digital crop sensor, noise will be a bigger problem than on a full-frame camera where the pixels have more room to "breathe." But I still call folly on this argument because camera companies are getting so good at noise reduction that high ISO noise really isn't that big of an issue on the latest cameras. And every time they release a new camera, the noise reduction gets better. So the noise on your new 18 megapixel digital crop sensor may very well be better than my 7-year-old 12 megapixel full-frame camera (I use an "ancient" first-generation Canon 5D). Besides, I could write an entire post about digital noise and how people make way too big of a deal about it. Unless you're printing gallery-quality billboards, stop worrying about noise. Most people's pictures end up about 2 inches wide by 3 inches tall on Facebook. And if you want to feel real good about your camera's noise performance at ISO 3200, try shooting ISO 3200 film for a week.

The last argument for full-frame that has any validity to it is that full-frame cameras give you a smaller depth of field. This isn't because a bigger sensor creates a smaller DOF. In fact, the size of the sensor has no bearing whatsoever on DOF. But the reason full-frame cameras create a smaller DOF is that with a full-frame camera, you have to use a longer lens to get the same shot. In other words, if you and I are both going to take the same picture and you're going to use a 50mm lens, well then I'll have to use an 80mm lens. Since your sensor is cropping the image, I have to use a lens with more magnification in order to match you. And since longer lenses have smaller depths of field, my lens will blur the background more than yours at the same aperture. So for portrait photographers who want real blurry backgrounds, that's a good thing. But for landscape photographers, that's not so great.

Also, look at the other side of the coin here. With a full-frame camera, you'll need a longer lens to get the same shot as with a digital crop sensor. For instance, if you need 300mm to get a shot of a bird on your small-frame camera, I'll need 480mm on my full-frame. A 300mm f/4 lens costs about $1400. A 500mm f/4 costs about $7000. I'll have to spend an extra $5600 to get the same magnification as you! This is why sports and wildlife shooters tend to prefer small-sensor cameras.

So don't feel like you need to get a full-frame camera. Your current DSLR is great. You can do amazing things with it. Instead of buying that new camera, spend some time learning the camera you have. Become a better photographer. Take classes, read books, practice like crazy and always remember that it's the photographer, not the camera.

 Parts of this article including the example images and graphics are from the "Composition for Dramatic Landscapes" online course.