One limitation of macro photography when using a conventional lens is that there is a limit to how close you can focus due to the lens's minimum focusing distance. Extension tubes allow you to shift the focus zone of the lens you're using so that the smallest of items are crystal clear and tack sharp. Let's take a closer look (pun intended.)
In another article on Using a Macro Lenses I looked into one method using a dedicated macro lens. In that article I also mentioned a few less expensive ways of getting into macro including the one I'm going to cover in this lesson – extension tubes.
So let's take a look at what they are, how you use them, pros and cons, and some purchasing tips for extension tubes.
What are extension tubes?
Every lens has a minimum focusing distance.
When doing macro photography that often becomes an issue because you can't get in close enough to shoot your tiny subjects because your lens won't focus that close.
One solution is to get a set of extension tubes.
What they are is exactly what their name implies – little tubes that extend the lens.
Essentially what it does is shifts the focus zone of the lens; you will no longer be able to focus at infinity but it will allow you to get closer so you can do those macro shots.
How do you use them?
You attach extension tubes between your camera body and the lens. You can use one or stack them for maximum effect. Make sure you get the right type for your camera body connector.
I recommend attaching the tube onto the lens first, then mount the whole thing to the camera body.
Once it's all attached you're ready to shoot like normal.
How close can you get with them?
You can buy extension tubes in different widths, so how close you can get will depend on which one(s) you buy and also the lens you use with it. But in some cases you can get pretty darn close!
Using a shorter lens like a 50mm will allow you to get REALLY close, in some cases almost too close.
It becomes awkward to work when you're less than an inch from your subject to obtain focus.
Choosing a slightly longer lens like an 85mm or your zoom will give you a bit more breathing room. You won't be able to make the subject as large but you'll be ale to have a usable working distance between the subject and the lens.
This was shot with an 85mm lens (on full frame) and all three extension tubes combined. It was still a manageable distance to the rose.
I tried with the 50mm lens and it was so close that the lens was almost inside the flower.
Not so workable.
How much does it magnify?
In this series of the rose I shot it first without any extension tubes, then with each one separately, lastly with them all combined. You can see the results visually.
Let's look at another example with a ruler so you can really see the difference.
Notice this one has a little blurriness to it? I must have jiggled something during the 10 second exposure. Remember to keep everything locked down tight for maximum sharpness – refer to the Ultimate Guide to Macro for tips
To get the image above once again using the 50mm lens I was painfully close to the subject.
This causes two issues:
- Depth of field is really shallow, and
- You end up casting a big shadow on the subject so it is dark.
I switched to the 85mm lens using all three tubes once again to show you the magnification difference between the two lenses.
Notice the image above is about the same magnification of the 50mm lens with the 36mm tube only. Still pretty good and a better working distance. So sometimes you have to play around a bit to find the right lens/tube combination for your subject matter.
Pros and cons
What are the advantages or using extension tubes?
- Light-weight to add to your bag
- Come with a way smaller price tag than a macro lens
- You can use them with your existing lenses
- You have the flexibility of combining them and trying different vocals lengths depending on your subject
What are the disadvantages?
- They can still be a little pricey if budget is an issue (don't get the cheapest ones, see shopping below for more info)
- There are more steps to put it together, so a bit of a hassle
- The results are only as sharp as the lens you put on them
- One more bulky thing to carry around with you
Shopping for extension tubes
If you've decided that extension tubes are the way to go for you, here are a few tips and things to consider before buying them:
- Do NOT buy the cheapest set, they are not all the same. Read the reviews – I read a few on Amazon and heard about some that got stuck on the camera (not good) and wouldn't come off. Others were too flimsy to hold a big lens and it flopped and the lens fell off (also not good). So lowest price is usually buyer beware and if you think “what could go wrong it's just a tube” – read the reviews first, particularly the one star ones! It's not worth damaging your camera to save $100.
- Be aware that some extension tubes do NOT have electronic connections. See the image of mine above that do have them. No connections – no aperture or exposure settings transferred and communicated to the camera. Make it much harder to work that way and you can't shoot a a small aperture like f/22 it always fires wide opened.
- Just get one to start if you can't afford a whole set. Get the widest one if you can swing that, it will get you the closest and most magnification.
Here is a link to a few I'd recommend. Stick to the camera brand if you can or one that is reputable. I have the ProMaster brand but I can't find them online other than on their website. You can check there and find a dealer new you to buy them locally.
So that's it for another installment of macro photography tips. In the next chapter of this ongoing lesson we'll look at reverse lens macro. Until then find some fun small subjects and get practicing.
Have you used extension tubes? Do you have a good shot to share with us? Or a brand you'd recommend buying or not buying, and why?