petrochemist Loc: UK

How close the camera will focus with extension tubes fitted is a function of the length of the tubes, and the focal length of the lens. This is part of the reason why they don't work so well with zooms, nudge the zoom & focus is in a different place...
With the lens set to infinity each focal lengths extension will add one to the magnification.
Higher magnifications mean the lenses image circle is larger so the light on the sensor drops.
With a suitable flash (typically well diffused) hand holding can work at even quite high macro magnifications (I avoided camera shake at 6x lifesize) but a focusing rail is much more controllable when the subject is static.
Generally avoid AF, changing working distance (camera-subject distance) is much better.

Working distance is typically longer with longer focal lengths and/or lower magnifications. It can be much closer than many beginners expect (so that lighting the subject can be a real pain).

It's easiest to start with the shortest tube (least effect) & step up as you get familiar with the effect. You may never want the longest options :)

amfoto1 Loc: San Jose, Calif. USA

What brand of extension tubes did you buy? Do they have the electronic contacts that match up with the electronic contacts on the lens and camera?

There are "really cheap" extension tubes that don't have the electronic contacts. Selling for under $25 for a set, they are worthless with most modern lenses. Without the electronic communication between camera and lens, there's no way to change the lens aperture on many modern lenses. There also won't be autofocus, but with most lenses manual focus isn't a problem. This type of tube can be used on lenses that have their own built-in, manual aperture control ring. But that's not the majority of modern lenses.

Better extension tubes with electronic contacts to match those in the camera and lens typically sell for between $50 and $120. They are usually sold in sets of three: 12mm, 20mm and 36mm... or 11mm, 21mm, 33mm... or similar.

The shorter the lens focal length, the less extension that will be needed to make it focus closer. The longer the lens focal length, the more extension that will be needed. Most commonly the tubes are used with lenses from around 35mm to 135mm. But they actually can be used with almost any lens, to make it able to focus closer. Experiment with the lenses you have.

Some examples...

I wanted to make a shot of a California poppy that blurred down others in the background, but still left them recognizable. To do that I decided to try a very wide lens. That meant using a very short extension tube. The shortest I have in that mount is 12mm. With that between the lens and the camera, the petals of the flower were in focus when touching the front element of the lens! Can't get much more of a "close-up" than that!


I learned how to use macro extension tubes many years ago and ever since have always made a point of having some in my camera bag, because you never know when you might need them, they take up very little space and are very light in weight. I was out shooting wildlife with telephotos when I noticed a spider web right in front of me, added a 25mm extension tube to my 70-200mm lens to get the following shot...


Extension tubes do cause some loss of light. Light fall off over distance is exponential. However, with certain lenses they also can cause vignetting... darkening of the edges and corners of the image... as well as some softening of the image. These aren't necessarily bad things, though. For example, I knew they would occur with my 50mm lens when it was used with some extension and set to a relatively large aperture and thought it might render an interesting image of this rose bud...


An extension tube also can be useful for more "normal" shooting distances too. Powerful telephoto lenses commonly have limited close focusing ability, to shoot small subjects. I was trying to photograph the tiny bush tit at its nest with a 500mm lens, but needed the lens to focus just a little closer. If I recall correctly I used a 36mm extension tube behind it for this shot...


Similarly, the 300mm lens I'd been using needed a bit of extension (20 or 25mm) to get a closer shot of this skittish little fence lizard...


Even macro lenses can use some help at times. The vintage macro lens I used for the shot below is capable of 1:2 magnification, so I used 20mm of extension to push it a little higher than that...


There are lots of ways to use macro extension tubes. Just get out there, look for some cooperative subjects, and experiment with them. You don't need to worry about light fall off because your camera's Through the Lens (TTL) metering will automatically compensate for that. Some suggested using a tripod, but all the above examples were hand held. Just look for good light where you don't need a slow shutter speed. That will be better with moving subjects, too.

Also, yes, in theory you need extension equivalent to a lens' focal length for it to be able to focus to 1:1 (life size) magnification. So that would mean that a 50mm lens will need 50mm of extension. But it doesn't. The reason is because that 50mm lens already has some built-in extension, some ability for focus closer. You can use extension tubes individually, in pairs or all three stacked. There will likely be some reduction in autofocus performance, the more tubes that are used. Personally I can't recall the last time I used more than one tube for a shot. When I need higher magnification than the tubes can render, I switch to a macro lens.

For use with my DSLRs I have three Canon tubes: two 12mm and one 25mm. They are top quality, but only sold individually and rather pricey. I also have a Kenko set of three: 12mm, 20mm and 36mm. They are equally good quality and the whole set cost less than the Canon 25mm tube. I don't know why, but for mirrorless systems they only sell macro extension tubes in sets of two... I have a pair of Viltrox tubes (10mm and 16mm) for my mirrorless camera and its lenses.

Architect1776 Loc: In my mind

Is AF of any value with extension tubes or bellows?
My experience is that with a regular prime like a 50mm from infinity to minimum focus is a negligible difference. The ability to adjust aperture is significant with modern lenses but AF I do not know has anyone tried to see if there is any noticeable difference, please excuse all macro lenses with far greater focus range.

JimH123 Loc: Morgan Hill, CA

Certainly, it is possible to AF with an extension tube, if it passes through the contacts, if you are at the right distance that it can AF. But DOF is small. With my Olympus cameras, I can use AF and have it take a series of images using focus bracketing or focus stacking so that they can be combined either in camera, or in post processing.

But if not doing that, then manual focus is likely your best bet, and a focus rail certainly helps since it is very hard to hand hold a lens at the optimum distance. I know that I wobulate without a tripod!

JimH123 Loc: Morgan Hill, CA

The reason for mirrorless only providing two is that the flange distance is so much shorter that the extension times have more effect. Think of it this way. If your camera has a flange distance of 44mm then a 44mm extension tube would double the extension. If your flange distance is only 18mm, then an 18mm extension tube would double the extension distance. So, if they provided 3 extension tubes, you would need a 6mm to go with the 10mm and 16mm to accomplish the same effect as you might have with a FF camera using 12, 20 and 36mm. Perhaps they just decided that 6mm for the mirrorless just wasn't worth adding to the set.

JimH123 Loc: Morgan Hill, CA

Just in case someone might want to know where the lost light has gone, it's not really lost, it's just not used. The lens outputs a cone of light that is sized to fill the sensor of the camera, and as you move the lens farther away, you are using less of that light cone with some of it falling outside the sensor. For instance, if the extension tube were to cause the lens to focus at a point that the image on the sensor is only using 1/2 the cone width and 1/2 the cone height, then you would be using 1/2 x 1/2 = 1/4 of the available cone of light. And 3/4 of the cone of light is now outside the bounds of the sensor. Or you could think of it as the light that is hitting the sensor has only 1/4 the light density as it would be if all the light were hitting the sensor.

And as you add more extension tubes, the light density continues to go even lower! And this is one of the reasons that zoom lenses, which often are slower lenses, aren't such a good match for extension tubes.

Next, I want to point out that it is possible to use a close-up lens (close-up filter) on a lens instead of an extension tube. Extension tubes are best for shorter focal lengths and close-up lenses are best for longer focal lengths.

But one advantage of a close-up lens is that there is no light loss. The close-up lens is actually a magnifying lens that increases the size of the object you are photographing and does so at a closer distance than you might be able to focus at. But beware. There are really good close-up lenses. And some real duds!

See this site for more information: https://www.creative-photographer.com/close-up-lenses/#:~:text=There%20is%20no%20light%20loss%20with%20close-up%20lenses%2C,electronic%20connections%20between%20the%20lens%20and%20camera%20body.

In addition to extension tubes, I have close-up lenses -- Canon 500D, Raynox DCR-150, and a set of 3 Minolta close-up lenses called #0, #1 and #2. And I have from many years ago, one of those sets with 4 different diopters in a set, but single element. And the link above is correct - the results from this cheap set cannot compare to the multi-element close-up lenses.

imagemeister Loc: mid east Florida

You can also combine CU lenses with tubes ! ......

JimH123 Loc: Morgan Hill, CA

Manglesphoto Loc: 70 miles south of St.Louis

NO AF will drive you crazy, in fact my first set of tube were Kenko auto Tube(junk as far as I'm concerned) I now use a Nikon Manual set!!

par4fore Loc: Bay Shore N.Y.

Take a look on YouTube.

jerryc41 Loc: Catskill Mts of NY

You probably figured this out already, but to remove most of those tubes, you have to slide that silver button. We've had a lot of people say that they can't remove the tube, even though they pushed the button.

I learned how to use mine by experimenting. Try the links below.

http://www.lightstalking.com/extension-tubes-affordable-intro-macro-photography
http://digital-photography-school.com/lets-get-up-close-with-extension-tubes/
https://www.digitalphotomentor.com/how-to-use-macro-extension-tubes/
https://www.digitalcameraworld.com/tutorials/how-to-use-extension-tubes-for-low-cost-macro-photography

rwww80a Loc: Hampton, NH

Get a Kodak Master PHOTO GUIDE. Probably our of print.

JimH123 Loc: Morgan Hill, CA

This mainly due to the fact that there is a limited range of distance that the lens will actually focus with the extension tube(s) in place. And you need to be in that range in order for AF to work.

And then if you are in a suitable AF range, the DOF is extremely narrow, so the camera will pick a point that it wants to focus on which may not be the point you want to focus on.

And by-the-way, I have used Kenko extension tubes before I went mirrorless, and I had no issue with them. They worked fine. As long as an extension tube firmly attaches, and provides a solid connection with the contacts, and doesn't bounce light all around the insides, there isn't much that can go wrong. But it is up to the user to be using it at a range the camera can actually focus in.

I have used extension tubes from 5 different manufacturers, and I couldn't detect any differences in how well they worked. There are no optics and there are no moving parts. There is not much that can go wrong outside of user error.

JimH123 Loc: Morgan Hill, CA

I remember that book.

Here is an online copy of it:

https://archive.org/details/KodakMasterPhotoguideD.D.TeoliJr.A.C.1/Kodak%20Master%20Photoguide%20D.D.%20Teoli%20Jr.%20A.C.%20%2812%29.jpg

fetzler Loc: North West PA

I don't think that your reasoning is correct. A 50mm lens focused to infinity with 50mm of extension gives 1x magnification. There is also the problem of making thin extension tubes. It seems that 10mm is near the limit for mechanical stability. I wish this was not so because so many wide angle lenses could be use for cool close up photographs. My micro 4/3 extension tubes only need a length of 25mm to reach 1x using a 25mm lens.