# Extension tubes vs. dedicated macro lens...



## splproductions (Nov 19, 2012)

I want to start dabbling in macro, but I don't have a macro lens.  Am I going to get lousy results if I got some extension tubes and used them with my existing lenses versus just saving my money and getting a true macro lens?

I'm shooting crop-sensor.  I've got Canon 40mm 2.8, 50mm 1.4, 85mm 1.8, 24-70 2.8L.

Thanks!


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## ryanwaff (Nov 19, 2012)

On the contrary, using extension tubes, if done correctly can yield some fantastic results. They just require a bit of practice. I recently had the same debate with myself that you are having now, and extension tubes won out. I cant speak for your 40mm 85mm or 24-70mm but I know that 50mm on extension tubes yields some great results.

But yes, a dedicated macro lens will yield better results, however they wont be that far off from the extension tubes results. Albeit you will have to add more light with extension tubes, they will still be great.
 If you'd like I can show you some examples of extension tubes with the 50mm that I have taken. (but will refrain until you say so, for want of not clogging up your post)


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## unpopular (Nov 19, 2012)

Etension tubes with the right lens can be very good, if not better than a dedicated macro of similar price. Using an enlarging lens or process lens is one way to do it inexpensively, moderately more expensive is microfilm objectives. Some wide-field microscope objectives are also very good - even better than any macro lens, but often cost a lot. Another option would be to use a large format lens.

A big advantage of a dedicated macro lens is that they'll be easier to use, with more working distance.

At moderate magnification, my Rodenstock handles well:







And very high magnification is possible






However, it is not an easy setup if your primary interest is insects.


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## MLeeK (Nov 19, 2012)

Tubes have no impact on the quality of the image because there is no glass in them to alter what is hitting your sensor. They are a great tool!!!! 
I REALLY want a set to use my 70-200 macro just to see if I can do some "uber whatsits" too!


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## splproductions (Nov 19, 2012)

ryanwaff said:


> On the contrary, using extension tubes, if done correctly can yield some fantastic results. They just require a bit of practice. I recently had the same debate with myself that you are having now, and extension tubes won out. I cant speak for your 40mm 85mm or 24-70mm but I know that 50mm on extension tubes yields some great results.
> 
> But yes, a dedicated macro lens will yield better results, however they wont be that far off from the extension tubes results. Albeit you will have to add more light with extension tubes, they will still be great.
> If you'd like I can show you some examples of extension tubes with the 50mm that I have taken. (but will refrain until you say so, for want of not clogging up your post)




Yeah - post some!  I'd like to see what that combination will do.  (Also - let me know which make and model extension tube you used).


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## Overread (Nov 19, 2012)

Few thoughts:

1) The rough maths for using extension tubes is:
(Length of the extension tubes in mm divided by the focal length of the lens) + base magnification of the lens = power :1

For example 65mm of extension tubes (eg one full set of kenko extension tubes) on a 50mm lens gives you:

(65/50)+x = power:1
=1.3:1

Now I've left x (the base magnification of the lens) at 0 because for most regular lenses its a very small value and it will also vary a lot lens to lens. What this shows is that you will get to more than 1.3:1 magnification which is actually more than you will get from a regular dedicated macro lens which gets to 1:1 at its closest focusing point.


2) Magnification is defined as:
Size of the subject reflected on the sensor by the lens  :  size of the subject in real life. 
As a result a ratio of 1:1 means that the object is being reflected on the sensor at the same size it is in real life. This point of magnification is generally (in photography at least) considered "true macro" and is what most prime (single focal length) macro lenses on the market will reach at their greatest possible magnification. 

3) Extension tubes work by reducing the minimum focusing distance of the lens and stripping the infinity focusing ability of the lens. So when attached you'll be able to focus very close, but you also won't be able to focus very far off. This limits them compared to a regular macro lens which does not lost its infinity focusing abilities.

Also note there is a practical limit as to how much tube length you can add before the point of focus becomes too close to focus upon with the lens or where the point of focus actually moves inside the lens (ergo it is impossible to ever focus). 

4) With the base maths you can see that shorter focal length lenses will give you more magnification per mm of extension tube, however keeping point 3 in mind you'll note that you can't just use a very short focal length lens. Generally speaking 50mm with a set of extension tubes is workable and a good base to start from. 

5) Always aim to get extension tube that come with the metal contacts. You'll need these to control the aperture on your lens (as well as AF). This is important as without aperture control you make the process a lot harder because of the tiny depth of field that you'll have in macro photography. Note that Kenko extension tubes are a popular brand offering good price for quality tubes with the metal contacts.


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## jfrabat (Nov 19, 2012)

^^^^^^  What he said; I woul donly add that you may want to use lenses with as much apperture as possible, as lenses with not so much apperture may have a hard time focusing with the extension tubes.  For example, my 70-300 f/4.5 lens has issues focusing with the big Kenko tubes attached unless there is a TON of light!


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## Overread (Nov 19, 2012)

Typically for macro - even with a dedicated macro lens - it is a lot easier to leave the AF off and to focus manually. Set the focus and then move the camera and lens closer to the subject, then rock gently to set the focus just where you want it. AF generally has a lot of trouble with macro and close up work, not just because of the lower light levels but also because of the back and forth natural body motion that it produces. 

Note that canon has recently been trying to change this with a new hybrid AF - although its a bit of a pain as at present it only engages for detected canon brand lenses set to macro focusing distances (ergo it won't work on 3rd party or extension tubes).


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## unpopular (Nov 19, 2012)

MLeeK said:


> Tubes have no impact on the quality of the image because there is no glass in them to alter what is hitting your sensor. They are a great tool!!!!
> I REALLY want a set to use my 70-200 macro just to see if I can do some "uber whatsits" too!



No. Some things do get exaggerated. I have noticed more coma with extension, i'd imagine CA as well, but a high quality lens will remain high quality.


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## Overread (Nov 19, 2012)

unpopular said:


> MLeeK said:
> 
> 
> > Tubes have no impact on the quality of the image because there is no glass in them to alter what is hitting your sensor. They are a great tool!!!!
> ...



Agreed. Whilst the extension tubes have no optics, they do move the lens away from its normal positioning. This does result in a minor image quality drop, however:

1) It's generally very minor

2) It is generally very hard to see in most situations because people often stop down to around f8-13 for macro work. Thus many minor losses in image quality which might be more visible wide open are totally lost with the smaller apertures.


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## ryanwaff (Nov 20, 2012)

Here are a few examples used with the very cheap kenko extension tubes. They are the ones with no metal contacts, which means to aperture control. But I found a way to get around that. Instead of turning the lens all the way when you attatch it. If you watch through the front of the lens while attatching it, you will see the aperture moving when you turn the lens, so on my 50mm prime, I just turn the aperture ring to the size I want it to be and then turn the physical lens until the aperture closes to the desired number.
I should note that I shoot Nikon. But the principle will still apply. ( I think)

 
This one was taken with three extension tubes all stacked up, and a 55-200 lens mounted. (what I found quite nice about this lens, is that you can focus with the zoom. Which is very nice if you have a small focus ring like the 55-200 has. External flash right.

 
This one was also taken using the 55-200. Flash mounted in hotshoe.

 
This one was taken using the 50mm prime. Three extension tubes if I remember. External flash above.

 
This one was also taken using the 50mm. Flash mounted in the hotshoe.

 
Also taken with the 50mm, again flash in the hotshoe.

 
This one was taken with the 18-55mm Lens with only one extension tube attached.

The thing I have found with extension tubes and others have said it before, is that you lose alot of light, especially with three tubes attached. So if you get them, then a speed light will go a long way.


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## unpopular (Nov 20, 2012)

Overread said:


> unpopular said:
> 
> 
> > MLeeK said:
> ...



yes. and because the image circle enlarges along with the image, the worst of the flaws will be cropped out. But in theory, anyway, all the aberrations will be enlarged, so using a decent lens is important.


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## Edsport (Nov 20, 2012)

ryanwaff said:


> Here are a few examples used with the very cheap kenko extension tubes. They are the ones with no metal contacts, which means to aperture control. But I found a way to get around that. Instead of turning the lens all the way when you attatch it. If you watch through the front of the lens while attatching it, you will see the aperture moving when you turn the lens, so on my 50mm prime, I just turn the aperture ring to the size I want it to be and then turn the physical lens until the aperture closes to the desired number.
> I should note that I shoot Nikon. But the principle will still apply. ( I think)
> 
> View attachment 26244
> ...



With canon the aperture can be set without using metal contacts. Put the lens on the camera, set the desired aperture, press and hold the DOF button while removing the lens and now put your tube and lens on. The aperture will be set. You'll still have to manual focus though...


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## Edsport (Nov 20, 2012)

I used a 12mm tube with a 350D and 18-55mm lens...


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## molested_cow (Nov 20, 2012)

Macro speaking wise, sure you can always find great photos taken with extension tubes, or even reverse lens method. However a dedicated macro lens isn't just a macro lens. It's also a great portrait lens, landscape and everything you want to use it as. It can focus from infinity to however close you want. It's tack sharp (at least mine is) and gives you great aperture settings to work with. Expensive? That's relative.

One photographer said to me, what matters is you get the shot you want. So it depends on what kind of sacrifices you are willing to make to get or miss the shot. For bugs, extension tube is probably not the ideal one. Even flowers or plants, things that move ever so slightly in the wind, is not ideal. 

With regards to macro lens being a great portrait lens. Imagine your 50mm being able to focus in whatever distance you want. No longer you have to step back because your subject is too close and now you are not getting enough of the person in the frame. I love mine!

BTW, a good set of extension tubes isn't THAT cheap either.


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## greybeard (Nov 20, 2012)

I haven't used extension tubes in a long time but I do have a dedicated macro.  I love the convenience of it.  Just mount it and shoot.


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## mjhoward (Nov 20, 2012)

Thomas Shahan uses an old cheap reverse mounted 28mm stacked on a 2X converter....  He seems to do ok: http://www.thomasshahan.com/photos/

Here's his setup (read the description, the photo includes a bellows which he very rarely uses): Macrophotography Setup | Flickr - Photo Sharing!


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## unpopular (Nov 20, 2012)

the 28mm tak might be cheap, but it's not a crap lens, either.


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