Tag Archives: extension tubes

Macro Photography on the Cheap.

Posted by 8dcphoto on

I mentioned in my previous blog entry that I’d go in to some detail about achieving good quality macro photography on the cheap e.g. without having for dish out for a dedicated macro lens.

I discovered my interest in macro or close-up photography last year when I was undertaking a 365 Project and was looking for a different challenge, something I hadn’t attempted before.  A few macro pictures grabbed my attention and I thought why not give it a try.  Unfortunately however I didn’t have the spare cash to shell out for a dedicated macro lens so was forced to do a bit of research on the subject to see what I could achieve without the expense of a new lens.

What is Macro Photography? Essentially macro photography is termed as extreme close-up photography or where the subject in the image projected on to your camera sensor or film is larger than the actual subject.  Where the image on the sensor is the same size as the subject you’re achieving a reproduction ratio of 1:1.  A reproduction ratio of 1:1 or more is classed as a macro photograph.  To make this a little simpler, but more generic, some categorise an image as macro where the vertical height of the subject shot is less than 24mm.

The Macro Conundrum As macro photography requires close-up, high detail images, a number of challenges become apparent which you need to deal with in order to get the best shot.  Two main issues impact the macro photographer, Light and Depth of field.

As you need to get close to the subject of your shot the amount of light entering the lens is less.  Traditionally if shooting in Manual or Aperture priority you could widen the aperture (decrease the f number) on the lens and let more light in… or increase the ISO on your sensor.  However opening the aperture wide narrows the depth of field e.g. the amount your subject is in focus across the depth of the image.  When shooting small subjects using macro the depth of field will equally be reduced meaning you could have a lot of your image out of focus if your aperture is wide open.

So the trick or balancing act is to maximise the depth of field across your image subject whilst trying to get as much light in as possible.  You’ll see later how this often results in having to use a slow or long exposure shutter so a tripod is a necessary item to get macro shots correct.  The use of a dedicated macro lens will ease the balancing you need to achieve and give you more flexibility but overall whether you use a dedicate lens or an alternate method the challenges above are still an issue.

How to do it on the cheap  There are a number of different methods for achieving macro images without having to use a dedicated macro lens on your DSLR.  I use fully manual macro extension tubes and I’ll discuss these in more detail but you can also use macro/close-up filters which magnify the image at the end of the lens (image quality can suffer using this method) or lens reverse mounts which allow you your flip your lens around on your camera.  All methods including dedicated lenses aim to extend the distance between the end of the lens and the sensor in order to increase to magnification on the sensor.

Extension Tubes What are extension tubes I hear you ask? Well they are and do as described.  They are a set of tubes of varying length that when placed between the lens and the camera extend that distance and achieve greater magnification of the image on the sensor, hopefully getting you a reproduction ratio of 1:1 or greater.

You generally get two flavours of macro extension tubes.  The expensive ones such as Canon’s EF 25 II Extension tube which retails at over £140 ($90) for a single length tube and the dirt cheap ones which can be found all over Amazon or ebay for less than £10 ($6).  So what is the difference?

Most importantly there will be no difference in image quality between the two different types, spending more in this instance doesn’t get you better image quality.  Extension tubes contain no glass elements, they are a tube, so despite the engineering and optical excellence of Canon and Nikon etc none of them can improve the quality of the air between your lens and camera.  The main reason you pay more for a branded set or single extension tube is they maintain the direct connection of the lens to the camera to support the use of auto focus and/or aperture control.

In my opinion it isn’t worth paying the extra as firstly you will in most instances need very fine focus control when shooting macro so would most likely need to use Manual Focus and secondly with a little bit of knowhow you can retain control of the aperture without the lens being electrically connected to the camera.

So what do you need? Apart from a DSLR and the aforementioned manual extension tube set you’ll need a lens and a Tripod and if you want even greater focus control I’d also suggest a macro focus rail.  Cheap adequate rails ones can also be found on Amazon and eBay for under £10 ($6).

In my setup I generally use.

I already had the camera and tripod so for a total of £97 ($60) I have myself a little macro rig and a decent fast 50mm prime… everybody should own a nifty fifty, for the price you can’t beat them.

By comparison the cheapest Canon Macro lens which is capable of achieving the all important reproduction ratio of 1:1 is the Canon EF-S 60mm f2.8 which retails at £365 ($230) and this won’t fit a full frame DSLR!!  The next cheapest is Canon EF 100mm f2.8 which retails for £429 ($270).  Also be aware that some lenses like the Canon EF 50mm f2.5 are marketed as being a macro lens but they don’t hit the 1:1 reproduction ratio so whilst they can get close they don’t go close enough.

Setting Up (Canon) When using an extension tube set the general rule is the longer the tube or the more you stack the tubes the greater the magnification.  Getting a eye for the correct amount to use comes with practice but in short the setup is a follows…

  • Set desired aperture with just the lens on your camera (see tip below on how to do this)
  • Remove lens and add required extension tube(s)
  • Re-attach to camera and shoot away.

Macro extension tubes basically fit between your lens, in my case the EF 50mm f1.8 and your camera.  However before you go running off to fit your tubes to the lens and the lens to the camera STOP!!! When using manual extension tubes we need to think about how we are going to set the aperture of the lens, without that control from the camera provided by the more expensive branded extension tubes.

TIP There are two methods that can be used to set the aperture on the lens before we connect the extension tubes, each method requires the lens to be connected to the camera and setting aperture as desired before removing the lens with the camera power remaining on.

A common method I’ve seen used by many on YouTube is to set the aperture whilst in Live View mode before removing the lens, with the power still on.  The second method, and my preferred because it reduces the exposure of the sensor to the elements when removing the lens is to use the little DoF preview button that is found on either the right or left side of the lower part of the lens mount on your Canon DSLR.  If you press and hold this button you’ll notice that the camera sets the aperture as desired so you can preview your shot through the optical view finder.  If you remove the lens whilst pressing and holding the DoF button you can effectively set the lens aperture without the mirror being locked up exposing the sensor as would be the case if you did this using the Live View method.  It can be a bit fiddly but practice makes this quite easy.

Once you have removed the lens you can power off the camera before attaching the lens to the extension tubes and then everything back on the camera.  That’s it, you are ready to shoot.

Things to consider As I mentioned above, normal depth of field reduces when using extension tubes so in order to get an image where you maximise the amount of subject in focus you’ll need to go for a small aperture (larger f number).  I find I shoot with nothing less than f7.  However using smaller apertures obviously means that less light is getting to the sensor so shutter speeds will be impacted.  Therefore in order to get a well exposed image you are more than likely going to need to either increase ISO or use a tripod to keep everything solid, unless you have a LOT of light available e.g. shooting outdoors on a bright day.  I’d stick with a low ISO and use a Tripod in order to maximise image quality but this is less useful if the subject can move e.g. an insect and you have long shutter times.

Lastly you’ll also notice that focus range becomes very short and focus adjustments become much more sensitive using macro tubes.  The slightest move of focus can have a very large impact which is why even when using the more expensive macro tubes and dedicated macro lenses most opt for manual focus to get that fine control.  The best method to get pin sharp focus is to shoot in Live View mode and use the screen magnify function to check everything is sharp before taking the shot.  For even finer control of focus, mount your camera onto a Macro focus rail then on to a tripod, this makes the whole focussing process much easier especially when you’re mounted to a tripod and you want to move your perspective around and take a shot from multiple angles.

So in a nutshell that’s Macro photography on the cheap.  Pop over to my Website and Flickr pages to see a selection of Macro examples all of which have been achieved using macro extension tubes.

Thanks for reading and in my next blog I’ll be reviewing the Sigma 30mm f1.4 DC HSM “Art” lens.