It’s been a while since I’ve done a GoA thread but I’ve been meaning to get around to a Macro one for some while. With the weather a bit changeable and being in a geeky mood, I thought it was about time to put pen to paper.
For those unaware, there is a bit of a series of these GoA threads, covering many aspects of photography – there’s a link to the index in the footer to make finding them easier. I use Canon terms occasionally as that’s what I’m familiar with, but the principles apply across any make & model.
OK, so, what do we actually mean when we say “Macro”? Technically, a Macro lens is one that is capable of throwing an image onto a sensor at life-size (known as 1:1) or larger. That means a picture of a 10mm bug would occupy 10mm of real estate on the sensor in your camera. The term (as is often the case) has been abused by manufacturers to sell more lenses – whacking the word “Macro” on a kit lens doesn’t make it a true macro, though it may be better than some at taking pictures reasonably close up. In truth, it doesn’t really matter as long as you know exactly what you’re using, regardless of any labels – even with a proper macro lens, you’re not often taking images at the minimum focus distance, so for this thread, I’ll simply define “Macro” as any shot where you’re getting up close and personal with your subject and assume you’re after detailed pics of bugs, flowers and the like. If you are interested in such subjects, a proper macro lens is a worthwhile investment however; they’re generally f/2.8 prime lenses with a flat focus plane (ie more likely to be in focus across the whole image). They’re also sharp – very sharp. I don’t think anyone makes a macro lens that isn’t sharp (it’s the whole point of them).
Whilst you can get a variety of focal lengths, something around 100mm is the most popular length. Shorter lenses are ok for product photography, but of limited use with bugs (you need to get close to the subject who have an irritating tendency to then fly away!). Longer ones (180mm seems to be the longest) are a bit heavy and cumbersome unless you’re used to using them, though they do allow you to hang back a bit and still get those close-up images. The large objective lens does make it difficult to get ancillary lights on the front too, so stick with something simpler until you’re familiar with the potential issues. This picture shows a Canon 80D with 100mm f/2.8L IS macro (bottom) and a 5D4 with Sigma 180mm f/2.8 macro (top) for comparison.
There are also some extremely specialised Macro lenses – Canon’s MP-E 65mm beast is probably best known. That allows images up to 5x lifesize (ie a 5mm bug would take up 25mm of sensor space!). I won’t be talking about anything quite so exotic though (not least because I don’t own one), I’ll stick to hardware that’s a bit more everyday. Most of the stuff I’ll demonstrate will be using the 80D/100mm combination (just because I don’t get to use it very often, it being Mrs WJ’s setup really). If you REALLY want to get up close to your subject matter, you could try some tubes. These simply attach between your camera and lens, moving the lens away from the body, giving you the ability to get closer (more magnification) at the expense of infinity focus. You may also lose AF completely (or it will be slow) and you’ll lose light – nearly 3 stops in this setup, where I have stacked all three sizes (12mm, 20mm, 36mm) together (which is also why there’s a ring light on the front of the lens). Note, if you’ve forgotten what a Stop is, see the earlier GoA thread
These two pictures were both at minimum focus, first with no tubes, then with all of them, to show how much closer you can get. You really are getting to the point where you need a solid tripod now though, my hand-held effort’s pretty poor!
Finally, as a novel way to get close on a budget, try a reversing ring. This nifty gadget is simply a double ended filter ring – it allows you to reverse a second lens on the front of your normal one. It allows for some fun playing around, but isn’t particularly practical for regular use. If we get snowed in at some stage this winter, I’ll think about doing a demo to add to this thread!
Part 2 coming up.....
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Find me on Flickr / All about your camera - The Getting off Auto Index
So what’s the big deal with macro photography then? Why dedicate a GoA thread to the subject at all? Point, click, done, surely? Well, sometimes, yes. Other times it isn’t so straightforward. The biggest issue with macro is the depth of field (DoF). Well, the lack of it really! At the minimum focus (30cm) that 100mm lens on an 80D gives me a DoF of less than 2mm at f/8. Even if I stop it right down to f/32 (ignoring any diffraction) it’ll just about give me 7mm. Closing down the aperture so much means high ISO images (and the resultant noise), slow shutter speeds (and camera shake) or a LOT of light. In this example, the f/32 image is 1/8th sec at ISO6400, the f/2.8 one 1/160th sec at ISO1000 and you can clearly see the different DoF
So what do we do?
First, decide what sort of thing you’re taking pictures of. Traditionally, a lot of macro work was done with a tripod in a studio. Controllable, no wind blowing your subject about, manual focus used to get the sweet spot for the most effective depth of field, mirror lockup and remote triggers to stop any vibration, batteries of lights to illuminate your subject. This approach still works extremely well – it’s classic for product photography and you can get little pop-up macro “studios” to help you control diffuse light, set up nice backgrounds etc should you be selling lots of handmade jewellery on Etsy and the like. However, I’m after bugs and beasties and they’re a bit more temperamental. That’s not to say a decent tripod isn’t useful sometimes, but it can be a bit of a pain having to shift it around all the time. If I’m leaving the tripod at home, the benefits of a stabilised lens come into their own – camera shake at close up distances is all too noticeable, so avoid the non-stabilised versions unless you know you’re sticking to tripod work.
Eventually you’ll have to do something about increasing the amount of light on the subject. There are quite a few options open to you, but they all divide into two basic options – lights or flash. Lights can be specially made LED ring lamps that surround the lens, or something you’ve knocked up in the garden shed using some rechargeable batteries and a 12 volt LED spotlight from a car accessory shop (see the next picture). On the flash side, you can simply use the built-in flash, a normal external one, or a dedicated ring flash (similar to the LED light in design).
Some dedicated macro flashes use two separate little flash heads instead of the ring, allowing you to control the angle and power of the flash. This can give you more pleasing results, allowing a bit of shadow in the image to make the subject look more 3 dimensional. Even if you stick to using a simpler ring lamp or flash, you can still vary the output on one side by sticking a bit of tissue paper over half the bright bit, like this
Choosing whether to cover the left or right half will vary the shadow – like this
Compare it to an image with no tissue paper on the lamp
Hopefully you can see shadow to the left, shadow to the right, a little shadow to both sides as you look at the three images. Which you prefer is down to personal preference, but I like the extra definition given to the ears by the brighter-light-on-the-left middle one, so would probably choose that. If you need even more directional or a harsher light, the little LED spotlight on rechargeable batteries may be what you need – here shining from the right
The last image is what turning off all the lighting gives me – a dark subject as I’m facing the back door (ie shooting into the light). The lighting has shown the subject detail nicely, as well as gaining me roughly 3 stops over the non-lit subject (more like 2 for the half-tissued ringlight) – allowing me to have a faster shutter speed and lower noise.
You can do all of this with flash instead of course. An external flash is ideal, either on the top of the camera or off to the side for better effects (controlled either by a cable to the camera hotshoe or wirelessly)
A word of caution should you use the internal flash however. It is very close to the camera body, so the lens hood can actually shadow the subject from the light. Take the hood off or you might end up with this sort of half-lit image
The ring flash gives you a similar result to the ring light, but there are pros and cons to think about before deciding whether flash or constant lighting will be your best bet. The LED lights are certainly easier to use – you can see what you’re going to get just by looking through the viewfinder. If you’re taking lots of pictures (often the case with moving bugs), you don’t have to wait for the light to recharge like a flash – it’s simply on all the time. However, flashes do have some benefits – they will freeze movement a lot better which can be very useful when those pesky bugs start jumping around.
Lastly, whilst talking about flash, be aware how your camera uses flash in different modes. For example, Canon DSLRs, in Aperture mode (which is what you’re often using with macro, seeing as you’re after DoF control), the camera will expose for the background, using the flash to light the (foreground) subject. In Program (auto) mode, it will simply expose for the subject. What that means in practice is that, leaving everything else the same (ie not switching to spot metering or anything), Aperture priority will give you a slower shutter speed/higher ISO and show you some background behind the subject, whereas Program will give you a subject against a dark background with no detail. Like this (Aperture first)
I’ve not tinkered with these pics – for most of the images in this thread I’ve been shooting jpgs (rather than my usual RAW) to avoid me “correcting” things by accident. Whilst these two could be massaged to get them closer in the overall look, you can’t reproduce one from t’other without a LOT of work (if at all). Understanding how your camera uses flash is handy in any situation, not just macro, but the ability to isolate the subject whilst getting rid of the background is used a lot with this sort of photography, so it’s handy to understand how it’s done.
Part 3 on its way.....
OK, so those particularly observant readers will be clamouring to know what that Helicon Tube is, laying on the worksurface in an earlier picture. With the Depth of Field problems inherent with macro photography, people have come up with various ways to try and overcome the issue. The principle way to do this is to stack images. All you do is take a number of nearly identical images, moving the focus point a tiny bit between each one (say 0.5mm). After you have a load of images, hopefully the first will be in focus at the front, the last, in focus at the back. You can then load these images into a software program that will blend them all together – giving you one image completely in focus. There are various ways to get the source images – use manual focus and shift the focus point yourself a tiny bit between images is possible. A better solution is a focus rail – mount the camera on the rail, manual focus to the start point, then turn a little handle to advance the whole camera forward a mm at a time for each image. You can even get software-controlled versions to automate the process with stepper motors. All very well, but both these methods need a lot of setting up, good support and patience. The Helicon Tube is a bit different. It mounts between the camera and lens like a normal tube, but the electronics in the tube interrupt the communication to the lens’ AF system. Focus on the front of your subject, then hold the shutter button down, machine gunning a load of pictures. Between each shot, the Helicon tube will advance the AF a tiny amount – so you end up with a whole bunch of images the same, just with shifted focus points. Blend them together and you have a picture with a deep depth of field.
The tube is configured with an App on your phone and I used Photoshop Elements with Elements+ to open up the stacking capability (various software tools are available if you search the Web). It works surprisingly well and, most importantly, I can use it handheld. These images are from a 20 shot stack; first shot – nose in focus, last shot – back in focus, the blended result of all 20 images
Be warned that you will need a PC with some serious horsepower for this sort of thing though – it starts by opening all 20 or 30 images you want to stack before running scripts against them, so best avoid trying it on the old laptop you use for emails!
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Regards, Hazel
Jim
My Pictures
My Fbook Group
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Nige Flickr
I agree with the others, a nice tutorial, and another one to the useful collection.
Macro is something I play around with, and get mixed results, and most of the time I have a pretty good idea why I've got the results I did.
I am a little OCD in that I will note what subject has what settings, so I can find the most optimum settings and set up.
Thankfully your thread confirms most of my suspicions, but I've still a lot to learn, which is the beauty of photography, especially digital, less cost, less waste....
Mike
Flickr: Peak Rambler
A little follow up on this thread - with all the windy and wet weather I haven't been able to get out in the garden much to update on further use of that Helicon tube. Finally today, I found a handy fly sat on the bench, so with the 7D2, 100-400 and Helicon attached, I had a crack at another image stack. This is primarily to prove you don't need anything too specialised for a lens, your normal birding telephoto can also give good results (OK, yes, I know the 100-400 is probably the best bug telephoto you can get, with its 3ft minimum focus, but you have the same depth of field issues you get with any close-up work, so it's a good one to try)
So, as usual, three images, close focus, far focus, then a stack of the 30+ images taken in between. This sounds a tall order, but remember, the 7D2 is a 10fps beast, so it's only a few seconds your subject has to stay still - and the software does a good job of aligning all the images to overcome the inevitable small movements I made whilst hand-holding
Unknown said:the builder has just postponed our completion by another month, now end March !
Oh dear! Mind you, that's pretty normal in my experience of builders!