I thought it might be worth returning to macro again immediately, having started touching on the subject yesterday.
When writing yesterday, I was feeling a little bit guilty about focusing so narrowly (if you’ll excuse my pun) on diopter lenses which generally only work with more expensive cameras such as SLRs / DSLRs / CSCs or bridge cameras. I thought, since this is a budget blog, I should return to the more accessible end of the market, using a mobile phone or cheap compact. In both cases, many have macro modes which allow you to get surprisingly close to small subjects.
“I was feeling a little bit guilty about focusing so narrowly (if you’ll excuse my pun) on diopter lenses which generally only work with more expensive cameras”
Here comes the science bit… I have included this under the title “Macro” because it is generally used to refer to close-up photography. Strictly speaking, though, the term macro isn’t right for most mobile phones or compact cameras, but it is the technical difference which gives these cameras some interesting properties.
Macro: A technical definition. – The ratio of the subject’s size on the film or sensor plane to its actual size is known as the reproduction ratio – macro normally describes reproduction ratios greater than 1:1.
So – now we’ve got this out of the way, why are mobile phones not macro? And what difference does it make?
Well, if you’re old enough to really remember 35mm film, you’ll know it was called this because each shot was taken on a 35mm wide piece of film. This is the same size as the sensor in expensive DSLRs. So, for a photo of a 20mm long insect to fill roughly two thirds of a photo, you would have needed a 1:1 (macro) reproduction.
Your mobile phone, though, will have a sensor which is considerably smaller, typically 1/3 inch, which is just 8.5mm across. This changes the reproduction ration from roughly 1:1 to 4:1. Don’t worry too much about the numbers themselves, but the point is that the insect you’re trying to shoot is now larger than the sensor you’re shooting it with, rather than the other way around.
Now, this reproduction ratio doesn’t mean you will actually be able to focus on something at very close distances (so you may struggle to shoot an insect which fills your whole frame, without some sort of adapter), but it will drastically increase the depth of field which can be achieved at the shortest distances your phone can focus at.
Here is an example, shot using my mobile phone, where you can see that nearly all of the flowers in the photo are in fairly sharp focus:
This increased depth of field is, in my opinion, generally a bad thing in macro photography, where you often want to remove distracting backgrounds with a tasteful blur. However, it does have some interesting applications, and you can have a lot of fun with them.
One of the great things about using a mobile phone is that you can often achieve greater depth of field from close-up of objects that otherwise would be impossible to keep in sharp focus when shooting at a short distance. This might be useful when shooting models, dolls houses, chess boards, or other miniature environments or landscapes. This can create some great fun opportunities to create some fun composite images. (See my articles on software such as PhotoScape or GIMP for some free applications to do this).
And the same shot after playing around with it in some software:
If you’re anything like me, you will doubtless have found yourself drawn in amazement to some of the photos out there of the very tiny, from very close up.
One of the great things about photography, is that it allows you to see things which are very difficult to perceive with the human eye, either because you simply can’t get close enough to focus well, or because you can’t “freeze” something whilst moving, and your eyes can’t keep up with it.
This is where the wonderful world of macro photography comes in – and there are some true masters of it. If you want to explore a vast array of images and techniques, the Flickr macros group is one of the largest on the site and is well worth a browse amongst its 300,000 or so photos (at the time of writing).
However, as with all things in photography, there is a catch. If you start getting serious about taking macro images and read all of the magazines, it becomes very clear, very quickly, that you can spend a LOT of money on gear. So is there any way to avoid this?
The short answer is yes – so long as you know and understand your equipment and its limitations. I am therefore intending, over a series of articles in the next few weeks, to cover off some of the ways you can achieve great results without splashing too much cash.
Supplementary Lenses (also known as diopters, close-up or macro filters, or simply close-up lenses)
Being a stickler for technical accuracy, I’m not keen on referring to these little beauties as macro filters, as technically they don’t filter out any light – they simply act as magnifying glasses. They are referred to as filters, though, as they tend to screw into the filter ring of your camera. (This is one of the reasons I recommend buying a bridge camera with a filter ring, or an appropriate adaptor).
As a general rule, you cannot use these sorts of lenses with more basic point and shoot cameras or mobile phones, which I will return to at another time.
There are a few reasons why I love these handy little tools, though, and why they formed part of every camera bag and setup I have ever owned:
They are really cheap (under £10; definitely the cheapest way of getting into macro photography to start with).
They can generally be fitted to any lens in a kitbag (either by choosing lenses with the same thread size, or a step-up ring, which can be bought for next to nothing).
They hardly take up any space, so you can have them with you all of the time.
The third reason, although not technically a cost saving piece of advice, is definitely one about getting value for money. One of the things I love about wildlife (particularly macro) photography, is that you can find things to take pictures of everywhere. Ants, spiders, wasps, bees, even common houseflies become a hundred times more interesting seen from close up. What you will find happens, is that you’ll go out with your camera and just stumble across things which you think are beautiful and interesting, and would love to take a photo of, but can’t because you don’t have the right lens, because it was too big or bulky. With these little screw-on lenses, that needn’t happen, because they’re tiny to start with.
But seriously – are they any good?
In all honesty, yes they are – so long as you know their weaknesses. Here are my “top tips” for getting the best out of your diopter lenses (with a few examples along the way):
Tip #1: Don’t just buy one diopter – by a set of three.
Or even a set of four! You will normally find that these are sold in sets of +1, +2 and +4 (sometimes +3 or +5), and some sets come with +10. I have a set of four, including a +10, but, to be honest, it’s a pretty crumby bit of glass, so stick to the lower numbers. You will also read that you can “stack” these lenses (with the largest diopter closest to the lens) but don’t bother doing that either, as it will rapidly degrade your image quality.
Tip #2: Keep your subject centre-frame.
Unless you can afford to buy a two-element diopter lens (also known as an achromatic lens), which are quite a bit more expensive, then these lenses suffer from chromatic aberration especially closer to the edges. This basically means that areas of high contrast end up with fringes of colour which should not be there. With an out-of-focus and even background, this won’t matter, but if it’s a key element of the photo, you will begin to notice. Therefore, when shooting (particularly in bright, high contrast conditions) try and keep your subject fairly central.
In this shot, you can see the chromatic aberration occuring on the right hand edge of the flower, though in the context of the shot, it detracts little from the action.
If you compare this with the following shot of a cricket, however, you can see how the image quality degrades as you reach closer to the edge of the frame:
However, if you shoot your subject dead centre, and against a low contrast (or single colour background) then you can hide the effect almost entirely:
Tip #3: Shoot on bright days!
There are a lot of comments out there about needing overcast light to shoot nice macro images, which is fine if you are able to shoot with an expensive ringflash or build complex artificial environments, but as a general rule, bright days are best if you’re on a budget. This is because they allow you to shoot your subject at a high enough shutter speed to freeze your action, and to give you more flexibility on the aperture you use.
Tip #4: Try using a longer focal-length lens, with a lower diopter number.
Especially if your subject is moving! This approach should allow you to shoot your subject from a sufficiently distant position, without scaring the subject off – it also means you won’t block out too much light by casting your own, huge shadow over the subject thereby extending shutter speeds. Also, the closer you get to your subject, the worse DoF problems can become making it hard to get what you want in focus.
Tip #5: Buy a mini-clamp tripod
These really are, cheap, low end bits of kit for about £5 – and would be rubbish for shooting birds, but for the small things they’re brilliant. They’re also really good for quick snaps on a self timer and attach to pretty much anything (and have tripod feet if needed). Again – they can be carried anywhere and used with any camera – so there’s not really any downside.