Macro! It sounds small and expensive, how do I get started and what are the options available?
There are a few budget zooms with "macro" capabilities ranging from 28-80 zoom to 70-300mm zoom with 1:2 and 1:3 macro-focussing capabilities. They are a fraction of the cost of "real" macro lenses, but generally not durable and the quality is not always great. Nikon introduced their 80-180 macro zoom, but it is expensive! The prime macro fast lenses of 50 to 200mm ranges are excellent, but they are expensive and only give 1:1 reproduction. There are other affordable options as well - like close focussing optics that screw in to your standard lens, extension tubes (hollow tubes that increase close focussing capability of any lens), bellows (the same principle as extension tubes), reverse rings for your standard lens and converters to a certain extent. The good news is that you can use any combination of the above. The drawback of close-up optical filters and reverse rings is that you can only use it for lenses with that specific diameter screw mount. Extension tubes, bellows and converters can be used with the full range of your existing lens collection. I like combinations of converters, extension tubes, macro lenses and close focussing filters because I want far more than 1:1 reproduction. I like to fill the frame with something that is only a few mm in size. The simple rule is that the more glass you add the more quality and light will be lost. You'll have to decide what magnification you need. Examples: A standard 50mm lens with a 50mm extension tube will give you 1:1 reproduction at the fraction of the cost of a 50mm macro lens. If you add a X2 converter you'll get 2,5 times the magnification.
The possibilities and combinations are numerous. You can use this with the most basic SLR to the most auto-everything SLR. You'll have to use your advanced SLR in more basic modes. You'll lose autofocus, lens to camera information and most of your advance flash functions. The good news is that you do not need any of it. If you insist on keeping all the frills on your camera, your best bet is a prime macro lens. There are +1 to +6 diopter filters for your macro lens and auto- extension tube sets if you want to do more than X1 magnification. The rest of the tutorial will concentrate on manual approach for more than X1 magnification. Magnification: Standard 50mm at 0,5m focus setting on the lens and the following extension tube combinations.
* 12mm extension tube => about 0,35 magnification
* 20 mm extension tube => about 0.5 magnification
* 36 mm extension tube => about 0.83 magnification
You can use combinations of above. For example 12mm + 20mm + 36mm with a standard 50mm lens would result in about 1,5X magnification. Now if you add a X2 converter you'll end up with a more than X3 magnification and should be able to focus down to 4-5cm distance between lens and subject. Aperture: DOF is very limited when doing macro and DOF preview button is essential (also powerful light so that you can see). You'll create a few artistic exposures with shallow DOF, but for the most part you'll need f-stops of 8-16 for most X1 magnifications. When doing X2- X4 magnification exposures this increase up to f 16-64. (Maybe one of the only virtues of converters). Shutter speed: With the F-stop range as discussed, it is obvious that it is going to be very slow even with faster films. For stationary studio work this does not matter and I like to use natural daylight and reflectors with or without fill flash. You can use shutter speeds as slow as you like with your tripod and cable release. If it gets down to the 1-20sec range you can even do a bit of light painting on the subject. You'll still have to compensate for some light loss and reciprocal failure. It will differ for different lens combinations and you'll have to do a few test exposures. An easy solution is bracketing in the positive range of the exposure. If your fancy is mobile subjects, then you'll need to use flash to freeze the action. Flash: For moving subjects your >1/1000 flash duration would stop most action. Different cameras dictate different flash synchronisation speeds, and you can use any shutter speed below that. TTL flash: If you use TTL exposure, you'll still have to compensate for some light loss. You'll have to make a flash bracket that allows for off camera flash placement close to your subject.
If you use TTL flash, set your camera on spot or centre-weighted metering and compensate for some light loss with converters and extension tubes. TTL flash in high magnification photography often results in under exposure. Magnification of 1:1 and less does not require much, if any compensation. They also recommend the use of softboxes or diffusers with close up photography. This creates a few problems with high magnification photography. The first is that your flash to subject distance is usually a few cm with high magnification photography (see manual flash use). The second problem is that your close up lens arrangement is very prone to flare. The fun thing about photography is that even though you know disaster is pending, try it anyway. Manual flash: Is the GN number of your flash true or fiction from the manufacturer? You can test this by exposing 100 ISO film with a standard lens and your flash on manual, and check if the GN number is as indicated with the following formula: Flash guide no = aperture X flash to subject distance. Example:
GN of 16 with 100 ISO film will give a spot on exposure at 2m and f8.
This also dictates a GN 11 for ISO 50 film and a GN of 22 for an ISO200 film.
The problem is that every addition of converters and extension tubes will result in progressive light loss and you'll have to make test exposures for each combo that you use. Start by what you think the exposure should be and bracket in half stops up. Once you know how much light loss each combination costs you in stops, write it down and you are set for fun. My memory is short and I misplace most things that I write down, so I guess my light loss most of the time. Converters will increase your f stop by the factor of conversion. Each 1mm of extension tubes correlates with an exposure factor of about 0,1. Example:
A 20 mm extension tube correlates with an exposure factor of about 2, or opening up 1 stop.
If you use TTL you can add 0.15 times the magnification for compensation. This is just a rough guide that I use for my Nikon set-up and I am not sure if it would be applicable for other systems. The bottom line is do not give up and make test exposures and get to know your equipment. Focussing: Decide what magnification you need and set-up your simplest lens arrangement at the minimum focussing distance. Focus is achieved by varying the camera to subject distance. There is no room for autofocus in high magnification photography. A few mm movement is all that is needed. You can appreciate the problem of finding a fast moving bug in the viewfinder, let alone keeping up with it and focussing on it. Sorry this got a bit out of hand and should solve problems with insomnia if you got this far without falling asleep. I wrote this mostly from memory and personal experience. Feel free to question and disagree as I usually make mistakes. I could continue this with specific examples of problems of macro shots and how to avoid it. Feedback would be appreciated, as I would like to avoid boring you to death. My apologies if some does not make sense, but English is a second language.
