Wednesday, September 08, 2010

I've got my eyes on you

Nick has been tinkering about with his new macro set-up, and wanted to share it for the benefit of other enthusiasts. What follows is his discourse on 'poor man's macro'. Alas, I have no words of simple English to interest the non-photographer; these last two days have been somewhat dull.


There are several ways to shoot macro. Firstly, buy a macro lens, Nikon make a nifty 105mm perfect for the job. However for all the others who are poor like us there are various other options. You can buy diopters, add an extension tube, use a bellows (only for the rich), or stack lenses. We have made been experimenting with this last method with some pleasing, though restricted results. The lenses can be stacked head to tail or head to head. The tricky part is connecting them. We have a Pentax 50mm 1.7 manual lens that we face mounted with sellotape to the face of a 52mm Sigma 35-70mm. The 49mm pentax fitted snugly into the rim of the 52mm Sigma making the use of sellotape possible. Not everyone will be able to copy this method. However various lens sizes can be fixed to each other using what is called a macro coupler. This is a ring that screws into the front of the lens, but has a male thread on both sides. This screws into the filter thread at the front of most lenses. Different thread sizes are accommodated, and they even make rings to attach the 49mm Pentax to the 52mm Sigma. (They also do 52-52, 52-55, 55-55, 55-58, 58-58, etc). The lens that goes on the front will have to have an aperture ring, this then needs to be set to wide open (In other words older lenses, this a great use for all those old 35mm fixed focal lengths that are going unused on those film cameras stashed away ready for the next garage sale). If you make the aperture on the reversed lens smaller you will notice vignetting in your images. Also the lens on the front needs to be of a smaller focal range than the lens it is mounted to, this will aid with the magnifying effect. The greater the difference between the two lenses the greater the magnification. So putting a 50mm on a 200mm will give you more macro ability than a 50mm on a 70mm. Our present macro ability is greater than 1:1, which is the ratio of the Nikkor 105mm.

Once you have got your lenses fixed, flick your camera to manual focus. Set the focuses on both lenses to infinity. I recommend the use of a tripod or setting the camera down on a surface, and then introduce your subject. Your depth of field is going to be miniscule so set your camera to about f11 for a functional depth of field to begin with. You are going to have a very small focusing distance and are going to have to get right in the face of whatever you are photographing. For this reason the best subject for this sort of photography is something that is not going to crawl or sway in the breeze. For our lens combination we have about 5cm between the front of the lens and the subject, so you aren’t going to get the close up of a skittish bug or venomous snake. Any flashes besides ringflashes will have to be bounced back at the subject using reflective surfaces; using the body flash your subject will be in your own shadow. It is limited, but it is fun and cheap and yields some great results for the persevering.

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