bellows and extension tubes

ive come across some on ebay, and ive read articles by photographers suggesting there use, but what are they, and what do they do?

The further you move the lens elements awy from the film/CCD plane, the closer you focus, so a bellows unit or extension tubes take this further by adding more extension between the lens and the camera body.

Tubes are provided as sets of various size, and a bellows unit uses a bellows on a rack that allows adjustment continuously over a wide range.

As you extend further, exposeure needs to be increased to compensate for the fall off in light reaching the film/CCD.

so i shoot faster, or slower?

Slower shutter speeds will let more light in, thus compensating for the light loss.

The aperture should be kept as small as practicable because there is very little depth of field close up.

There is less light hitting the film/sensors, so you need to increase the exposure by a) wider aperture, b) slower (longer) shutter speed, c) combination of a) and b) or d) by altering the sensitivity of the film or CCD.

Therefore, to shoot at the same speed you need a wide aperture and/or high ISO speed (or of course a brighter subject!).

Quite right John, we're talking extreme close-up here so as smaller aperture as possible is a must.

Extension tubes are cheap, but lighting the subject can be tricky. As mentioned above, you generally need to use the smallest possible aperture.

The best lighting is a ringflash, which encircles the lens. However it is not cheap. Without one, you will need to resort to various techniques to throw an even light all over a very small object which is already in the shadow of a lens and photographer.

Just remember this before you plunge in!

George

If you have a digital SLR of a couple of cheap halogen desk lamps and the appropriate white balance settings (and a good tripod of course) will make a pretty versatile tabletop studio - epscially if you get lamps with dimmers on (though dimmers can alter colour teperature so double check white balance)

Alternatively there is a Vivitar ringflash for pentax AF bodies for only about £80 new

As regards set-ups for close up work, it will also depend on what end product you have in mind.

As an example, I take pictures of items to put on eBay, some quite small, so a very simple set up is used. Two Jessops print mounting boards 20" x 16" are set up as the background, one flat, one upright and slightly tilted. Lighting comes from one large window. Digital cameras focus very close, so a bridge SLR-style is used to take 3MP pictures. There is no need for bellows or extension tubes for this sort of photography with this sort of camera.

Digital is so good at taking close-up pictures that I have actually stopped using film cameras for this. Film is now used for portrait (sometimes), architecture and landscape work.

Sorry if that strays from the point a little, but I hope the thoughts are useful anyway.

i dont have a digital slr, i have a pentax k-1000

The principles of photography are the same, whether you are using digital or film. Just think of digital as a different sort of film, but with greater control over processing. Up 'til and including the point where you press the shutter these isn't really any difference most of the time.

However, two exceptions are the problem of light balance, and the fact that with film you don't get instant (and free) feedback on whether what you've done has worked.

Light balance can be a problem with film if you aren't using either daylight or flash. For that reason, lighting with daylight or conventional electronic flash is by far the best idea.

If that's not possible, you can use halogen and hope that the balance can be corrected in printing, or special tungsten-balanced film (for ordinary light-bulbs), or a dark blue filter (which will remove about two stops), or blue photo-floods.

With a K1000 (and lacking the funds for ringflash) I would buy two cheap manual flash guns, and experiment using reflectors and diffusers (make your own from aluminium foil, handkerchiefs, etc).

Good luck

G

I've been thinking of getting hold of some bellows for my LX. How well would an AF400T work as a macro flash, if used off-camera?