Archived posting to the Leica Users Group, 2001/10/20
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Trish, as I love close focus to macro it will be a pleasure to answer. Bellows; an adjustable extension tube, think of a view camera attached to a camera. Slow and deliberate but for 1:1 reproduction ratio's and closer really the hot ticket. You typically lose control over the diaphragm unless your system allows a double cable release system to stop down the diaphragm before the shutter trips. You should probably use a camera that allows TTL metering so you can easily set whatever reproduction ratio you want. 1.4 APO extender; magnifies by 1.4 and you lose one stop of light. That means that a 200mm lens becomes a 280mm. The 1.4 APO in the Leitz stable is highly corrected for chromatic aberrations so if you are using a APO prime lens you retain the correction. Because the Leitz 1.4 has a snout it will physically fit only some of their lenses mostly the telephoto APO designation lenses, but for specifics ask. I bet that you could use the 1.4 on a body, then mount a bellows unit, then a lens to get more magnification than the bellows alone. 2X APO extender; much the same applies except magnifies two times and you lose 2 stops of light. Macro adapters: here I believe you are discussing the two element cose up lenses that Leica and others produce. They work just like reading glasses, let you focus closer. Benefits are that you can focus closer than your normal lens can, you don't have any exposure compensation, they are small and light, and you don't lose your lens correction for infinity. Most lenses are designed to produce their best quality at about a 1/10 reproduction ratio and degrade as you focus closer. Downsides to these critters is that even the best of them provide a curved field so for flat subjects you need to stop well down. If on the other hand you were asking about extension tubes, they extend your lens usually a fixed distance further from the film allowing you to focus closer. You lose light in a ratio to your focal length used; one stop for 50% focal length. Benefits are no glass to degrade the image, cheap, and light weight. Downside is that for the most part you only get on magnification with each lens/tube combination. Some people would use the focusing mount for the viso as a variable extension tube which would allow some choice in magnification. Right angle viewers let you focus the camera 90 degrees from normal. These are very useful devices when you want an unusual angle. To name a few, groundlevel, over your head say on a tripod raised way up, around corners or from the side. This assumes your right angle viewer pivots so you set up your camera or shot then figure out a way to see what you set up. Also, the better ones allow you to increase magnification so focusing is more exact. Focusing rail: lets you set up your shot then adjust focus by sliding your rig forward or back and in some cases sideways. These are wonderful for fine tuning composition when you have lights and reflectors set up from the camera. Off camera flash cord: lets you get your TTL flash off your camera and direct it to mimic the sun. Extremely useful when you have stopped down to F11 or so to have a some depth of field, lost four stops to extension, and have blocked the natural light with your camera and would like to photograph a dragonfly eye. If you have more questions please ask. Don Dory dorysrus@mindspring.com - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html