max_ebb
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- Nov 2, 2006
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That's one reason I went to Linhof for one job, even when I had Hasselblads: c/u with tubes and Proxars is horribly limiting next to a bellows. An RB would have been better still. I was shooting an airbrush artist at work, showing technique (distance from ground, finger movements, etc.) and continuous focusing is MUCH easier.
Cheers,
Roger
There are two distinct advantages of using bellows instead of extension tubes (assuming the bellows are long enough for macro). The most obvious advantage is that changing the length of the bellows is much faster and easier than changing the length or number of extension tube(s).
The biggest advantage though is with a bellows rail system that has movement at both ends (or a 4x5 rail system with movement on both ends). If you are doing extreme close up, with the front of the lens about 6" away from the subject, trying to focus without moving the camera itself can be an exercise in futility. When adjusting the focus (whether using a bellows or extension tube), the distance from the lens to the subject changes while you are trying to focus.
It can be like a dog chasing his tail. If you need to focus closer, the lens gets even closer to the subject as it moves farther from the film, so it's still out of focus. The same thing if you need to focus farther. As the lens gets closer to the film it's getting farther from the subject so it's still out of focus. With extreme close up, you generally have to move the camera to get it in focus.
With a rail system, you can leave the lens at a fixed distance from the subject, and focus by moving the film plane. Then move the lens when you need to change the degree of macro (ie; going from 1:1 to 1:2).
Another thing that I found to be extremely handy for macro is through the lens metering. With extreme close up, it's difficult to use a spot meter because you can't get the same angle of view that the camera is getting, and you also have to figure out how many stops you have to compensate for the length of the extension tube(s) or bellows.
I use a Pentax 67 with a set of extension tubes and metered prism finder for extreme close up macro work. I get great results and find it fairly convenient to use. I would like to have the bellows rail system for it, but it costs $500. For that kind of money, I'll just stick with the extension tubes.
My original question though was about using a macro lens as opposed to (or in combination with) macro extension tubes or bellows. I can get a macro lens for my Pentax 67 for about $70. I'm wondering if there are any advantages to using a macro lens (possibly in combination with the extension tubes) over using just the extension tubes with a regular lens.