The 150mm f4 CF lenses

[BrianShaw]

Extension tubes will allow you to focus closer than the minimum focus capability of the lens.

They came in various thicknesses: 8, 16, 32, etc. The bigger teh extension tube, the closer you can focus... and the more you need to compensate exposure.

[Alan W]

I use an 8 tube with my 80mm when I want a "head shot",it allows you to get closer than the lens alone,almost like a bellows.And yes the 8 is definitely the most useful one to have.

[bdial]

The extension tubes let you focus a closer distances than the lens can on its own, they fit between the body and the lens, and include the necessary linkage for the shutter.
The minimum focus distance on the 150 is 1.4 m, and if you want to do a tight head and shoulders portrait, that isn't quite close enough.

There are several extension tubes available designated by their length in mm, the 8 is the shortest, the longest is about 55 mm.
The longer ones are only good for macro use, but tubes like the 8 or 16 will bring your focus distance close enough for a tight head and shoulders portrait.

There is a chart and more info at Hasselbladhistorical; http://www.hasselbladhistorical.eu/P...ls/Extubes.pdf

[Sirius Glass]

Great portrait lens. About the right price. I use Kodak Tri-X and do not have a grain problem at all.

[darinb]

Just to be even clearer on the extension tube issue...

You'll note that when you focus a lens it gets longer and shorter. When it is at infinity it is at its shortest--rotating the focus ring doesn't move it any farther in. Likewise, when you focus closer, rotating the focus ring makes the lens get bigger--it sticks out more. If you do this, back and forth, with the lens off the camera you'll see that all that is happening is that the entire lens assembly is just moving toward and away from the film--the lens barrel just provides a hollow tube. Now, focus the lens all the way out, focus it as close at it will go. At some point the focus ring will stop rotating and you can't get the lens assembly any farther from the film. That's the closest the lens will focus--without extension tubes.

But note that what is stopping you from focusing closer isn't the optics, but the lens barrel itself. But since the barrel is just a hollow tube, what if there was a way to make the tube just a little bit longer--to move the lens a tad farther away and to thus focus even closer?

That's what extension tubes do. They add a little bit of length to that hollow tube called a lens barrel (which is why extension tubes themselves are nothing more than hollow tubes without any g). They come in different sizes which you can combine in any way you want because once you start doing this you'll start getting fancy about it. The bigger the tube you add the closer the lens will focus (since the glass keeps getting farther and farther from the film).

Note: Depth-of-field? Very slim. Exposure adjustment? With a prism looking through the lens the adjustment is automatic. With a handheld meter you have to tell the meter that you added tubes --the glass is farther away down that hollow tube called a lens barrel and/or extension tube so the light is dimmer, right? In fact, it was dimmer even without the extension tubes, as you focused closer and the glass got farther from the film, but we all just sort of ignore that most times

--Darin

[ted_smith]

I took the plunge! This is winging its way to me from FFordes.co.uk! I can't wait!

[RalphLambrecht]

congratulation!. now, you need a sunshade and a filter...that's why ha$$y stands for:hassy enough money left for film, but once you have them, you don't want to be without.