M42 extension tube

[Neil Grant]

I am using a Meyer-Optik Domiplan (good sample) but finding the min focus of 0.7m a bit restrictive. I now have an extension tube set - but the thinnest 12mm tube is a little too powerful for some purposes. Does anyone know if much thinner tubes were available in m42? or could I get something machined down a bit? The lens has no A/M switch which precludes manual tubes. The camera, an unused Chinon M1 found in a dustbin, also lacks a DOF preview - are all m42 cameras lacking this feature?

 

[John Koehrer]

Opt for a set of close-up lenses rather than paying big bucks to have an extension tube made.
If you still decide to go the tube route, you're going to do some calcumaltions for the length. Any length added behind the lens
will limit the focusing range.

The same focus limitation applies to the CU lenses but there's no loss of light.

 

[lxdude]

The M-1 uses stop-down metering. So moving the meter switch on the side of the mirror box above the self-timer will stop down the lens, and you can preview depth of field.
M42 cameras which meter at full aperture usually have a stop-down/DoF preview button. I don't know if all do though

 

[Neil Grant]

The M-1 uses stop-down metering. So moving the meter switch on the side of the mirror box above the self-timer will stop down the lens, and you can preview depth of field.
M42 cameras which meter at full aperture usually have a stop-down/DoF preview button. I don't know if all do though

Wow, so it's got a light meter - just how advanced is this thing? The previous Chinon lens had an A /M switch - which I used to preview DOF, but it was a bit hazy so I threw it away. I didn't know what the switch on the mirror box did - so thanks for telling me! I'm not too keen on CU lenses - I want to keep the optical path as simple and as flare free as possible, and try to provoke the lens to deliver the rather special bokeh that it was once known for (these days more likely forgotten about)

 

[lxdude]

If the close up lens is high quality- made by one of the major manufacturers like Nikon-the low power one you need to get a little closer will not likely have any significant effect on optical performance. High quality CU lenses are usually two element designs.

 

[compasiune11]

This tube sends TTL info to the sensor? I don't think is has electrical contacts.

 

[John Koehrer]

Presuming the camera has ttl and is manual the tube doesn't need contacts. Any reading
is indicated by the meter and you set the camera to the indicated values.

 

[Fixcinater]

I use a Pentax close up lens #1 for this purpose on a 58mm f/1.9 Primoplan and Helios 44. It softens contrast a bit wide open but stopped down to f/4 it works very well. The Nikkor 3T works very well, but I have the Pentax handy so it gets more use. I should dig out the 3T and do a bit of comparison.

You can also get a bit more close focus by unscrewing the lens a bit and being very careful not to let it unscrew off the body while in use.

 

[Jim Jones]

. . . You can also get a bit more close focus by unscrewing the lens a bit and being very careful not to let it unscrew off the body while in use.

I've fabricated a washer to fit over the lens mount thread to keep the lens from seating completely on the camera. This functions like fixcinater suggests, but with with better security. It provides only slightly closer focusing.

A tele-converter between the lens and camera gives a larger image than the lens alone for the same lens-to-subject distance.

An enlarger lens mounted on a m42 bellows via a Leica to m42 adaptor may work well enough. A 135mm enlarger lens might provide infinity focus to 1:1 magnification. However, most enlarger lenses don't stop down far enough for some macro and micro photography.

 

[Neil Grant]

"You can also get a bit more close focus by unscrewing the lens a bit and being very careful not to let it unscrew off the body while in use."

I did try the lens 'unscrew' technique - but wasn't really happy with it. I also tried making a washer from an old Nikon F mount - it was too fat to alow the lens thread to engage. I managed to get a very thin extension tube (7.5mm?) and this helps for many things - without getting you too close. The lens is just a nuisance with it's limited focus rangebut can give interesting results. f/4 or f/5.6 + thin tube gives very shallow DOF.