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My earlier Pentacon SIX and M42 lenses


  1. M42 mount, Pentax old standard that are widely used of others
  2. Pentacon 6x6 medium format lenses

1: M42 mount

Pentax M42 thread lenses

My M42 equipment, as you can see there is a new Canon 350d digital camera and a lot of old lenses. What is needed is an adapter to this old lenses, my lenses are of the M42 construction or Pentax screw mount. The M42 lenses are not very expensive and there a lot of them out at the used market, some of them of poor quality.

If you want the best, Carl Zeiss has started to manufacture them once again, but this new ones are very expensive.

But why do this?
Because Canon EF lenses are very expensive and they don't have a manual aperture controll.

The funny thing is that the good old Canon FD lenses with manual focus don't fit even with an adapter, but Nikon, Pentax M42 and a few others do.

The adapter I used can you see in the front of the lenses, this one made of Jolos, Russian I think. One problem with adapters could be that they don't have the right size and give focus problems. So I have done a simple focus test below. The lenses are focused for 1.5 meters distance and a photo is taken along a folding rule. Aperture set to max.

If you want to use M42 lenses as I have done, go for better quality, by old Carl Zeiss lenses!

By the way, M42 is not the same as T2, don't destroy your lens adapter with that combination!

This is the Zenitar 16mm/3.5 fisheye lens. This lens is new. It's little hard to say were the focus is at this small scale. On the original image I can see that it's where it should be.

This is the second lens, Pentacon 29mm/2.8, former East Germany built. Here you can se focus is to close, about 1.35 relative 1.5m where it should be. I have to adjust this lens later.

Also this a Pentacon lens but 50mm/1.8, this one focus almost perfect.

The fourth lens, a short telephoto from Makinon, 135mm/2.8, it have a big aperture. It focus where it should. It will be interesting to see where I have to set the aperture to get sharp astronomy photos from this. Makinon don't have a very good reputation.

The fifth lens, a 400mm/6.3 telephoto from Yashica, It don't have this short distance to focus. But I have rebuild it to focus beyond infinity so focus isn't a problem for astrophotography.

After this test I can se that the adapter work well. Astronomy photos will always be focused at the infinity. Sorry to say that the Canon camera are very hard to get to focus because of a poor focus screen, it's never meant to be used with other lenses than autofocus.

Best if I can adjust the lenses to focus to infinity at the mechanical stop. Maybe I find out a way to do this with high precision.

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2: Pentacon 6x6 medium format lenses

Pentacon SIX

Pentacon SIX, those old famous lenses are manufactured by Carl Zeiss Jena, made in former East Germany.

From left to tight:

50mm f/4.0 Flektogon

80mm f/2.8 Biometar

180mm f/2.8 Sonnar

The last one has the reputation to be the sharpest lens in the world (fifty years ago, made for the Olympia games), but maybe not today anymore. Compare sizes with the matchbox at upper left, they are huge! You could compare the biggest lens with a 65mm triplet refractor with a two element flat field corrector and with a 80mm image circle. But no telescope don't come even close to aperture 2.8, it's an astrograph!

They are designed for the medium film format 6x6 or 56x56mm film size. It will be perfect for the future, nowadays ccd sizes are at the best 48x36mm, and are only used in expensive cameras as Hasselblad. Carl Zeiss lenses with the Pentacon Six holder as this ones have are very cheap on the used market compared to Carl Zeiss made for Hasselblad cameras. Yes they are old but still very good and have bigger aperture than the ones for Hasselblad. The medium format has many big advantages relative 35mm, one is the distance between backend of lens and focus plane are about 75mm compare to 45mm. That means you can put filter and other accessories between them.

Later I sold these Pentacon lenses and bought a Pentax 67 165 mm f/2.8 lens. It's easier to find camera adapters to Pentax. But it doesn't look as nice as these Carl Zeiss lenses.

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